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savanna afforestation 

in africa 

lecture notes for 

the fao/danida training course 
on forest nursery and establishment techniques 

for african savannas 

and papers from 

the symposium on savanna afforestation 

with the support of 

the danish international development agency 

kaduna, nigeria 


Rome 1977 

First printing 1977 
Second printing 1978 
Third printing 1979 

The designations employed and the presentation 
of material in this publication do not imply the 
expression of any opinion whatsoever on the 
part of the Food and Agriculture Organization 
of the United Nations concerning the legal 
status of any country, territory/ city or area or 
of its authorities, or concerning the delimitation 
of its frontiers or boundaries. 

ISBN 92-5-100273-8 

The copyright in this book is vested in the Food and Agriculture Orga- 
nization of the United Nations. The book may not be reproduced, in whole 
or in part, by any method or process, without written permission from 
the copyright holder. Applications for such permission, with a statement 
of the purpose and extent of the reproduction desired, should be addressed 
to the Director, Publications Division, Food and Agriculture Organization 
of the United Nations, Via delle Terme di Caracalla, 00100 Rome, Italy. 

O FAO 1977 

- Ill 


This compilation is the result of a Training Course on Forest Nursery and Establish- 
ment Techniques for African Savannas which was to have been held in Kaduna, Nigeria, from 
16 February to 21 March 1976 at the invitation of the Government of Nigeria with funds made 
available from both the Danish^ International Development Agency (BAN IDA) and the Forest 
Research Institute of Nigeria-/. The course was planned in collaboration with the Forest 
Research Institute and the Food and Agriculture Organization of the United Nations (FAO) 
and was to have been held in conduction with the Symposium on Savanna Afforestation 
organized by the Forest Research Institute 9 with part of the training course running jointly 
with the symposium. Regrettably, the closing of Nigeria* s international borders in response 
to political disturbances in the country forced cancellation of the training course. The 
symposium was held as scheduled but with reduced participation. 

The training course was to have been the latest in a series financed by BAN IDA on 
aspects of forest plantation establishment with emphasis on tree improvement and seed 
handling. Previous courses in the series were held in Denmark (1966) and Kenya (1973) on 
forest tree improvement and in Thailand (1975) on forest seed collection and handling. 

Although it was not possible to realize at least two of the main purposes of the 
training course to provide demonstration of good nursery and plantation establishment 
techniques in savanna Africa and to facilitate the interchange of ideas and experience 
between francophone and anglophone participants - it was thought that reproduction and 
distribution of the lecture notes and papers prepared for the training course and symposium 
would be useful. This report (printed both in English and French) therefore, contains a 
set of lecture notes prepared in advance of the training course y the principal symposium 
papers and the country statements contributed by "wouldbe 1 * course participants. As lecture 
notes were planned to complement f but not duplicate, material in Tree Planting Practices in 
African Savannas (FAO Forestry Development Paper No. 19 by M.V. Laurie, 1974) f readers may 
wish to refer to that FAO book for further information on a given subject. One part of the 
symposium was devoted to the presentation of a number of short case studies on aspects of 
planting pine, neem and euoalypte in the Nigerian savanna. Only the summaries of these 
case studies are reproduced here; the full texts are available from the Forest Research 
Institute in Ibadan. A few lectures and papers have been shortened for inclusion in this 
report, especially in oases where duplication occurred. The order of presentation here 
departs from that planned for the symposium and training course, in that all papers on a 
given subject are together. 

Permission from the Forest Research Institute of Nigeria to publish papers prepared 
for the Sjymposium on Savanna Afforestation is gratefully acknowledged. Thanks are also due 
to that organization, and especially its staff at the Savanna Forestry Research Station in 
Samaru, for the many local arrangements and preparations made for the training course and 
to the forest departments of Kaduna, Kane and North East states for similar assistance in 
providing for the planned study tours. The support of the FAO/UNBP forestry project in 
Samaru, the UNDP offices in Kaduna and Lagos and the FAO Senior Agricultural Adviser was 
invaluable and is most gratefully recognized. Appreciation is also extended to the many 
authors of symposium papers and training course lecture notes for their efforts. Finally, 
regrets are offered to the training course participants who were inconvenienced and 
disappointed by the unavoidable cancellation of the course. 

then the Federal Department of Forest Research. 

- iv - 

The natural savanna woodlands are 
sparsely stocked, low yielding and made 
up of species of poor stem form, 
illustrated here "by Uapaoa togoensis 
and Iso'berlinia doka in the northern 
Guinea savanna* 

Qr the judicious selection of exotic 
species for the planting sites available 
and the application of intensive cultural 
techniques, savannas can be converted to 
fast growing forest plantations, such as 
this 8-year old stand of Eucalyptus 
cloesiana at Afaka, Nigeria. 



Preface -iii- 

The Savanna Environment 

Definition, classification and extent of African savanna (C.F.A. Onochie) 1 

Climate of the Guinea and Sudan savannas of West Africa (M.A* Ogigirigi) 9 

Soils of the Guinea and Sudan savannas of West Africa (0. Kadeba 

and A.V. Barrera) 20 

Climates and soils of the arid and semi-arid savannas of West Africa 

(J.C. Delwaulle) 37 

Species Introduction and Seed Handling 

Species and provenance trials in Nigerian savanna (G.O.A. Ojo and 

D.E. lyamabo) 45 

Provenance trials (R.H. Kemp) 53 

Seed collection and certification (H. Keiding) 59 

Seed handling and storage (B.S. Ezumah) 67 

Tree improvement, seed stands and seed orchards (H. Keiding) 78 

Nursery Practice 

Nurseiy design and irrigation (D.E. Greenwood) 86 

Soil mixtures, use of containers and other methods of plant raising 

(J.C. Delwaulle) 93 

Nursery cultural practice (j.K. Jackson) 97 

The role of mycorrhiza in afforestation the Nigerian experience 

(Z.O. Momoh, M.A. Odeyinde and R.A. Gbadegesin) 100 

Results of nursery research (J.K. Jackson) 106 

Plantation Establishment and Maintenance 

Soil and site selection (A.V. Barrera) 11? 

Land clearing and site preparation (D.E. Greenwood) 120 

Land clearing and site preparation in the Nigerian savanna 

(T.G. Allan and E.C.C. Akwada) 123 

Plantation planting and weeding in savanna (T.G. Allan) 139 

Notes on chemical weed control in savanna plantation forestry (J.B. Ball) 149 

Use of fertilizers in savanna plantations (J.K. Jackson) 152 

- vi - 

Special Techniques for Problem Areas 

Species, techniques and problems of semi-arid zones the Sahel 

(J.C. Delwaulle) 160 

Irrigated plantations (J.K. Jackson) 168 

Shelterbelts and environmental forestry (J.C. Delwaulle) 173 

Afforestation of difficult sites, eroded areas and steep slopes: 

with special emphasis on the Mambilla Plateau (A.V. Fox) 161 

Mine reclamation areas (M.O. Orode, B. Adeka and T.G. Allan) 190 

Plantation Protection 

Fire protection in industrial plantations of Zambia (w. Ross) 196 

Protection against insect pests and diseases (Z.O. Momoh and M.O. Akanbi ) 20^ 

Protection of plantations against animals and man (Alhaji Hamza Turabu) 209 

Plantation Planning and Costing 

Forest plantation planning at the national level (A.M. Oseni) 214 

Planning of savanna plantation projects (T.G. Allan) 220 

Cost accounting and the maintenance of records for monitoring and 

evaluating plantation projects (J.B. Ball) 234 


1. Summaries of special case studies ?47 

Part A: Pines 247 

Part B: Neem 250 

Part Cx Eucalypts 251 

2. Examples of Zambian plantation costs (A.C. Finch) 254 

3. Country statements 259 

Benin 259 

Congo 263 

Ghana 267 

Ivory Coast 271 

Kenya 274 

Senegal 278 

Sudan 283 

Togo 287 

Uganda 29 1 

Zambia 296 

4 Savanna afforestation in the People's Republic of the Congo 

(Zinga Kanza) 300 

5. Savanna afforestation in Ghana (A* Yawo Korala) 309 


C.F.A. Onochie 
Onitsha, Nigeria 



Definition 1 

Classification 2 

Extent 5 

References 7 

Figure 1s Map of West African vegetation zones 8 


The word 'savanna 1 is from the Spanish zavana or cavana and is thought to have Carib 
origin. It means a grassy plain with scattered trees and in particular refers to such 
plains in tropical and subtropical regions. The term is used also for a tract of level 
land covered with low vegetation or any large area of tropical or subtropical grassland 
covered in part with trees and spiny shrubs. 

Richards (1952) gives the following definition, and remarks on the probable ecolo- 
gical status of savannas. 

"Savanna is a name applied to plant communities of varied physiognomy and status 
found over a wide range of climatic conditions; some are serai stages , others are 
certainly stable climaxes. Savanna on which trees are dominant (with or without a 
continuous ground-cover of grasses) may be a climatic climax, but many types of 

savanna should be regarded as fire-climaxes Open savannas with trees growing 

scattered or in occasional clumps, and treeless grasslands may arise by the de- 
gradation of the forest or savanna woodland by excessive cultivation or burning 
but in some cases they axe probably edaphic climaxes due to local soil conditions 
unfavourable to the growth of trees. The nature of the factors responsible is un- 
certain but one which probably operates in some cases is seasonal waterlogging 
alternating with dry conditions during the rest of the year. There is little 
support for the view that lowland tropical grasslands are ever a climatic climax 
in equilibrium with a * tropical grassland climate'; grassland therefore should 
not be regarded as occupying a place in the natural climatic ecotone from 
tropical rain forest to desert.' 9 

Sohimper (1903) gives the following definitions: 

"Savanna forest is more or less leafless during the dry season, rarely ever- 
green, is xerophilous in character, usually, often much less than 20 m high, 

I/ Paper for Symposium on Savanna Afforestation 

- 2 - 

park-like, very poor in underwood, lianes and epiphytes, rich in terrestrial herbs, 
especially grasses. 91 

"Thorn forest, as regards foliage and average height, resembles navanna forest, 
but is more xerophilous, is very rich in underwood and in slender-stemmed lianes, 
poor in terrestrial herbs, especially in grasses, and usually has no epiphytes. 
Thorn plants are always plentiful." 

Used loosely and in the African context the term may cover an array of types of tropi- 
cal vegetation, ranging from the relatively dry to the semi-arid, which lie between the 
tropical rain forests of the equatorial region and the deserts to the north and to the south. 
These consist of a wide variety of transition types ranging from woodland savanna, including 
the so-called derived savanna (Keay 1959)? to the semi-arid steppe with scattered trees, 
consisting mostly of species of Acacia. This belt extends from near the equator to latitude 
25 to 30 degrees north and south. 

A distinguishing climatic feature of the savanna is the distinct dry season. The 
rainfall cycle results from the poleward shift of the global wind belts in the summer and 
their equatorward shift in the winter. A savanna climate has one or more months with less 
than 60 mm (2.4 ins) of rainfall. The climate is warm with a short summer rainy season 
and a dry winter. In areas of heavy rainfall there is a season of up to 1 000 to 1 500 mm 
(40 to 60 inches) of rainfall interrupted by a distinct dry season. 

The general appearance of the savanna is one of rolling plains, and the vegetation is 
tall grass with scattered trees. The tree cover ranges between the one extreme of a closed 
canopy near the border with the rain forest and where there has been little human inter- 
ference, and the other extreme of very open grassland with dwarf trees (or even with very 
few trees) dotted all over the landscape. The latter occurs at the edge of the desert and 
where excessive cultivation or extensive burning or heavy grazing has resulted in the dis- 
appearance of the original tree cover. 

The grass grows to a great height, 1.5 to 4.5 metres (5 to 15 ft) in some places, 
particularly where the giant elephant grass (Pennisetum purpureum) grows in the wet season. 
At the other extreme the grass is very short reaching up to a height of 30 cm (12 inches). 

In order to oombat the effects of the long hot dry season, savanna vegetation has 
developed a number of adaptations: the deciduous habit, leathery leaves, thick or corky 
barks, the thorn habit, small leaves, cactus nature and the development of storage systems, 
long and extensive root systems, and so on. 

Several florisitic types are easily recognised, such as the Doniellia - Parkia, the 
Daniellia - gymenooardia - Lophira and Comb return woodlands which are characteristic of 
certain areas in Central Africa, the stretches of Acacia woodlands covering vast areas in 
West, East and Central Africa; also the Hyphaene palm savannas, and the Borassus savanna 
which is associated with seasonally flooded sites. 


While it may not be true to say that there are as many classifications as there are 
workers in the field, the literature on African vegetation is replete with systems of 
classification and of names used by individual workers for the various types of vegetation 
encountered (Kuchler 1970). Most often different names are applied to the same type. This 
is, of course, inevitable in view of the vast area involved in the study, the general lack 
of communication and consultation between workers, the large number of habitats and life 
forms encountered in the field and the determination of each worker to map what he con- 
siders are clearly distinct and discrete types in his area of operation, even though this 
may be a very small and irrelevant type in the context of the whole continent. The situ- 
ation is also bedevilled by the lack of a generally accepted criterion for classification. 

- 3 - 

Individual authors have used the climate, the soil, the general geographical location, the 
physiognomy of the vegetation and the phyto-choro logical divisions (Phillips 1959, Monod 
1957 t Keay 1956). 

In Nigeria, this problem has for some time been resolved by the acceptance by most 
workers of the classification proposed by A.P.D. Jones and R.W.J. Keay (Jones 1945* Jones 
and Keay 1946, Keay 1953)* In this classification the Nigerian savanna is arranged as 
follows (from south to north) (see Figure 1): 

Derived Savanna 
Southern Guinea Savanna 
Northern Guinea Savanna 
Sudan Savanna 
Sahel Savanna 

This is in line with the classification adopted by French workers in the neighbouring 
countries of West Africa. 

Recent workers in Nigeria have rightly questioned the validity of the basis of this 
classification! and consequently a new classification based on the recommendations of the 
Scientific Council for Africa South of the Sahara (C.S.A.) Specialist Meeting on Phyto- 
geography in Yangambi (c.S.A. 1956, Boughey 1957) and on the Association pur 1' Etude 
taxonomique de la Flore d'Afrique tropicale (A.E.T.F.A.T.) Vegetation Map of Africa (Keay 
et al 1958) has been adopted by Charter (1970) for the new Vegetation Map of Nigeria, 
which is included in the National Atlas of Nigeria* 

The aims of the Yangambi meeting were: 

1. "to establish a common terminology for all African phyto geographers"; 

2. "to limit this terminology to African vegetation only", and 

3. "to exclude from African nomenclature some of the terms used in other 
countries of the world which illustrate various types of vegetation the 
homo logy of which is not proven". 

The meeting accepted the proposal "to illustrate, particularly by profile diagrams, the 
description of the various types of vegetation or plant communities". It concluded that in 
the interests of a co-ordination which was highly desirable, there was a need for essentially 
physiognomic definitions of the various types of vegetation. It therefore recommended the 
adoption of a broad system of classification based on this principle, but left the use of 
intermediary physiognomic terms corresponding to the various recognisable transitions in 
the field and the designation of certain very particular formations to the initiative of 
the phytogeographers, according to local conditions. 

Two main groups of vegetation formations were recognised, namely: 

1. Closed Forest Formations, including "Thickets", the latter being described as 
"Shrubby vegetation, evergreen or deciduous, usually more or less impenetrable 
often in clumps, with grass stratum absent or discontinuous" (Some thickets, 
like the Comb re turn mioranthum thicket, come within our definition of savanna). 

2. Mixed Forest-Grassland Formations and Grassland Formations. 

The latter is the subject of this Symposium. There are four primary subdivisions: 

1. "Woodland", defined as open forest; tree stratum deciduous consisting of small 
or medium-sized trees with the orowns more or less touching, the oanopy remaining 
light f grass stratum sometimes sparse or mixed with other herbaceous and suffru- 
tssoent vegetation* 

- 4 - 

2. "Savanna", defined as formation* of grasses at least SO cm high, forming a 

continuous layer dominating a lowr stratum; usually burnt annually, leaves of 
grasses flat, basal and oaoline; woody plants usually present. This is sub- 
divided into: 

(a) Savanna woodland, having trees and shrubs with light canopy; 

(b) Tree savanna with scattered trees and shrubs; 
(o) Shrub savanna; 

(d) Grass savanna, in which trees and shrubs are generally absent. 

3* "Steppe 11 , defined as open herbaceous vegetation sometimes with woody plants, 

usually not burnt, perennial grasses usually less than 80 cm high, widely spaced; 
leaves of grasses narrow, rolled or folded, mainly basal, annual plants very 
often abundant between the perennials. This is also subdivided into: 

(a) Tree and/or shrub steppe with trees (mostly small) present; 

(b) Dwarf shrub steppe; 
(o) Succulent steppe; 

(d) Grass and/or herb steppe in which trees and shrubs are virtually absent. 

4. "Grassland", sub-divided into: 

(a) Aquatic grassland; 

(b) Herb swamp; 

(c) High montane grassland. 

Following this meeting, Keay and other authors (1958) published "Vegetation Map of 
Africa South of the Tropic of Cancer" on behalf of L f Association pour I 1 Etude Taxonomique 
de la Flore d'Afrique Tropicale (A.E.T.F.A.T. ) with the assistance of Unesco, which is the 
basis of the vegetation map given in Tree Planting Practices in African Savannas (Laurie, 
1974). Altogether 35 types in 19 broad groups are recognised of which the following come 
within our definition of savanna: 

A* 8. Forest savanna mosaic 

9* Coastal forest savanna mosaic 

B. 10. Dry deciduous forest (with savanna): with 

abundant Baikiaea plurijuga 
11. Dry deciduous forest (with savanna): 
Madagascar types 

C. 12. Thickets: Itigi types 

13* Thickets: Madagascar types 

14* Thickets: Ethiopian evergreen types 

D. 16. Undifferentiated: relatively moist types 

17. northern areas: with abundant Isoberlinia doka and I. tomentosa 

18. South-eastern areas: with abundant Braohystegia and 

Julbe rnardi a 

19. South - western areas (principally on Kalahari sand): with 

abundant Braohystegia, Julbe rnardia, Cryptosepalum psuedot axus , 
Quibourtia ooleosperma and areas of steppe (type Ho. 24). 

-5 - 

E 20* Undifferentiated: relatively dry types 

21. Ethiopian types 

22. With abundant CQlophospenmim mopane 

P. 23* Madagascar grass savanna and grass steppe 
24* Grass steppe on Kalahari sand 

0* 25* Wooded steppe with abundant Acacia and Commiphora 
26. Grass steppe with thick clumps: western Uganda type 
27* Grass steppe: Luanda type 

I. 28. Karoo succulent steppe 

J. 29* Subdesert steppe t Karoo shrub and grass 

30. Subdesert steppe: transitional and mixed Karoo 

31. Subdesert steppe: tropical types 

To these may be added the following: 

Montane grassland, Sub-tropical grassland and 
Oxytenanthera bamboo thickets. 

A second edition of the A.E.T.F.A.T. map designed to incorporate the criticisms and 
revisions of the first edition is in preparation (White, in press). An interim report 
(White 1974) indicates that there are now 60 mapping units (as against 35 in the earlier 
edition). These have been reduced to 14 in the report, of which the following represent 
the savanna types: 

6. Broadleaved woodland and wooded grassland; 

7. Thorn (Acacia) woodland, wooded grassland and semi desert vegetation; 

8. Karoo-itamib semi desert shrub land; 

9. Grassland. 

To this may be added: 
Deciduous thicket. 

Savanna vegetation occupies a vast area in Africa. According to Shantz and Narbut 
(1923)9 the comparative areas occupied by the three main types of vegetation are: 

Area -Area 

(Square miles) (Square kilometres) Percentage 

Forest 2 056 700 5 326 853 18.4 

Grassland 4 736 400 12 267 276 42.3 

Desert 4 406 900 11 413 871 39-3 

Total land surface (without lakes 

and excluding Madagascar) 11 200 000 29 008 OOO 100.0 

- 6 - 

In West Africa, the savanna belt sweeps from Mauritania, Senegal and Oarabia in the 
west through Mali, parts of northern Guinea* Ivory Coast, Ghana, Togo and Benin, Upper Volta, 
Niger, the northern four-fifths of Nigeria!; Chad and northern Cameroon, continues into the 
Sudan and through the greater part of the Eastern Horn (Ethiopia, Afars and lesae, Somalia 
and Soootra). It then wheels south to the three East African countries of Kenya, Uganda 
and Tanzania and thereafter turns to the west to Rwanda, Burundi, Zaire (surrounding the 
central forest block) and Gabon (15$ of the surface area). Further south it fans out to 
Angola, Zambia, Malawi, Mozambique, Rhodesia, Botswana, Namibia and northern parts of 
South Africa* It occurs too in the territories of Lesotho and Swaziland as grassland, 
thorn savanna and mixed tree savanna. Much of the island of Madagascar is covered with 
grass savanna and grass, and thickets, perhaps as a result of severe degradation of the 
forest by cultivation and burning. 

It is not possible, nor indeed is it desirable, in a paper of this length to describe 
in any detail all the savanna types in all countries in which they occur. But, perhaps as 
a suitable conclusion to this paper, the new classification adopted by Charter (1970 ) for 
Nigeria's savanna vegetation is shown in the table below against the well-established 
classification by Keay and other authors. 

Table 1 


Keay and Jones 

Roeevear (1953) 
and other authors 

Forest -savanna mosaic 

Mixed Leguminous wooded savanna 

a. with Afzelia afrioana 

b. with Isoberlinia doka and 

L* tomentosa 

c. with Burkea afrioana 

d. with all the species above 

Mixed Combretaoeous woodlands with 
Combretum nigrioans or Anogeisus 

Mixed Acacia woodland with 
Acacia Senegal 

Undifferentiated wooded savanna 

Wooded tropical steppe 

Plateau grass savanna (sub-montane 
grass savanna) 

Derived savanna 

Southern Guinea 

Northern Guinea 


Sudan savanna 

Sudan savanna 

Sahel savanna 
Montane vegetation 

Guinea savanna 
Guinea savanna 


Sudan savanna 

Sub-Sudan savanna 
of Clayton (1957) 
and other authori 

Sahel savanna 

I/ The actual extent of the savanna in Nigeria is 86. 4$ of the land surface (Anon. 1974) 

- 7 - 


Anonymous. Agricultural development in Nigeria 1973-1983? Lagos. 

Boughey, A.B. The physiognomic delimitations of West African vegetation types. 
1957 Jour. W. Africa Sci. Asso. 3, PP. U8-165* 

Charter, J.R. Nigerian vegetation (Ecological Zones). National Atlas of Nigeria* 
1970 in press. 

Clayton, W.D. A preliminary survey of soil and vegetation in Northern Nigeria. 
1957 Internal Report. Ministry of Agriculture, Northern Nigeria. 

C. S.A. Scientific Council for Africa South of the Sahara. 

Specialist Meeting on phytogeography. Yangambi, C.S.A. Publication No. 22. 

Jones, A.P.D. Notes on terms for use in vegetation description in Southern Nigeria. 
1943 Farm and Forest 6, pp. 130-136. 

Jones, A.P.D. and Keay, R.W.J. Descriptive terms for the vegetation of the drier parts 
1946 of Nigeria. Ibid. 7, pp. 36wK). 

Keay, R.W.J. An outline of Nigerian vegetation. Ed. 2. Lagos. 

Keay, R.W.J. African vegetation. Economic Atlas of Africa. Oxford. 

Keay, R.W.J. et al. Vegetation map of Africa south of the Tropic of Cancer. Oxford. 

Keay, R.W.J. Derived savannah - derived from what? Bull, IFAN TXXI, Ser. A., No. 2 
1959 PP. 427-438 

Kuchler, A.W. Vegetation maps of Africa, South America and the world (General). 
1970 Kansas, U.S.A. 

Laurie, M.V. Tree planting practices in African savannas. Forestry Development Paper 
1974 No. 19. Rome, FAO. 

Monod, Th. Les grandee divisions chronologiques de 1'Afrique. 
1957 C.S.A. Publication No. 24. 

Phillips, J. Africa south of the Sahara. Agriculture and ecology in Africa. London. 

Richards, P.W. The tropical rain forest. Cambridge. 

Rosevear, D.R. Vegetation, forestry and wildlife in Nigeria. 
1953 Nigerian Handbook. London. 

Schimper, A.F.W. Plant geography upon a physiological basis. Oxford. 


Shantz, H.L. and Marbut, C.F. The vegetation and soils of Africa. Amer. Oeogr. Soc. 

1923 Hes Ser. 13. 

White, F. A.E.T.F.A.T. Vegetation map of Africa. Interim report in Africa south of the 
1974 Sahara. London* 

White, F* A.E.T.F.A.T. Vegetation map of Africa. 
(in press) 

- 8 - 





2 5 20 15 

\J For A.E.T.F.A.T. map, ac Lauri* (1974). 

10 s 

- 9 - 


M.A. Ogigirigi 
Shelterbelt Research Station, Kano, Nigeria 



Introduction 10 

General Causes of the West African Climate 10 

General Characteristics of West African Climate 11 

Rainfall 1 1 

Temperature 1 1 

Sunshine 1 1 

Relative humidity 11 

Climate of the Guinea Savanna 11 

Accra-Togo dry coastal savanna 12 

Southern Guinea savanna 12 

Northern Guinea savanna 12 

Jos Plateau 13 

Climate of the Sudan Savanna 13 

Some Implications of Climatic Conditions for Savanna Afforestation 14 

References 14 

Figure 1: General Characteristics of the Climate of West Africa 15 

Figure 2: Map of Annual Rainfall (millimetres) in West Africa 16 

Table 1: Mean Daily Sunshine (hours) for Freetown (Sierra Leone) and Kumasi (Ghana) 17 

Table 2; Mean Relative Humidity ($) in January and July in West Africa 17 

Table 3: Maximum and Minimum Temperatures and Rainfall in West African Savanna 18 

Table 4: Mean Monthly Soil Temperature in the Savanna Zones of Nigeria 19 

I/ Paper for Symposium on Savanna Afforestation 

- 10 - 


The interaction of climatic, edaphic and biotic influences largely results in the 
distribution and characteristics of various vegetation types in West Africa as in other 
parts of the world. As a result of this, broad vegetation zones more or less coincide with 
olimatic zones. Localized variation, often due to corresponding localized physical features, 
however, are sometimes found to occur within these broad zones. 

As West Africa lies almost entirely within the tropics, the climate is often classi- 
fied as tropical. In the tropics, climatic changes throughout the year are much more 
dependent on rainfall than on radiation, which shows only minor variations during the year; 
thus the year is divided into rainy and dry seasons. 


Climate changes from place to place in West Africa as a result of the seasonal effect 
of three main factors: air masses, ocean currents and altitude. The most widespread 
features are the tropical continental and tropical (or equatorial) maritime air masses 
which alternate seasonally over the West African land mass. 

The effect of the tropical continental air mass is more predominant from September to 
February. It spreads southwards from the Sahara to about 5N latitude, causing the hot, 
dry weather which characterises most of West Africa during this time of year. It is often 
accompanied by the dry north-easterly wind known as harmattan. 

The tropical maritime air mass is predominantly active over much of West Africa from 
March to August extending northwards to about 21N latitude. Associated with it are the 
rain-bearing southwesterly winds. 

These two air masses are separated by a zone known as the intertropical front (some- 
times referred to as intertropical discontinuity or intertropical convergence zone). Prom 
March onwards, the position of the intertropical front moves northwards allowing tropical 
maritime air to penetrate far inland. From about September it moves southwards toward the 
equator and the drier continental air spreads southwards across the West African land mass. 

This alternating northward and southward movement of the intertropical front is 
largely responsible for the orientation of the climatic and vegetation zones in an almost 
latitudinal pattern in West Africa. 

Ocean currents largely contribute toward the dry weather conditions which partly 
result in the coastal savanna of eastern Ghana, Togo and the Republic of Benin (formerly 
Dahomey)* Cool ocean currents of uncertain origin occur in the middle of the year off 
these ooasts thereby cooling sea and air temperatures and restricting convection. In 
addition to the effects of the ocean currents, the relief features of the Guinea Highlands, 
Cape Three Points, the Mampong Scarp and the Akwapim-Togo Mountains cause the rain-bearing 
southwesterlies to lose their moisture on the highlands, so becoming dry westerlies. 

Similarly, the occurrence of monsoonal and mountain grassland along the latitudinal 
belts of Guinea and Sudan savanna in Senegal and Guinea are due to the effects of the Fouta 
Djallon Mountains. The Jos Plateau has a similar effect on the occurrence of derived 
savanna vegetation on its southwestern slopes. 


In the -tropic* rainfall is the most vital element in the climate ae the natural vege- 
tation largely depends upon its quantity (and especially its effectiveness), its degree of 
certainty, its length and how it falls* Figures 1 and 2 show the general picture of the 
annual rainfall. The very heavy rainfall of the southwestern coast and the Cameroon 
Highlands is evident. The low rainfall of central Ivory Coast , eastern Ghana and Togo are 
also clear. Apart from these contrasting features along the West African coast , annual 
rainfall decreases regularly northwards from the coast t both in amount and duration* There 
is a south to north spread in the beginning of the rainy season and a corresponding north 
to south retreat at the end* For this reason the rainy season gets progressively shorter 
further north in the area* 

The rainfall is extremely variable in amount, in time of onset and cessation as well 
as regime. This variability is greatest in the interior. 


Because of its situation in the tropics, there is the general belief, especially 
among non-Africans, that temperatures in West Africa are exceedingly high throughout the 
year. This is more often an exaggeration. The very high temperatures characteristic of 
many months in the lowland parts of similar latitudes in East Africa and India are attained 
in West Africa only in or near the desert for short periods of the year. 

On the whole, average temperatures in West Africa are lower than the world average 
for similar latitudes in the northern hemisphere during winter, during the rains in the 
south and almost all year round in Senegal, the coastline of eastern Ghana and Togo, and 
in highland areas. On the other hand, temperatures are higher than the world average for 
similar latitudes in April, July and October. 

A very common feature of the temperature conditions in West Africa is the diurnal and 
seasonal range of variation. There is a gradually increasing range from the Guinea coast 
northward and a sharper increase from the Senegal coast inland. The greatest ranges occur 
during the change of seasons. 


Because West Africa is situated in the tropics, night and day lengths are almost 
always equal. For this reason sunshine seldom exceeds twelve hours. During the wet season, 
clouds and early morning mist often obscure the sunshine, while during the dry season, the 
sun is often obscured by dust - haze. As a result of this, the recorded sunshine is often 
reduced. Table 1 shows representative figures of mean daily sunshine in hours for Freetown 
(Sierra Leone) and Kumasi (Ghana). 

Relative Humidity 

High relative humidity is common in rainy areas and during the rainy seasons. During 
the dry season, relative humidity drops considerably. Table 2 shows mean percentage rela- 
tive humidity in January and July for some places on the coast and in the interior. 


The map on page 8 shows the vegetation cones of West Africa* The Guinea savanna lies 
roughly between latitudes 7 and 9 30'N and occurs to the north of the lowland rain forest 
exoept fer the southern portions of Ghana, Togo and the Republic of Benin where it extends 
southward to the Atlantic coast* The southern and northern portions of this vegetation zone 

- 12 - 

show some difference* in structure and florirtic composition which are consistent enough 
to subdivide it into southern and northern Guinea savanna. The climatic differences between 
the southern and northern portions of the Guinea savanna, however, are more a degree of 
severity of conditions rather than of kind* 

Accra Togo Dry Coastal 

Some of the reasons for the occurrence of this type of vegetation in this area have 
already been mentioned. 

The rainfall pattern for this southward extension of the Guinea savanna is similar to 
that of the lowland rain forest , but the monthly and yearly totals are low. The coastal 
fringe between Elmina and Grand Pope has an average annual rainfall of below 35 inches 
(875 nan). The number of rain days are few and there are only two or three months in the 
year with more than 4 inches (100 mm) of rainfall. 

Relative humidity is only a little lower than in the rain forest zone. Temperatures 
are generally a little higher than in the rain forest zone except from July to September 
when they are much cooler for reasons already mentioned above. 

Table 3 shows average monthly maximum and minimum temperatures and rainfall for Accra 
(Ghana) and Lome* (Togo). 

Southern Guinea Savanna 

This zone lies roughly between latitudes 730' and 9N and extends from Nigeria to 

Temperatures are moderately high with a wide diurnal variation in the dry season 
which lasts about four to five months. Then follows a rainy season of about seven to eight 
months with lower temperatures and less variation. 

Relative humidity varies between 50 and 80$ but is generally below 70$ at 9*00 a.m. 
daring the dry season. Table 3 shows mean monthly maximum and minimum temperatures and 
rainfall for some principal towns within the zone. 

In Nigeria, total annual rainfall in this belt ranges from 'about 40 to 50 inches 
(1 050-1 250 mm) 9 with two peaks. The rainy season begins in early March and reaches its 
first peak in Nay. Rainfall then declines till July and increases again at about August 
to reach a second peak in September before declining sharply to an end in October/November. 
Because their timing varies from year to year, the peaks are often not evident from average 
figures (e.g. Table 3). 

In Lokoja (Nigeria), mean maximum temperatures range from about 96F (36C) in 
February/torch to about 85F (29C) during July to September, while mean minimum temperatures 
range from about 76P (24C) in February/March to about 66F (19C) in November to January. 
Corresponding figures for Mokwa (Nigeria) are: mean maximum temperatures 100F (38C) in 
February/faarch to 86F (30C) in July to September, while mean minimum temperatures vary 
from about ?6F (24C) in March to about 60F (16C) in December and January. 

At Mokwa, although mean daily relative hmidity during the dry season ranges between 
70 and 30j, humidity often drops sharply during the day to below 20^ by early afternoon. 

Northern Guinea Savanna 

extends from abou 

Nigeria, 12N in Upper Volta and 13N further west. 

The northern Guinea savanna extends from about 930'N to about 11 N latitude in 

- '13 - 

Maximum diurnal variation in temperature occurs in the dry season, with less variation 
during the wet season (see Table 3). At Afaka (near Kaduna, Nigeria), mean maximum tempera- 
tures range from about 100F (38C) during February to April to about 78P (26C) in July 
to August. Mean minimum temperatures range from about 74F (23C) in April to about 58F 
(14C) during November to January. 

The rainfall pattern in this zone is generally of a single peak. Annual total rain- 
fall in this zone ranges from about 40 to 55 inches (1 000 - 1 375 nan). The dry season 
lasts about 5 to 6 months (October/November to March) with a rainy season of six to seven 
months (April to October). The rains increase in frequency and amount from April, reaching 
a peak in August/September and then decline sharply to an end in October. 

Mean relative humidity is in the range of 45 - 35$ during the dry season months. 
Humidity figures of below 20$ are common in early afternoon from November to January. 

Jos Plateau 

The Jos Plateau within the Guinea savanna is regarded as a highland varient of the 
northern Guinea savanna (Harrison Church, 1968) and, because of its altitude, temperatures 
are generally lower. Table 3 shows mean monthly maximum and minimum temperatures as well 
as rainfall for Jos (Nigeria). 

The rainfall pattern on the plateau is similar to that of the northern Guinea, but at 
the southwestern edge of the plateau, annual rainfall is generally higher. Average annual 
rainfall for Miango (Jos Plateau) and Nimbi a (southwest of the plateau) are about 55 inches 
(1 375 mm) and 70 inches (1 750 mm) respectively. 

At Miango, diurnal variation of temperature is small compared to typical northern 
Guinea savanna. Mean maximum temperatures vary from about 94P (33C) during February to 
April to about 78F (25C) in July to September. Mean minimum temperatures are generally 
about 66F (19C) from March to May, dropping to about 56F (13C) during December and 

Mean relative humidity is generally above 80$ during the height of the rains from 
July to September and drops to below 30$ during December to February. 


This vegetation zone lies north of the northern Guinea savanna and extends between 
approximately 11 and 13^ latitude in its southern limit and between 12 and 14N in its 
northern limit. It includes the southern interior of Senegal, interior Gambia, central 
Mali, most of Upper Volta and most of the extreme northern parts of Nigeria. 

In comparison with the northern Guinea savanna, rainfall is less - about 22-40 inches 
(550 - 1 000 mm) annually. The rains fall for five to six months followed by a dry season 
of six to seven months. The rainfall is much more variable than in the northern Guinea 
savanna. Table 3 shows mean monthly temperatures and rainfall for some principal towns in 
the Sudan savanna. 

Sokoto and Katsina in Nigeria have an average annual rainfall of about 29 inches 
(725 mm) each; Kano receives about 34 inches (850 mm). The rainy season starts in May, 
with the amount and frequency of the rains increasing steadily to a peak in August or 
September before declining rapidly to an end in October. 

Mean maximum temperatures in both localities are about 102F (39C) in April and May. 
During this period, temperatures of 106 F (41C) are often attained during the day. At the 
height of the rains during July to September, maximum temperatures average about 88HF (31C), 
Mean maxima turosraturos ax* lowtst during the months of December and January averaging 
about 54 F (12 C) but ofton dropping bolow 50 F (10 C). Minimum temperatures rise to about 
75 F (24c) in April and May just before the onset of the rainy season and drop to about 
70F (21C) at tho peak of ths rains. 

- 14 - 


The rains begin first in the southern portion and progress northward, while their 
cessation begins first in the north and progresses southward, resulting in the relative 
shortness of the rainy season in the north compared to the south. 

North of about latitude 730 I N, total annual precipitation becomes progressively less 
than annual evapo transpiration. This means that all areas above this latitude are deficient 
in moisture on an annual basis. This deficit increases with latitude. The difference be- 
tween the commencement of the rains around Lokoja and Katsina is about three months and the 
length of the rainy season about 200 and 100 days respectively (Kowal and Knabe, 1972). 

Forest plantation establishment in the northern savanna zones would therefore require 
more drought hardy species which can sufficiently establish themselves during the compara- 
tively short rainy season to be able to survive the long dry season. It appears that the 
southern Guinea and possibly the southernmost parts of the northern Guinea savanna zones 
could support a greater number of plantation species than the Sudan and Sahel zones because 
of the comparatively less critical moisture conditions. 

Irrespective of how favourable moisture and light conditions may be, plant growth 
ceases when the temperature of the environment either exceeds a certain maximum or falls 
below a certain minimum value. Between these maximum and minimum values, there is usually 
an optimum range. It is important to distinguish between air and soil temperatures in 
considering the effect of temperature on plant growth. Equally important is the fact that 
plants differ in their adaptation to ranges of temperature regimes. 

While many annual and biennial agricultural crops have been classified into cold 
season and hot season crops on the basis of their adaptability to different temperatures 
(Kowal and Knabe, 1972), there has not been any such classification for forest trees. 

Unsuitability of air or soil temperatures during the whole or part of the growing 
season may be a decisive factor in the success or failure of exotic or indigenous species 
as plantation candidates in the savanna zones of West Africa. Air temperature conditions 
have never been found too drastic to limit plant growth in the savanna areas. 

Table 4 shows mean monthly soil temperatures at three principal towns in the savanna 
zones of Nigeria. Too high soil temperatures may inhibit proper root development and 
growth. Consistently high soil temperatures at places such as Mokwa may militate against 
successful development of mycorrhizae for good growth of pines in spite of its low latitude 
and annual rainfall compared to places like Afaka. 

Other factors of the environment such as daylength and sunshine and values of potential 
photosynthesis computed from them have been estimated to be adequate for plant growth in 
the savanna zones. Successful afforestation in the savanna zones of West Africa, therefore, 
will depend on the proper selection of plantation species which are sufficiently adapted to 
utilize the very limited soil moisture (and sometimes the very low levels of nutrients) for 
maximum dry matter production under the prevailing environmental conditions. 


Harrison Church, R.J. West Africax a study of the environment and man's use of it. 
1968 6th Ed., Longman. 

Kowal, J.M. and Knabe, D.T. An agroclimatological atlas of the Northern States of Nigeria* 
1972 Ahamadu Bello University Press, Zaria, Nigeria. 

- 15 - 

























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- 16 - 








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- 17 - 











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- 18 - 


Location ' 














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Tot. Ann. 

Aoora-ToffQ Dry Coafftal S^wMm*. 

5 max 1 92.0 I 96.8 , 101. 4i 103. 8,100.8, 94.3 
5 Bin 63.0 67.0 73.6 76.6 77.8^ 74.2 
10 aTff I ' 0.1 ' 0.6" 2.9 1 5.3 


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5.1| 0.5| | 

88.01 93.51 92.5 
69.4 68.1 61.6 

5.11 0.5i 





























Votes The unbox* after T and R indicate the number of year* from which temperature (T) 
rainfall (R) raluee were calculated. 


- 19 - 







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- 20 - 


0. Kadeba 

Savanna Forestry Research Station 
Samara, Zaria, Nigeria 

A.V. Barrera 

Savanna Forestry Research Station 
Samara, Zaria, Nigeria 



Int roduct i on 21 

Climate 21 

Geology 21 

Soils, General 22 

Soil Chemical Properties 22 

Organic matter and nitrogen 22 

Phosphorus 23 

Exchangeable nutrients and cation exchange capacity 24 

Nioronutrients 25 

Soil Classification 25 

Raw mineral soils 25 

Weakly developed soils 26 

Brown and reddish-brown soils of arid and semi-arid regions 27 

Vert iso Is and similar soils 28 

Ferruginous tropical soils (fersiallitic soils) 28 

Ferrisols 29 

Ferrallitic soils (sensu strioto) 30 

Hydromorphio soils 31 

Summary and Conclusions .31 

References 32 

Geological Map of West Africa 35 

Nap of Soil Groups in West Africa 36 

I/ Paper for Symposium on Savanna Afforestation 

- 21 - 


The term West Afrioa is commonly used in referring to countries laying east of and 
along the Atlantic coast of continental Afrioa. In this paper West Africa will include 
(Plight and Perry, 1960) Mauritania, Senegal, Gambia, Guinea-Bissau, Guinea, Sierra Leone, 
Liberia, Ivory Coast, Ghana, Togo, Benin, Mali, Niger, Upper Volta and Nigeria. These 
countries lie between the latitude 5N and the Tropic of Cancer and cover about 2 200 miles 
from east to west and 1 200 miles from north to south with a total area of 2 333 041 so^iare 
miles. The 10-inch isohyet where the density of population is about 2 persons per square 
mile is more or less the northern boundary of the Sudan zone and of West Africa. 


Climate is a very strong and active factor affecting soil formation as well as plant 
growth in West Africa. Its effect on the soil is shown directly in rook weathering, 
leaching of bases, soil development and indirectly by its influence on the nature of 

Rainfall distribution in West Africa ie fairly constant. Rains are caused by two 
main movements of air masses - a dry continental air mass to the north and a moist body of 
tropical maritime air to the south. 

The latter brings rain which produces the wet and dry seasons, whilst the former 
brings in the cold, dry air from the north which is called harm at tan. North of latitude 8 
or 9^N there is only a single wet season with a single peak and followed by a long dry 
season. South of this latitude there are two distinct rainy seasons with double peaks, 
namely April -July and October-November. 

In the savanna areas, average annual rainfall is generally less than 1 150 mm; the 
range would be from 510 mm to 1 150 mm. Potential evapo transpiration ranges from 1 270 mm 
to 1 520 mm (50 to 60 inches) a year (Ahn, 1970). This creates a general deficit of soil 
moisture throughout the zone. The findings at Afaka Forest Reserve (Sarnie, 1973) showed 
that the 1 360 mm (54 inches) of rainfall in 1969 provided an ample supply of available 
soil moisture to grow plantation trees in this area. It was also reported that regions 
with less than 380 mm of rainfall are unlikely to support natural forests (USDA, 1938) 
and areas with less than 760 mm do not readily allow economic production of timber. Heavy 
and concentrated rainfall effects leaching of weathered materials in the profile. The 
amount of rain infiltrating into the soil depends upon its intensity, vegetation cover, 
slope of land, soil moisture content, soil texture and compactness and time of day. Less 
rainfall and sparse vegetation with warm temperatures allow less percolation in the soils 
of the northern parts of the savannas than in the high rainfall, high forest belt of the 
southern parts of West Africa. Slow and even rainfall permits the water to penetrate into 
the soil, whereas a sudden downpour creates runoff and also causes soil erosion. Due to 
this difference in amount of rainfall between the northern and the southern parts of West 
Africa, (see Rainfall map, page 16)* leaching also variee f being great where the rainfall 
is heavy so that the tendency of the soil reaction would be slightly alkaline to neutral 
in the northern part and acidic toward the southern part (Ann, 1970;. 


West African geology consists mainly of three known classes of rock formations. The 
first two are crystalline rooks, or igneous (granite) and metamorphic (gneiss and quartzites), 
which are the oldest (pre-Cambriaa) (see Map 1) and together these are commonly called rocks 
of the Basement Complex. Less extensive are the younger sedimentary rooks which cover most 

I/ A more detailed discussion on climate is presented in the preceding paper 
by M.A. Ogigirigi. 

- 22 - 

of the Niger River valley and western parts of Senegal and Guinea. The very much older 
sedimentary rocks (sandstones) are found mainly in the Northern areas of the Ivory Coast 
and Guinea. Most of these sedimentary rocks also rest on the Basement Complex sometimes at 
very great depths. Some of the old rocks weathered very slowly or were resistant to erosion 
with the result that they form the upland features of the Guinea Hi^ilande, the Atakora 
Ranges, the Jos Plateau, the Fouta Djallon and the Adamawa Highlands. Most rocks on the 
Basement Complex are less resistant to erosion and subsequently levelled the lands almost 
to wide plains, known by some authors as peneplains. Widely scattered over the peneplains 
are isolated hills in the form of domes made up mainly of granite. They are commonly bare 
or covered by very thin soils or gravels and stones and are known as insolbergs. Rocks of 
the Basement Complex produce poor soils as the minerals composing them are very resistant 
to weathering and contain very low reserves of weatherable minerals. Upon cropping, the 
soil fertility is soon depleted. Through traditional experience the farmers have learned 
that in order to produce good crops it is better to abandon the farms for a while and settle 
in another virgin area. Five or more years later when native vegetation has been re- 
established in the abandoned area, farmers will clear and farm again. This is the basis of 
what is known as "shifting cultivation". 

Volcanic rocks are located in the area around Mambilla, south of Potiskum, on the 
Jos Plateau and to a small extent in Senegal. Soils formed from this rock are generally 
much more fertile than those from the Basement Complex, as the content of weatherable 
minerals is high. 


The depth of soil that can be formed depends upon the factors affecting soil forma- 
tion. The texture as well as the fertility of a soil depends principally upon the factors 
affecting rock weathering. 

The breaking of rocks into fine particles is accomplished by either a mechanical or 
chemical process, or by both. Where temperature is high and rainfall is low as in the 
northern parts of West Africa, rock weathering is mainly by mechanical means and thus pro- 
duces coarse textured soils which are usually of low fertility. But towards the southern 
parts, rainfall becomes progressively greater and rock weathering gradually changes to 
chemical means producing fine textured soils. The rock minerals change into more soluble 
forms thus producing more fertile soils. In the drier areas, the savanna vegetation (grass 
and trees) dominates, but in the much wetter areas, high forest becomes dominant. In 
general, the volume of vegetation in savanna areas is less than that in the forest areas 
(Ann, 1970). Trees tend to extract nutrients from the soils at much greater depths than 
grasses. Due to seasonal burning in the savannas, large amounts of organic matter and soil 
nutrients are lost. Burning is not frequent in high forest areas and the nutrients in the 
top soils are greater than in savanna soils. From 15 cm and deeper the amount of nutrients 
in the horizons is practically the same for both savanna and high forest soils. 


The chemical aspects of West African savanna soils were discussed in detail by Nye 
and Greenland (i960), Ann (1970) and Jones (1973). The following discussions will be 
limited to the chemical characteristics of the soil that were found to influence the 
establishment and growth of exotic tree species. 

Organic Matter and Nitrogen 

Many West African savanna soils are low in organic matter and nitrogen. This is 
caused primarily by the effects of environmental factors and human interference on vege- 
tative growth. Usually in undisturbed soils, the level of organic matter builds up to a 
limit governed by the type and production of vegetative materials. 

Table 1 shows amounts of soil carbon and nitrogen for some sites in the savanna areas 
of West Africa. At Yambawa in Sudan savanna, for example, the average contents of carbon 
and nitrogen were 0.22 and 0*022 percent, respectively; whereas corresponding mean values 
of 0.98 and 0*058 percent were recorded at Afaka in the northern Guinea savanna* A striking 
feature of organic matter and nitrogen in savanna soils is the similarity in their distri- 
bution to vegetation patterns. This is basically so, as the vegetation serves as a medium 
through which other factors that influence organic matter level express themselves. 










Ivory Coast-/ 

1 143 
1 780 








Upper Niger 







Afaka, Nigeria 

1 245 






Mokwa, Nigeria 

1 118 






Yambawa, Nigeria 







Hadejia, Nigeria 







\J Data quoted by Nye and Greenland (1960). 

Jones (1973) has shown that the two major factors governing the amount of carbon and 
nitrogen in well drained West African savanna soils are clay content and a moisture factor 
measured by the length of the wet season. Recently, Kadeba (1975) showed strong significant 
correlation between organic matter and mean annual rainfall for some sites in the savanna 
zone for Nigeria. The effect of latitudinal position on organic matter level was also 
demonstrated. There was a decrease of 0.40 and 0.03 percent, respectively, in soil carbon 
and nitrogen contents per degree latitude to the north. Not only does quantity of organic 
matter in the soil vary with environmental conditions, but also the quality. Work done on 
savanna soils showed the C/N ratio decreases with decreasing rainfall, in keeping with the 
findings that the degree of humification of organic matter increases with dryness of 
climate (Buohaufour and Dommergues, 1963; Jones, 1973). 

Burning, cultivation and grazing are common features of peasant agriculture in West 
Africa. The degrading effects of these practices on soil organic matter and nitrogen have 
been demonstrated (Jenkins, 1964? Moore, 1960; Nye and Greenland, 1960; Jones, 1971; 
Jones 1973). The suppression of nitrogen mineralization by annual early burning was docu- 
mented in a study at Afaka in northern Guinea savanna (Kadeba r 1973). 

Available data provide evidence of the influence of soil parent material on soil 
organic matter. This is expected, in as much as parent material determines soil texture. 
In a region of predominantly sandy soils, the influence of clay on soil fertility and hence 
on vegetative growth could be considerable. 


Phosphorus is one of the primary elements limiting the growth of forest trees in 
savanna areas of West Africa. Most savanna soils have less than 100 ppm total P. Little 

- 24 - 

concentration of phosphorus occurs through vegetative cycling and spectacular responses to 
applied P have been observed in several areas (Nye and Greenland t 1960), 

The data of Ipinmidun (1973) shown below provide information on the levels of total 
and organic P that could be met on some sites in the Nigerian savanna region. 


Soil Category 

Organic P 

Total P 


Juvenile soil on 
aeolian sand 




Undif f erent iat ed 
ferrisol and lithosol 







Many West African studies have shown that values of organic P constitutes a signifi- 
cant propotion of total P (Omotosho, 1971; Acquaye, 1963; Friend and Birch, 1960). It 
has also been suggested that input from organic P through mineralization to available P 
could be comparatively large in these highly weathered soils. 

The deficiency of P in savanna soils is often attributed to the occurrence of 
relatively large amounts of free Pe and Al oxides that lead to strong P adsorption. This 
may be true in certain instances as in volcanic soils. Most tropical soils possess oxides 
that are highly crystalline, of low surface area and hence they fix small amounts of 
applied P, Low addition of P fertilizers will maintain satisfactory P concentration in the 
soil solution. Residual effects of phosphate gave significant correlation with crop yield 
on such soils in a field experiment in Samaru (Ipinmidun, 1973). 

In ferruginous and other soils of West Africa, the amounts of 'active 1 oxides and 
their participation in phosphate sorption may depend on the organic matter content of the 
soil and hence the depth of sampling, Juo and Maduakor (1974) found that a surface and 
subsurface Puntua soil in the Guinea savanna, required 96 and 45^ kg/ha of P respectively 
to maintain an equilibrium soil solution of 0.2 ppm P. 

Exchangeable Nutrients and CEC 

The most important parameter determining the cation exchange capacity (CEC ) of savanna 
surface soils is the soil organic matter content. In the Guinea savanna, it has been 
estimated that between 60 and 85 percent of the cation exchange surface is provided by the 
organic matter (Kadeba and Benjaminsen, 1975); the CEC of organic matter was calculated as 
lying between 282 to 322 mE q /100g. In the subsoil it is the mineral fraction of the soil 
that makes significant contribution to the CEC. In keeping with the kaolinitic nature of 
the clay as well as the low organic matter level, the CEC of the soils are generally low, 
often lees than 10 mEq/100g. 

The levels of the exchangeable cations are determined primarily by the kind of soil 
parent material. Soils derived from Basement Complex contained between 0.35 and 3.99 per- 
cent total K compared with 0.06 and 0.11 percent total K for soils derived from sandstone 
(Wild, 1971). Except in sandy soils, cation deficiency is not a serious problem under the 
non-intnsive farming conditions which prevail over most of the savanna region of West 
Africa. Moreover, because of the low CEC, the percentage saturation of the exchange 
complex by the individual cations is relatively high and this might be a favourable factor 
in their availability. 


There is limited evidence of the effects of mioronutrients on growth of exotic tree 
species in the savanna zone of West Africa. In Nigeria, the die-back of eucalypts has been 
associated with boron deficiency. At Samaru, hot-water-soluble boron, which is used as an 
index of availability, ranges from 0.03 to 0.13 ppm with a mean value of 0.076 ppm. There 
is evidence that sulphur and molybdenum levels are often marginal for groundnuts. 


As a consequence of the different factors of weathering and soil formation, a large 
number of different types of soil were produced. To study these different kinds of soil 
individually is impossible and it is, therefore, necessary to classify them into units - 
each unit with soils of similar characteristics. A system of broad classification of soils 
was developed by Pugh and Perry (i960) in which the soils in West Africa were classed into 
four groups as follows: 

Northern sandy soils* These generally cover the Sahel and part of the Sudan zones. 
Vegetation is mainly grass with a few low trees. The area is used mainly for pasture. 
The sandy materials are usually blown by wind during the dry season. 

Zone of lateritio soils. The soils in most of this area are poor and clearing of new 
lands often exposes the soil to laterite formations thus extending the areas of poor 
soil. Soil erosion is also common and fertilizers are needed to produce economical 

Equatorial forest soils. High forests are found in this zone of high rainfall and 
humidity. Soil is less eroded and is highly desirable for agriculture. This forma- 
tion is found in the lower parts of the Guinea zone. 

Coastal swamp soils. The soils in this class are mostly mud and sand mixed with 
organic matter and are usually saturated with brackish water. Vegetation is mostly 
mangrove. When properly washed and drained, the soil can be used for farming. 

Another more precise and technical classification was prepared 'by D'Hoore (1964). A 
similar soil classification was also prepared by Unesco and PAO, but in as much ae the 
soil map published in PAO Forestry Development Paper No. 19 (PAO, 1974) is the one based on 
D'Hoore, the authors decided to use this and to describe the soil units based on D'Hoore* s 
report on the Explanatory Monograph No. 93 dated 1964 In this system, the different soil 
units were classified into main groups according to their developing genetic criteria. 

The soil map presented in this paper ie a reproduction of that published in PAO 
Forestry Development Paper No. 19. Only soil units covering the Sudan and Guinea zones of 
West Africa are included in the following discussions. The soil units numbered in figures, 
correspond to those in the legend on the soil map. 

Raw Mineral Soils 

The term "soil 11 may scarcely be applied under this group; The environmental condi- 
tions encountered here are so unfavourable to biological activities that living processes 
and the pedogenesis they promote are lacking almost completely. These are "pre-soils" , or 
soils near zero time in soil formation. The raw mineral "soils" are of particular import- 
ance because of the enormous surface they cover, specially in the northern parts of West 

- 26 - 

1. Desert Soils t Undifferentiated 

Definition. This includes all loose materials, mostly sandy and submitted to desert 
conditions. Associated with this are also desert pavements that are transported and some 
halomorphic soils, which are not differentiated* 

Pi s t ri but i on . Pound mainly in the Sahel or north of the Sudan zone of West Africa. 

Value for forestry. At present these soils do not have much value for forestry. 
However, with irrigation they can be made to support some species of trees intended for 
fuel or posts. The soil needs application of abundant organic matter to increase water 
holding capacity. 

Weakly Developed Soils 

Soils in this group are classified with the order entisols (USDA 7th Approximation, 
except for the sub-desert soils that belong to aridisols). These noils have a low level of 
profile development reflected in a very weak differentiation of horizons. Factors contribu- 
ting to their poor development are: 

a) Parent materials low in alterable or transferable minerals and 

b) Erosion processes that remove loose superficial layers as soon as they are 
formed, either due to strong relief, intense winds or rainfall, or by all of the 
these factors. 

6. Skeletal Soils, Mostly Rock Debris with Pockets of Soils 

Definition. Soils with very weak differentiation of genetic horizon, containing 
coarse elements and having solid rock within a depth of 30 cm. 

Distribution. Found mainly in the high-lands as well as widely distributed amon^ 
other soil units, especially within the ferruginous tropical soils. 

Value for forestry. Generally low. This soil requires erosion control measures, 
such as contour trenching, planting on the contour and application of fertilizers, to raise 
the level of fertility. This soil can be used for reforestation of shallow rooted trees 
or trees whose roots can penetrate the plinthite layer. 

7. Weakly Developed Soils on Young Allevium, Often Halomorphic or Hydromorphic 

Definition. Deposition is still proceeding intermittently in these soils and they 
are characterized by a great heterogeneity. They differ not only from one spot to another 
but also after a flood, as reflected by the stratifications in the profile. Moreover, the 
age of the deposits is not the same throughout. It is mapped as complexes. 

In the most recently deposited soils, humic horizons are often lacking whereas the 
gley horizon is barely discernible, but on older formations covered by vegetation there 
are humic horizons, showing structural development and a gley horizon becomes perceptible. 

Distribution. This soil unit although not very extensive, is well distributed. It 
may be found under every climate near bodies of water which fluctuate periodically. 

Value for forestry. The forestry potential is influenced largely by the composition 
of the sediments and the type of climate. Alluvial plains often comprise the soils with 
the highest potential for planting. It is seldom that these favoured soils make up all of 
the alluvial deposits. Hence detailed soil mapping prior to reclamation is always useful. 
Areas with deep and moderate textured soils, however, will support good growth of trees - 
provided there is sufficient moisture available. 

13 Lithomorphic Soils with Dark Non-Kaolinitic Clays, Developed on Calcareous and Basic 
Igneous Rooks t but as a Rule not in the Humid Areas 

Definition* These lithosols on a calcareous crust may still be forming and are a 
product of present day soil formation. They are found on loose sediments, generally in 
association with brown soils of arid and semi-arid tropical regions and in areas with flat 
or slightly undulating relief. A thin layer of brown to red aeolian sand overlays a 
calcareous crust of variable thickness. The pH is neutral to slightly alkaline. In the 
clay fraction illite and montmorillonite are the dominant minerals. Of course, these soils 
may be considered lithosols only in so far as the loose overlying layer is sufficiently 
thin (30 cm). 

Distribution* This formation is limited to the relatively arid regions situated near 
the border of the desert or in the northern part of Senegal. In North Africa its presence 
seems linked to calcareous bedrock. 

Value for forestry. These soils have a certain potential for forestry. In North 
Africa they often carry vineyards and also may be used for extensive grazing. Their use 
for forestry may be a problem due to insufficient rainfall in the area. Irrigation may 

Brown and Reddish-Brown Soils of Arid and Semi-Arid Regions 

The brown or reddish soils are darkened by organic matter in the greater part of the 
profile under steppe vegetation, are without an A2 horizon, but have a textural structural 
or colour B horizon. The reserve of weatherable minerals in the soils is often considei>- 
able but this depends on the composition of the parent material. Ordinarily they contain 
appreciable quantities of clay minerals with 2:1 lattice. The cation exchange capacity of 
the mineral complex, which is medium to high, is more than 50 percent saturated in horizons 
B and C and often contains free carbonates. These soils are situated between the desert 
areas and the eo^iatorial region. 

12. Brown Soils of the Arid and Semi-arid Tropical Regions, Generally with Highly 
Saturated Non-Kaolinitic Clay Complex 

Definition. These soils are formed under a hot dry climate where annual rainfall 
rarely exceeds 500 mm. They are often formed on aeolian deposits where the climate is 
rather more humid and the parent rock rich in bases. Impeded external drainage seems to 
favour their development. 

Although the total organic matter content is low (less than 1$) it is well distributed 
throughout the profile. The French classification subdivides the group "sols bruns sub- 
airdes" into two subgroups: the brown soils proper and the red brown soils. The latter 
differ from the former in that they are generally developed on sandy parent materials, have 
a greater thickness, generally do not contain any free carbonate, are lower in organic 
matter and are neutral to weakly acid. It is necessary to bring in climatic variations and 
chronological successions to explain their present co-existence. 

Distribution. Parent materials are not only of aeolian sand deposits that border the 
desert regions but also weathered sandstones or paleopedological mantle material as well. 

Value for forestry. Generally, these soils are not suitable for forestry due to low 
rainfall, but under irrigation they may be able to produce early maturing trees. Cultiva- 
tion tends to deteriorate the good structure and permeability of the soil. Addition of 
organic matter should be maintained but excessive irrigation should be avoided as this 
could induce more destruction of the structure and cause the soil to become compacted. 

- 28 - 

Vertisols and Similar Soils 

Vertisols are important in view of the possibilities for agriculture. African 
vertisols have all of the morphological characteristics of true vertisols but the clay 
fraction is rather lower in expandable minerals and consists more of amorphous gels, than 
those defined under the U.S.D.A. 7th Approximation. 

Vertisols are subdivided into (1 ) lithomorphic vertisols and (2) vertisols of 
topographic depressions. Each subdivision is related to distinct geomorphological features 
that can be mapped readily and correspond respectively to the usterts and aquerts of the 
USDA 7th Approximation. 

14 Soils with Dark Non Kaolinitic Clays Confined to Topographic Depressions; Occurring 
in Semi Arid Areas with a Marked Seasonal Distribution of Rainfall 

Definition. These soils are found in topographic depressions with poor external and 
internal drainage. They seem to develop under climates where potential evaporation is high 
during part of the year and on parent materials (often sediments) of enriched insoluble 
constituents derived directly or indirectly from surrounding higher land. Accordingly, 
they are more commonly associated with soils having sodic, calcic or gypsic horizons than 
are the vertisols of lithomorphic origin. The reserve of weatherable minerals is often 
high. The clay fraction usually consists mainly of 2:1 lattice clays, especially the 
montmorillonite and mixed layer clay minerals. The cation exchange capacity of the complex 
is high and is generally more than 50 percent saturated, mostly with bivalent cations 
(normal ammonium acetate at pH 7). 

Distribution. These soils are found only in areas under conditions of relatively 
well marked seasonal drought: three months of dry season and a mean annual rainfall of 
1 000 mm or less. The Sudan depressions are probably the largest expanse of these soils 
in the world. 

Value of forestry. Their topographic situation frequently associates them with 
calcimorphic or halomorphic formations and impedes drainage and desalinization. After 
drainage, these soils may be used to grow trees with high water requirements like Eucalyptu 
robusta. In the Sudan zone trees like Acacia nilotica, A. seyal, A. albida and A+ Senegal 
may be tried. 

Ferruginous Tropical Soils (Fersiallitic Soils) 

These are soils with an ABC profile; some have an A2 horizon and a textural B horizon 
showing uniform or a weakly prismatic structure. There is a frequently observed marked 
separation of free iron oxides, which may either be leached out of the profile or precip- 
itated within the profile in the form of nodules or concretions. The reserve of weatherabl 
minerals is appreciable. The silt/clay ratio is generally above 0.15. Ths clay is mostly 
kaolinitic but often contains small amounts of 2:1 lattice clays. Gibbsite is generally 
absent. The SiC^/AJ^Oj ratio is near 2 or slightly higher, while the Si02/R203 ratio is 
always below 2. The cation exchange capacity of the mineral complex is low but higher than 
that of ferrisols and ferrallitic soils having comparable (granulometric) clay contents. 
The cation saturation of the B horizon generally exceeds 40 percent (normal ammonium 
acetate at pH7). 

As compared to the ferrallitic soils that often overlay weathered layers several 
metres thick, the ferruginous tropical soil profiles are seldom thicker than 250 cm. The 
thickness of the altered layers that separate them from the fresh rock is always less than 
100 cm over crystalline acid rocks. 

Colours are duller than those of ferrallitic soils and fall in the 100 YR and 7.5 YR 
range, exceptionally in the 5YR range. There is generally a difference of 2 to 3 points in 
value and ohroraa between colour of wet and dry soil. Most ferruginous tropical soils would 
fall under the ultustalf . 

Their high content of alterable ferruginous minerals may give rise to important 
liberations of iron and frequently to formation of iron crusts at slight depth. Moreover, 
like all but the most permeable of the ferruginous tropical soils, they are very vulnerable 
to erosion* 

15* Ferruginous (Fersiallitic) Tropical Soils; on Sandy Parent Material Clay Complex 
Dominantly Kaolinitic, More ' 
Confined to Semi-Humid Areas 

Dominantly Kaolinitic^ More Than 4070 Saturated. Often Appreciable Mineral Reserve* 


Definition* Unlike other ferruginous tropical soils, the one on sandy parent material 
does not have a textural B horizon. In other words, leaching is not a dominant factor. 
Rainfall usually ranges from 500 to 1 200 mm. The reserve of weatherable minerals is often 
appreciable and clay is mostly the kaolinitic type. Soil drainage and depth to the 
plinthite layer are the principal characteristics of this soil unit. 

Distribution. The distribution of this soil is zonal, generally covering the Sudan 
zone and the northern parts of the Guinea zone. 

Value for forestry. This soil is generally used for planting of many species of 
Eucalyptus and some species of pines. Although relatively poor, the land is suitable for 
mechanized farming and gives good response to fertilizers. Better response to fertilizers 
is achieved by increasing the organic matter content of the soil. In spite of the low 
rainfall in the area, soil erosion needs attention. 

16. Ferruginous (Fersiallitic) Tropical Soils: on Miscellaneous Rocks. 

Definition. Because of the high quartz content of their parent materials, these soils 
are generally lighter than those cf the other units. Since they contain less iron they 
are less frequently iron crusted, but their leaching may be important and often leads to 
a textural B horizon. 

Distribution. On the map this unit reflects the frequent outcrops of more or less 
basic veins that traverse the pre-Cambrian Basement Complex and the post-Cambrian sediments 
that cover it locally. In climatic zones more humid than those favourable to the formation 
of ferruginous tropical soils, such outcrops give rise to ferrisols or ferrallitic soils, 
where the dominant colour is red, on rocks rich in ferromagnesian minerals. These soils 
are specially dominant in the Guinea zones. 

Value for forestry* Low to average. These very erodible soils should be used with 
care. The little rainfall limits the species of trees that can be planted. Eucalypts and 
neem were found to be doing well. 


Like the eutrophic brown soils of tropical regions, the ferrisols are a transitional 
group which are evolving under a hot and humid climate and whose normal development is 
retarded compared with that of neighbouring soils. In the case of the ferrisols, this is 
effected mainly by surface erosion which forces the profile to develop in depth at the 
expense of less weathered parent material. The ferrisols, just as the eutrophic brown 
soils of tropical regions, are distinguished from neighbouring soils by their better 
structure, their higher biological activity and, therefore, by their higher fertility. 
More widespread than the eutrophic brown soils of tropical regions, they also developed 
under more humid climates. 

- 30 - 

17* Ferrisolst Clay Complex Almost Entirely Kaolinite and Oxides. Lees than 50$ 
Saturated* Low Mineral Reserve, Confined to Humid and Semi Humid Areas 

Definition* Ferrisols have a profile closely resembling that of ferrallitic soils, 
often having a structural B horizon with aggregates having glossy surfaces. These coatings 
are not always evident when a profile has become dry. They are not necessarily coatings of 
clay but may be due to the presence of mixed alumino-silica gels. The reserves of weath- 
erable minerals are generally low but may exceed 10 percent of the 50-250 micron fraction. 

The clay fraction consists almost entirely of kaolinite, free iron oxides and 
amorphous gels, sometimes with small quantities of 2:1 lattice clays and gibbsite. The 
Si02/Al20^ ratio is near 2 t mostly slightly below 2. The cation exchange capacity of the 
(granulometric) clay fraction of the B horizon generally exceeds 15 rnEq P er 100# and is 
intermediate between that of ferruginous tropical soils and that of t'errallitic soils 
sensu strioto. The saturation of the B and C horizons is less than 50 percent (normal 
ammonium acetate at pH7). 

As for their place in the USDA 7th Approximation, the absence of oxic horizons 
requires that they be classified provisionally among the ultisols f although certain objec- 
tions might be raised to the truly argillic nature of their B horizon. 

Distribution. In the equatorial zone these soils are generally found at altitudes 
higher than 1 600 m, such as on the Jos Plateau, and in Sierra Leone and Liberia. 

Value for forestry. Although these soils are higher in plant nutrients than ferrall: 
tic soils (sensu stricto), they appear to be relatively poor soils as compared to the 
eutrophic brown soils of tropical regions which have developed on similar parent materials, 
When climate, landform and altitude permit, they are suitable for most trees like teak, 
Qmelina and pines. 

Ferrallitic Soils (Sensu Stricto) 

On the African continent ferrallitic soils cover approximately 5 338 000 km 2 or more 
than 18 percent of the total surface. Consequently, the ferrallitic soils are the most 
extensive group of soil units in Africa. (Less homogeneous desert detritus, with 
5 913 000 km 2 , can hardly be considered soil.) Ferrallitic soils reflect the final stages 
of weathering and leaching, wherein only the least mobile and least weatherable constitu- 
ents remain and where even kaolinite may become altered. 

Notwithstanding their apparently zonal distribution, a major part of these soils is 
not exclusively the result of present day soil formation. Many are polygenetic, i.e. recei 
soils developed in old weathered layers that have undergone ferrallitic pedogenesis and 
which have remained in place or have been reworked and redistributed according to the new 
relief of the rejuvenated landscapes. Such ferrallitic mantles are most frequent in inter 
tropical Africa, where they persisted due to the flatness of the major part of the conti- 
nental massif. 

The subdivision that has been maintained is a compromise among the different systems 
of classification that were in use in Africa at the time when the partial maps were 
established. It is based on criteria that at first glance may appear somewhat ill-assorte 
and where colour occupies a paramount place. 

20. Ferrallitic Soils: on Miscellaneous Rocks 

Definition. These are soils that are often deep, whose horizons are only slightly 
differentiated with diffuse or gradual transitions, but sometimes having an A2 or textural 
B horizon. This B horizon may have slight structure in the more clayey profiles but the 
aggregates do not show clearly developed glossy surfaces as are described for the ferrisol 
The structural elements are often very fine subangular blocky peds, more or less coherent 
and forming a very friable, porous mass. There is little or no reserve of weatherable 

- 31 - 

The silt/clay ratio (20/2 miorons) is generally less than 0.25 in horizons B and C. 
Clay minerals are predominantly of the 1t1 lattice type and are mostly associated with large 
quantities of iron oxides. Although they are generally associated with hydrated oxides of 
aluminum, gibbsite, one of the crystalline forms, is not an essential constituent, though 
it is frequently present. The Si02/Al 2 03 ratio is sometimes near 2 but usually below. The 
cation exchange capacity of the (granulometric) clay fraction is generally below 20 mEq per 
100g and the level of saturation in horizons A and B is generally below 40 percent (normal 
ammonium acetate at pH7). It must be noted that this definition is slightly more restric- 
tive than that of the French classification. In the USDA classification, ?th Approximation, 
certain ferrallitic soils could be ranged among the oxisols, but the absence of oxic 
horizons excludes many others which tend toward the ultisols. 

Distribution. This element is as equally well distributed to the north as to the 
south of the equator but the total surface occupied is much less than that under yellowish- 
brown ferrallitic sandy soils, even though both units cover similar geological formation. 

Value for forestry. The low fertility level of these soils varies with their clay 
content (20 - 60^>), with the nature of the rock from which they are directly or indirectly 
derived, with the present-day climate that ranges from per-humid to sub-humid and with the 
vegetation the climate has induced. 

Due to their low base saturation, the quantity of bases that must be added to increase 
yields significantly often is rather high and under current circumstances, often prohibi- 

Their value for forestry is comparable to that of yellowish-brown ferrallitic soils 
on loose sandy sediments. Trial planting of species of trees which have very low nutrient 
requirements is recommended. Casual observations showed Qmelina as a promising species. 

Hydromorphic Soils 
22. Hydromorphic Soils, Temporarily or Permanently Waterlogged 

Definition, These are soils, other than vertisols and similar soils, whose develop- 
ment and characteristics (presence of gley and/or pseudo-gley in at least one of their 
horizons) are influenced by permanent or seasonal waterlogging. Some of these soils have 
a relatively high level of cation saturation. 

Distribution. From the climatic point of view, distribution of these soils is not as 
extensive as that of the juvenile soils on riverine and lacustrine alluvium with which they 
are most frequently associated. In more arid regions, hydromorphy is replaced by halcmorphy. 

Value for forestry. Several of these soils have relatively little value for forestry 
especially those that are waterlogged either temporarily or seasonally. Their reclamation 
may necessitate control of the water level. However, some species of trees like Eucalyptus 
robusta may be tried. 


Two main problems confronting afforestation in West Africa are (1 ) climate and 
(2) soils. The effect of climate is shown both by its influence on the growth of trees and 
by its influence on soil formation. 

The different kinds of parent materials and living organisms acted upon by the 
different elements of climate resulted in the formation of different kinds of soils. To 
be able to study diligently all these kinds of soils would first require a systematic 
classification so that similar soils needing similar treatments or management could be 
grouped together* 

- 32 - 

The ferruginous tropical soils are the most widely encountered soils in the Sudan and 
Guinea zones of West Africa as the rainfall (500 to 1 200 mm per year) and a well separated 
dry and wet season seemed to favour their formation. Many pilot plantation trials of 
different species of euoalypts and pines (P. caribaea and P. oooarpa ) have given very good 
results when grown in the Guinea zones. "" 

The soils north of the ferrugineous tropical soils are the largest in extent in West 
Africa but, having very little rainfall (less than 500 mm per year), produce scanty 
vegetation. They also have very little value for forestry. Trees like Azadirachta indioa 
seemed to be favoured north of the 500 mm isoyeth, but lately, Acacia Senegal , /L. albida, 

A. seyal and A nilotioa are becoming important trees in this area; k. Senegal for its gum 
arabic and ,A. nilotioa for its tanning material. 

South of the ferruginous tropical soils, rainfall becomes much heavier, vegetation 
much thicker and both crops and tree production much higher. In this area, teak and 
Gmelina are more adaptable, and in the much elevated areas, pines are promising. 

The best soils in West Africa are those developed from volcanic rocks (newer basalt) 
but are of very limited extent. Teak, Qmelina and pines have shown very good results. 

In relation to chemical properties the soils most suited to plantation development 
are those in which there is a; sufficient depth of soil above the parent rock and 
b) a sufficient amount, and in proper proportions, of mineral nutrient elements. Pew 
sites meet these criteria. Quite a good number of the various species of eucalypts being 
tried in the afforestation programme will thrive well on sites with marginal fertility if 
the problem of die back caused by boron deficiency is rectified. Pinus species need an 
adequate level of phosphate for successful establishment in the field. Because of the 
acute phosphorus deficiency of most savanna soils, application of phosphate fertilizer to 
pines has become a standard practice both in the nursery and in the field. Significant 
responses to nitrogen are obtained if P deficiency is first corrected. Apart from N, P and 

B, incidence of other deficiencies have not been detected or described for the various tree 
species being tried. 


Aoquaye, D*K. ! Some significance of organic phosphorus in the phosphorus nitrogen of cocoa 
1963 in Ghana. 1 Plant and Soil 19 f 65-80. 

Ann, P.M. 'West Africa Agriculture: I. West African Soils. 1 3rd Edition, Oxford University 
1 970 Press. 

Alexander, L.T. and Cady, J.G. ! Genesis and hardening of laterite soils.' United States 
1962 Department of Agriculture. Soil Conservation Service Tech. Bull., 1232. 

Annual Report. Savanna Forestry Research Station, Samaru, Zaria. Min. of Agric. and 

1970 Natural Resources. 1969/70. 

Barrera, A. and Amujo, S.J. Report on the semi-detailed soil survey of the Afaka Forest 
1969 Reserve, North Central State, Nigeria. Ibadan, Federal Department of Forestry 

Research in co-operation with the Savanna Forestry Research Station, Samaru, 


Barrera, A. 'The use of soil survey in assessing sites for forestry potentials in some 

1971 areas of the northern states in Nigeria.' Rome, FAD Technical Report 5, 


Barrera f A. 'Soil Survey of Yambawa Fuel Plantation.' Kano State. Savanna Forestry 
1973 Research Station, Federal Department of Forest Research, Samaru, Zaria. 

- 33 - 

Boughey, A.S. 'The physiognomic delimitation of West African types.' Hour. West African 
1957 Sci. Assoo. 3*No. 2. 

Clayton, W.D. A preliminary survey of soil and vegetation in northern Nigeria. 1 Min. of 
1957 Agric. Northern Nigeria. Not Published. 

D'Hoore, J.L. La carte des sols d'Afrique au 1/5 000 000. Lagos, Commission de cooperation 
1964 technique en Afrique. Publication No. 93. 

Duchaufour, P. and Dommergues, Y. f A study of the humic compounds of some tropical and 

1963 subtropical soils. 1 African Soils 8, 25-39. 

PAO. 'Guidelines for soil profile description. 1 Soil Survey and Fertility Branch. 

PAO. 'Definition of Soil Units for the Soil Map and the World. 1 PAO and Unesco of 
1968 the United Nations. 

PAO. 'Savanna Forestry Research Station, Nigeria. Silviculture and Mensuration, 
1974 based on the work of J.K. Jackson. 1 PO:SF/NIR 16. Technical Report No. 7. 

PAO. 'Tree planting practices in African savanna 1 f by M.V. Laurie. Rome. PAO Forestry 
1974 Development Paper No. 19. 

Friend, M.T. and Birch, J.F. 'Phosphate responses in relation to soil tests and organic 
1960 phosphorus.' J. Agric. Sci. Camb. 54, 341-347. 

Higgins, G.M. and Mould, A.W.S. 'Progress of Soil Survey in Northern Nigeria.' Proc. of 
1959 the Third Inter-African Soil Conference. Dalaba, 1. 

Ipinmidun, W.B. 'Comparison of some methods for determining organic phosphorus in some 
1973 Nigerian soils.' Soil Sci 115 f 324-325. 

Jackson, J.K. and Ojo, G.O.A. 'Productivity of natural woodland and plantations in the 
1973 savanna zones of Nigeria.' Research Paper No. 20. Federal Department of Forest 
Research, Ibadan. 

Jenkins, R.N. 'The effect of different cultural treatments on the normal annual cycle of 

1964 variation in the ammonia - and nitrate - nitrogen contents of the soil. 1 In 
Proceedings Nig. For. Conf. Kaduna, Nigeria. 

Jones, M.J. 'The maintenance of soil organic matter under continuous cultivation at 
1971 Samara.' J. Agric. Sci. 77, 473-82. 

Jones, M.J. 'The organic matter contents of the savanna soils of West Africa.' J. Soil 

1973 Sci. 24, 42-53. 

Juo, AS,R. and Maduakor, H.O. 'Phosphate sorption of some Nigerian soils and its effect on 

1974 cation exchange capacity.' Comm. Soil Sci. Plant Analysis 5, 479-497. 

Kadeba, 0. 'Effects of management practices on soil carbon, nitrogen and nitrogen 
1973 availability in the Northern Guinea savanna.' Paper presented at Nig. For. 
Conf. Enugu, Nigeria. 

Kadeba, 0. 'Organic matter and nitrogen status of some soils from the savanna zone of 

1975 Nigeria. 1 In Press. 

- 34 - 

Kadeba, 0. and Benjamin sen, J.N. 'Contribution of organic matter and clay to the cation 
1975 exchange capacity of soils in the savanna zone of Nigeria. 1 Comm. Soil Sci. 
Plant Analysis. In Press. 

Moore, A.W. ! The influence of annual burning on a soil in the derived savanna cone of 
1960 Nigeria. 1 7th Int. Cong. Soil Sci. Trans. IV, 257-264. 

Nye, P.H. and Greenland, D.J. 'The soil under shifting cultivation. 1 Tech. Commun. 51 
1960 Comm. Bur. Soils, Harpenden. 

Omotosho, T.I. 'Organic Phosphate Contents of some cacao growing soils of southern 
1971 Nigeria.' Soil Sci. 112, 195-199. 

Pugh, J.G. and Perry, A.E. 'A short geography of West Africa. 1 University of London Pres 
1 960 Ltd. , London. 

Sarnie, A.G.A. 'Contribution of rainfall to the moisture storage in some soils at the 
1973 Afaka Forest Reserve, North Central State.' Fed. Rep. of Nigerian Research 
Paper No. 25. 

USDA. 'Soils and Men.' Yearbook of Agriculture. United States Government Printing 
1 938 Office. 

Wild, A. ' The potassium status of soils in the savanna zone of Nigeria. ' Experimental 
1971 Agriculture 7 (3): 257-270. 

- 35 - 













s ~ 


* * 

& I S 1 
V I 8 



- 36 - 







Desert, undifferentiated. 

Skeletal Boils mostly debris with pockets of Boils. 

Weakly developed soils on youn alluvium oftn halomorphic or hydromorphic. 

Brown oile of th arid and smi-arid tropical ragiona. 

Lithomorphio soils with dark non-kaolinitic claye. 

sou, of dark non-kaolinitic claya confined to topographic daprions in Bni-arid area 

psrruginouB (fsrsiallitic) tropical aoilB on Bandy parent material. 

PorruginouB (fersiallitic) tropical BOilB on miBoellaneouB rookB. 

FBrriBolBS clay complex almost entirely toaolinitic and oxides less than 5<# saturated. 

Perrallitic eoilst on miBoellaneous rooks. 

Hydromorphic soils, temporarily or permanently water logged. 

\J For greater detail and other regions, see Laurie (1974). 

- 37 - 


J.C. Delwaulle 

Centre Technique Forest ier Tropical 
Nogent sur-Marne f Prance 


Climates ^g 

Background ^g 

Sahel - Sudan climate ^g 

Sahel - Senegal climate -^o 

Guinea lower Casamance climate -*g 

Sahel Senegal coastal climate ^o 

Sahel Sahara climate ^Q 

Sahara climate -Q 

Climatic Changes 4^ 

Geologicalscale fluctuations in climate 41 

Present day changes in climate 42 

Choice of Forest Tree Species in Relation to Climate and Different 

Soil Types 43 

The climate 43 

Soil types 43 

Production stands 43 

Choice of species in relation to soils 44 

References ' 44 

Paper for Symposium on Savanna Afforestation 


The climate classification most commonly used in French speaking Africa is the one 
established by AubreVille and discussed by him in particular in the texts Climates, Forfets 
et Desertification de 1'Africpie Tropical (AubreVille, 1949) and Flore Forestiere Soudano- 
Chiine'enne lAubreVille, 1950)* These climates are described only schematically in Tree 
Planting Practices in African Savannas (FAO, 1974)* 

The principal biological factor is rainfall and, in particular, the duration of the 
dry season and of the true rainy season* This factor is represented by an "index of rainy 
seasons" or rainfall index which covers three sets of figures: 

a) the first gives the number of very rainy months (^>100 mm); 

b) the third gives the number of ecologically dry months (<I 30 mm); 

c) the second, usually the smallest, is that for the intermediary months, neither 
dry nor wet. 

This rainfall index supplements the information on rainfall, i.e. the average annual 
rainfall expressed in mm. 

The next most important factor after rainfall is the saturation deficit and its 
fluctuation over the year. Unfortunately only very few weather stations record atmospheric 
hygrometric measurements. 

Finally, average temperatures, whether annual or monthly, are of only secondary 
significance in making climatic divisions within the geographic area in question. 

Five main types of climate have been defined for tropical Africa: 

the humid tropics; 

the semi humid tropics, of which the Sudan Guinea zone is typical; 

- the Sahel-Sudan; 

- the Sahel-Sahara; 

the Sahara. 

It is only the last three types of climate that are of interest to us here. 

Sahel-Sudan Climate 

This is a characteristic type of climate in Africa. It occurs in a long strip roughl 
paralleling the equator from Senegal to the mountains of Ethiopia. It is definitely con- 
tinental and does not reach the seas. On the west, the Sahel Sudan gives way to maritime 
climates that may be considered as variants (e.g. the Sahel climate of Senegal and the lowe 
Casamance climate). 

The area stretches 3 to 4> its limits being slightly inclined on the parallels witfc 
its northern limit in Senegal at 16 N latitude and at the Nile, 12 or 13 N latitude. 


Average annual temperature: 26 to 31 5 

Average maximum monthly temperature: 30.5 to 36.5 

Average minimum monthly temperature: 24 to 28.2 

Minima: in January and August 
Absolute maximum: in April /May 
Relative maximum? in October 

-39 - 


Rainfall index: 400 to 1 200 mm, almost always less than 1 000 mm 

Rainy season: short to very short with 2 to 4 very rainy months; maximum in August 

Dry season: severe with 6 to 8 dry months, more rarely 5 

Rainy season index: 

2-2-8 3-2-7 3-3-6 
3-1-8 4-1-7 4-2-6 
2-3-7 2-4-6 4-3-5 

Sahel-Senegal Climate 

This is a transition climate between the marine trade winds climate of the coast of 
Senegal and the Sahel-Sudan continental climate. 


The temperature regime is similar to the Sahel-Sudan. 

Average annual temperature: 26.5 to 28.3 
Average maximum monthly temperature: 29 to 32 
Average minimum monthly temperature: 23 to 238 


Rainfall index: 500 to 900 mm 

Rainy season: short, running June to October with three very rainy months 

Rainy season index: 3-2-7 

Guineas-Lower Casarnance Climate 

This is a maritime subzone climate of the Sahel-Sudan occurring in Gambia, lower 
Casamance, Guinea-Bissau. 


Average annual tempertaure: 25.2 to 26.3 

Average maximum monthly temperature: 26.5 to 27.8 

Average minimum monthly temperature: 23.2 to 24.6 

Absolute minimum: in January 

Relative minimum: in August (contrary to the maritime Guinea climate) 


Rainfall index: 1 200 to 1 750 mm 

Rainy season index: 4 - 1 - 7 or 5-0-7 

Sahel-Senegal Coastal Climate 

This is an exceptional climate due to two influences: the fresh North Atlantic trade 
winds during much of the year, and the Guinean monsoons for a short part of the year. This 
olimate prevails only on a narrow coastal strip of Senegal. 



This climate IB much cooler than the Sahel-Sudan at the same latitudes* 

Average annual temperature: 23.7 to 25 
Average maximum monthly temperature: 28.4 
Average minimum monthly temperature: 20 to 21.6 


Rainfall index: 400 to 550 mm 

Rainy season index: 2-1-9; 2-2-8; 2-3-7 

Sahel-Sahara Climate 

This is a subdesert climate, transitional "between the Sahel-Sudan and Sahara climi 
It occurs across a broad strip of Africa running from Mauritania to the Red Sea along tl 
southern fringes of the Sahara* 


Average annual temperature: 24.5 to 28.5 
Average maximum monthly temperature: 29.5 to 33 
Average minimum monthly temperature: 18,5 to 21 

Absolute minimum: in January, sometimes a second minimum in August 
Absolute maximum: in May /June 


Rainfall index: 200 to 400 mm, maximum in August 
Rainy season index: 

0-1-11 1 - o .* 11 1-1-10 

0-3-9 1-2-9 2-1-9 

0-4-8 1-3-0 

Sahara Climate 

The 200 mm isohyet is conventionally considered the limit of the Sahara, 

Average annual temperature: 27.5 to 29 

Average maximum monthly temperature! 32.5 to 36*5 

Average minimum monthly temperature: 16 to 222 

Excessive maximum: in June 

Absolute minimum: in January 

Relative minimum: sometimes, in August 

Relative maximum: in September and October 


Rainfall index: 200 mm 

Rainy season indext 0-0-12; 0-1-11; 0-2-10; 0-3-9 

-41 - 

Geological-Scale Fluctuations in Climate 

During the Quaternary period and, especially the Pleistocene epoch, the whole world 
underwent extremely severe changes in climate and in Africa, as it has been possible to 
demonstrate, there were three major rainy ages: the KaguSrien, Kamasien and Gamblien. 
These wet ages lasted far longer than the arid ones between. 

In the Qamblien age, between the VIII and III millennium B.C., the Sahara was par- 
ticularly wet. Between 8000 and 6000 B.C., it sheltered an equatorial type fauna that 
attracted many hunters. Prom 6000 to 3000 B.C., a Neolithic civilization flourished in the 
Sahara (Adrar des Iforas, Air, Tibesti) while Tfrigre, Niger, this "desert in the desert 11 , 
was then a large lake that became a vast marsh toward 3000 B.C. 

Between 3000 and 2500 B.C., there was a brusque change of climate in which it turned 
dry, so that the population moved toward the south along the valleys (in particular the 
Azawak wadi). 

A considerable mass of humanity, therefore, migrated between the 12th and the 15th 
parallels from 2500 to 500 B.C. 

The discoveries of geologists and students of prehistory are corroborated by the 
presence of plant species that were able to survive locally although their ecological 
environment is now much further south. Although these species also went along with the 
general withdrawal, it was possible for them to retain a hold on certain sites. AubrSville 
mentions several of these species, namely i 

schimperii f found in an area ertending from north of Tahoua, Niger, 

along certain marshes and streams although with some difficulty there; regeneration 
is not easy; 

- Celtis integrifolia; 

- Daniellia " 

- the tamarind, the regeneration of which is becoming more and more rare. 

Other species that can be included perhaps aret Diospyros mespiliformis f Mitragyna 

From these observations, it might be concluded that what happened was an encroachment 
of the desert during geological ages, leaving behind a few islands of vegetation to the 
south, but can it also be concluded that at present the desert is still encroaching on 
other land? Certainly not because, inversely, there are vestiges of an advance of the 
desert further southward. For instance, throughout the Sahel one finds traces of many sand 
dunes that once were moving and are now fixed; the most notable examples are in the Ferlo, 
in Senegal, but there are also some in Mali, Upper Vblta and Niger, if even only in the 
immediate vicinity of Niamey. It is often surprising, too, to find in the Sudan species of 
definitely Sahel affinity, such as the numerous acacia (Acacia gourmensis down to the borde 
of Ghana and Upper Volta) and Balanites aeprptiaca, that is found as far south as Parakou 
in Benin. It is possible to attribute this to transport of the seed by livestock, but it 
is also not impossible that these may constitute vestiges of a more pronounced thrust of 
the Sahara than at the present time. 

The above analysis, therefore, does not explain the current desertification in Africa 
so it is necessary to consider present-day changes in its climate, 

-42 - 

Present-Day Changes in Climate 

Studying such changes of climate means essentially considering fluctuation in annual 
rainfall over several years* In certain localities marked fluctuations occur from one year 
to another* For instance y following are the fluctuations recorded at Niamey between 1943 
and 19521 


657.5 mm 
357.5 mm 
596.5 mm 
566*0 ram 
900.5 mm 

Under these circumstances , it is understandable that it ie hazardous to draw con- 
clusions from fluctuations over only a few years. For instance, in the period 19611970 
the average rainfall from 1961 to 1965 at Niamey was 657.3 mm as compared with only 589*6 mm 
from 1966 to 1970 f because of which the "prophets of doom 11 scream about "rapid conversion 
of the land into desert"* 

Investigating whether a change in rainfall pattern could be proven, meteorological 
data were consulted from stations set up in Niger since 1932, or before that, 13 stations 
in all, and the average rainfall for the n/2 first years and the n/2 last years were 
established. (When the number of data is uneven, the middle year was counted as belonging 
half in the first and half in the second halves)* Following are the results, cut off as 
of 1970. 


Number of 

Average Rainfall 



1st half 

2nd half 












Dogon-Eout chi 




1 011.6 






1 048.0 












1 108.1 














Niamey Ville 






























Great caution must be used in handling these figures as it is certain that not all 
these readings were made with all the necessary care* Furthermore, annual 
fluctuations are such, and the amplitude of the fluctuation is so great, that we would be 
deluding ourselves In the thinking that it is possible to draw conclusions based on a 
maximum of fifty years of observations* 

From these figures one might be led to conclude that there is a trend toward rehumidi- 
fioation (8 stations out of 13 give figures showing that rainfall is on the increase)* We 
would not, however, go as far as to say that and merely conclude that the meteorological 
statistics now available to us are not reliable enough and above all that they cover too 
short a period for us to be able to make any pronouncement on the present evolution of the 

-43 - 

In any oase the above figures show at least that, if there is any change, it is 
extremely slow and definitely does not explain the rapid desertification that is occurring 
at present* So other reasons for this conversion into desert than a change in climate have 
to be sought* 

Finally, certain periods seem to be definitely drier than others, although the 
periodicity of the change is far from clear, 

Our conclusions are, therefore, identical to those of AubreVille in 1936: to date 
there is nothing to prove any trend toward a permanent change in climate. It would, 
however, be extremely valuable to pursue such research in depth because rainfall is far 
from being the most important factor: rainfall distribution and the duration of the rainy 
season are eo^ially useful factors for both agronomists and foresters, 


The Climate 

Laurie (FAO, 1974) identifies various species now in use for reforestation in the 
various climatic zones in the savanna, 

Soil Types 

It is not the intention here to go into the details of soil science, but as far as 
is known to the author, no serious statistical survey has been made which would enable us 
to answer the following question accurately and objectively: "What soil type is particularly 
suited to a certain species?" Or conversely, "What species will give the best results on 
a certain type of soil? 11 

In order to conduct trials along these lines, it is necessary to have several dif- 
ferent kinds of terrain (often difficult to find) and to do replicated planting all during 
the same season and with the same technioiies, with the risk that rainfall may vary. Such 
a trial is to be conducted in Upper Volta in 1976* 

What foresters know in this field is therefore somewhat subjective, though nonethe- 
less valuable, 

Preduotien rfeanda 

The goal of the Upper Volta project is to obtain the maximum yield of timber per unit 
area, essentially to supply the town of Ouagadougou with fuelwood and poles, it being 
understood that this should be done in the context of maximum profitability. If the 
production goal is taken to be the prime one, obviously the best yields will be obtained on 
fertile farmland. For this, the land capability maps drawn up in the past cannot *e 
accepted. In fact, usually after a soil science/morphology survey the land is classified 
as follows* 

- the most fertile soils are defined as suited for farming? 

- bottomlands, generally flooded during the crop-growing season, are defined as 

wh^h^ff ce a :rf::^o 8 be unfertile (definitely granite or lateritic 

are classified as land unsuited for growing anything - whether agricultural 

r^Lfif di^ded up somewhat arbitrarily between land suited for 
of forest trees, grassland or as suited only for forest trees. 

Suoh a classification is useless because as far as concerns foresters the most 
fertile, rich soils should be those suited for growing crops- whether they be agricultural, 
forest or forage and fodder crops* On the other hand, soils defined in the past as suited 
for growing grass or forest trees are not generally, with some exceptions, really cropland. 

Proper management would consist of intensive utilization of fertile land for all 
three purposes - agricultural, forest, and forage or fodder crops - entailing a dividing 
up of the land for these various purposes. As for the rest of the land it could be managed 
on an extensive basis, natural forests being put under management with regular felling 

Choice of Species in Relation to Soils (Below the 800 mm Isohyet) 

The species mentioned here are all capable of producing a great deal of wood. The 
better the soil is, the more they will produce, and the poorer the soil, the less. 

Eucalyptus camaldulensis. Prom the site comparisons, it appears that it is possible 
to grow Buoaiyptus camaldulensis almost everywhere. As a matter of fact this is an 
astonishingly "plastic 11 or adaptable species and is the one that will certainly be used for 
most plantations. 

It must nevertheless be stated that this species is here at the ecological limit of 
its range and in this sense can be said not to be a suitable species, even though its use 
is still recommended. 

It actually has a very short life span and begins to die when it reaches six or seven 
years of age so, in fact, the plantations are cut only shortly before they would naturally 

Qmelina arborea. This species has been imported from the East Indies, the specimens 
of foreign provenance being adapted to a rainfall on the order of from 1 000 to 1 300 mm. 
Its use under the 800 mm isohyet, therefore, takes it beyond its normal range, but it is 
still a good, usable species. Still, soils that conserve water best should be reserved for 
it, whereas muddy bottom lands where it does not flourish should be avoided. 

Amdiraohta indioa. Neem is an astonishingly adaptable species that flourishes down 
to the 400 mm isohyet. Probably its preferred area is around 800 mm. Sometimes neem will 
regenerate underneath its own stands in this zone, this being an excellent sign of good 

Prom the standpoint of soils, best conditions are achieved with a light soil, with 
the water table at a depth of 1.5 - 2.5 m, although these are rather exceptional conditions. 
The plasticity of the species is however such that no soil is excluded except those that are 
extremely heavy which are to be avoided. 

Cassia siamea. This species, like neem, gives good results within a rainfall range 
as extreme as from 500 mm to 1 500 mm. 

However the parallel stops there because, contrary to what is true of neem, it is 
more demanding as regards soils, requiring for good growth a rich, deep and neither too 
light or too heavy soil. Consequently, both poorly and excessively drained soils should be 
avoided for this species and hydromorphic brown soils sought. 


Aubreville, A. Climat, fortts et decertification de I'Afrique tropicale. Paris, 
1949 Sooitttf d' editions gtographiques, maritime* et coloniales. 

Autotville, A. Flore forevtitre soudano-guineenne. Paris, Socilt* d 1 editions gtfographiques, 
maritime* et ooloniales. 

FAO. Tree planting practices in African savannas, by M.V. Laurie. PAO Forestry 

Development Paper Mo. 19. Re 

-45 - 


G.O.A. Ojo 

Forest Research Institute of Nigeria 
Ibadmn, Nigeria 

D.E. lyamabo 

Agricultural Research Council, Moor Plantation 
Ibadan f Nigeria 


Introduction 46 

Methodology 46 

Procedure 4 

Species elimination trial 47 

Species growth trial 4o 

Plantation trial 4S 

Results 48 

Sudan Zone 4 

Northern Guinea Zone ~[ 

Southern Guinea Zone and derived savanna W 

Provenance trials 



Appendix 1 i List of species used in the species trials 

I/ Papsr for Symposium on Savanna Afforestation 



Species trial* taxied in the savanna areas of Nigeria about 60 years ago in response 
to the peculiar circumstances of the area* The natural savanna woodlands are sparsely 
stocked and low yielding (Jackson and Ojo, 1970) and, more often than not f have suffered 
from overcutting in the past. Near the larger towns and centres of population tree 
growth has virtually disappeared leading to acute local shortages of wood. The result of 
this was the introduction of a few species such as Aaadiraohta indioa A. Juss (neen) 9 
Dalbergia sissop, Qmelina arborea L. and Teotona grandis L.f. (teak). The fuel plantations 
around such towns as So koto, Katsina 9 Nguru y Hadeija, Naiduguri etc. are a testimony to 
the efforts of the early foresters. 

It was not, however, until 1959 that a comprehensive programme of species trials was 
started; provenance trials are even more recent, the first having been established in 1964* 
About 130 species have been tried so far including a few indigenous species, about 20 
"tropical 11 pines and 60 eucalypti. 


The primary objective of the species trial is to test plants of identical seed 
origin and nursery treatment simultaneously on sites covering a range of different climatic 
conditions under identical cultivation and maintenance regimes, 3 

Savanna vegetation occurs in 17 of the 19 states of Nigeria and covers about 85 
percent of the land area - about 800 000 square kilometres (300 000 square miles). 
Zoologists recognise four different cones, namely the Southern Guinea, Northern Guinea, 
Sudan and the Sahel (Keay, 1955)* In addition to these four true savanna zones, a 
transition sone along the border with the rain forests, the derived savanna, is distinguished. 
These zones correspond well with climate - increasing length of the dry season from south 
to north, and decreasing mean annual rainfall from south to north. 

It was, therefore, recognised from the start that all the forest reserves could not 
be covered at the same time and that representative sites would have to be chosen. It 
was also understood that the trials should be on the best sites available for afforesta- 
tion. Initially only one or two sites in each vegetation zone were selected and all the 
seedlings were raised in a central nursery under close supervision. Later planting was 
expanded to about $Q other sites. This necessitated the raising of plants in several 
widely scattered nurseries with consequent poorer supervision. The value of the extra 
information obtained from these sites was diminished because the planting stock was not 
uniform. In addition, care and maintenance also varied because supervision was inadequate. 
It became obvious that the number of sites had to be limited to one or two within each 
vegetation belt. This led to the development of the present experimental areas in 
Yambawa, Afaka, Mokwa, Miango and Nimbia. 


The procedure used, which has been fully described by Kemp (1969), consists of 
three stages, namely: (a) elimination trials; (b) growth trials and (c) plantation 

-47 - 

Species Elimination Trials 

These started as nine tree plot* with a randomised block design and four replications 
but with a provision to include one large plot, of 36 trees, of each species in each trial. 
The idea was to maintain the larger plots as arboreta after the final assessment of the 
trials at the end of the second dry season. High mortality of most species led to the 
plot sice being increased to 25 trees and the discontinuation of the larger arboreta plots. 

Normal plantation espacement of 1.8 m x 1.8 m (6ft x 6ft) was used initially but 
this was changed to 0.9 m (3ft x 3ft) in 1962 to reduce maintenance costs and the possibi- 
lity of site variation within each trial. 

Certain criticisms have been levelled against this stage of the species trials. 

(a) The degree of replication is said to be unnecessary to distinguish such gross 
differences in survival and growth as the experiments were designed to reveal; in fact, 
statistical analysis of the results was never made. 

While it is true that statistical analysis was not necessary to distinguish gross 
differences in survival and growth, the soil conditions of the savanna, which vary 
greatly over short distances, make replication very important. 

(b) Two years were found to be insufficient to assess potentialities, even of 
survival in some cases. 

This is a justified criticism, and in practice the length of trial was increased 
to four years because some species are slow starters while others may show early promise. 
This caused other difficulties as very vigorously growing species tended to suppress those 
growing in adjacent plots. The answer to this may be to increase the espacement to 
between 5ft - 6ft ( 1.5 m - 1.7 m). 

(c) The trees were not planted under normal field conditions e.g. large espacements 
with mechanised weedings. 

This criticism is unjustified as there was no plantation technique in use when the 
trials began and equipment for cultivation was not available to forestry personnel. The 
plantation technique, including mechanisation, was developed using some of the species 
chosen at the beginning of the species elimination trials. In any case, species that 
were chosen grow better under mechanical cultivation than under hand cultivation 
(lyaaabo and Ojo, 1971 ). Moreover, Nigerian results agree very closely with those from 
other parts of the world in that no species that failed here has succeeded in any similar 
area of the world. One can, therefore, conclude that no species was lost through this 
method of maintenance. 

(d) That the plots were virtually useless for other work after their original 
purpose had been fulfilled; i.e. whether this stage is in fact necessary if it is to be 
followed \xy a second stage of replicated trials with individual 100 tree plots. 

The elimination trials were not designed to do more than eliminate useless species. 
The second stage is meant to yield all the other information that may be required of the 
chosen species. The time lag in obtaining these data (2-4 years) if the species elimina- 
tion trials had been larger is more than compensated for by the reduction in costs and 
space* It must be remembered that only about a quarter to half of the species reach the 
second stags and if the trials are repeated for two or three years in succession, management 
of the experimental areas will be difficult because of the "empty* 1 plots. 

The authors, therefore, recommend that (l) this stage be retained in P*cies 
introduction, with replication or without depending on soil variability on the sites on 

-48 - 

on which afforestation is envisaged and (2) that spacing be determined by existing techno- 
logy and facilities of the country Baking the introduction. For example, if Nigeria were 
to try now species in the savanna areas, they would probably bo planted at 2.8 x 2.8 m 
(9ft z 9ft), about 0.4 ha (1 aero) in sice at a corner of the yearly plantations. 

Species Growth Trials 

These are usually of randomised block or latin square design with four replications, 
and woro originally spaced 1.8mx1.8m(6ftx 6ft). When mechanical cultivation was 
introduced, spacing was incroasod to 2.7 x 2.7 (9ft x 9ft) or 2.7 m x 1.8 m (9ft x 6ft) 
depending on whether cultivation was to bo in one or two directions* The trials are 
assossod throughout the entire rotation of the species. 

Plantation Trials 

Obis, the third stags, consists of un re plicated plots at normal spacing comprising 
an area of 0.4 to 2 ha or more* Ideally this stage should bo reserved for species that 
have passod through the growth trial stage; in practice species that perform satisfactorily 
in growth trials for five years are considered qualified. 

The objective is to obtain quantitative data on crop performance under plantation 
oonditions f in addition to supplying information on problems encountered in planting on a 
larger scale than small trial plots. They also provide material for further experimental 
work, such as thinning and pruning trials. Assessments follow usual "sample plot" procedure. 


Some species emerged through the three stages and today form the basis for the 
reforestation in the savanna areas. To this extent, the procedure adopted could be said 
to have fulfilled its purpose. Although some species tried and rejected might be found to 
be more promising if certain improved techniques were used (e.g. mechanical cultivation, 
application of boron to eucalypts, and of phosphates to pines), it is believed that no 
species of improtance has been missed. 

Detailed results were published by Kemp (1969); Appendix 1 shows a list of species 
that were used in the trials. The results may be summarised as follows. 

Sudan Zone 

More than 40 species have been tested but results have been almost entirely negative 
and no species has yet proved equal to the performance of neem (Azadirachta indica) on sites 
favourable to it. Eucalyptus micro theoa has consistently showed high survival and satis- 
factory growth; its main defect being poor stem form. E^ carnal dulensis , Kathcrine 
provenance, shows promise. E.^ tesselaris has shown high survival, but its rate of height 
and diameter growth is poor. An interesting feature of this zone is the success of 
indigenous species. Such species include Acacia albida, A^ senega! and A^ nilotica which 
are planted for specialised products such as fodder and shade during the dry season, gum 
arabic and tannin materials , respectively. 

Northern Guinea Zone 

The most encouraging progress has been achieved here. Thirty six species, of which 
20 were eucalypts, reached the species growth trial stage and about 15 of these qualified 
for the plantation trial stage. Among these are Pinus oaribaea. P^ oocarpa, P^ merkusii* 
P kesiva, Eucalyptus oamaldulensis. B^ teretioornis. E^ citriodora. E^ "salima" (hybrid). 
E. oloeiiana E. punctata, B. propinqua. 

-49 - 

Of importance here is tha lesson learnt from the early success of some species which 
later failed* These "early starters 11 include Acrocarpus fraxinifolius, Eucalyptus 
pilularis. E*. robusta. Albisia lebbek and Callitris int rat ro pica. If the various stages 
of trials had not been gone through before a choice was made for plantation work in this 
sone t any of these species could have qualified but would have resulted in a oollosal waste 
of funds some years later* 

Southern Guinea Zone and Derived Savanna 

Generally the results of these zones correspond with those of the Northern Guinea 
Zone with the exception of the pines for which a successful establishement technique has 
not been found. It is probable that pine plantations will not be possible here until a 
suitable mycorrhiza (that can survive high temperatures) has been introduced !/ In this 
zone, however 9 teak and Qmelina are the current plantation species* 

On the Jos Plateau, 1 300 m (4 000 ft), species which have shown promise include 
Pinus caribaea. P^ kesiya. P^ oocarpa and P^ merkusii. The list of eucalypti is as for 
the Northern Guinea Zone* 

At the still higher altitude of the Nambilla Plateau, 2 000 m (over 6 000 ft), 
Pinus patula and P_ merkusii show promise. Cupressus lusitanioa grows well in this area. 
Eucalyptus grandi s (probably a hybrid, but not the same as the hybrid grown on the low- 
lands; which was introduced about 30 years ago from Bam en da, Cameroons, gives the best 
growth of the Eucalyptus species tried so far. Growth of a few scattered trees of Eucalyptus 
globulus suggests that trials of this and other euoalypts which prefer cooler climates 
would be worth-while. 


Some of the earlier species trials included more than one provenance of a species 
and from these and other trials it was clear that provenance was very important in some 
species, especially those with wide geographical natural distribution. Provenance trials 
are, therefore, a logical stage after the species trials. Systematic provenance trials of 
Eucalyptus oamaldulensis began in 1967, and of pines in 1968. They have since been 
extended to Eucalyptus teretioornis t E^ citriodora f E.. gran dig, E. saligna, E. deoaisneana. 
E^ alba. E.. cloesiana. Pinus caribaea, P^ oocarpa. P^ kesiya. P._ merkusii and Teotona 

Host of these are replications of international trials with seed supplied by the 
Commonwealth Forestry Institute. Oxford (Pinus oaribaea and P^ oocarpa). Forestry Research 
Institute, Canberra, Australia (P., kesiya). Comit* de la Recherche Fbrestiere M*diterra- 
niene (E. oamaldulensis). 

A full account of the results of the E. oamaldulensis provenance trials has been 
given (Jackson and Ojo, 1973). W*e important results aret 

1. The markedly superior growth of the Pet ford provenance in the Guinea Zone. 

2. Good survival of the Katherine provenance in the Sudan Zone and its generally 
good performance in the other zones, except in the Sahel Zone. 

!/ See also the mrtiole by Momoh, Odeyinde and Gbadegesin entitled "The role of myoorrhiaa 
in afforestation - the Nigerian experience, page 100. 


3* General superiority of provenances from the northern summer rainfall area* of 
Australia, again with the exception of the Sahel Zone, and the Lake Albaoutya 

4* Hie very great improvement in volume production which can be obtained by using 
the best provenance. At Afaka the ratio of the volumes of the best and worst 
provenances is 3*4 to 1. 

Preliminary results of the pine provenance trials have been published (Ojo and Shade, 
1973)* The results were summarised as follows s 

(i) That Pinus oaribaea var. hondurensis is to be preferred to the other varieties 
and that Belize (formerly British Honduras) and Guatemala are likely the best 
seed sources* 

(ii) That Pinus oooarpa gives better growth than F> oaribaea and that the only source 
of seed that should be ruled out at the moment is the Mexican provenance 
because of its poor stem form (on the Jos Plateau) and low yield on the lowland* 

(iii) That Pinus kesiya and Pinus merkusii are likely to remain "second string" 
species in Nigerian forestry* 

lyamabo, D.E. & Ojo, 0.0. A. 

Jackson, J.K & Ojo, G.O. A* 

Jackgon, J.K. & Ojo, 0.0. A. 

Keay, H.W.J. 

Kemp, R.H. 

Ojo, 0.0. A. ft Shade, M.B. 

Plantation establishment techniques in the savanna areas 
of Nigeria* Nigerian Journal of Forestry l(l)* 

Productivity of natural woodland and plantations in the 
savanna sones of Nigeria* Nigerian Journal of Forestry 

Provenance trials of Eucalyptus oamaldulensis in the 
savanna region of Nigeria. Research Paper No* 14 f 
Savanna Forestry Research Station Series, Samaru, Zaria* 

An outline of Nigerian Vegetation. 
Printer, Lagos. 

2nd Ed* Qovt. 

Trials of exotic species in the savanna region of 
Nigeria* Part 1* Aims, procedure and summary of results. 
Savanna Forestry Research Station Samaru, Research Paper 
No. 4. 

Preliminary results of pine provenance trials in the 
savanna areas of Nigeria* Research Paper (Savanna 
Series) No* 19 Fed* Dept. of Forest Research* 

-51 - 


List of Specie* Used in the Species Trials 

Acacia cyanophylla 

Aero carpus fraxinifolius 

Albicia falcataria 

A. lebbek 

Arauoaria cunninghamii 

Astronium urundeuva 

Acadirachta indica 

Baikiasa plurijuga 

Call! trie endlicheri 

C. fauegelii 

C. in t rat ro pica 

C. robusta 

Cassia siamea 

Cedrela odorata 

Ceratonia silicpaa 

Chlorophora re^ia 

Gryptomeria japonica 

Cupressus ariconioa 

C. lindleyi 
C lusitanica 
Balbargia lati folia 

D. sissoo 
Eucalyptus alba 

E. astringsns 
E. bioolor 

E. blakslyi 


E. bridgssiana 

S. oalophylla 

B carnal d\il ens is 

E campanidata 

I. eitriodora 

oitriodora x I. torslliana 

Eucalyptus clado calyx 

E. cloeziana 

E. ccrymbosa 

E. crebra 


E. fastigata 

E. gomphocephala 

E* gran die 

E. hemiphloia 

E. intertaxta 

E. kirtoniana (hyb. ) 

E. laevopinea 

E. leucoxylon 



. melliodora 

E. micrantha 

. microcorys 

E. micro the oa 


E. occidentalis 




E. pilularis 

E. poly oar pa 

E. propinqua 


robust a 


E. saligna 


. siderozylon 


-52 - 

Eucalyptus teretioornis ( My sere) 

E* teretioornis (Zaneibar) 

E. tessellariB 

E. tetrodonta 

E. torelliana 

trans continent alls 



E. woollsiana 

Melaleuoa lucadndron 

Pinus ayaoahuit* 

P. oanarisnais 

P. oaribaaa 

P* douglaslana 

P. lliottii 

P. ngelmannii 

P. halpniB 


P. li*phylla 

P. luohuansi* 

P. maasoniana 

P. miohoaoana 

P. mon-tKuma 

P oooarpa 

P palustris 

P. patula 

P pseudostrobus 

P. radiata 

P. Bafeiniana 

P. taiwanensiB 

P. teocote 

Widdringtonia cuprsBOides 

W. achwartzii 

Although early trials with Pinus kesiya 
were promising, with the Philippine 
provenance shown here giving best results, 
the species as a whole has not performed 
well in Nigeria below 1 200 m elevation 
where development is apparently hindered 
by high temperature* Even at higher 
elevations, growth has not been as good 
as P. oocarpa or P. caribaea. 

- 53 - 


R.H. Kemp 

Unit of Tropical Silviculture 

Commonwealth Forestry Institute 

Oxford, United Kingdom 



Int roduct i on c 3 

Definition of the term "provenance" c/ 

Planning provenance trials 54 

Phasing of trials 54 

Design of trials 54 

Choice of provenances 55 

Conducting provenance trials 55 

Nursery practices 55 

Field trials 55 

Field assessment and records 57 

International cooperation 37 

References 58 


Provenance trials are the logical continuation of the process of selection that 
began with the species elimination trials, and the methodology involved is essentially 
similar. However, one fundamental difference exists that affects all stages of provenance 
research from exploration and seed collection to field trials and evaluation. Whereas in 
species trials we try to determine accurately the comparative values of populations which 
we know to be genetically different, provenance research is concerned with differences 
which at the outset can only be surmised. One of its functions is therefore to establish 
whether real differences exist between the populations, as well as to determine their 
comparative value for particular uses in various environments. 

- 54 - 

There have been several published definitions of provenance ( see Jones and Burley, 
1973 f for a review) but in this lecture the word Mans the place in whioh any stand of tree 
is growing or refers to the seed derived from those trees* For an indigenous stand the 
provenance is also the origin but for a non-indigenous stand the origin is the place from 
whioh the .seed or plants were originally introduced* These usages are in accordance with 
the OECD-L/ definitions and are now widely accepted. 


Well designed comparative experiments are needed to determine genetic differences 
between populations* The principles governing the location, design, replication and 
management are the same as in species trials but the need for careful control at all stages 
is even greater* Therefore, the need for written control plans must be emphasised , showing 
clearly the objectives, the expected duration, the methods and the resources to be employed 
in the experiment* Since representative seed collections for provenance research are more 
difficult to obtain than single samples of a species, and may necessitate special collecting 
expeditionB 9 planning of provenance trials must start several years in advance of their 
actual establishment in the field* 

Phasing of Trials 

Three successive phases of provenance trials are commonly recommended (e,.. Burley, 
1969; Kleinsohmit, 1974)* The first range-wide phase is intended to investigate the extent 
and pattern of inherent variation between populations (provenances) and may reveal broad 
regions whioh are either suitable or unsuitable as seed sources for a given area of intro- 
duction* This phase is analagous to the species elimination trial, but the number of pro- 
venances may be large or small depending on the extent of the natural range and the varia- 
bility of the species and its environments within the range. The number included should 
not be less than five and 10 to 30 widely separated sources are recommended (Lines, 1967)* 
Large plots are not needed as the duration of the trial is normally not more than half 
rotation age* These trials may be located on two or three of the major site types, 

In the second phase a restricted number of provenances are tested for a longer 
period, usually up to a full rotation, on all the important site types* These trials must 
be designed to reveal relatively small differences between provenances. Larger plots are 
needed, to provide sufficient trees for reliable estimation of population differences 
throughout the life of the trial, and to minimise the effect of tree to tree differences* 

Finally , the provenance proving phase, often with only one or two provenances, 
requires large replicated plots, capable of accommodating mensuration studies, management 
trials and wood quality evaluation* 

Design of Trials 

Even in the first stage of provenance trials, it is essential to use valid statisti- 
cal designs that will reveal significant differences between populations at a given level 
of precision (e.* for height measurements, a difference of 5$> of the mean)* It is also 
important to estimate the variability within each provenance, particularly for stem form 
and branching habit* In savanna conditions, it is desirable to maintain the trials long 
enough to test the security of different populations against severe drought, particularly 
if the moisture storage capacity of the soil, or effective rooting depth, are limited* 

OBCD - Organization for Economic Co-operation and Development 

- 55 - 

In uoh oases t important differences between provenances may only become apparent after 
several years. For all these purposes, it is preferable to use scjuare plots of several 
trees, in replicated, randomised designs. When the number of provenances in a trial is 
very large, single-tree plots may sometimes be considered. However, they are complicated 
to lay out and the risk of confusion is very great if accidental errors occur in plot 
labelling. They also hinder the assessment of intra-provenance variability. 

The most widely used design is the Randomised Complete Block (RGB). This has the 
advantage over fully randomised designs that it does not demand such uniform site conditions 
throughout the trial and can accommodate differences of treatment between blocks. However, 
if very large numbers of provenances (e.g. 16 or more) are included, the large size of the 
blocks increases the danger of site differences within blocks. In such cases, the use of 
an incomplete block design may be indicated^ in which each block contains fewer than the 
total number of plots. These designs are complex and the analyses are best undertaken on 
an electronic computer. The lattice designs have the advantage that they can be analysed 
as an RGB if necessary, although with some loss of information. For further details and 
examples see Cochran and Cox (1966) or Burley (1976). 

Choice of Provenances 

Attempts to match environmental conditions ( latitude, altitude, rainfall distri- 
bution, temperature, soil type) between the source area and the site of introduction, by 
homoolimal comparisons, are not always successful. The necessary information may be lacking 
or unreliable. Moreover, natural distribution may reflect past climatic, geological or 
historical occurrences rather than present conditons. Special attention may be given to 
marginal sites, near the edge of the ecological or geographical range. For savanna 
afforestation the security of the crop against infrequent years of very severe drought may- 
be important and marginal populations which have been subjected to such conditions are 
likely to be more resistant as a result of past selection pressures. 

Very rarely is the seed user able to collect the seed personally. He must, therefore, 
ensure that his objectives are clearly understood and if necessary detail the desired 
method of sampling and the provision of all information (climate, soil, vegetation, history, 
methods of collection, etc.; needed to interpret the results of studies and experiments 
based on the material collected. 

For provenance research, it is desirable to sample as fully as possible the range of 
potentially valuable genetic variation within the population. In the absence of any 
estimate of population variances, this means collecting from relatively large numbers of 
trees - Callaham (1964) suggested 25-50 trees in heterogeneous populations - well spaced to 
avoid closely related neigibours (half-sibs). It is best to collect only in a year of 
abundant seed production. The selection of better than average phenotypee IB not recommended. 
For some purposes, it is preferable to keep seed of each tree separate and to preserve the 
identity of each parent tree, but for most provenance trials this is not essential and 
often not possible. 

For farther information on seed collection see e.. Kemp (1976) and Turnbull (1975). 

Nursery Practices 

The primary concerns are ( i) to maintain the identity and integrity of each prov- 
at all stSes aS (ii) ** ~~ uniform treatment so that results are truly 
JS.. D^JSnSs in nursery stock resulting from different ^S^^J^lSl 
intothe field and may be detectable several years later. To some extent these two aims 
oorfliX tnoe^t Easier to avoid accidental mixing or wrong labelling of Provenance, 
if eadh is kept in one discrete block with physical barriers between. On the other hand 


to guard against unknown nursery effects it is preferable to use the same replicated, 
randomised designs that will later be employed in the field trial. Conditions within each 
replication should be as uniform as possible and sowing should be done one replication at 
a time* Pricking- out and transplating are two operations during which the danger of mixing 
different provenances is high. This danger can be lessened by careful attention to 
labelling and by moving only the seedlings of one provenance, in each replication, at one 
time* The position of the provenances within each replication should be re-randomised when 
pricking-out or transplanting* 

Culling of poor or deformed plants is permissible in accordance with normal nursery 
practice | but the number of plants culled of each provenance should be recorded* Edge 
effects in transplant beds or in blocks of pot plants are common and if possible , the outer 
one or two rows should be regarded as guard rows and not used in the inner assessment plots 
of the field trials* If, due to shortage of stock, it is necessary to use such plants, or 
those that would normally be culled, their field positions should be recorded. 

Nursery records of germination, survival and growth at successive stages in the 
nursery must be meticulously maintained* Additional assessments to reveal differences 
between provenances should also be made whenever possible, such as the number, length and 
colour of cotyledons, length of hypoootyl and phonological observations, production of 
secondary needles in pines or mature leaves in eucalypts* It is sufficient to make such 
observations and measurements on random samples of perhaps 20 seedlings in each plot. Where 
facilities are readily available, comparative studies of different provenances in controlled 
environments (growth cabinets or phytotrons) may reveal differences in physiological 
response to drought, for example, which could be significant for savanna afforestation* 
Biochemical studies may also be helpful in revealing differences between populations, based 
on characters which are under more direct genetic control than such production variables 
as height and diameter (Lever and Burley, 1974)* The value of such studies lies not only 
in their contribution to biosysteraatios, but also in the possible indications they may give 
of later performance in the field. They also help to prevent or reveal errors in identi- 
fication! if consistent differences between provenances at this stage are established* 

Field Trials 

The main principles involved in selection of representative sites for trials, 
collection of site data, the use of valid experimental designs and careful labelling and 
recording, are the same as those applied to species trials* However, because all species 
included in provenance trials have already been shown to be sufficiently well adapted to 
the local environment to make them potential plantation species, we are concerned not with 
gross differences, such as very high mortality, but with subtler differences of growth and 
form* For this reason even greater care is needed in all aspects of design and execution. 
This applies particularly to plot labelling and recording, since it is usually much more 
difficult to recognise different provenances than different species. 

To minimise possible errors due to differential effects of weed growth on different 
parts of the experimental site, complete removal of competing vegetation prior to planting 
is recommended, followed by a very high standard of subsequent weedings and cultivations. 
The use of insecticides, or fertilisers, may also be recommended in certain circumstances, 
if uniform treatment throughout the experiment can be assured* Generally larger plots are 
used in provenance trials than in the equivalent stage of species trials, to minimise the 
effects of tree to tree differences, and to provide sufficient trees for reliable estimation 
of population differences throughout the life of the trial* The recommended size of the 
inner assessment plot is 25 trees , with a surround of one or two guard rows* Recommended 
spacing between trees is 3 x 3 m as a general rule* 

- 57 - 

* 4 v ^ nform * tion / rom Bpeoies trials may be available that can be used to calculate the 
desirable number of replications, in order to achieve a certain probability of obtaining 
a significant result (see Cochran and Cox, 1966). In practice some compromise is usually 
reached between the degree of precision desired in detecting differences and the practical 
limitations imposed by the site, the availability of planting stock and so forth. However, 
it may sometimes be preferable to reduce the plot size, or to use a complex design such as 
a lattice, to maintain the required precision. 

Field Assessment and Records 

The principles in regard to method and frequency of measurement of survival, height, 
diameter and volume production are the same as in species trials, although the degree of 
precision demanded may be greater. In addition to these basic data, very often consider- 
ations of tree form assume greater importance at the provenance trial stage. The problem 
of ensuring uniform standards of assessment of such characters is usually met by a standard 
scoring system, such as is employed in tree breeding. (See e.. Hans, 1972). For assess- 
ment of branch characters a standard assessment point for all trees is needed (e_.. half 
total height) . Number of branches per whorl, and mean branch angle may be measured directly 
and branch size may be related to the diameter of the bole at that point. Burley, t al, 
(1975) give further information on uniform standards of assessment. 

When provenances are grown in different environments not only the comparative rates 
of growth may vary, but the patterns of growth and wood formation may also change, as a 
result of genotype /environment interactions. It is important when comparing provenances 
to take into account possible differences in wood quality, such as migfct arise from 
different patterns of latewood formation, or overall density, since these might materially 
affect the value of the product for certain end uses. Studies to detect differences 
between populations may include detailed examination of leaf or needlemorphology, 
cyto logical characteristics or biochemical products (see Lever and Burley, 1974)* 

The use of standard forms to record measurements and observations is strongly 
recommended. For design and analysis of experiments and specimen forms for records and 
calculations, see Burley (1976). 


Provenance research requires well documented seed of known origin and for this 
special collecting expeditions are usually required. The same expedition can collect seed 
for use in a number of trials in different countries and this can have advantages not only 
in reducing the cost that would otherwise be involved in several separate expeditions, but 
also in making seed for provenance research available to countries that could not otherwise 
obtain it. Where the country of origin has the staff and other resources to undertake 
exploration and collection, it may extend the activities as a form of aid overseas, as in 
the case of Australia, where substantial quantities of seed of many euoalypts are stored 
and tested at the Australian Government's seed bank in Canberra and samples are made freely 
available for research in other countries. Elsewhere, where local resources are inadequate, 
bilateral aid programmes of countries outside the region concerned have financed similar 
seed collections, such as the work of the Danish/too Forest* Tree Seed Centre in S.E. Asia, 
or of the Commonwealth Forestry Institute, in Central America (Kemp et al, 1972). These 
activities are coordinated through FAO (I974a) which has prepared proposals for an inte- 
grated Global Programme (FAO, 1974b). 

These international programmes have the further advantage that it is possible to 
compare ""perforce of the same provenance on a wide range of sites in many different 
ooStSes and thereby to gain a better understanding of ** Pj-Jioi* *^ ***** 
and its site requirements. This may help in predicting performance on other sites where 
trial, hive not been established. In order to make such comparisons po.sible, centralised 
^.teL o7*l etormge and retrieval are needed (Burley, et al, 1973). By this mean, also 


results of trial* 9 or of more detailed laboratory studies, may be made more widely and 
readily available, to assist the interpretation of local experiments and the choice of 
provenances for plantation establishment, or for further trials* The greatest amount of 
information possible is needed in order to identify precisely the pattern of phenotypic and 
genetic variation* International programmes may also provide the basis for effective 
conservation of genetic resources and for future tree improvement through selection and 


Burley, J. Methodology for provenance trials in the tropics* Unasylva 23(3), 24-8. 

Burley, J. ed* A manual on species and provenance research with particular reference 
1976 to the tropics, C*F.I,, Oxford, 

Burley, J* et al* INTFORPROV: computer based data banks for international tropical 
1973 provenance experiments* In: Tropical provenance and progeny research and 

international cooperation* Ed, J, Burley and D.G. Niklee. Proc* IUPRO Mtg. 

Kenya* Commonw* For* Inst*, Oxford pp* 357 65 

Burley, J. e_t al* Information collection, storage and retrieval in forestry* Paper 10th 

1975 Commonw. For. Conf*, Oxford. 39 P 

Callaham, R*Z* Provenance research - investigation of genetic diversity associated with 
1964 geography. Unasylva 18 (2 - 3) s 40-50. 

Coohran, W.G* and Cox, G*M. Experimental designs* 2nd ed. Wiley, New York. 611 p. 

FAO . Report of Third Session of the FAQ Panel of Experts on Forest Gene Resources, 
1974a FAO, Rome* 

FAO* Proposals for a Global Programme for improved use of forest genetic resources* 
1974b FO>MISC/74/15. FAO, Rome* 

Hans, A.S. Development of an instrument for assessment of stem straightness. Commonw* For* 

1972 Rev* 51, 336-45- 

Jones, N. and Burley, J* Seed certification, provenance nomenclature and genetic history 

1973 in forestry* Silvae Genetioa 22, 53-8* 

Kemp, R*H* Seed procurement for species and provenance research* In: A manual on 

1976 species and provenance research with particular reference to the tropics* 
Ed* J* Burley, C*F*I*, Oxford* 

Kemp, R.H. et al* International cooperation in the exploration, conservation and 
1972 development of tropical and sub tropical forest gene resources* Paper No*071, 
7th World Forestry Congress, Buenos Aires* 15 p* 

Kleinschmit, Yon J* Geschiohtliche Entwioklung, Stand und zukunftige Aufgaben forstlicher 

1974 Herkunftsforsohung. Allg, Forst- u*J*2tg* 145* 197-205* 

Lever, K.G* and Burley, J* The application of biochemical methods in forestry* Paper 

1974 10th Commonw* For. Conf., Oxford, 20 p. 

Lines, R. Standardisation of methods for provenance research and testing* Proc* XIV 
1967 IUFRO Congress, Vol. 3 t Munich. 

Turnbull, J.W. Seed collection - sampling considerations and collection techniques. In: 

1975 Report on the FAO A) AN 3D A training course on forest seed collection and handling, 
Thailand. 1975* Rome, FAO* 

- 59 - 


H. Keiding 

Danish/FAO Forest Tree Seed Centre 
Humlebaek, Denmark 


Features of Seed Procurement for Savanna Regions 59 

Documentation, general 59 

Seed procurement, general 60 

Seed Collection 60 

Certification 63 

Reference* 66 


Tree Planting Practices in African Savannas (FAO, 1974a) discusses the prevent and 
future requirements for forest products in the savanna region of Africa* Certain trends 
relevant to seed procurement emerge in spite of the difficulties in making such forecasts. 
Due to expected increases in population and living standards and in the development of wood- 
based industries, wood consumption is estimated to increase from 29$ for fuelwood to 185$ 
for paper and paperboard in the period 1960-1975- Such a rise in consumption cannot be met 
from the existing low productive savanna woodland? the establishment of plantations, there- 
fore, becomes a necessity* 

The next questions that arise are what species may be the most suitable under varying 
conditions and purposes and what areas are required for fulfilling the stipulated demand. 
A number of species and provenances have already been tested and those most widely planted 
are listed and described in the above mentioned FAO publication on African savannas (see, 
for instance, Chapter 7). A good deal of testing, however, still remains. In most circum- 
stances, experience from species testing has shown that exotics are superior to indigenous 
species with respect to ease of establishment, growth and utilization. This results in the 
problem of having to import seed, or the long term process of developing seed production 

Documentation, General 

The importance of tracing promising plantings back to their origins, irrespective of 
their status as small-scale or large-scale plantings, has been recognized for quite a long 
time in forestry and has led to the formation of control systems for seed and plant transfer. 
Where more deliberate action has been taksn to establish improved seed sources, including 
selective breeding and the formation of seed orchards, the control system has developed 
into certification schemes. 

In the savanna region, the problems in these respects do not differ from those of 
temperate regions, but they may be more pronounced as the procurement of seed for some time 


to come will be largely dependent on import. Ono characteristic of seed import in that it 
involves cooperation between countries; it is, therefore, of groat importance that inter- 
national agreement* be reached on the tens and documentation of collection*. Such an 
international system presupposes the development of national or local control systems, and 
in order to discuss the coordination of these we eh all need to look briefly at the principal 
aspects of seed collection and documentation. 

Seed Procurement f General 

The considerable role that seed import may play, as indicated above, has certain 
implications which may decisively affect the procurement and production of seed. Problems 
connected with the importation of tree seed may comprise: 

1. Inadequate resources in funds, manpower and organization for seed collection 
in the host countries; 

2. Lack of accessible seed stands and seed production areas, especially of desired 

3. Lack of reliable data about the seed origin and the collection method; 

4. Risks of reduction in quality of seed, i.e. reduced germination capacity due 
to transport; and 

5. Restrictions on the export of seed in bulk quantities imposed in several 

In addition to these problems there are those which are specific to individual species. 
They may comprise periodicity in seed production, short viability, low seed production, 
difficulty of access to specified stands or eco types, etc. 

In general it is easier to obtain small quantities of seed for experimental purposes 
either through international seed centres or by exchange of seed. However, because of the 
difficulties and restrictions in getting bulk imports of desired species and provenances, 
it is necessary to seriously contemplate how to produce seed locally as soon as a seed 
source has shown promise. 


Two things make it relevant to discuss seed collection in connection with tree planting 
practices in African savannas. The first is the general trend for countries in the savanna 
region to build up their own seed production and thus free themselves of the dependency on 
import; the second is that a better understanding of the various operations applied in 
other regions with tradition and knowledge of seed collection may help to make one's own 
collections more efficient in a shorter time. Therefore, we shall briefly consider the more 
important and principal aspects of seed collection. The subject is extensive, as is evident 
from the report of a recent training course on seed collection and handling in Thailand 
(PAO, 1975a). It is recommended to consult the report of that training course for details 
on the principles and techniques of seed collection and handling, especially as concerns 
tropical tree species. 

When discussing seed collection in general terms, it is convenient to ask "where", 
"when 91 and "how" to collect. 

- 61 - 

Where to collect locally will mainly depend on the extent of trial, with exotic 
species ana the length of time they have been conducted. Indigenous specie* in the savanna 
regions are so far only used on a very limited scale. Looking at table 9, page 78-79 of 
Tree Planting Practices in African Savannas, it appears that out of 35 species only 6 may 
be considered indigenous to parts of the savanna region. It is natural to start collection 
of a species as soon as it has shown itself promising. This has been done in many instances, 
sometimes with remarkably good results (e.g. teak, gmelina, southern U.S.A. pines, Cupressus 
sp.; f but sometimes also with disappointing effects perhaps showing up only a fairly long 
time later. 

A common case is collection from an early introduction of a species with very vague 
or inaccurate information about origin and which often was planted at only one or two places 
in small plots ( acre or 0.2 ha) without replications. Here the problem ie that the seed 
to be used is from a single, very small population of trees, which perhaps has shown promise 
in only a limited number of the varied environments in which it is to be planted. The un- 
certainty concerns the genetic effect of using a small population, perhaps from a restricted 
location, for improvement purposes and the adaptability of the offspring to conditions 
differing from the test site. Although good results have been obtained by using seed from 
such small introductions, it is advisable to carefully select seed sources or to collect 
seed from stands which have a broader basis for selection and more precision in testing. 
Prom a technical point of view, seed collection in excessively small units, say below 2-3 ha, 
is generally less satisfactory. Cost of collection is relatively high and the seed may be 
of lower quality due to insufficient interpollination. See Keiding 0975a) for details on 
seed stands and Jones and Burley (1973) for information about the genetic implication. 

To improve seed collection possibilities within the shortest possible time in areas 
relying on exotics, it has been recommended, and I believe also practised, to establish 
larger blocks of certain provenances beside the actual provenance trials. The purpose of 
this is to have larger units ready as seed sources, as soon as the results from provenance 
testing become available. Such blocks of provenances may also serve the purpose of con- 
servation ex situ if the sources of origin are threatened in one way or another. A valuable 
reference material for this very important aspect of seed collection is "The Methodology of 
Conservation of Forest Genetic Resources" (FAO, 1975*0* 

Concerning "where" to collect, circumstances vary considerably within the savanna 
region, from having very little choice of sources locally to having selected seed stands 
and seed orchards. Procurement of seed is very often an act of balance between getting 
sufficient quantities of seed and getting seed of satisfactory genetic quality. Thus, 
which sources to use and how to utilize them should be closely coordinated with tree 
improvement programmes. This applies to all stages of seed procurement from importation to 
selection of seed stands and establishment of seed orchards. As it is not possible to cover 
the broad subject of the relation between seed procurement and tree improvement in the 
present paper, reference is made to more thorough treatments of the various aspects involved 
as given in the Report on the FAO/DAHIDA Training Course on Forest Seed Collection and 
Handling (FAO, 1975a) and by Ouldager (1974). 

"When" to collect is a matter of timing in respect of age and season. When planning 
seed collections it is essential to know at what age the individual tree species can be 
expected to reach sexual maturity, their possible periodicity in flowering and fruiting, 
and at what time of the year the seed collection is best carried out. For the more 
important economic species such as pines, teak, Qmelina arborea and eucalypts, plus a 
number of other speoies, a fair amount of knowledge about flowering biology has been 
accumulated. Still, fairly large variations may occur within a species depending on 
origin (provenance) and the environnents to which it may have been introduced. In some 
oases flowering and fruiting starts at a younger age in exotic environments than in the 
natural habitat, e.g. teak in Trinidad and certain areas of West Africa, while other exotic 
stand? haXly pioduoe any viable seeds at all, e.g. some tropical pines in Malaysia. Still 
ieJ may ohsW their mode of flowering from being distributed more or less evenly 
Jne JJaTt^eooming seasonal, e.g. Pinus merkusii on Java. It is, therefore, 

- 62 - 

important to observe and register the flowering and fruiting habit of species, especially 
exotica, under local conditions. Such studies of the reproductive biology are also neces- 
sary to build-up and improve seed production, as they may help to determine the size and 
soope of seed production units, treatment of seed stands, seed handling and storage, etc. 
ven individual trees show variation in seed production which may be of some concern for 
the composition of seed orchards (see Keiding, 1975*0 

Closely related to flowering and fruiting habits is the physiological quality of the 
seed which, among several factors, is also influenced by the right time and method of col- 
lection. Within the collection period of a certain species there is usually an optimum 
period in which the quality of the seed is best. Teak seed in Thailand, for example, may 
be collected over 3 months: February-Apr i 1 , but the month of March is normally the best, 
while the first and early fall in February often has a certain portion of immature seeds. 
Similarly, it can be of great importance to collect pine cones when they have reached just 
the right stage of maturity, indicated usually by the colour of the cone scales. Pinus 
merkusii is particularly sensitive to the timing of seed collection which is further compli- 
cated by the variation in ripening of cones between localities, between trees and even within 

Although the majority of species being used in the savanna region have more or less 
seasonal fruit bear ing correlated with the change between wet and dry seasons, there may be 
fluctuations between years. It is often advantageous to make a survey and an assessment of 
the coming seed harvest well ahead of the actual collection in order to determine the best 
time for collecting and the size of the crop to expect. Again, for further information, 
reference is made to the report on the PAO/DAKIDA Training Course on Forest Seed Collection 
and Handling (FAO, 1975a). 

Finally in respect of "how", the subject of collection techniques has been reported on 
and described for many different situations. Naturally, the techniques vary according to 
the scale of collection, tree species and their economic importance, funds available, 
organization, etc. and they represent all stages from highly mechanized equipment requiring 
very little manpower, such as tree shakers, to climbing with or without ladders and to 
picking of seed from the ground with many collectors involved. It is not possible here to 
discuss the merit of the different methods and how to apply them under different circum- 
stances, but it may be useful to briefly consider some of the more general aspects. Techni- 
cally speaking, seed collection should aim at getting the largest possible quantity of seed 
in the best conditions, i.e. the highest possible physiological quality as efficiently and 
economically as possible. For the majority of species, the fruits have to be taken on the 
trees, which usually implies climbing. This requires a certain skill and training and may 
become fairly technical, involving ladders of different kinds, safety and other equipment. 
In highly developed seed production areas such as special seed stands and seed orchards of 
easy access, tractors with elevating platforms or tree shakers may be considered. As in 
nearly all circumstances it is important to utilize selected seed sources continuously, the 
fruitbearing portion of the tree should not be damaged. The practice of collecting fruits 
or cones from felled trees or by lopping large branches should generally be avoided unless 
the stand(s) are due for felling anyhow or it is the only possibility left because of lack 
of climbers. The handling of fruits and seed in the field and their transport also influence 
the quality of seed. If cones are packed tight in big bags they make "take heat", especially 
if they axe picked a little too early. Similarly, fruits of Qmelina may be difficult to 
store if the pulp is allowed to ferment for too long a time. 

To get a seed collection programme to function properly a certain amount of specialized 
knowledge and technical skill is required, combined with good coordination of the various 
operations involved. In many countries, therefore, it may be advantageous to establish 
seed centres or seed handling stations where all seed collection and seed handling are con- 
centrated. Such seed centres may contain seed extraction machines, such as drying kilns 
for coniferous species, and equipment for cleaning, dewinging and grading the seed. Further 
facilities for seed testing, i.e. tests of germination capacity and moisture content, plus 
adequate store rooms should be available. It is also necessary to properly register all 

- 63 - 

operation, connected with seed handling and seed distribution. Depending on the magnitude 
of wed collection and the funds available, equipment may be more or less refined, but a 
fairly great flexibility can be exercised; often rather simple arrangements may work satis- 
factorily. For consultation regarding the establishment of seed centres see, for instance, 
Ouldager (1974) and the previously mentioned FAO/DAfflDA training course report (FAO, 1975a). 


The importance of obtaining seed from the right sources and of good quality has been 
stressed several times already. Another question which needs to be discussed is how the 
consumer can be assured of receiving the seed he wants or, if he does not know exactly what 
to request, how he may be provided with intelligible information to help him in his 
selection. For this purpose, certification schemes have been introduced in several countries 
and regions. Certification in relation to forest trees is defined as follows (Matthews, 
1964 f ex Barner, 1974a)i 

"The object of certification of tree seed and plants is to maintain and 
make available to the practising forester sources of seed, plants and other 
propagating materials of superior provenances and cultivars so grown and 
distributed as to ensure the genetic identity and high quality of the seeds 
and plants." 

"Genetic identity" is a key-word in connection with certification and the reasons why 
so much attention is given to this concept are very aptly summarized by Barber (1969, ex 
Barner, 1974a): 

"Exact control of genetic identity of reproductive material is necessary 
if success is to be achieved in tree breeding and in forestation programs. We 
should seek the goal of using only reproductive material with known genetic 
identity. However, the precision with which we identify material will vary 
according to the species, location, and final use. 

"The tree breeder must have complete knowledge of the source of the germ 
plasm with which he works. It is particularly important that the identity 
of each tree be maintained so that the breeder can consider the risks of any 
adverse traits associated with the mating of related individuals. As progenies 
are produced and grown, the breeder must be able to trace the pedigree record 
of each individual in order to locate parents contributing certain charac- 
teristics, either desirable or undesirable, and he must be able to duplicate 
all of his crosses as needed. The breeder has the responsibility to catalogue 
his material and to identify accurately all material exchanged or released 
for use. 

"The forester should know what source or strain will best meet his needs, 
and he must know the exact source of material used in establishing plantations 
and in regenerating stands if he is to provide optimum management, as knowledge 
of the genetic identity of the material used is necessary for planning proper 
pacing and culture. For example, since the use of a disease -resist ant strain 
will result in less mortality and fewer defects, the manager may either use 
wider spacing or undertake more frequent thinning. Reports of substantial geno- 
type environment interaction indicate that tree breeders can develop cultivars 
that will respond favourably to differences in site quality and culture. Where 
seed or seedlings of the proper source are not immediately available it may 
be economically feasible to delay planting for a year or more." 

If a certification scheme is to be successfully established, it is necessary to con- 
sider all parties involved in the procurement of seed and reproductive material, including 
ooSeroial swd dealers and nurserymen, state agencies for seed collection and Plant pro- 
duction, research institutes and consumers. In addition, the scheme must be backed ty 

- 64 - 

legislation. National certification schemes are operating in many countries, but a few 
regional ones have also been established (e.g. Vorth America). As seed and, to some extent, 
plants or parts of plants are moving aoross state boundaries, the need for internationally 
applicable rules has been felt for some time. As a consequence of this and on the recom- 
mendation of the World Consultation on Forest Tree Improvement in 1963, work was initiated 
by the Organization for Economic Cooperation and Development (OECD) that year. Four years 
later, in 19^7, the OECD certification scheme was finally implemented. Amendments were made 
in 1970 and 1974 (OECD, 1974). 

This scheme is based on voluntary participation by members of the organization, but 
is open to other states which are members of the United Nations. Thus the OECD scheme is 
the first of its kind which aims at world-wide application. For a detailed description of 
the scheme, its background and definitions of terms, see Earner (1974*). There are, of 
course, many problems involved in getting such a scheme to function for so many different 
conditions. However, a very useful framework is available from which a better control of 
genetic identities may be obtained and thereby some safeguard against gross mistakes. 

A few main points of the scheme are outlined in the following: 

If a certification scheme is contemplated, the necessary funds must be allocated and, 
therefore, authorities controlling the finance have to be convinced about the justification 
of the scheme. To quote Earner (1974a) the best approach is "to furnish estimates of the 
real losses caused by sustained carelessness rather than those of costs and benefits of 
initiating long-term breeding programmes". 

To implement a comprehensive scheme the following elements should be considered 
(Earner, 1974a): 


1. Preparation of maps showing distribution of important species, 

2. Delimitation of regions of provenance of these species, 

3. Delimitation of major regions of afforestation and reforestation and 

4. Estimation of supply and demand of seed and plants; 


5. Organization and management, 

6. Classification and approval of sources, 

7. Recommendations for choice of provenances and transfer of reproductive material, 

8. Production and control procedure, 

9. Data recording and documentation and 
10. Marketing of reproductive material. tf 

Items 1 and 2 have special reference to countries or regions with extensive areas of 
species covering different ecological conditions. The direction and distance of seed 
transfer may be of considerable importance. 

"Organization and management" (item 5) concerns the appointment of various groups of 
responsible authorities such as: 1) a designated authority or management committee, 2) an 
advisory group, 3) a working group on approval of sources and 4) inspectors. 

Item 6 is a broad and fundamental subject in connection with the development of the 
scheme (Earner, 1974b). Basically the sources may be classified according to an increasing 
degree of selections 

-65 - 

a) regions of provenance 

b) stands 

o) seed production areas 

d) individual trees 

e) seed orchards. 

Approval of the sources according to some minimum requirements should be the responsi- 
bility of the working group on approval of sources, mentioned above. A national list of 
these sources must be made in which the most necessary information is recorded, such as: 
Latin name, identification (reference no. or letter), location, origin, ecological conditions 
and test results. Definition of classes and prescriptions for the recording of information 
are given by Barner (1974b). It should be emphasized that the national list does not neces- 
sarily comprise all the types of sources stated above, as they simply may not be present, 
but allowance should be made for extending the list as new sources become productive. 
Another important aspect of setting up a national list is its applicability in an inter- 
national context. 

A further development of the approval of sources is the "recommendations" (item 7) of 
them for either general or specific utilization. Very often seed sources are approved on 
the basis of the performance or phenotypic appearance of the seed trees without, or with 
very limited, testing of the offspring. Recommendations must be based on tests, but as 
these take time and seed has to be produced, it is necessary to make use of seed sources 
which are not yet tested. Certification schemes, therefore, distinguish between tested 
or untested material within each class of approved sources. For species which have a wide 
geographic distribution, it may be appropriate to give directives for the transfer of seed 
both in respect of altitude and in latitude and to delineate planting zones and regions. 
The establishment and the development of a certification scheme, therefore, should take 
place in close co-operation with research, especially in the field of tree improvement. 

A certification scheme should furthermore contain rules for "production and control 
procedures" (item 8). Barner (l974a) has given the rules and minimum requirements applied 
by the OECD-soheme which ensure that the material produced from the approved sources of 
different categories is of the right identity and has been treated correctly, when it reaches 
its destination. The rules prescribe how inspections should be carried out in forests, 
plantations and nurseries and how the material should be labelled and packed. "Data 
recording and documentation" (item 9) are of course necessary elements of the control 
measures. Each seed lot, for instance, will have to be furnished with a standard set of 
records comprising detailed identification, year of collection, quantities of fruit/cones 
collected and seed extracted, storage and quality of seed. In addition, records should be 
kept of handling in nurseries, and reference made to institutes (organizations) and persons 
responsible for the execution of the different operations (see Barner, 1974a). When the 
designated authority is satisfied that all operations have been made in strict accordance 
with the directives, certification will be issued. 

Although the description above is just a brief outline of a certification scheme in 
operation, it may give the impression of a fairly cumbersome system with a heavy load of 
bureaucracy or papers. True, a scheme which has to cater to so pany interests will require 
a good deal of checking and registration. But it has also provided a clarification of the 
many concepts and terms which are used in connection with collection, handling and testing 
of seed, and thus given an international basis for the procurement and control of seed. It 
should be stressed that the OECD scheme has been developed with particular consideration 
given to circumstances in temperate regions of the Northern Hemisphere. Therefore, before 
implomonting the rules and directives to tropical conditions the scheme should be critically 
examined and altered where rules do not apply, which may mean simplification. Referring to 
tho purpose of certification as defined by Matthew. (1964), _*$-? ^^ d ""*" available 
oed fro* tho be.t souroos, properly identified genetically, and of the highest possible 
Physiologioal quality. A. explained above, this necessitate, control ^ *"* *'** 
it may bo appropriate to warn against a too elaborate control system if the result becomes 
itfaS ThiSnoo to the provision of seed or a temptation to evade the system. 

- 66 - 

Barber, JC 

y J.C. 


Barner, H. 


Barner, H. 





Quldager, P. 

Jones, N. A Barley, J. 

Kamra, S.K. 

Keiding, H. 

Keiding, H. 

Matthew*, JJ>. 


Control of genetic identity of forest reproductive material. 
Second World Consultation on Forest Tree Breeding, 
Washington, B.C., Vol. 2, 11/3. 

Seed Certification. In i Seed Orchards, Chapter 14, p. 143-149* 
Forestry Commission Bulletin, No. 54, London. 

Certification of Forest Reproductive Material. Im: Report on 
the FAO/DANIDA Training Course on Forest Tree Improvement, 
Kenya, pp. 151-161. 

Classification of Sources for Procurement of Forest Repro- 
ductive Material. In: Report on the FAO/DANIDA Training Course 
on Forest Tree Improvement, Kenya, pp. 110-138. 

Tree Planting Practices in African savannas, by M.V. Laurie. 
Rome, FAO. FAO Forestry Development Paper No. 19. 

Report on the FAO/DANIDA Training Course on Forest Tree 
Improvement, Kenya. Rome, FAO. 

Report on the FAO/DANIDA Training Course on Forest Seed 
Collection and Handling, Thailand. Rome, FAO. 

The Methodology of Conservation of Forest Genetic Resources 
(Report on a Pilot Study). Rome, FAO. 

Tree improvement. Savanna Forestry Research Station, Nigeria. 
Technical Report 1, FO: DP /NIR/7 3/007. Rome, UNDP /FAO. 

Seed certification, provenance nomenclature and genetic 
history in forestry. Silvae Oenetica Vol. 22, No. 3sp53-58. 

Seed Problems of some Developing Countries in Asia, Africa 
and Latin America and Scope for International Cooperation. 
Stockholm, Royal College of Forestry. Research Notes No. 49, 
57 P. 

Seed Stands. In; Report on the FAO/DANIDA Training Course on 
Forest Seed Collection and Handling, Thailand. Rome, PAO. 

Seed production in seed orchards. Ins Report on the FAO/DANIDA 
Training Course on Forest Seed Collection and Handling, 
Thailand. Rome, FAO. 

Seed production and seed certification. Unasylva, Vol. 18 

OECD Scheme for the control of forest reproductive material 
moving in international trade. Paris. 

- 67 - 


B.S. Ezumah 

Forestry Research Institute of Nigeria 
Ibadan, Nigeria 




Transportation of Fruits 68 

Seed Extraction ~ 

Seed Cleaning o 

Effects of Extraction and Cleaning Treatments &? 

Methods of Seed Drying 6 9 

Sun drying ^ 

Use of ambient air jg 

Use of heated air b ? 


Reasons for Seed Storage 9 

Techniques of Storing Seed ' 

Dry and cold storage ^ 

Moist and cold storage ' 

Factors Influencing Storage 7 

Temperature and storage ' 

Seed moisture content 


Protection against Theft, Rodents, Birds and Insects 73 

Sanitation 73 

Fumigation 74 

Temperature Control ^4 
Moisture Control 


Use of desiccants 74 
Effects of airtight /sealed storage 

Choice of Containers 




Packing for Shipment 77 

Transportation of Seed 


- 68 - 


The importance of seed in any forest plantation programme oannot be over-emphasised 
mm seed is a key element in plant production. A prerequisite in any planting programme ia 
an assured aupply af aaad (FAO y 1955)* Usually, tha idaal thing would be to BOW aaad in 
tha field or nursery aa aoon aa it ia collected. However, in view of tha groat damanda for 
aaad by large-scale plantation prograomea, thia ia not alwaya poaaibla ao aood must bo ool- 
lootod in adTanoa and atorod, Tha aim 9 however, ahould bo to atoro aaod for aa abort a time 
and aa porfootly aa poaaiblo in ordor to ensure minimum loaa of germinative energy. 

Baldwin (1942) dafinad a tor ago aa tho proaorvation of aaod from tha time of collection 
or extraction until it ia deal red that it ahall germinate. From a phyaiologioal point of 
view, however, tho atoraga period alao inoludoa the time on the plant between maturity and 
harreat, where weathering ia often a aerioua factor. Detailed aapeota of phyaiologioal con- 
aiderationa involved in atorage will be given leaa treatment in thia lecture; emphaaia in- 
atead will be on the practical aapeota of aeed preaervation from the time of collecting to 

Transportation of Fruit a 

Seeda require transportation from their aouroea of collection to their destination 
for extraction and cleaning before storage. When fruit a or oonea are collected they ahould 
not be delivered to the processing centres in suoh air-tight containers that air circula- 
tion is prevented* On the other hand, cloth bags should not be of suoh open weave that 
seeds can escape during transportation* To prevent "heating 11 and mould in warm weather, 
the collected seed should not be piled closely in a confined space, and they ahould be 
delivered for extraction as soon as possible. It is advisable to move bags about daily to 
provide sufficient aeration. 

Seed Extraction 

After collecting cones or other fruits, a very important atage in seed handling is 
the extraction and cleaning of seed. Generally, cones and several other type a of fruits 
require pro-drying to facilitate extraction of the seeds. On the other hand, some fruits 
require a period of soaking in water before seeds can be released for easy extraction. 
Whether drying or soaking in water ia required, great care is needed during the operation 
in order to ensure minimum injury to the seeds. 

Mechanical devioea have been developed for the extraction of seed, but in Nigeria 
and many other developing countries, seed extraction is still done by hand. In either 
oase, be it manual or mechanical extraction, the technique a vary with the species. 

Seed Cleaning 

There is usually the practical problem of inadvertently collecting immature fruit* 
during harvesting. This is because not all the fruits of a given crop mature at the same 
time, and since it is not usually economical to harvest eaoh seed or fruit as it matures 
by repeatedly going over the crop, immature seeds are often harvested along with mature 
ones. Sinoe immature seeds are low in viability and have a shorter longevity than mature 
seeds, they are less desirable for storage and should therefore be removed during cleaning. 

When a seed lot is harvested, it contains trash, broken seeds and light seeds which 
should be separated from the sound seed before storage. However for some speoies, suoh as 
most euoalypts, it is not practical to separate sound seed from the smallest impurities 
(e.g. unfertilised or aborted ovules called "chaff 11 ). Also, as more and more evidence 
indicates that tho seeds of greatest longevity in a given seed lot are those with the 

-69 - 

only MedB of high densit y - hould 
Ol " nin pro 6dm " for 

Effects of Extraction and Cleaning Treatment* 

Haack (1909) states that the first pre-requisite for successful storage in good 
extraction and cleaning. Seed cleaning can be damaging to seeds, especially dry seeds. 
Damaged or weakened seeds will not keep well in storage; therefore, it is of vital importance 
to exercise maximum care during extraction and cleaning to avoid injury to the seeds. Seeds 
which have been injured by abrasive dewinging and scarification, or weakened by wetting, 
fluctuating temperatures, or other influences never regain their original vigour. 

Methods of Seed Drying 

When seed moisture content after harvesting and cleaning is too high for storage, 
the seeds must be dried. Harrington (1972) describes the following three ways of drying 


Seeds can be dried by spreading them on to the ground, on a paved surface or on a 
canvas for sun-drying. This method, however, fails during rainy or highly humid periods. 
Also, seed germination capacity can be decreased if the days are extremely hot. 

Use of Ambient Air 

Seeds can be placed in a bin or other container through which ambient air is blown. 
Such drying is inexpensive, but is effective only as long as the relative humidity of the 
air is lower than the equilibrium moisture content of the seeds. If the relative humidity 
of the air exceeds equilibrium moisture, the seeds will gain moisture. Also, if the seeds 
are not dried fast enough, storage fungi will invade the seeds, thereby reducing longevity. 

Use of Heated Air 

This method is most commonly used. The temperature of the drying air is heated to 
increase the moisture gradient between the moist seeds and the hot air, thus drying the 
seeds faster. However, excessively high temperatures and rapid drying can be harmful and 
may seriously diminish seed vigour or even kill the seeds outright. The maximum safe 
drying temperatures will vary depending on the species. 


Reasons for Storage 
The main reasons for storage of tree seeds can be summarised as follows (PAO, 1955)' 

(i) to preserve seeds under conditions that best retain germinative energy 

during the interval between collection and time of sowing; 
(ii) to protect seeds from damage by rodents, birds, insects and other 

enemies; and 

(iii) to preserve quantities of seed collected during years of heavy seed to 
furnish a supply during years of little or no crop. 

- 70 - 

Techniques of Storing Seed 

Tree seeds are commonly stored under one of the following conditions as described 
"by Baldwin (1942) t 

(1) Dry and cold storage, simulating conditions in the cone or dry fruit on 
the tree; or 

(2) Moist and cold storage , simulating conditions in the forest litter and humus. 
Dry and Cold Storage 

All seeds can "be kept longer at low temperatures than at high temperatures, since 
respiration and chemical processes are retarded. Cold dry storage involves the control of 
temperature, moisture, and to some extent light, atmospheric conditions (pressure, gases) 
and other environmental factors (Baldwin, 1942). Generally, it has been established that 
fluctuation of factors, especially temperature and/or moisture, has adverse effects on seed 
under storage. 

Moist and Cold Storage 

Large heavy seeds are best preserved in cold moist storage. Prevention of mould and 
maintenance of moisture may be obtained "by mixing the seeds thoroughly with clean, moist 
sphagnum moss. Damp sand, peat, sawdust, cork, or ground charcoal have also been used 
successfully (PAO, 1955). 

Factors Influencing Storage 

Although species differ markedly in their storage requirements, the same factors are 
involved for all. Many of the factors which influence the longevity of seed in storage 

(a) type of seed; each species differs from every other in its capacity for 
retaining viability; 

(b) stage of maturity at collection; 

(c) prestorage treatment including extraction and cleaning operation; 

(d) viability and moisture content when stored; 

(e) air temperature, humidity and oxygen pressure during storage; 

(f) degree of infection by fungi and bacteria before and during storage; 

(g) light; since light may occasionally act as a stimulant of vital activity, 

if not germination, it is generally believed that seed retain their viability 
better in darkness (Baldwin, 1942); and 

(h) pressure. Low atmospheric pressure is apparently favourable for retention 
of viability. Most of the effectiveness is probably due to reduction in the 
partial pressure of oxygen (Baldwin, 1942). 

The complexities of the interrelationships among these various factors notwithstanding, 
a few generalizations provide guidelines in sustaining seed viability (Holmes and Buszewicz, 
1958 and Roberts, 1972 as given by Stein et al, 1974)* 

11 (i) Fully ripened seeds will retain viability longer than seeds collected when 

(ii) Seeds of high initial viability will store better than those with low 
initial viability. 

(iii) Seeds with hard, impermeable seed coats will retain viability longer than 
those with soft permeable seed coats. 

(iv) Undamaged seeds will retain viability better in storage than seeds physically 
damaged during collection or processing. 

(v) At low moisture content or low temperature, the adverse activities of insects 
and diseases are effectively slowed or stopped. 

(vi) Fluctuations in temperature or moisture are less 'favourable than constant 

(vii) For many species, the lower the temperature and the lower the seed moisture 
content, the longer the period of viability. 11 

Proper storage should, in fact, begin with sound seed. Given seed that is mature, 
highly viable, and undamaged, its life span will hinge primarily on species characteristics 
and the temperature and humidity conditions prevailing during storage. Obviously, seedlots 
known to contain damaged, immature or low viability seed should be scheduled for earliest 
use and the best seed should be retained for long-term storage (Stein et al, 1974) 

Temperature and Storage 

One of the major environmental factors affecting seed longevity is storage temperature. 
Generally speaking, all seeds keep better at relatively low temperatures than at high. In 
other words, the cooler the temperature the more slowly seed vitality declines. This rule 
continues to apply even at temperatures below freezing. 

It is a known fact that temperature fluctuations are more unfavourable to keeping 
qualities than an even temperature. 

Just as with high relative humidity, high temperatures are conducive to the activity 
of micro-organisms, especially insects. At 5C and below, insects become inactive. There- 
fore, besides retaining seed viability, low temperature storage automatically prevents or 
controls insect damage. 

The role of high temperature in speeding seed deterioration is not fully known. It 
is generally assumed that the high seed respiration at high temperatures is related in some 
way to rapid loss in germination. In spite of this assumption, it is quite obvious that 
the cause of death is not depletion of stored foods (Harrington, 1972). The effect of 
temperature on seed longevity still remains a fertile field for future research. 

Seed Moisture Content 

Seed moisture content is one of the two main factors influencing seed longevity. 
Generallv the hiSer the seed moisture content the more rapid is the decrease in gennina- 
22 iS! ^S! at ^r^ely low moi.ture contents of seeds, a slight increase in the 
rate of loss in germination occurs. 

seed are described in the ISTA Rule, and Regulations (ISTA, 1966 and 19(4). 

elusions i 

- 72 - 

(a) When seed moisture is above 40-60 percent , germination will occur; 

(b) When it in 18-20 percent, heating nay ooour; 

(0) When it im 12-14 percent, multiplication of micro-organisms will result; and 
(d) When it is 8-9 percent, inseots become active and reproduce. 

Thua the problem* of high aeed moist ure content include germination during storage, 
fungal attack and insect attack. In addition, there is a serious longevity - halving effect 
with each one percent increase in seed moisture. 

Critical moisture content levels. It is important to note that critical moisture 
content levels for seeds of most genera have not been worked out, but a range between 3-12 
percent has been recommended for most species which can be dried. It is also important to 
note that even though low moisture increases longevity, over-drying can also be harmful, 
often leading to complete death of the seed. 

Normally, seeds are stored with a moisture content low enough so that germination, 
with resulting death of seed, will not occur during storage. 

Methods of controlling moisture content. Moisture content in seeds can be controlled 
in many ways; these include: 

(1) Air-drying in the sun, or in a warm room, or in a seed extraction shed. This 
is the safest and the most simple. 

(ii) Oven-drying. This is often not economical, and great care is required to avoid 

(iii) Use of desioants, e.g. calcium oxide, charcoal, and silica gel beads. These 
are very effective and harmless to seeds if used in the right proportions. 

(iv) Other chemical solutions have also been effectively used. However, great care 
is needed in using any chemical for regulating humidity and seed moisture content 
since the chemical may directly affect the seed or cause excessive reduction in 
moisture content. 

Moisture content and control of insect and mioroflora. Insects and fungi are usually 
held in check by dry, near-freezing or sub-freezing storage of seed, but in moist storage 
at cool temperatures, pre-storage fumigation may be necessary (Holmes and Buszewicz, 1958). 

At seed moisture contents of 12-20 percent, the activity of micro-organisms, particu- 
larly fungi, can be great. The higher the moisture content in this range the more rapid 
is the growth of organisms and the greater is the danger that they will destroy the capacity 
of seeds for germination. Storage fungi are mostly species of Aspergillus and Penioillium, 
which are ubiquitous on decaying organic matter. 

Since it is almost impossible to keep seeds free of storage fungi, the easiest and 
best alternative is to keep seeds dry - in equilibrium with a relative humidity of 65$ or 
drier. Under such conditions, these organisms cannot damage seeds (Harrington, 1972). 

At seed moisture contents below 8-9$, little or no insect activity occurs and insect 
reproduction will not take place. If seed moisture content is maintained below 8$, and the 
storage is completely sealed so that respiration reduces the oxygen content below 14$, in- 
sects cannot survive in the seed (Harrington, 1972). 

- 73 - 


Certainly, the longevity of seed in storage is intimately related to its storage 
facility* There must be protection against theft, rodents, birds, insects, and fungi that 
might enter the storage and destroy the seed from outside. There must also be adequate 
control of temperature and relative humidity to minimize biochemical destruction of the seed. 

Protection Against Theft, Rodents, Birds and Insects 

A good seed storage unit should have no windows and only one door, thus minimizing 
the chances of theft. The door should be sealed properly against rodents and insects, and 
looked when the storage is not in use. Care must be taken not to let in rodents through 
the door when loads of seed are being brought in or taken out* 

Wooden construction is less desirable than brick, stone, concrete or metal. When 
wooden constructions are used, the foundation should be of stone or concrete and should 
extend three feet(l nO above the ground. There should be a lip around the building at a 
height of 3 feet (1 m) extending out 6 inches (15 on). Such a construction makes entrance 
T^y rodents through the walls virtually impossible as long as the foundation remains un- 

Storage insects can even be more damaging than rodents and usually constitute a 
greater problem in the tropics than in temperate countries. Construction of the floor, 
walls and ceiling of the storage should be such that no cracks exist which can harbour 
insects. Plaster, insulation and plywood, properly applied, can minimize cracks. Venti- 
lation openings should be screened against insects. All openings, such as electric conduits, 
ventilation openings and doors, should be thoroughly sealed. A yearly painting of the 
interior with a residual insecticide will further minimize the possibility of insect infesta- 


Sanitation, both inside and outside the building, is very important. Discarded 
seed and cleanings should be hauled away and not dumped just outside the door and left to 
harbour storage insects. 

One. th. ...d .t.r. i. fr.. of itt..ct., * 

controlled by fumigation. 

be dried to below this value before fumigation. 

, ^wssrirs^rs 

\oom. inf.t.d, th.n fumigation im n.o.ary. 

- 74 - 

Temperature Control 

Temperature is one of the two most important factor* influencing seed longevity* 
The lower the temperature the longer seeds maintain their germinative capacity. Temperature 
control may be achieved by ventilation, insulation and refrigeration. These methods axe 
not mutually exclusive and are normally used to supplement each other. 

In tropical countries, refrigeration is necessary to keep storage temperatures below 
the usual ambient tempe: atures for long-term storage of seed. 

Moisture Control 

Experience has shown that refrigeration alone is not sufficient for seed storage. 
Hence y refrigeration storage is used in combination with dehumidification or with sealing 
the dried seeds in moisture-proof containers before they are placed in refrigerated storage. 
This is the technique principally adopted in Nigeria. 

If seeds axe dried to safe moisture levels and then stored scaled in raoistuxe- 
vapourproof containers, the low moisture content of the seed will be maintained even under 
storage conditions of high relative humidity. Seeds sealed in such containers and stored 
in cold storage can keep their germinative capacity for long periods. 

Use of Desiooants 

Since moisture-proof containers axe difficult to open and reseal, they axe not use- 
ful for plant breeders and seed control officials, who must store many small samples that 
must be readily accessible. Such samples could be stored in a dehumidified, refrigerated 
room. Such rooms sre in use though they are very expensive. Also in many areas of the 
world, electricity is often unreliable, so refrigeration and dehumidification may not always 
work. An alternative is to store seed samples in metal boxes with gasket ted snap-on lids, 
with desiooants (e.g. silica gel) enclosed with the seed samples. 

Silica gel is available with all or some of the granules treated with cobalt chloride, 
which makes the silica gel turn from blue to pink at about 45% relative humidity. A quantity 
of silica gel is enclosed with the seed in the metal box in the ratio of 1:10. When the 
indicator granules turn pink, the silica gel is removed, reactivated by drying in an oven 
at 175C, cooled in a sealed container, and returned to the metal box. Thus, the seeds are 
kept below equilibrium with 45$ relative humidity, a moisture content desirable for several 
years of storage in a temperature range of 20 to 25C. 

In addition to easy accessibility, the metal box or such other container has other 

(i) It is rodent and insect-proof as well as moisture-proof f 

(ii) The boxes which are not very expensive are easily stacked on shelves 
in a small area; 

(iii) Also, seeds in equilibrium with 45$ HH will not be damaged by stored 

(iv) The only care required is periodic inspection to make sure the indicator 
silica gel remains blue. 

Effects of Airtight/Sealed Storage 

Haack (1909) t by carefully controlled experiments, showed that while airtight con- 
tainers cannot wholly prevent deterioration of seed with storage, they help prolong life 

- 75 - 

It is now believed that the main virtue of sealed storage is not only to preserve 
the moisture content, but also to prevent contamination by fungi and possibly other enemies 
^Baldwin, 1942;. It is of vital importance to ensure that seed is dried to optimal moisture 
content level before being sealed, otherwise, sealing will serve only to prolong an un- 
favourable condition, resulting in deterioration. 

Choice of Containers 

Several types of storage containers have already been mentioned. The important factor 
in the choice of containers is primarily the degree of sealing required. 

Most large-scale storage of seeds is done in tightly-closed containers. Such con- 
tainers slow down but do not entirely stop gas exchange between the contents of the container 
and the air within the storage facility. Obviously, the more contrast there is between 
inside and outside, the greater the need for minimising exchange. Other factors to consider 
in the choice of the best container for a given use were listed by Stein et al (1974) as 

11 (i) When seed requires further drying in storage, do not use a tight-closing con- 
tainer because enclosing excess moisture is harmful to the seed (Barton, 1961). 

(ii) Use a tight-closing container if gain in mositure content can be damaging and 
relative humidity in the storage facility is high. 

(iii) Containers and seed can quickly gather unwanted condensation when brought 
out of cold or subfreezing storage. Wanning to room temperature is recom- 
mended before opening a container brought out of such storage. 

(iv) Four to 10 mil polythylene bags will exclude or retain moisture but still 

allow exchange of oxygen and carbon dioxide with air outside. Such exchange 
may be beneficial or harmful depending on the species. 

(v) A container that is easy to open and close is desirable when quantities of 

seed are likely to be added or removed repeatedly. Open only when necessary 
to minimize temperature and relative humidity fluctuations. Alternatively, 
store seeds in small containers, so that the entire content can be stored or 
emptied at once. 

(vi) Pill containers completely to ensure minimum exchange of moisture between the 
seed and the entrapped air. 

(vii) When seed moisture content or relative humidity is high, the container must 
be made of moisture resistant material. 

(viii) When seeds are fragile and easily damaged, a rigid-trailed container should 

be used. Moisture-proof plastic bags are often used as liners for rigid con- 

(ix) Choose a container shape and stacking arrangement which facilitates uniform 
temperature and aeration throughout the storage facility. 

(x) Some containers may be of substances that are harmful to tree and shrub seeds 
(Barton, 1954). Unproven containers should be tested for toxity." 

- 76 - 


Any seed storage programme , whether for commercial seed or germ-plan seed, need* 
to have a teed testing programme as well* The storer of commeroial seed needs to know 
which lot* will begin to deteriorate most rapidly 00 he can sell them first. Also, the 
director of a germ-plasm storage must be able to ascertain when to "grow out" a seed lot 
before it is seriously reduced in germination capacity or even completely lost (Harrington, 

The various kinds of seed testing and the procedures are described in the Inter- 
national Seed Testing Association (ISTA) rules and regulations (1966 and 1974)* Among other 
tests, it is important that every seedlot should be germination-tested when it is received 
for storage | so that the seed quality is recorded. Subsequent periodic tests should be 
made to detect deterioration. If deterioration occurs, storage conditions should be checked 
to discover the reason and corrective measures taken (Harrington, 1972). 


Packing for Shipment 

Experience has shown that loss of viability has been traced to exposure to high 
temperatures and varying humidity in transit. Some seeds require preservation in dry con- 
ditions, others moist. 

The type of packaging selected for a seed shipment will depend on the nature of the 
seed, quantity to be shipped, time in transit, mode of transport, and expected weather con- 
ditions. The following helpful practices are recommended by Stein et al (1974): 

(i) Double-wrap the seed. Enclose the seed container in a sturdy, preferably 
rigid, outer container. 

(ii) Small or moderate size containers generally withstand shipment better than 
large containers. 

(iii) Fill containers completely to minimize air content and jostling of seeds 
during shipment. 

(iv) Seal in plastic, foil, or moisture -resist ant kraft bags or in rigid containers 
such as vials, plastic bottles or tins. 

( v) Seeds requiring high moisture should be mixed in moistened fine sphagnum moss, 
peat or sawdust and placed in water-resistant containers. 

(vi) For some species, a chemical germination inhibitor may be added to the 
moistened medium (Barton 1961). 

(vii) Large, moist seeds can be sealed individually with paraffin or latex. 

(viii) All packages should bear a good identifying label on the innermost covering 
and another one within the container. 

(ix) For long distances, shipment of sensitive seeds by air is desirable. 
Hermetically sealed containers may explode at high altitudes. 

(x) Seed packages should permit ready opening and reclosing if destined for 
export to a country requiring fumigation. 

- 77 - 

Transportation of Seed 

In addition to transportation from field to storage, seeds also undergo transporta- 
tion between storages, as well as from storage to the planting site. All these involve 
periods of storage during which deterioration can be serious. It is important to note that at 
all stages of transportation, the principles of good storage apply equally. Steps must be 
taken to avoid high and fluctuating temperatures and adverse humidity which are the major 
oauses of loss of viability. 

With adequate packing and carefully planned shipment, most lots should arrive at 
their destinations in good condition. It is wise to send adequate instructions on post- 
shipment care with each lot. 


Baldwin, H.I. Forest tree seed of the north temperate regions, with special reference to 
1942 North America. Waltham, Massachusetts, U.S.A., Chronica Botanica Company. 
240 p. 

Barton, L.V. Storage and packeting of seeds of Douglas fir and western hemlock. Contrib. 

1954 Boyce Thompson Inst. 7: 379-404. 

Barton, L.V. Seed preservation and longevity. New York, Interscience Publishers, Inc. 
1961 216 p. 

PAO. Handling forest tree seed, by H.I. Baldwin. Rome, FAO. FAO Forestry Development 

1955 Paper No. 4$ 110 p. 

Haack, O.H.A. Die Beschaffung des Kiefern-und Fichtensamesn, einst, jetzt, und kttnftig. 
1909 Mitt. d. Deutschen Forstvereins 6: 32. 

Hannond, J.E. et al. Mechanical seed cleaning and handling. Washington, D.C., U.S.D.A. 
1968 Agricultural Handbook No. 354. 56 p. 

Harrington, J.F. Seed storage and longevity. In Kozlowski, T.T., ad. Seed biology, Vol.3, 
1972 Insects, and seed collection, storage, testing and certification. New York, 
Academic Press, pp. 145-245. 

Holmes, O.D. and Buszewicz, <J. The storage of seed of temperate forest tree species. 
1958 Forestry Abstracts 19 (3): 313-322 and 19 (4): 455-476. 

I.S.T.A. International rules for seed testing, 1966, Proceedings of the International Seed 
1966 Testing Association 31(1): 1-152. 

I.S.T.A. Report of the International Seed Test ing Workshop, Copenhagen and Lund, 1973. 
1974 Seed Science and Technology 2(2): 163-266. 

Roberts, E.H., ed. Viability of Seeds. London, Chapman and Hall Ltd. 448 p. 

PP. 98-125 

- 78 - 


H. Keiding 

Danish/FAO Forest Tree Seed Centre 
Humlebaek f Denmark 


Tree improvement 

Fhenotypic selection and environment 
Selection intensity 
Vegetative propagation 
Progeny testing 
fypes of progeny 

Seed stands 

Age, area and development of stands 


Treatment of seed stands 

Seed orchards 

Seed orchard approach 
Clonal vs. seedling orchards 
Benefits or gains 














Tree improvement implies, generally speaking, all the activities based on utilizing 
the genetic potential of the species. This means that between and within species there is 
variation that we can use to our advantage* Variation is the result of interaction between 
the environment and inherited qualities of tree populations and individuals* In other 
words 9 it matters a good deal how we treat a particular population si Ivi culturally and what 
kind of site it is planted on. Tree improvement may be applied in different circumstances 
and at varying degrees of intensity ranging from the conservation of gene resources and 
species and provenance trials to seed orchard establishment, controlled crossings and 
progeny trials. 

A prerequisite for a tree improvement programme is plantation forestry. As soon 
as seed is collected and plants are raised and artificially cultivated, there is a chance 
to select and improve. Thus, it is convenient to consider tree improvement in relation 
to afforestation and reforestation programmes. It is obvious that tree improvement is 
particularly relevant to savanna conditions as all forest establishments will have to rely 
on planting, and to a large extent with introduced species. 

- 79 - 

Tree improvement, and in a more narrow sense tree breeding, or selective breeding, 
involves various stages of selection, beginning at the species and population level and 
ending with individuals, if we use the logical sequence. Species and provenance selection 
have already been discussed; we shall therefore turn to selection of superior single trees. 

Phenotypic Selection and I&ivironroent 

Any selection of individual trees is a phenotypic selection as we cannot separate 
the influence of the environment and the genotype without progeny trials. At more advanced 
stages of tree breeding, where single trees are selected in replicated experiments, the 
selection becomes increasingly "genotypic", but the most common situation is probably 
the selection of plus trees or superior phenotypes in natural stands or plantations in 
order to initiate an improvement programme. 

The relationship between the three concepts, phenotype, genotype and environment, 
is expressed in the well-known equation: 

Phenotype genotype + environment 

The breeder's interest lies in securing the good genotypes, i.e. the trees that 
irrespective of environmental influences perform well or better than average. Such trees 
will possess a favourable genetic constitution, and they will, when grouped together, 
change the gene frequencies in a positive direction. 

The phenotypes are selected on the basis of a number of characters whose superiority 
should usually be equal to or better than a certain, fixed percentage above the population 
mean. Instead of the population mean, a representative portion of the population is 
often used for comparison. This may be the four or five nearest dominant trees. 

Which selection procedure to follow will have to be decided for the individual 
breeding programme, as each species and local market will have different requirements. 
Some guidelines on which method to follow may be attained by examining the relative 
importance of the individual characters in utilization or economic return. If a grading 
system (characters weighted) is employed, as for instance in the Texas Forest Service, 
U.S.A., the composite evaluation of the individual tree may be expressed as: total 
score - height score + diameter score + form score. In the allocation of a point score 
for a given characteristic, three factors have to be taken into account: (1) the amount 
of superiority of the trait, (2) the strength of inheritance of the trait, and (3) the 
economic worth of this superiority. 

The number and type of characters used for selection vary of course, but some of 
the most common are listed below: 

1. Superior heigftt growth 

2. Superior diameter growth 

3. Good pruning ability 

4. Straight, no crook or spiral bole 

5. Flat ( wide) branch angle 

6. Narrow, compact, well- formed crown 

7. Disease resistance 

8. Insect resistance 

9. Drought resistance 

10. Wood characteristics 

Of the three factors to be considered before employing a grading system, the first 
can be measured, but the other two may be much more difficult to estimate. The strength 
of inheritance of the trait (2) for instance is only possible to assess after progeny 
testing i.e. in the course of the breeding work for which we have to select material. 

- 80 - 

Therefore in the initial phases of a breeding programme it may be advisable to use a selec- 
tion procedure for individual trees which only registers the necessary information without 
weighting. What is actually "necessary" may be difficult to foresee so there is an under- 
standable tendency to work out more elaborate plus tree record forms than is really justi- 
fiable* A measure of how much is reasonable to register can be obtained from breeding 
programmes which have been in operation for some time and from actual usage in the field. 
From the former it may be seen how much and to what purpose the data have been used and 
from the latter whether the forms and descriptions are practical to handle. 

A measure of the intensity of selection is the selection differential, which is the 
difference between the mean of the selected trees and the mean of the population from which 
they ore selected (see Fig. 1). As mentioned above, the mean of the whole population may 
be replaced by the mean of the four to five nearest, dominant trees. The reason for doing 
this is partly the difficulty or impossibility of measuring the whole stand, especially in 
natural mixed forests, and partly that a better basis for comparison is probably obtained 
as the nearest trees are more likely to have been exposed to the same environmental 
influences as the potential plus-tree. The comparison trees should be found within a 
radius of 25 to 50 m from the plus tree. 

Selection Intensity 


Diagrams show how the selection differential, S, depends on the 
proportion of the population selected, and on the variability of 
the character. All the individuals in the stippled areas, beyond 
the points of truncation, are selected. The axes are marked in 
hypothetical units of measurement. 

(a) 50% selected; standard deviation 2 units: S1.6 units 

(b) 20^0 selected; standard deviation 2 units: S2.8 units 

(c) 20$ selected; standard deviation 1 unit: S-1.4 units 

Fig. 1 From D.S. Falconer (1960) 

The "effect" of selection is termed response (R) or genetic gain ( A 0), and it 
will be seen that in addition to the selection intensity the response is also affected by 
heritability. If the same selection intensity is applied to two characters with different 
heritabilities, the one with the lowest heritability will give the smallest response. 

Vegetative Propagation 

A technical problem which by no means should be ignored is the ease with which the 
different species may be propagated vegetatively. In several oases the development of 
a suitable method of grafting, budding or cutting has been decisive for the progress of 
breeding. The patch budding method, for instance, gave rise to the intensive breeding of 
rubber CHevea brasiliensis) and was later used for large-scale establishment of clonal 

- 81 - 

plantations. The same method with certain modification has made breeding of teak feasible, 
and it seems suitable for some other tropical hardwoods as well. Thus the development of 
techniques for vegetative propagation is an indispensable part of individual tree selection. 

Progeny Testing 

The purpose of progeny testing in the traditional sense is "to assess the genotype 
of an individual or the performance of a parent by a study of its progeny under controlled 
conditions". Progeny testing was first introduced by Gregor Mendel about 100 years ago, 
so it is an old story. 

Testing of progenies is also a means of estimating genetic parameters such as 
variances of different kinds (phenotypic, genotypic, additive and interaction between them), 
breeding value, combining ability, heritability etc. The latter, which may be termed 
"strength of inheritance", is of great importance for our selection work, as indicated 
above under selection of individuals. 

Types of Progeny 

The type of the progenies, among other things, determines how much information may 
be retrieved from the trials. Distinction is made between two main groups: half-sibs 
and full-si be. 


Half sibs comprise individuals deriving from one mother tree or one mother clone 
pollinated by the surrounding trees. Thus only the female parent is known. Many progeny 
trials axe composed of half-sib families, a family being the group of trees with a common 


In full-sib families both parents are known, ELS in the case with controlled crosses. 
More information can be obtained from such trials than from trials with half-sibs because 
an estimate of genetic variance can be made for both the female and male partners. 

The following definitions are adopted in accordance with the OBCD I/ scheme : 

Stand: "A population of trees possessing sufficient uniformity in composition, 
constitution and arrangement to be distinguished from adjacent populations". 

A stand may be classified as plus, almost plus, normal or minus. 

Seed stand, seed production area: "A plus stand that is generally up-graded and 
and opened *y removal of undesirable trees and then cultured for early and abundant seed 
production" (Snyder, 1972 and Barner, 1974). 

I/ OECD - Organization for Economic Co-operation and Development 

- 82 - 

The objectives of forming seed production areas , or seed stands, are, according to 
Matthews (1964) toi 

1. produce seed of improved inherent quality by selecting and favouring seed trees 
which are vigorous, straight stemmed and healthy and produce wood of good 

2. concentrate seed collection into a few specially treated parts of the forest, 
thus making seed collection easier to organize and control; 

3. improve the germinative energy and germinative capacity of the seed collected. 

Age, Area and Development of Stand 

The stand must be old enough to have proved its value in various respects and it 
should be in a good stage of flowering and seed production, and not too old to allow seed 
to be collected for a reasonable number of years ahead. 

In special cases, however, it is justifiable to select younger stands, if they axe 
showing great promise. It is recommended to register such stands as canditate seed stands 
for later inspections. See Earner (1974)* 

Seed stands should be of sufficient area, which normally means not less than 5 ha, 
in order to produce enough seed to be worth collecting and also to avoid possible risks 
in collecting from very small populations. 


Isolation from inferior sources is very important. In wind- pollinated tree species 
such as most conifers, proper isolation can be quite difficult to obtain, while insect- 
pollinated species like teak and rubber are easier to handle. If the seed stand is 
surrounded by undesirable pollination sources, contamination may be avoided or at least 
reduced by using isolation belts or filters either of the same or other species. 

Treatment of Seed Stands 

According to the definitions used earlier, a seed stand or seed production area is 
distinguished from a seed source by the treatments given to it in order to promote seed 

Such treatments may comprise: 

1. Removal of inferior trees to improve the genetic quality of the seed. 

2. Thinnings to give the seed trees better spacing in order to improve conditions 
for flowering and seed production. 

3. Removal of undergrowth to facilitate seed collection. 

4. Application of fertilizers to improve seed production and seed quality ( technical ) 
5 Proper demarcation of the seed stand. 

6. Various other treatments, such as pruning and application of insecticides to 
protect flowers and fruits. 

- 83 - 


Seed Orchard Approach 

Stated briefly, the seed orchard method involves selection of superior individuals 
(within a large, satisfactory population or one known to be of superior provenance) and 
transference of their genes in the form of clones or seedling progeny into an area which 
is isolated from undesirable sources of pollen contamination, and where the object of 
management is efficient seed production. This procedure may or may not be taken further 
to include the development of new improved orchards. 

Thus a tree seed orchard is a planted stand that is located, designed, established, 
composed, and managed to produce a reliable supply of genetically definable seed for 
purposes of forest management. 

This description of the seed orchard breeding procedure and the above definition of 
a seed orchard do not imply a static strategy in which all worthwhile gains will accrue 
from the first orchard. In fact, a tree breeding programme should be dynamic, the objective 
being to continuously up-grade the genetic quality of the unit which produces the seed 
for reforestation (the seed orchard) by adding to the existing orchard or creating new 
orchards with improved clones of families. 

Clonal vs. Seedling Orchards 

Seed orchards may be established with clones (grafted ramets or rooted cuttings) or 
seedlings of selected trees. An entire double issue of the journal Silvae Genetica (1964) 
was devoted to discussions of seedling and clonal seed orchards (Toda, 1964); reference 
can be made to the several papers therein and a more recent and brief resum of Kellison 
(1969) for details of arguments for and against each of these types of orchards. Suffice 
it to say that, as regards the breeding of tropical coniferous species, a recent survey 
by Nikles (1973) showed that only seven orchards of about ei^rty seed orchards established 
by countries surveyed were seedling seed orchards. 

Benefits or Gains 

A comparison of seed orchard offspring of F^ radiata (30 clones) with that from 
commercial sources showed after 3^ years an improvement of 16 percent in height growth 
and 20 percent in diameter, both characters of fairly low heritability. The experiment 
was conducted in Australia and reported by Griffin (19^9) Hybrid seed orchards for larch 
(Larix decidua x leptolepis) have constantly given offspring with a 10 30 percent increase 
in vigour plus improved form and resistance to canker when compared with the respective 
species in Denmark. In rubber (Hevea brasiliensis) t where seed orchard development has 
reached an advanced stage, offspring are yielding 4^-5 times as much latex as the base 
populations from which breeding started (Keiding, 1972). 

Porterfield (I974) f as quoted by Zobel (1974), had analysed the heritabilities of 
different qualities and worked out the gains that migjit be expected. In relation to the 
economic considerations of seed orchards his results were as follows: 

"1. Ttotal volume gains from seed orchard seed over unimproved plantations varied 
from 12 to 14 percent for unrogued seed orchards in the tree-improvement pro- 
grammes assessed. Additionally! there was a gain of 5 percent for specific 
gravity f while bole straightness and crown improvement were in excess of 5 
percent. Volume gains of more than 20 percent are quite possible by increasing 
roguing intensity and intensifying wildUstand selection intensities. 


The profitability of a tree improvement programme is closely related to seed 
yields from the orchard. The best genetic stock is of no value until sufficient 
seeds are collected and planted - the more seeds 9 the more acres that can be 
planted with superior seedlings. Porterfield's study illustrates the extreme 
importance of maximizing seed yields from orchards by use of the best parent 
trees | fertilization, irrigation and pest control. Only 8 pounds of seed per 
acre per year in the seed orchard (after age 10) are necessary to break even for 
seed which produces seedlings 10 percent genetically superior in volume 9 at an 
eight percent rate of return; however t each pound of this kind of seed has a 
present value of S 116 and every effort should be made to obtain maximum seed 


There exists a wealth of literature on the subject of forest tree improvement 
extending from the basic principles of quantitative genetics to very practicable descriptions 
of techniques and applications of tree breeding. For those who want to broaden their 
knowledge of this complex of subjects, a few of the more recent publications! mainly of 
relevance to tropical conditions or because of their general treatment of the topics f have 
been given below. 

Earner, H. 

Barley | J. A 
Nikles, B.C. (eds.) 

Bur ley, J. & 
Nikles, D.G. (eds.) 

Falconer y D.S. 






Faulkner, R. (ed. ) 

Classification of sources for procurement of forest reproductive 
material. Report on the FAO/DANIDA Training Course on Forest 
Tree Improvement, Kenya, 1973* Rome, FAO. 

Tropical provenance and progeny research and international 
cooperation. Oxford, U.K., Commonwealth Forestry Institute. 

Selection and breeding to improve some tropical conifers, 
2 Vols. Oxford, U.K., Commonwealth Forestry Institute. 

Introduction to Quantitative Genetics. Oliver and Boyd, 
London. 365 p. 

Proceedings of the World Consultation on Forest Genetics and 
Tree Improvement, Vol. I & II, Stockholm. 

Second World Consultation on Forest Tree Breeding, Vol. I and 
II, Washington. 

Forest Tree Breeding. Unasylva, Vol. 24 (2-3), Numbers 97-98. 
Rome, 132 p. 

FAO/DANIDA Training Course on Forest Tree Improvement, Kenya, 
334 P. 

The Methodology of Conservation of Forest Genetic Resources* 
Report on a pilot study. Rome, 12? p. 

Seed orchards. London, Forestry Commission, Bulletin No. 54. 

-85 - 

Griffin, A.R. 

Guldager, P. 

Keiding, H. 

Kellison, R.C. 

Matthews, J.E. 

Nikles, D.G. 

Porterfield, R.L. 

Silvae Genetica 

Snyder, E.B. 

Toda, R. 

Zobel, B. 


A comparison of Pinus radiata of seed orchard origin with 
alternative commercial sources - 3g year assessment. Second 
World Consultation on Forest Tree Breeding, Washington, B.C., 
U.S.A., 1969. Vol. 1. 

Savanna Forestry Research Station Nigeria, Tree Improvement. 
Rome, 69 p. 

Seed orchards of Hevea and teak. In: Symposium on seed orchards 
in honour of C. Syrach Larsen. Forest Tree Improvement, No. 4. 

Application of genetics, racial variation and adaptation to 
tree improvement. Lecture Notes, FAO/North Carolina State 
University Forest Tree Improvement Training Course, 1969* 
Raleigh, N.C.,U.S.A. School of Forest Resources. 

Seed production and seed certification. Unasylva Vol. 18 (2-3), 

Nos. 73-74. 

Improvement of tropical conifers: report on a questionnaire. 
In: Burley, J. and Nikles, D.G. (eds.), Selection and breeding 
to improve some tropical conifers, Vol. 2. Oxford, U.K., 
Commonwealth Forestry Institute. 

Predicted and potential gains from tree improvement programs - 
a goal programming analysis of program efficiency. Raleigh, 
N.C., U.S.A., School of Forest Resources, North Carolina State 
University. Technical Report No. 52. 

Vol. 13 (1-2). 

Glossary for forest tree improvement workers. Southern Forest 
Experiment Station, USDA. 

A brief review and conclusions of the discussion on seed 
orchards. Silvae Genetica 13 (1-2). 

Increasing productivity of forest lands through better trees. 
Berkeley, U.S.A., University of California. The S.J. Hall 
Lectureship in Industrial Forestry. 

1. Silvae Genetica. J.D. Sauerlander f s Verlag, Frankfurt 
A. M. Publication schedule, 6 numbers per year. 

2. Pbrestry Abstracts. ODC classification: 

165.3/7: Heredity, Genetics and Breeding f Variation. 
232.1 : Choice and Trials erf species, races etc. 
Published monthly by Commonw. Agricultural Bureau, 
Famham, U.K. 

3 Fbrest Genetic Resources Information. Forestry Occasional 
Papers. FAO, Rome. Issued about twice annually. 

- 86 - 


D.E. Greenwood 
Division of Forest Research, Kitwe f Zambia 



Introduction 86 

Choosing a nursery site 86 

Planning the nursery layout 87 

Water supply requirements 89 

Water quality 89 

Water supply installation 89 

Irrigation methods 90 

References 90 

Sketch 1: Nursery layout examples 91 

Sketch 2x "Flow-working" principle - Mishishi 92 

Sketch 3: Tipping soil - Mishishi 92 


The production by the forest nursery of a sufficient number of plants of the right 
size and adequate quality at the right time is an important factor in successful plantation 
establishment. The first step towards the achievement of this is to have a properly-sited 
well-designed nursery with an efficient system of irrigation* Good nursery techniques, 
however skilfully applied, can rarely make up for a badly sited or badly designed nursery 
or one with an unsatisfactory system of irrigation. It must be remembered, however, that 
without a good nurseryman even the best designed nursery is unlikely to produce good stock. 


The decision must first be made whether the programme can best be met by having a large 
central nursery or several scattered small ones. Where communications are inadequate or 
transport facilities not available there is no alternative to a number of smaller nurseries. 
When there is a choice, one has to consider the relative economics of the two systems as 
well as several technical factors : 

(a) The cost per plant of mass production in a large nursery is likely to be 
much lower but the cost of transport from such a nursery to the planting 
sites is bound to be higher. There may be a labour transport and subsis- 
tence cost to be considered in the case of remote smaller nurseries. 

(b) The total capital cost of establishing several small nurseries has to be 
balanced against that of establishing the large central nursery. Equipment 
in the small nurseries will be simpler and the housing and related facilities 
of poorer quality but the total labour force will be higher awl many items 

- 87 - 

may have to be duplicated* 

(o) In a large nursery you have the advantage of being able to concentrate 
your skilled supervisory staff, you can provide more sophisticated 
equipment and you can provide better facilities for your staff and 
labour* The supply of materials and the repair and maintenance of 
equipment are easier to organise* 

(d) When you have a series of small nurseries, then you have the advantage 
of being able to isolate disease outbreaks and limit their effects on 
total production* The overall effect of equipment breakdowns will be 
less, and it will usually be easier to obtain the necessary quantities 
of soil and water. 

(e) The effect on the mrsery plants of transporting them long distances 
from a central nursery over rough roads must be taken into consideration* 
Plants can suffer from wind-burn if not protected, but even with 
adequate protection deaths can occur as the result of the breakage of 
fine roots by continual vibration* 

Each nursery site should be on well-drained level ground. Where well-drained land is 
not available, then a slight slope is desirable but care is needed to see that erosion does 
not develop* A system of surface irrigation dependent on gravity flow may also demand the 
use of a sloping site* A mid-slope position to allow cold air to drain away is preferable 
and one has to avoid the temptation to choose a topographically unsuitable site such as a 
valley bottom or stream bank in order to facilitate the supply of water* 

The nursery must of course be situated where an adequate and suitable supply of water 
can be provided (not forgetting domestic demands) and it must be situated as near as 
possible to a source of suitable soil or of the major constituents of whatever soil mix 
may be used (balancing the cost of transport of soil against the cost of transport of the 
planting stock)* 

Shelter is very important and unless the site is naturally sheltered a wind-break 
against the prevailing wind will have to be established* Hedges should also be 
established around the nursery, with gaps for cold air drainage, and in large nurseries 
internal hedges may be helpful provided they do not interfere with transport and work flow* 
In short term nurseries artificial screens can take the place of hedges and wind breaks and 
are likely to be needed in the early stages of a long-term nursery before the hedges and 
wind-breaks are fully established* 

Air pollution has to be taken into account in the vicinity of industrial plants* 
Sulphur dioxide can have adverse effects at considerable distances under certain 
atmospheric conditions* This has already proved a serious problem in one nursery on the 
Zaabian Copperbelt* 

The presence of existing labour accommodation and related facilities and existing road 
access may be a further factor to be taken into consideration in the final choice of a site* 


It is convenient for both planning and operational purposes to divide a nursery into 
blocks, sections and beds: 

(a) The bed is the basic unit, and the term 'bed 1 includes an area where 
boxes or plant containers are laid out when in use, in addition to the 
obvious structural formation used as a seed-bed or transplant bed. 

- 88 - 

(b) The section might consist of anything from two to eight beds and is the 
unit which will be subjected to the same treatment at the same time. 

(o) The blook is merely a group of a convenient number of sections which will 
vary according to the ground layout of the nursery* A blook must always 
have space for a road through the centre 9 along the long axis preferably, 
so that truck off-loading or loading can take place from both sides* 

A seed bed or transplant bed should be not more than 1 metre in internal width for 
comfortable working but standing-out beds in which containers or boxes are stacked may be 
up to 1.2 metres wide y the actual width preferably being arranged to take a round number of 
containers* Bed length is a matter of scale of operations and space available* The length 
of standings-out beds should be arranged to take a round number of containers y as this sim- 
plifies counting and organisation* It is usually not convenient to have any beds longer 
than 10 metres or lateral access is impeded* The orientation of seed beds should ideally 
be East-West to avoid sun-scorch* 

Seed beds would normally be in separate blocks from the transplant and standing-out 
beds but should not be remote from them. 

The total number of beds and sections required has to be calculated from the planned 
plantation programme taking account of culls f an allowance for blanking, and a safety 
margin* Allowance also has to be made for future expansion in the case of long-term 
nurseries* It must also be remembered that where plants have to remain in the nursery 
for over a year, additional bed space will be required. 

Facilities for shading may have to be allowed for, but the precise form of these, as 
of the bed structures themselves, will depend on the types of bed, the techniques employed 
and the materials available locally* Where root pruning by means of a wire is standard 
practice, the design of the shade supports and other bed features must allow for this* 

In the overall design and the layout of sections, blocks and beds, vehicle access and 
vehicle flow must receive considerable attention* A width of 5 metres should be allowed for 
a single track road* There must be adequate turning space, and there should be no necessity 
for reversing or other ground-churning manoeuvres. Any water draining from the beds over 
the surface should be led away from roads to avoid the development of soft patches* 

The paths between the beds must be wide enough to take whatever hand-trucks, trolleys 
or barrows are used* One metre width is usually ample (see sketch 1). 

The layout should be such as to enable a "flow" system of working to be employed 
(see example in sketch 2) and should enable the handling of soil, containers and 
other material to be kept to the minin 

The type of irrigation system in use will also affect the specific layout* Examples 
of the layout of parts of actual nurseries in Zambia are given on the diagrams (sketches 1-3) 
to illustrate this. 

In nurseries where soil has to be mixed with fertiliser or other ingredients, or where 
the soil is to be sterilised in 'clamps 1 , then a section of the nursery has to be set aside 
for this* If the soil is to go into containers, then a further space immediately adjacent 
to the mixing/sterilising area will have to be set aside for the filling operation* In 
nurseries where soil is used without any admixture or where sterilisation is either not done 
at all or done in the pots in situ, then these special areas will not be required as the soil 
will be offloaded directly in the bed areas* Where such areas are required they must be 
located with work flow and minimum handling and wi thin-nursery transport in mind (sketch 3), 

In areas where mycorrhizal inoculation is expected to be necessary, it is useful in a 
long-term nursery to have a special mycorrhisal bed where pines are kept growing* The soil 

-89 - 

with which the bed is started should be brought from an established pine stand f but it can 
be kept topped up thereafter with ordinary woodland soil. 

In long-term nurseries, it is always as well to allow extra space in any case, to allow 
not only for unforeseen expansion but also for changes in technique and experimentation with 
new techniques 

In addition to covered storage for barrows, containers and other equipment, special 
storage has to be provided for fertilisers, insecticides, fungicides and other chemicals. 
This latter should be conveniently located in the nursery where possible to minimise hand- 
ling of dangerous materials. 

Some provision should be made for the recording of meteorological data, in particular 
maximum and minimum temperatures and humidity. 


It is important to estimate the quantity of water which will be required. Where a 
domestic supply is also required the water source at its lowest level must be able to 
yield not only the peak requirement for the plants but also the peak domestic demand. 

The nursery requirements obviously vary enormously according to local conditions and 
the type of stock being raised. Where there is no local experience on which to base an 
estimate then rough calculations can be made on the basis of evapo transpiration rates (see 
Appendix 6 of Laurie, 1974)* Figures on which to base domestic demand estimates will 
usually be obtainable locally. 


The water should be relatively free from silt and other undis solved solids and the 
content of dissolved salts must also be low. pH should normally be not more than 7. It is 
not possible to be absolutely dogmatic about the limits of these factors, however, as 
different species and different soils react differently and the cultural practices em- 
ployed will also affect the tolerance of the plants. Laurie (in Chapter 11 and Appendix 6) 
suggests limits which could be used as a guide until local knowledge has accumulated. 


Water may be delivered to the nursery by gravity feed, hydraulic rams or pumps. 
Details are given in Appendix 6 of Laurie. 

When the irrigation is done by hand held watering cans or knapsack sprayers or when it 
is a system of surface irrigation, then storage can be at ground level. It is, however, 
still essential to have storage, especially when the water source (a well, for example) 
cannot supply high peak flows over a short period although perfectly capable of supplying 
the required quantity per day. A common way of calculating the storage capacity required 
is to take the peak daily requirement, allowing for future expansion, and then to double it. 

For hand watering by hose-pipe and spray rose and for all systems of overhead sprinkler 
irrigation, overhead storage is needed. A head of at least 10 metres when the tank is half 
full is needed in order to give the pressure required to produce small droplets. One should 
not rely upon continuous pumping against a closed valve to produce the required pressure. 

Where domestic water is supplied from the same source, the domestic main must be 
separate from the nursery main so that varying domestic demands do not cause a fluctuation 
of pressure in the irrigation system. If a completely separate system can be provided 
then so much the better. 


Wherever pumping is involved it is advisable to have a standby pump* If this is not 
feasible y the storage capacity should be farther increased to cover breakdown periods. 

Whatever irrigation system may be in use y the water has to be distributed to various 
points in the nursery by a series of either stationary or portable lines. Details of the 
various alternatives are described in Appendix 6 of Laurie. 

Silt traps should be installed and a means of flushing out the system provided wherever 
sprinkler irrigation is in use. 


Hand watering with cans fitted with a spray-rose or with knapsack mist sprayers is the 
obvious method for small nurseries (say, up to 10,OOO plants). An adequate number of 
filling-points must be provided. 

Hand watering with hose-fitted with a spray-rose can be used in small nurseries where 
the necessary head of water can be provided. This method can of course cope with larger 
nurseries but suffers from the same defect as the other hand methods in that uniformity 
of coverage is difficult to achieve. It is necessary to provide plenty of stand-pipes for 
this method y say one at each end of each block. 

Surface irrigation can be applied to large nurseries but it is not a method very widely 
used. A good deal of skill is required in laying out such a system though it is comparative- 
ly inexpensive to operate. It is moreover difficult to control the amounts of water 
supplied and it is inefficient in water use. Fertilisers, insecticides and fungicides 
which cannot be used in sprinkler systems can be introduced with the water in surface 
systems but this also tends to be wasteful and difficult to control. 

The ideal system for large nurseries is overhead sprinkler irrigation. A large 
number of systems are available but they can all be classed as either rotary sprinklers, 
nozzle lines, or perforated pipes. Rotary systems tend to produce larger droplets than 
the other two and owing to the shape of their spray pattern it is more difficult to arrange 
uniform coverage. They are however more tolerant of small particles in the water and so 
less liable to blockages. Nozzle lines are easier to maintain than perforated pipes. Both 
give a good uniform coverage. 

No sprinkler system is perfect, however, and it is often found in practice that some 
supplementary hand watering is required, particularly in turbulent conditions. 

Whenever a sprinkler system is being designed it is helpful to obtain expert advice 
before a final decision is made. Potential suppliers of equipment should be consulted and 
should be given very full information about the requirements. This should include: 

(i Area to be covered 

(ii Frequency, strength and direction of wind 

(iii Maximum permissible droplet size 

(iv Required rate of delivery per square metre of bed 

(v Pressure available 

(vi Size of main pipe from storage tank 
(the last two where water supply already installed) 

If you cannot get advioe then at least get hold of the makers' manuals and study them 
before ordering the equipment. 

Laurie, M.V. Tree planting practices in African savannas. FAO Forestry Development 
1974 Paper No. 19 Rome, FAD. 185 p. 

- 91 - 

Central Section 
Sprinklers Block 2 dram Block 1 2 

1 a r" x "n x ~r~ x ^r~ x ~i X ~T~ X ~T x n r~ x ~r~ x ~T~ X ~T~ X r~ x nr *n x Beds* 

iiil *l H a| -I -1 -1 H| s| H e l -1 "II Hj=3*:r 

S x x Sprinklers 
" Sprinklers 
g r~ X ~T * 1 X 1 X 1- X r-X I X -1 pX r X 1 X r X r- X ..- X -. , X , Beds , 

1 1 -1 =1 "1 -1 "I -1 HI -1 =1 "1 "1 "II H^^S; 

(5 Sprinklers Section 

| | * 

CO "Q tO CO 

l|g Sprinklers x Sj^i-x-x-j-'!^ [ y ^ Beds I 

^J x x Knad ' ri J T ^ 

" Sprinklers X X x k x 

I - \ ^ \ - - 

o Sririnklpi'sv y w v * 

X X V i *>H e 
x \^ \x *" '*^- o R*rls 4 "5 

l rt |- .s 

- >> 

Section 3 Section 1 ^ 

Bed 4 ) | Bed 2 | Bed 4 J | Bed 2 _ 

3 (m 

2 ^itn. 3 4 | 

2 a f 4 ' 2 
c Section 6 

'~ S I - 

Section 5 

3 1 ' 

2 , 4 

1j IO 

5 i 





Center path 
with spray valves Sprayline 

Bed3 ^H Q II J > J 




Bed 2 || || I S 

Bed 1 ]| Jl J />] 60 - 

g Road 
t i , 

2 . Bedi =|| o>|[ _rj StoU ro 

Section I 

MJ < 


l|i II II 1 1 

-*: -szr-\r ii i. II * 

| U - - - " m 

g | 
^ ho co 


Sprayline S 




g Road 


B W * > ^ CO 2 



-92 - 

S I 

n-4 ' 


? "S 

1 g 

a OS 





; a 
: c 

J, " 
? 1 ^ 

3- c5 

















Block 7 

Block 6 

Block 3 

Block 2 

Block 8 

Block 5 

Block 4 

Block 1 

1 1 1 

! 1 








The same system is used at Mukutuma and Kafubu 
with slightly different spacing due to the existing 
sprinkler systems. See sketch 1 







o ~: 



O "; 





8 j 




^ : 


;O 2 


o " 

! o 

;O " 

io B 

o * 

ca -/^\ 
S ; , 

j o K 
io " 







i i0 i 

: "* 

o- 8 

1 !.o..J 

1 a 

o' j 


i ol 

1/2 load in 
middle of 
each section 


- 93 - 


J.C. Delwaulle 

Centre Technique Forestisr Tropical 
Nogent-sur-Marne, France 


Basic Research on Nursery Soil Mixtures 93 

Growing Seedlings in Nursery Beds vs. Pots 95 

Use of Pots 95 

Other Methods of Raising Plants 96 

Growing of shoot cuttings 96 

Direct sowing 96 

References 96 


Two contrasting hypotheses have been put forward for plant-raising in the particularly 
difficult conditions of the Sahel: 

1. Great care should be taken to raise vigorous plants in the best nursery 
conditions so that they can grow rapidly during the first rainy season 
and survive the following dry season* 

2. Nursery plants should not be given special care in the nursery y in order 
that they become used to the difficult conditions which they will 
experience in the field and in order that only the most resistant indi- 
viduals survive to be planted. 

In order to settle this question, trials were conducted in Niamey (Niger) in 1971 
involving the following nursery treatments: 


S1 - compost 

32 - black earth and sand 

S3 - sand 


F1 - no fertiliser application 

F2 - 2 g fertiliser applied per pot 

P3 - 4 g fertiliser applied per pot 

- 94 - 


W1 - limited watering 
W2 - average watering 
W3 - heavy watering 

Thus, by factorial combination, 27 different treatments were given, 
selected was Eucalyptus oamaldulensis 8298. 

The test species 

- These plants were planted out in the field in July 1971 in a cubic lattice design 
(3 treatments), 25 plants per plot, spaced 3 x 3 m, with three replications. 

Starting with the first season, important differences in rate of growth were dis- 
tinguishable, depending on the types of soil - 31, 32 or 33 and on the amounts of fertilizer 
applied, P3, P2 or P1. Ho clear difference was revealed as regards results due to different 
rates of watering. 

The conclusion was that good treatment of plants in the nursery is desirable because 
it helps the "take-off" of plants out in the field and guarantees better growth and better 
rate of take. 

Another experiment of the same kind, but in which the plants were followed only 
through the nursery stage, was undertaken in 1975 *t Ouagadougou (Upper Volta) . The test 
species was Eucalyptus oama Idulens i s and the trial involved seven different treatments 
using mixtures of sand, earth, manure (cow dung) and oompost in different proportions as 

1/4 sand 

1. 1/4 manure 

2. 1/10 manure 

The results as of 14 July 1975 were as follows: 

1/2 earth 
6/10 earth 




1/4 oompost 
1/10 oompost 

1/4 sand 
3/10 sand 
1/2 sand 

1/2 earth 
6/10 earth 
1/2 earth 
1 earth 

1 sand 


% of live plants 

height reached 

average height 





























The best results were obtained with the mixture: 1/4 compost, 1/4 sand and V2 earth. 
A definite depressive effect was noted when manure (cow-dung) was used, an effect which needs 
to be discussed, because there is "manure" and " 

Aside from the conclusion that it is worthwhile to provide good treatment of plants 
in the nursery, these results still refer to local sites and it would be necessary to 
determine the best mixtures for use on other sites, and to determine what are the possibili- 
ties of obtaining local supplies of potting media* 

- 95 - 

The points in the discussion of soil potting mixtures in Tree Planting Rpaotioes in 
African Savannas (PAO, 1974) are valid as broad principle; that is f the soil should bo 
relatively ligfrt and oohesive, and have good water retention oapaoity and a higjh organic 
and mineral matter content. The practical forester must never forget, however, that theee 
are only general principles and hie skill consists entirely in working out which mixture 
of materials available to him ie most appropriate for each site. 


Plants traditionally used for fore station purposes in the Sahel - Sudan sone are 
usually grown in seed beds, vis: nee* (Asadiraohta indioa) . cassia (Cassia siamea) . and 
gmelina (Qmelina arborea) . Since this simple method has proved satisfactory, no further 
experimentation has been done* Still it should be noted that potted plants have better 
chances of good "take 19 than those set out with bare roots, this being all the more true 
the harsher conditions are. By way of illustration, following are the survival 
rates for neem 6 months after planting in a trial conducted in Vigor in 1972 (total annual 
rainfall only 28 1 mm). 

Plants crown int 

Dat. of planting 
in the fild 

Survival rat. 































The results are particularly clear. They were obtained during an extremely dry year. 
When rainfall is more abundant these differences diminish; and when rainfall is on the order 
of 500 mm, no sharp differ enoes are found between the field survival rates of plants orig- 
inally grown in pots and those grown in beds and planted bare-rooted. Below the 800 mm 
isohyet, it is therefore normal to plant neem, Qmelina. Cassia, and Dalberaia with bare 
roots. It is, however, not impossible - and this is a matter for discussion - that one 
would be quickly led to advise the planting of euoalypts bare-rooted. 


The use of plastic (polythene) pots is now very common in the arid parts of Africa. 
The manual Tree Planting Practices in African Savannas (FAO, 1974) dwells a great deal on 
this point. 

In some oases the use of small pots, whioh is often advised and certainly makes for 
appreciable savings in transportation costs, may lead to the production of sickly and 
generally too small plants. The pots whioh we feel combine maximum advantages for many 
speoies have the following specifications* 

- 96 - 

Height: 20 to 25 om 

Diameter: 10 om 

Thioknesss 40 microns 

Color i preferably black 

Holes* approximately 10 9 the highest at 13 om from the seam. 

Rfcrtioular emphasis should be laid on the need to out away the bottom of the pot at 
planting time in order to eliminate our led roots at the bottom of the pot, which are a 
problem for many speoies. The plastio sheath obviously also has to be carefully removed; 
this point oan stand repetition because all too often bad plantings are the result of care- 
less methods used in removing the plastio pots* 


As there has been previous discussion on the growing of plants in beds, coverage 
here will be confined to the use of cuttings and direct sowing* 

Growing of Shoot Cuttings 

It is necessary to stress the great hopes vested in the growing of genetically 
selected Eucalyptus clones, mist propagated from shoot cuttings* The People's Republic 
of Congo has accumulated valuable experience in this field and it was intended that its 
research programme would lead to industrial plantations of Eucalyptus clones (whioh have 
perhaps already been started). 

Quite aside from the programme of genet io improvement of plants, which goes beyond 
the scope of this report, the multiplication phases comprise: 

- selection of plus trees from among improved speoies; 

- possible multiplication by grafting; 

- felling the grafted trees (above the graft) or plus trees to produce coppice 

- taking cuttings from among the sprouts (with consideration of the position 
along the branch) ; 

- determining what kind of soil is suitable for striking cuttings (very well- 
drained, inert soil like gravels); 

- definition of mist; 

- hormonal treatment; 

- pricking out of rooted cuttings; 

- possible establishment of clone banks for industrial-scale production of 
cuttings or for other research purposes (controlled hybridization, etc.) 

As regards the using of Eucalyptus cuttings for planting, note that the techniques 
devised in the Congo are rather local in*oharaoter; they are not suitable for use either 
in Tunisia, where other techniques have been worked out, or in Niger, where after 4 years 
of such trials the project was abandoned. 

Direct Sowing 

Mention should also be made of forest at ion by means of direct sowing in the field, 
but in the savanna this method is useful only in very special oases (e.g. Ana oar di urn and 
Acacia Senegal) as described by Laurie (FAO, 1974)* 

FAO Tree planting practices in African savannas, by M.V. Laurie. FAO Forestry 

1974 Development Paper Vo. 19. Rome. 

- 97 - 


JK Jackson 

Mate Sa Integrated Watershed and Forest Land Use Project 
Chiang Mai, Thailand 



Introduction 0,7 

Shade and shelter 0,7 

Weeding o,g 

Root pruning 0,3 

Grading 0,9 

Packing and transport 0,0, 

References 0,9 


Other lectures are dealing with sowing, soil mixtures, irrigation and protection, so 
the subjects to "be considered now are shading, sheltering, weeding, root pruning, grading 
and packing. 

The notes which follow refer mainly to plants raised in polypots as this is the most 
common practice in savanna regions* 


The use of shade in forest nurseries is a matter of considerable difference of opinion 
among foresters. In Jfelaysia for pines, seedbeds are shaded with a dense shade made from 
palm leaves, and after the seedlings are pricked out, a high shade is used for another 
three weeks (Paul, 1972). However in northern Thailand, where conditions are more severe 
than in Malaysia, shading pines after pricking out is only recommended during March and 
April, the hottest time of the year, and then only for three days after pricking (Granhof, 
1974). In Samaru, Nigeria, seedlings were usually unshadei though there was some mortality 
from overheating in the outside rows of blocks of polypots, and one experiment did show 
increased height growth of pine seedlings when these were grown under shade. Unfortunately 
the performance of the shaded and unshaded seedlings in the field was untested. Shading is 
needed for small seedlings sown in boxes or trays, but for pricked out seedlings, or 
seedlings raised by direct sowing into containers, shade, if needed at all, should be 
removed one to three weeks after sowing or pricking out. 


A number of different materials oan be used for shade. For seed trays a building with 
a translucent corrugated perplex roof suoh as is used in Samru, tfigeria, is very suitable 
though expensive. A special type of shade oloth f known as "Sari on" is used in Malaysia for 
transplant beds in the form of high shade about 2 m above the ground; the material used in 
felaysia transmits about 50 per oent of the light falling on it, but this shade oloth oan 
also be obtained in other shade intensities from 30$ to 95$. White ootton cloth has been 
used in Thailand. Often only partial shade is needed; this oan be made from laths, or 
bamboos 9 or corn stalks , separated so as to give about half shade. It is possible to 
fasten these together with wire or cord to form rolls. This enables the shade to be 
rolled up during the early morning and later afternoon y and also to be rolled up while the 
plants are being irrigated by spray lines or sprinklers. 

In areas exposed to drying winds, such as the harmattan of northern Nigeria, provision 
of shelter in the form of screens of mate or coarse cloth round the nursery is desirable. 
A hedge or windbreak of closely planted trees would serve the same purpose. Such shelter 
not only reduces the desiccating effect of the wind f but also by reducing the effect of 
wind on spray irrigation, gives a more regular irrigation pattern. 

Small seedlings sometimes need protection against heavy rains occurring at the begin- 
ning of the rainy season. Light oloth or polythene sheeting oan be used for this. 

Further information on nursery shade and shelter can be found in Laurie (1974) 


Hand weeding is still the commonest method in African savanna nurseries, but in Zambia 
the weedkiller "Gramoxone" is used. This might well result in considerable savings in cost 
(see Laurie, 1974* PP 126-127). Fumigation of the soil before the seed is sown oan greatly 
reduce the number of weed seeds in the soil; a full description of the method, using methyl 
bromide, is given in Appendix 5 to Laurie's paper. Weeds on paths etc. can be controlled by 
the use of a flame gun. 


If plants are grown in containers the roots will tend to emerge from the drainage 
holes into the soil beneath. The prupose of root pruning is to prevent this happening, as 
otherwise a long tap root is formed. The simplest method of root pruning is by lifting 
the pots and breaking off the roots; an improvement, when doing this, is to cut the roots 
with a sharp knife. Another method is to draw a piano wire between the bases of the pots 
and the soil. The method of air pruning, in which the plants are raised above the soil 
surface, so that when the roots emerge they are killed by exposure to the air, is described 
in Laurie, p. 98, where there are also descriptions of other pruning methods. Methods of 
root-pruning in boxes, and in undercut beds, are described on p. 94* 


About one month before the beginning of the planting season the plants should be 
graded and arranged in groups with the plants of approximately even size, while at the same 
time culls are discarded. Culls are plants which are excessively stunted, forked, or 
otherwise abnormal. They may also include oversized plants. If planting is to extend over 
two or three months the large plants should be planted first, and the rest as they success- 
ively attain a size large enough for planting. Otherwise an attempt may be made to attain 
more uniformity of size by reducing water to the larger plants, and increasing that to the 
smaller plants, and also possibly by application of fertilizers to the smaller plants. 

- 99 - 

Holding back smaller plants until they become big enough for planting has certain 
drawbacks, as these plants way be genetically inferior, or have been so checked in the 
nursery that subsequent growth in the field is poor. It is better to try to spread out 
sowing dates so that plants come to the right size at the time they should be planted out. 

The question of the best size of plants to use is a matter of some controversy, and 
little experimental work appears to have been done on this. There is some discussion of 
this in laurie, p. 99. It may be that a much greater range of sizes can be planted satis- 
factorily than is commonly thought. Certainly in Thailand excellent results have been 
obtained from one year old Pinus kesiya seedlings 30-40 cm high, though there the standard 
size is 15-20 cm. In India also Eucalyptus plants over 1 m tall are sometimes used. 

footers influencing the optimum size of plants include the size of the container, the 
severity of the climate, and the amount of competition by grass and weeds. Another factor 
which should be considered is that large plants will be more expensive to transport, and 
more likely to be damaged in the process. 


Packing of container- raised seedlings presents few problems. They are merely put in 
trays, and are loaded into vehicles. Wooden trays are sometimes used, but these are 
heavy, and trays made of wire mesh are preferable. A simple tray of wire mesh has been 
designed in Thailand, capable of holding 20 to 25 seedlings. These are provided with a 
spacer, so two or three tiers can be carried. This type of tray was designed so that it 
could be used in conjunction with a carrying frame, so that a labourer can carry two full 
trays on his back. This is very useful in mountainous country, where plants often have to 
be carried fairly long distances by human transport. 

It is important that the containers should be packed tightly, so that they cannot 
move. Lashing a rope over the containers is sometimes advisable, when carryings-distances 
are long. The vehicle carrying the plants should be provided with a tarpaulin shade, and 
should travel at a moderate speed. 

Bare-rooted plants should have the roots puddled in mud, and be packed in bundles of 
50 or so in a large polythene bag. 

Teak stumps are very easy to transport. Trials in Thailand have shown that plants 
stumped to about 2 cm stem and 15 cm root, with all side-roots removed, can be stored in 
boxes or trenches filled with dry sand for several months without losing their viability. 
Stumps are thus prepared in March or April, for planting in June. 


Granhof, J.J. Nursery technique as practised in the Pine project. Thai/ 

1974 Danish Pine Project. 1969-1974. Bangkok. 

Laurie, M.V. Tree planting practices in African savannas. *AO Forestry 

1974 Development Paper No. 19- Rome. FAO. 

Paul D.K, A Handbook of nursery practice for Pinus oaribaea var. 

-1972* hondurensis and other oonfiers in West TfeTaysia.~ UNDP/FAO 

FO: SF/MAL 12. Working paper no. 19 Kuala Lumpur. 

- 100 - 


Z.O. Morooh 

Federal Ministry of Industries 
Lagos f Nigeria 

M.A. Odeyinde 

Savanna Forestry Research Station 
Samaru, Zaria v Nigeria 

R.A. Qbadegesin 

Savanna Forestry Research Station 
Samaru, Zaria, Nigeria 



Introduction -j 1 

Areas of successes and failures 102 

Prospects of Pisolithus tine tori us 102 

Future lines of research 103 

Techniques of collection and inoculation 103 

Paper for Symposium on Savanna Afforestation 

- 101 - 


There are several record* in different part* of the world which show that exotic pine* 
usually fail to establish unless suitable ngroorrhizal fungi have been imported for inocula- 
tion purposes (Mikola f 1973)* This statement is also true for Nigeria where it has been 
shown that pine plantations cannot be established unless the seedlings have been infected 
by mycorrhizal fungi* 

According to Redhead (I974) t the first record of introduction of pine into Nigeria 
was in 1925 when Pinna longi folia Roxb. was introduced into the country from India. 

This and several other introductions in the following decade failed apparently 
because no mycorrhiza was supplied. According to Madu (l96?)t P-L halepensis Mill, and 
P. oanariensis Smith were tried in Naraguta nursery, Jos, in 1950 while P^ oooarpa was 
also sown in the nursery in 1951. In 1952 they were inoculated with soils collected from 
pine stands in Oxford and flown to Nigeria. These seedlings were planted out in Vom in 
1954 without any visible evidence of njyoorrhizal infection. Also in 1954 f P patula 
Schiede A Deppe and P^ radiata P. Don seed from South Africa was sown and inoculated with 
soil collected from P^ patula stand in Bamenda, Cameroons. Obese seedlings were also 
planted in Vom in 1954. The set of 1954 plantings in Vom were the first successful pines 
raised in Nigeria. 

Redhead (1974) quoting other unpublished records indicated that soil and fine root 
material was brought from Ndola Hill, Zambia, in 1959 and used to inoculate P^ insularis 
and P. kesiya. These and other one year old seedlings of P.. caribaea t P.. Patula t and 
P radiata previously inoculated with mycorrhiza soil and root material collected from 
Vom and Naraguta were planted out in Miango in 1961 

Since the establishement of the Miango plots, infected soil collected from there has 
been the normal source of inoculum for pines raised for plantation establishments in other 
parts of Nigeria. It is not very clear which of the original sources of inoculum succeeded 
but it is probably either the one from Zambia or the Cameroons or both. 

Attempts to study mycorrhizae, technically, in Nigeria were initiated by Olatoye 
(1966) who made some general observations on nycorrhizae of pines at Ibadan. He also 
noted that soil inoculum collected from under pines at Vom, Naraguta and Bamenda were 
suitable for inoculation purposes. Mikola (1968) visited Nigeria among other countries to 
study the importance of mycorrhiza in afforestation. He made a number of valuable 
recommendations for future work. Momoh (1970) noted that temperature and aeration probably 
played vital roles in mycorrhizal establishments. Later on he synthesized mycorrhiza of 
Pinua oooarpat using pure culture of Rhizopogon luteolus. The seedlings so raised were 
successfully grown in the field (Momoh, 1975) 

Redhead (1974) carried out a number of studies on iqycorrhizae in Nigeria, including 
some ect^r^hic ioc"tions. Ekwebelam (1973) as well as Odeyinde and Ekwebelam ( 1974) 
"so Se soe attempts to study ngrcorrhizae in Nigeria. They worked with ^ **" 
of mycorrhizae forming fungi with limited degrees of success. They found that Qenoriz 
(a mixture of different species of Boletus) and Coenococcum firanxforme promoted better 
growth of P^ oaribaea than the other fungi they worked with. 

Despite these various studies, the normal practice of raising pines in Nigeria is 
still using soil inoculum collected from established pine plantations. 

- 102 - 


With the current technique of using soil inoculum collected from under old pine 
plantations for the inoculation of seedlings, a reasonable degree of success has been 
achieved in the country. Pines have been successfully grown on the Jos Plateau (elevation 
1 200 metres), Mambilla Plateau (average elevation of about 1 600 metres) and Obudu Cattle 
Ranch Plateau (about 1 600 - 1 700 metres). Pines have also been grown fairly successfully 
at lower elevations in Afaka (600 metres) and Ibadan (about 180 metres). In the case of 
Ibadan, there are only 3-4 rainless months while in some other localities such as the 
Jos Plateau or Afaka f the rainless period can be of 4-6 months duration. 

In some localities such as Bida and Mokwa (elevation of about 140-160 metres and 
about 4-5 rainless months) , pines have almost always failed to grow successfully even 
after a successful myoorrhizal infection of the seedlings in the nursery. Die reasons 
for this are not yet completely known but it is suspected that certain soil factors and 
the soil temperatures in particular migjrt be a major factor. 

The sporooarps of Hhizopogon luteolus have been found in some plantations in the 
country (at elevations above 300 metres ) . Laboratory studies of cultures raised from 
such sporooarps showed the optimum growth of this fungus on Hagem agar as 23 C. In 
culture the fungus was incapable of growing above 34 C (Momoh y 1970). It is also known 
that the temperatures of the soil near the surface can sometimes be as hi gb or even higher 
than 34 C. When the temperature remains high in the desiccated soil over a prolonged 
period in the dry season Y it is not impossible that this might lead to the death of 
myoorrhizae and subsequent failure of the pines. 

In nurseries situated in dry areas of the country such as Samaru, Zaria, it is 
common to see dead inactive mycorrhiza on the sides of polythene bags facing the sun (in 
a block of bags) while the mycorrhiza remains active on the opposite side of the same 


Redhead was the first to import Pi soli thus tinctorius (Pers.) Coker & Couch into 
Nigeria. He got his cultures from Dr. Zak in Oregon, U.S.A. He tried to inoculate 
seedlings with this and other pure cultures of mycorrhizae fungi but did not get any 
infection. In his report, he (Redhead, 1974) noted that "None of the pines showed any 
sign of mycorrhizal development' 1 after 4 months. Redhead however gave some cultures to 
Ekwebelam who indicated that he had some successful inoculations (Etcwebelam, 1973)* Since 
Ekwebelam worked with many fungi under a closely packed situation, it was not clear if the 
reported success with some of the cultures was not due to contamination from others. 

Nevertheless, P^ tinctorius is known to be a very good mycorrhizal former in some 
hot zones of U.S.A., especially in Georgia* Both cultures and sporo carps of this fungus 
were therefore imported into Nigeria for further trials in the areas where other fungi 
like Hhizopogon luteolus initially introduced into Nigeria through soil inoculum had 
failed. Nomoh and Gbadegesin (1975) have described the introduction of this fungus and 
the successful initial experiments carried out with it. Successfully inoculated seedlings 
of Pinus oooarpa were planted out in the field at Miango, Afaka, Mokwa, Bida and 
Ejidogari. So far, the inoculated seedlings have continued to grow quite well* The 
fungus is also being inoculated onto P^ oaribaea for similar and more extensive trials. 
Eventually, it is hoped that "myoorrhizal banks' 1 of P^ tinotorius will be available to 
all pine growers in the country. 

- 103 - 

It is clear that P. tinotorius has great prospects in Nigeria* In culture it has 
its optimum growth at 30C and continues to grow at 42 G, while other known myoorrhizae 
fungi in Nigeria are incapable or growing at this high temperature. For example, IjU 
luteolus has an optimum of 23 C and dies at 34 C. Ofce rate of growth of seedlings inooular- 
ted with P. tinctorius is very much faster than what has been achieved with any other 
mycorrhizal fungi tried in Samara. The fungus also forms sporocarps very readily (Momoh 
and Obadegesin, 1975). Thus large quantities of pure forms of inoculum could be readily 
obtained through spore inoculation. 


In his studies Redhead (l968a & b) discovered that some indigenous Nigerian forest 
trees have ectotrophic nqyoorrhizae which is the type found in pines. These were Afzelia 
bella, A., afrioana, Braohystegia euryooma and Uapaoa togoensis. This fact suggests that 
there might be naturally existing fungi in Nigeria that might be capable of forming 
mycorrhiza with pines. Further studies in this respect are desirable. If suitable pine 
mycorrhiza fungi axe found in natural savanna lands y a new dimension might be introduced 
into pine inoculation problems. 

The current success of Piaolithus tinctorius will be pursued with vigour. The fungus 
will be introduced into various localities on a wider scale so that its inoculum can be 
available to all pine growers in Nigeria and probably elsewhere. The seedlings of pines 
already inoculated with ._ tinctoriue and planted out in the field will be assessed from 
time to time and more field trials will be set up. 


In the interest of pine growers , broad guide lines on mycorrhiza collection and 
inoculation will now be given. Further details can be found in earlier publications 
(Momoh, 1970 f and Momoh, 1974) 

Most foresters | tend to collect their inoculum from under old pine stands. This is 
very practiced. However, in areas with pronounced dry season, as is normally the case in 
savanna areas, the mycorrhiza in the soil may not be active all the year round especially 
at lower elevations. The inactive phase is the dry season which is also the usual nursery 
season. It is, therefore, necessary to carefully inspect the proposed site of collection 
to ensure that the mycorrhiza collected for nursery inoculation is taken from an area where 
the mycorrhiza is in its active phase. 

The mycorrhiza soil should be used as soon as possible after collection. The soil 
inoculum should not be allowed to dry out before use. Inoculation can be done ty mixing 
mycorrhiza soil with the sowing mixture or lay introducing a pinch of the inoculum into 
close proximity of the roots of the seedlings. 

Since excessive temperature can be detrimental to many mycorrhizal fungi, light shading 
migfct be necessary in very hot areas. It must however be remembered that excessive shading 
can lead to etiolation of the seedlings. 

Technically, pure culture inoculations are the best. They are however laborious 
and are normally limited to scientific research. Nevertheless, pure culture inoculations 
nan be used to establish mycorrhizal banks of desirable fungi. 

- 104 - 


After some initial failures, pines were successfully introduced into Nigeria in 1954 
after necessary uycorrhizal inoculations. There are now some promising stands of pines , 
especially P^ oaribaea and P^ oooarpa, in different parts of Nigeria. Pisolithus 
tinotorius appears to be a very promising fungus for the areas where pine growth is still 
difficult as a result of nycorrhizal fed lures. 

All pine growers in tropical savannas are advised to always ensure that their seedlings 
are well inoculated with suitable raycorrhizae before they are planted out in the field. 

Ebrcbelam, S.A. 

Nadu, N. 

Nilola, P. 

Nikola, P. 

Nomoh, Z.O. 


Mtornoh, Z.O. 

Nomoh, Z.O. 


Studies on pine nqyoorrhizae at Ibadan. Fed. Dept. For. 
Res. Research Paper (Forest Series) No. 18, 10 pp. 

The biology of ectotrophic inycorrhiza with reference to 
the growth of pines in Nigeria. Obeche Journal of Tree 
club, University of Ibadan 3. 9-18. 

The importance and Technique of iqycorrhizal inoculation 
in the afforestation of treeless areas. Final report of 
a study conducted under an AFA Andre Mayer Fellowship. 
Dept. of Silviculture, University of Helsinki. 111 pp. 

Application of mycorrhizal symbiosis in Forestry Practice. 
Ectomycorrhizae. Academic Press. Inc. N.Y. and Lend. 

The problem of mycorrhizal establishment in the Savanna 
Zone of Nigeria. In: The development of forest resources 
in the economic advancement of Nigeria. Edited by C. F. A. 
Onoohie and S.K. Adeyoju. Proc. Inaug. Conf. Forestry 
Association of Nigeria 1970. 408-415- Published 1972. 

The importance of mycorrhizae in pine plantations in 
Nigeria. Paper presented at Annual conference of Forestry 
Association of Nigeria, Jos, 1974* 

Synthesis of mycorrhiza of Pinus oocarpa Schiede. Annals 
of Applied Biology vol. 82. (In press). 

Momoh, Z.O. ft Qbadegesin, R.A. Preliminary studies with Pisolithua tinctorius as a 
1975 mycorrhizal fungus of pines in Nigeria. Fed. Dept. For. 

Res. Research Paper (Savanna Series) No. 37. 

Odeyinde, N.A. ft Ekwebelaro S.A. In search of a suitable fungus for pine mycorrhization in 
1974 southern Nigeria. Paper presented at Annual conference of 

Forestry Association of Nigeria, Jos, 1974. 

Olatoye, S.T. 

A report on mycorrhizal investigations (investigation 317). 
Dept. For. Res. Tech. Note No. 33, 11 PP* 

- 105 - 

Redhead, J.F. 

Redhead, J.F. 

Redhead| J.F. 

Ifyoorrhizal associations in some Nigerian forest trees* 
Trans. Brit. Jfcrcol. Soc. 51: 377-38?. 

Inocybe sp. associated with ectro trophic mycorrhiza on 
Afzelia bella in Nigeria. Comra. For. Rev. 47: 63-65 

Aspects of the Biology of mycorrhizal associations 
occurring on the trees species in Nigeria. A thesis in 
the Dept. of Agric. Biology, in partial fulfilment of the 
requirements for the degree of Doctor of Philosophy, 
University of Ibadan. 

- 106 - 



J.K. Jackson 

Mae Sa Integrated Watershed and Forest Land Use Project 
Chiang Mai 9 Thailand 


Introduction 106 

Container size 107 

Potting mixtures 10? 

Shading and mycorrhiza inoculation 106 

Conclusions 109 

References 109 

Table 1: Growth in plantation of seedlings raised in different 

sizes of bags 1 10 

Table 2: Effect of potting mixtures and fertilizers on growth of 

Eucalyptus carnal dul ens i s 111 


This lecture will deal mainly with results from experiments in nursery methods at 
the Savanna Forestry Research Station at Samaru t Nigeria* Nursery research formed a 
relatively small part of the programme, as satisfactory techniques for raising most of the 
important species had been found before the establishment of the station* These included 
the use of polythene bags for raising seedlings, the incorporation of dieldrin dust in the 
potting mixture to prevent termite attack on Eucalyptus , and the technique of pregermina 
ting seeds 9 especially of pines, in a mixture of sand and vermiculite. However, this is 
not to say that more research into nursery methods would not be desirable. Although the 
methods used are successful in producing satisfactory planting stock, it is certainly 
possible that even better and cheaper methods could be found* 

J/ Paper for Symposium on Savanna Afforestation 

- 107 - 

The main experiments undertaken were on container size, soil potting mixtures, and the 
effect of shading and different methods of inoculation by mycorrhizal fungi. 


The standard polythene bag used in northern Nigeria when full had a length of 25 cm 
and a circumference of the same length, and weighed, when full, about 1 800 g. Obviously, 
considerable savings in the amount of soil needed in the nursery, in nursery space, in road 
transport of seedlings, and in handling seedlings in the field could be obtained if smaller 
pots were used. Thus a number of experiments were undertaken to compare survival and growth 
in the field of plants raised in containers of different sizes* Results are given in 
Table 1; both survival and height were recorded nine months after planting. 

In the Eucalyptus trials, the smaller bags had little effect on survival, but caused 
some reduction in growth, which could possibly be tolerated* In the pine trials the 
smallest bags caused lower survival and growth, but there were no significant differences 
between plants raised in the two other sizes* 

Thus for pines 15 x 25 cm bags are satisfactory, but not the smaller ones, in the 
conditions of Afaka. This will save about 40 percent in weight* The smallest bags would 
give a much greater saving, as they are only 22 percent as heavy as the largest ones* 
Such bags are, in fact, used in Zambia but the conditions are not as severe there as in 
Nigeria. Under more severe conditions than those at Afaka, larger bags might be desirable* 


Different combinations of potting mixtures and fertilizers have been experimented 
with for Eucalyptus carnal dulena IB t E* gran dig hybrid, and Pinus caribaea* A full account 
is given in Jackson et al (1971)* Some of the more important results are given below* 

For eucalypts three rooting media were tried: river sand, sand mixed with rotted 
cow dung, and sand mixed with loamy top soil from Mairabo Forest near Zaria, both of the 
last two in the proportion of three parts sand to two parts of the other constituent* For 
both Eucalyptus species, tested germination was best in the sand and cow dung mixture, 
though there were indications that the cow dung increased mortality in *_ grandis hybrid 
seedlings, though not enough to offset the better germination* E^ camaldulensis showed 
little difference in germination between the sand, and the sand and soil mixtures, but 
germination of ._ grandis was slightly better in the sand. 

Subsequent height growth of both species was best in the mixture of sand and cow dung, 
and worst in the sand only. In the sand, growth was very poor indeed unless, in addition 
to phosphate, at least 0*9 gm of nitrogen per seedling were added to the potting mixture* 

The effect of phosphate was tested in only one experiment. At the rate of 3 leg of 
superphosphate per cubic metre of mixture, or 0*3 g of phosphorus per seedling, it 
increased the height growth of the seedlings from between two to four times, depending on 
what other nutrients were present* In other experiments this quantity of superphosphate 
was added as a standard procedure* 

There was also a very pronounced response to nitrogen, whether in the form of urea, 
or of hoof and horn flakes* At a level of 0*3 gfl of phosphate per plant, each additional 
gramme of nitrogen increased height growth of 96-day old E*, camaldulensis seedlings by 
17.8 cm. 

- 108 - 

The most rapid growth of eucalypt seedlings was obtained from a mixture of two parts 
of rotted oow dung, and three of sand, to which superphosphate at the rate of 3 kg/m3 and 
fertilizer at the rate equivalent to 700 g of nitrogen per m3 was added* However, in 90 
days this produced seedlings 50 cm higfc, which are probably over the optimum size for 
planting. Indeed, if cow dung is used in the potting mixture, satisfactory growth of 
seedlings can be obtained without additional nitrogen fertilizer. In the soil and sand 
mixture used, about 500 g per m3 of nitrogen equivalent would need to be added* Sand 
alone, even with the addition of fertilizers, gave generally poor results. 

Pinus caribaea differed considerably from the eucalypts in its responses, especially 
to nitrogen. There were two experiments. The first compared different mixtures of sand 
and topsoil in proportions of 5:0, 4:1, 3:2 and 2:3 respectively, combined with the 
addition of urea, at 0, 1 and 2 kg/m3 and superphosphate at 0, 1 and 2 kg/m3. The topsoil 
had a clay content of 16 percent, a nitrogen content of 1.16 percent and a phosphorus 
content of 75 PP*n. Survival was best in the 4*1 and 3:2 soil mixtures, but the mean height 
of survivors was much the same in all mixtures, except in the sand without soil, where 
it was markedly lower. Two kg of urea per m3 significantly increased mortality from 
an average of 14 percent to an average of 32 percent but the slight increase by 1 kg/m3 
was not statistically significant* Urea had negligible effects on the height growth of the 
seedlings. Superphosphate increased the mean height of 6 month old seedlings from 10,2 
to 17*7 cm, except in the pure sand, where effects were negligible: 1 kg of superphospate 
per m3 was as effective as 2 kg. The superphosphate, except in the sand, increased the 
percentage of seedlings with mycorrhiza visible to the bare eye from 33 to 66 percent. 
There was also better mycorrhiza production in the 4x1 and 3:2 sand soil mixtures, than 
in the pure sand or the 3:2 mixture. When no phosphate was added, over 60 percent of the 
seedlings were stunted and with yellowish needles, and even with the phosphate 35 percent 
of the seedlings grown in pure sand were of this type. In the other mixtures the number 
of these stunted seedlings was neglegible. 

The second experiment compared the effects of using topsoil (as above), compost, 
and cow dung in the potting mixture, at the ratio of 3 parts of sand to 2 of the other 
constituent, together with addition of urea at 0, 0.25, 0*5 and 0.75 kg/m3. In this 
experiment 1 kg of superphosphate per m3 of mixture was used throughout. The only 
significant effect was that the use of cow dung increased seedling mortality, and reduced 
height growth and the numbers of seedlings with mycorrhiza. Urea had negligible effects 
at all levels tried. 

Thus pines showed great benefits from phosphate, but 1 kg/m3 was sufficient. Added 
nitrogen (at least in the form of urea) had negligible effects at lower levels, and was 
harmful at higher levels. Cow dung also contained some substance injurious to pines. 

The harmful effects of urea on pines were also found in plantation experiments, 
where it greatly increased mortality. Thus a suitable mixture for pines would be sand 
and topsoil in the proportions of 4* 1 or 3:2, and as sand is easier to obtain than forest 
topsoil the former proportions would be preferable. One kg of superphosphate (or its 
equivalent in phosphorus) should be added per m3 of mixture, but no nitrogenous fertilizer 
is necessary or desirable. 


In general it has been found at Samaru that satisfactory nursery seedlings can be 
raised without artificial shade, though some mortality of the outmost seedlings in a block 
has been caused by insolation and heating of the black polythene bags. However an experi- 
ment was designed to compare the effect of shade, and of different methods of inoculation 
with mycorrhizal fungi, on Pinus oocarpa seedlings in 1970. 

Shade was provided by guinea corn (Sorghum) stalks tied in a roll, in two ways, one 
with the stalks as close together as possible, and the other with them separated to give 
half shade* No shade was the third treatment* Eight and a half months after pricking 

- 109 - 

out percentage survival in fall shade was 80, in half shade 82, and in the open 71. The 
differences were not significant statistically, but the test, based on only four degrees of 
freedom, was not very sensitive* Mean heights of surviving seedlings at the same age 
were 24* 1 f 24*0, 16*1 cm respectively, showing highly significant effects from shade* 

Hyoorrhizal inoculation was effected in the following waysz use of roots and soils 
from bags containing 1 year old seedlings of pine, chopped up and added to the potting 
mixture, at two months before the time the seedlings were pricked out, immediately before 
pricking out, and 45 days after pricking out (three treatments); use of topsoil from a 
Pinus oaribaea plantation immediately before pricking out, and 45 days after pricking out 
(two treatments); and no inoculation* Use of the forest topsoil either before pricking out 
or 45 days after, produced the best height growth, but mycorrhizal development was slightly 
better when the topsoil was added before pricking out* It is also much simpler to mix 
the topsoil with the potting mixture, than to apply it to individual seedlings in bags, so 
this method would be preferred on economic grounds* 


It is obvious that this research has only touched on a few aspects of nursery 
production, and even in the subject most studied, potting mixtures, considerably more 
could be done, in particular to find the cheapest satisfactory potting mixture* This 
might differ at different localities* Other important factors, at present little studied, 
include watering regimes; use of soil fumigants to control fungi and weeds, and herbicides 
to control the latter; and the optimum size of planting stock in relation to bag size, 
based on performance in plantations* Another aspect of nursery work needing study is how 
to organize and manage nurseries so that seedlings can be produced as economically as 


lyamabo, D.E. Practice and research in tropical nursery techniques* FAO 

1967 World Symposium on man made forests and their industrial 

importance, Canberra* 1:249-264* Rome. 

Jackson, J.K,, Experiments on nursery potting mixtures. Savanna For* Res* 

Brandes, H*W* & Stn., Samaru, Res* Paper No* ? 
Ojo, G.O.A* 

Laurie, M*V. Tree planting practices in African savannas* FAO Forestry 

1974 Dev. Paper No. 19, Rome: pp. 89-100. 

Ojo, G.O*A* & The use of fertilizers in forestry in the drier tropics. 

Jackson, J,K* FAO/IUFRO/International Symposium on Forest Fertilization, 

1973 Paris, 1973. 

- 110 - 







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- 111 - 
















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- 112 - 


A.V. Barrera 

Savanna Forestry Research Station 
Samaru, Zaria, Nigeria 


Introduct i on 11? 

Essential requirements 113 

Procedure of soil surveys 113 

Suitability classes for tree planting 114 

Bibliography 116 

Appendix 1: Office and field equipment for soil surveys 117 

Appendix 2: Comparison of sampling density, rate of progress and 118 

scale of systematic soil survey 

Appendix 3: Soil profile description 119 


Afforestation in West Africa is confronted by two important problems involving (1) the 
soil and (2) the climate. In this paper only soil will be dealt with although climate, 
which is intricately associated, will be mentioned as it affects the soil. 

Soil critically affects the growth of trees, and good growth requires that the soil 
be in such condition as to favor good root development. The seven important soil factors 
that affect development of tree root systems are: (1) depth, (2) texture, (3) structure 
and consistency, (4) moisture, (5) aeration, (6) soil fertility and (?) toxic substances. 
An ideal soil for the proper development of roots of trees, therefore, should: 

- be deep enough to serve as anchorage for the trees and allow for the 
storage of sufficient soil moisture; 

- have favourable texture, structure and consistency so that roots are able 
to absorb the needed moisture, nutrients and air; 

- have moisture in an available form throughout the year; 

- be well aerated (Aeration is correlated to soil texture, structure, 
oonsistenoy and depth of water table. Proper aeration is important in 
the metabolism of the plants and also prevents the formation of toxic 
substances in the soil*); 

- 113 - 

- be fertile (A fertile soil has the ability to provide the proper 
compounds in the required amounts and in the oorreot balance for the 
growth of plants when other environmental conditions are favourable); and 

- low in toxic substances (Any layer of toxic substances will limit soil 
depth by preventing the roots from developing downwards through the 
toxic layer.). 

In the Guinea zones of West Africa, the two principal limitations in soils affecting 
tree growth are: (l) soil depth and (2; soil drainage. In the Sudan zone, they are 
(1) availability of soil moisture and (2) soil texture. 

Soil conditions, however, vary tremendously from one place to another due to differ- 
ences in climate and living organisms acting on the different kinds of parent materials. 
Some soils are very shallow and others are very deep; some are very compact and hard, others 
are friable; some are high in fertility, others are low; some are very wet and others are 
dry, etc. Forest trees also vary in their soil requirements. One has either to choose the 
kinds of trees to suit the soil or to a certain extent, change soil conditions to suit the 
requirements of the trees. 

The scope of this paper is to show the procedures used in determining soil conditions 
in the field that will serve as a guide in selecting sites for afforestation. 


Site selection for afforestation purposes involves soil surveys, i.e. the study of 
soils in the field. Equipment both for the office and for the field is needed (see 
Appendix 1). Prior to field work, aerial photographs (stereoscopic pairs), maps and refer- 
ences covering the area under study for afforestation should be obtained. If aerial photo- 
graphs are not available, the soil surveyor has to make the base map himself. Needless to 
say, the aerial photographs should be of very good quality. Geological, topographical, 
physical, climatic and vegetation maps covering the area for soil survey are important 
prerequisites. References involving the geology, climate, geography, agriculture and 
forestry of the area of study, or nearby areas are also needed. 


Depending on the objectives, soil surveys can be classified as detailed, semi-detailed 
or reconnaissance. For site selection, a semi-detailed soil survey is required; this calls 
for mapping of soil units on a selected scale from 1:20,000 to 1:50,000 (see Appendix 2). 
The soil units used in mapping are series, types and phases. 

The field work starts by examining the soils along the roads; later traverses are made 
from several points along the roads. The characteristics of the soil profiles are studied 
in as many places as required using, as much as possible, the hydraulic powered soil corer 
mounted at the rear of a Land Rover truck. When the Land Rover cannot be used due to lack 
of accessibility, the soils are examined with the use of an hand auger. Pits one metre 
square by 1.5 metres deep are dug for the detailed description of a representative profile 
of each soil unit. One side of the pit facing the light is cleaned to show the horizons 
or layers. The boundaries of the different horizons are marked and their depths measured. 
The FAO Guidelines for Soil Profile Description (FAO, 1968) are used as the basis for 
describing the colour, texture, structure, consistence, pores, inclusions, presence of 
roots and reaction of soil in each horizon of the profile. The Munsell Colour Chart is 
used to describe soil colours in wet and dry conditions. The finger feel method is used in 
the field to determine soil texture, plasticity and stickiness. The soil reaction is de- 
termined using colour indicators (Chlorophenol red for soils with reactions between pH 5*2 
and pH 6.8 and Thymol blue for soils with reactions between pH 6.0 and pH 76). 

- 114 - 

Whenever possible, the soils below 150 cm depth are also examined with the soil auger. 
Soil samples from eaoh of the horizons studied are taken for mechanical and chemical 
analysis. Additional composite samples are also taken at random all over the area for 
fertility analysis. 

The trees, shrubs and grasses growing around the area of each pit described are 
identified. Likewise, other physical characteristics of the area such as relief, slope 
of the land, class of drainage, degree of soil erosion, stoniness, depth of water table, 
land forms, and animal activities are also noted. Prepared forms (see Appendix 3) for this 
purpose are used and the items recorded on the spot. The use of such forms prevents the 
possibility of some features of the land being overlooked. 

Soils with similar characteristics in profile development and external conditions are 
classified as a soil series and are given a geographical name. Lokoja, Afaka, Okene and 
Osara are some of the soil series described in the Guinea Zone. When the textural class 
of the A horizon is added to the series name, together they are called the soil type. In 
the case of the Lokoja soil series, the texture of the A horizon is loamy sand, thus, the 
soil type is Lokoja loamy sand. Sometimes within an area of a soil type, minor differences 
in characteristics may exist which are important only in soil management. This may be a 
variation either in soil depth, erosion, drainage, slope, or stoniness. In such a oase, a 
phase of the soil type is recognised, rather than separating such an area into another soil 
series. Thus, in the case of Lokoja loamy sand, some areas with relatively shallower soils 
than is normal for the Lokoja series, are named Lokoja loamy sand, shallow phase. 

The delineation of the boundaries of the soil series, types and phases are made 
directly on the aerial photograph using a wax coloured pencil. The lines made by this 
type of pencil can be erased with a medium type eraser. If it is desired to keep the face 
of the aerial photograph clean, an overlay is placed on the aerial photograph. The overlay 
has one matte surface where the soil data can be written on with a pencil or crayon. 
Boundaries of terraces, depressions, ironstone hills, eroded areas, inselbergs and escarp- 
ments are determined from stereoscopic study. Soil boundaries can also be determined on 
the photograph from the differences in tones of the vegetation, density of vegetation and 
colour tones of the soils. All soil information on the aerial photographs is transferred 
to the soil base map with the use of a Grant Projector. 

The base map becomes the draft of the soil map and this is given to a draftsman to 
make into final form for reproduction. The area of each soil mapping unit is determined 
and their relative extent is computed. 


The characteristics of each of the soil units mapped are further classified by group- 
ing into capability classes soil units with similar characteristics or suitability for 
plant growth and similar responses to treatment or soil management. There are five land 
capability classes defined for agriculture in Nigeria. These have been broadly related to 
plantability or suitability classes for tree plantations as follows: 

I. Very suitable: This includes land with deep and well drained soil where roots of trees 
can grow well down through the profile. The supply of soil moisture is adequate for normal 
growth. There is no impediment to mechanization. Trees adapted to the area respond very 
well to ordinary soil conservation practices. 

II. Modarat e ly suit ab le : This class includes; (l) land with moderately deep soil with 
good dra i nage ; ( 2 ) land with deep soil that is moderately well drained; and (3) land whose 
supply of soil moisture is somewhat limited for normal growth of trees. There may be a few 
impediments to root growth in the soil profile, such as slight salinity, but mechanization 
is possible. Simple soil conservation practices are needed. 

- 115 - 

Fairly suitable: This olaas includes; (1) land with moderately deep to shallow soil 
but well drained; (2) land with poorly drained but deep soils; and (3) land where the 
upply of soil moisture is often times a critical factor. Pew species of trees are adapt- 
able to the area, and the soil may be moderately affected by salinity. Mechanization is 
somewhat restricted due to some physical obstacles. Intensive soil conservation practices 
are needed. 

IV. Poorly suitable: This class includes; (1) land with shallow but well drained soils; 
(2) very poorly drained but with deep soils; (3) land with extreme climatic conditions; 
(4) land where mechanization is very difficult due to obstructions like boulders; (5) land 
with very hard and compacted soils; and (6) land whose soils are very severely eroded. 
Soils in the profile may be highly saline or alkaline, thereby adversely affecting the 
growth of many tree species. The choice of trees for planting in this class is very limited. 

V. Not suitable: This class includes; (1) land with very shallow or skeletal soils 
where the bedrocks are near or exposed on the surface; and (2) land with extremes of mois- 
ture conditions (too wet or too dry). Mechanization or planting of trees is not recommended, 

The suitability classes are determined from data on both the physical and chemical 
analyses of the soil units, taking into consideration the local climate. In classifying 
soils for plantability or suitability for trees, the soil surveyor should bear in mind that 
what constitutes a very suitable soil, cognizant of climate, should favour root development. 
He must then find out what constitutes the principal limitation and the intensity of the 
limitation on the use of the land being classified and from this select its place in the 
suitability classification. 

Rainfall of the area should be considered when one determines effective soil depth. 
Under similar rainfall conditions, site quality generally increases with soil depth. A 
100 cm soil depth with 1,270 mm of rainfall may be just as good a site as another with 
deeper soil receiving less rainfall. With restricted growing season rainfall (1,000 mm), 
a suitable soil depth is over 2 metres (Sarnie, 1973) 

Flint hit e, which is a very common characteristic of savanna soils, is often a limiting 
factor in soil depth, but the roots of some species of trees like Eucalyptus propincpa can 
penetrate 120 cm of dense plinthite. On the other hand, roots of Isoberlinia doka bend 
horizontally upon encountering the plinthite layer. Effective soil depth also varies 
depending upon soil textures, kind of clay mineral in the profile and the bulk density of 
the plinthite layer. An average bulk density of savanna soils is (surface soil) 1.55 g/cc ; 
those with 2.05 g/cc are impenetrable by roots of most species ( Sarnie, 1973) 

Soil fertility is another factor in site quality. Based on the results of chemical 
analysis, roots of endemic trees concentrate their growth in the upper part of the solum 
where soil fertility is much higher than the C horizon. This is generally true where the 
texture of the C horizon is coarse sand, as found in the Ejidogari Forest Reserve, Nigeria. 

Soil drainage is another limiting factor in tree growth. Preliminary studies on a 
soil catena at the Afaka Forest Reserve planted to Pinus caribaea, showed it to be progres- 
sively affected as drainage became poorer. However, in the case of Eucalyptus citriodora, 
E. saligna and E. teretioornis, these trees do not seem to be affected by seasonal drainage 

Eroded soils, iron stone outcrops and soil depth (effective depth) directly affect 
tree growth. Again, the preliminary studies made in the 1971 pilot plantation at the Afaka 
Forest Reserve on a 4-year old E. camaldulensis showed an average height of 9.8 metres on 
the non-eroded soil, and an average height of 4. 5 metres on the eroded parts of the plot. 
Similarly, in the case of E. grandis, the presence of ironstones affected their height 
growth by 2 metres over those where ironstones were not present. 

- 116 - 

Also in a soil catena at the Afaka Forest Reserve, growth of E. saligna during the 
first year was adversely affected by difference in soil depth (thickness of soil horizons). 
However, it appears that after subsequent years (3rd year) growth difference became gradu- 
ally less significant. In this case, effective depth is more important than soil horizon 
depths as a site quality factor. 



Guidelines for soil profile description, MI/70805, Land and Water Development 
Division, 53 PP- 

Sarnie, A.G.A. Contribution of rainfall to the moisture storage in some soils at Afaka 
1973 Forest Reserve, North Central State, Nigeria. Research Paper No. 25, Savanna 

Forestry Research Station. 

Plinthito can be a Uniting factor for tree growth, 
specially whon indurated and near the aoil surface. 
Sons ipooioB, howovor, are able to penetrate the 
plinthito and draw water from beneath. Horo Eucalyptus 
oloosiana roots pass through a 10 om thick plinthito 
layor about 60 om bo low the surface. 

- 117 - 

Appendix 1 

Office Equipment 

1. Stereoscope. This oan "be either the scanning or the mirror type but large enough to 
examine the full view of a 23 x 23 cm aerial photograph. This machine is essential in 
studying the physical features of the aerial photograph as it will reveal the landscape 
in its tri dimensional features. 

2. Pantograph (mechanical). Used for enlarging or reducing maps. 

3. Projector. Similar in use to the pantograph above, this is used generally for en- 
larging the features from aerial photographs to the scale of the desired map. This equip- 
ment, however, produces some distortion in the size of image, being a natural physical 
characteristic of the lenses. This distortion oan be corrected by proper manipulation of 
the machine. 

4. Planimeter. An instrument used to determine areas on maps. It registers the number 
of square units (usually square centimetres), so that by correlation with the scale of the 
map, the area of any soil unit can be determined. 

Field Equipment 

1. Soil auger. This is used to examine soils below the surface of the ground. It is 
usually provided with extensions and is able to dig down to 3 metres. There are various 
types to suit different soil conditions. 

2. Spade. To dig soil profile Pit or to get soil samples. 

3. Bronton compass with attached clinometer. The former to determine directions and the 
latter slope of the land. 

4. Munsell Colour Chart with supplements for use in the tropics. 

5. Geological hammer, with one prong chisel-shaped. Used to break rocks for examination, 
to break hard pans or for sampling small lumps of soil. 

6. Soil testing kit for pfl. The reactions of most soils in West Africa range from pH 35 
to pH 8.5, pH 5.0 to pH 6.5 being the most common. 

7. Trowel. This will be used to sample soils, especially in the profile. 

8. Broad blade knife. To examine and mark on faces of soil profiles. 

9. A 3-metre steel tape measure. To measure depth of horizons. 

10. Plastic bottle with spout. To moisten soils with water for examination with fingers. 

11. Hydraulic-powered soil coring machine. (Optional). This is a versatile machine which 
oan save much of the surveyor's energy. It can bore holes with augers to any depth as long 
as there are extension rods. It can thrust a steel coring tube through soft soil to get 

an undisturbed soil profile sample. 

12. Vehicle. For movement of personnel and to carry equipment, supplies and soil samples. 
A four-wheel-drive vehicle is preferable. If there is a hydraulic powered coring machine 
this has to be mounted on a pick-up truck. This vehicle should also be of four-wheel 
drive and provided with power take-off. 

13. Soil sample bags, either cloth or plastic. 

- 118 - 

Appendix 2 




























c6 CD C 

fe 6b e 

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O LT> O t O 

tt CD CH 

P, +* * 





S S S S & 




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1 f 

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LP\ lT\ ITN 

0=5 C^ 

O *~ -^ VO LTN T- 








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4 4* *rJ ti f> -H 

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>> >> J rt H o 

f^ fs 4* 4* 6 O 
> > ^ rH CO DCJ 





*- oj co ir\ o 

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E O 


x e 
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o> E 

rH OS 

CtJ 0? 



X LT\ 

-p CO 

f-. O 


> C 

O 0) 


P -P 
H (D 
0) ,0 

<D CO 

T^ Cl> 


C? S 

S * 

S rH 
5 rH 
CO Oj 


> CD 

P rH OJ 

C P> -H 

CD E 03 

CO 0) OX 

CD co ,ri 

& 0) 

0) rH 

^ *s 





0) O 

g P. 













-P CO 


0> rH 

CO (rt 

O P 


e; H 

'H CD 

S) o 


CD -H 

^ g -H H 

- 119 - 


Appendix 3 


Profile No. 



Looat i on 




Phy B i ography 

Slope and Aspect 





Or. Water 

Root Distribution 











- 120 - 


D*E. Greenwood 

Division of Forest Research 

Kitwe, Zambia 

The objectives of ground preparation in savanna conditions are summarised in 
Chapter 9 of Laurie (1974). The choice of methods by which to achieve them will depend 
on local conditions and on the results of local research and user trials* 

The factors to be considered in choosing between hand and mechanical methods are 
also stated in Laurie but an additional factor which has arisen fairly recently is the 
rapid rise in the price of fuels and oils a rise which seems likely to continue* This 
seriously affects the relative cost of mechanical operations, not only directly, by 
increasing the cost of carrying out the operations but also indirectly, by increasing the 
cost of the machines themselves, their spares and their transportation* In some countries 
the cost of labour is also rising, but usually not nearly enough to maintain the relative 
costs of hand and mechanical operations* 

Where the supply of labour is inadequate, or the time available is too short, for 
hand methods to be practicable, there appears to be little alternative to mechanical 
methods of clearing* In view of the already enormous and still rising costs, however, 
further thought needs to be given to the situation* Several approaches are possible. 

(a) Recoup some of the costs of the clearing by making another use of the land before 
raising trees on its 

(i) utilise the standing timber before clearing takes place or after knocks 
down e.g* producing veneers from selected stems, chipping or pulping, 
producing charcoal efficiently on a large scale in kilns (these processes 
also affect the clearing costs, mostly favourably); 

(ii) hire the land out to a commercial farmer for the production of agricul- 
tural crops for one or two years (strict contract conditions necessary); 

(iii) produce agricultural crops on the land using paid forestry labour. 

The practical, technical and economic aspects of these schemes need careful 
study; field trials, and in some cases research, are essential* 

(b) Devise cheaper methods of doing the present jobs 
(i) Use lifter machinery 

Whether this is practicable or not depends very much on the density of 
the bush and the average size of trees to be dealt with* If the bush is 
light enough then lighter machinery can be used* Not only is this 
cheaper to operate on the clearing process itself but such machinery can 
be economically used on other forestry jobs during the remainder of the 
year, thus reducing the capital costs to be charged to the land-clearing* 
The Himbia project described by Laurie (1974) has shown that the job can 

- 121 - 

It cannot be too strongly emphasised, however, that where the tree cover 
is heavy, calling for machine* such as Caterpillar B-7 1 * and B-8'0 9 then 
it is no economy to try to "make do M with lighter machinery* At best, 
you will end up with greater expense owing to delays and breakages; at 
worst | you may find yourself with broken machinery and the job unfinished* 

(ii) Use new types of machinery 

Machines such as the Hydra stumper and Tree Extractor, which are mounted 
on wheeled tractors and are said to be able to pull up the whole tree by 
the roots, have recently been publicised and demonstrated. The published 
results of the demonstrations have been difficult to assess owing to lack 
of data about the trees concerned and the time taken* The only demonetra- 
tion in Zambia so far convinced the audience that the machine was not 
likely to be of interest to the Industrial Plantations Project* It was 
too slow and did not appear able to cope with trees of the size we are 
usually dealing with* It might be of use to have around, however, for 
cleaning up operations and migfrt even have a use in small-scale clearing 
operations in areas of light woodland* 

(c) Eliminate parts of the present job* 

(i) The windrowing could be eliminated to a large extent if more charcoal 

were made or if the wood could be chipped (as already mentioned this could 
also bring in revenue to help pay for the knock-down). To do the job 
within the season, however, charcoal would have to be made in kilns* 

(ii) Alternatively, the knooked-down timber, instead of being windrowed could 
be left in situ and burned in the late dry season* Two such burns would 
be necessary, however, and there might still be a difficulty in getting 
the larger logs to burn* On many soils a heavy growth of Hyparrhenia 
and Loudetia species can also arise* 

(iii) Omit the ploughing, research in Zambia has shown that this ploughing 
is not strictly necessary. However, the maintenance of the crop in a 
clean-weeded condition during the first year JLB necessary, and if the 
land has not been ploughed the first-year weeding will be much more 
expensive* So these costs have to be balanced against each other, not 
forgetting the possible saving in capital investment in heavy ploughs. 

(d) Re-examine the need for the present complete clearing of the land. 

(i) Methods of ground preparation which were written off as failures in the 
early days of exotic plantation silviculture might now be modified to 
produce a viable plantation* New factors favouring this include the 
ability to produce high quality nursery stock, the development of chemical 
methods of bush killing and weeding, and the development of stump- jump 
ploughs and harrows* 

(ii) Research in several directions is in progress or planned in Zambia, but 
the applicability of results elsewhere can only be determined by local 
triads and costings* Successful establishment is not the only consi- 
deration the overall effect on growth rates will influence the final 
cost of the plantation* The saving on land clearing has to be balanced 
against a possibly longer rotation and other incidental costs* 

- 122 - 

The essentials of the various methods of clearing by hand and by machine are 
described by. Laurie (1974) and do not need to be repeated here* If hand methods are 
used, then getting the job done is a straightforward matter of organisation and administra- 
tion* If mechanical methods are to be used, then the situation is more complicated (quite 
apart from the considerations discussed above v decisions on which have to await the results 
of field trials and research)* This is particularly the case where the woodland is heavy 
and demands the use of heavy machinery which is expensive enough when in use but most 
uneconomic if lying idle a large part of the year* 

Zambia's Industrial Plantations Project has been lucky in the past in having in the 
country a contractor with the necessary heavy equipment and with a lot of experience. This 
is now changing in Zambia and may never be the case in other countries* In such cases then, 
several courses of action may be possible. 

(a) join forces with another government agency which already does land-clearing 
for agriculture and/or road making. The addition of a forestry contract 
could help to make their operations profitable* 

(b) encourage private enterprise with some sort of initial loan or subsidy to set 

up a land clearing unit, the government support involving some form of contractual 
obligation to undertake government's clearing programme* The promotion of one 
large company on which government then becomes dependent has many drawbacks* It 
may be better to support several smaller enterprises which could each do part of 
the work* This has many advantages but is only practicable if the total land- 
clearing work required is large. 

(c) acquire a land-clearing unit for the plantation project. This is not likely 
to be undertaken since to make it viable, it may be necessary to hire out the 
unit for other landclearing or road-rooking projects* 

Whatever methods of landclearing may be chosen from these currently known to be 
effective y the operation will take a fairly high proportion of the costs of plantation 
establishment in savanna areas. Nevertheless , the growth rates attainable are such 
that in countries where the demand for timber is high, local supplies inadequate and 
imports increasingly expensive , plantation grown timbers will still be able to compete 
in the market at a price which gives a reasonable rate of return on the investment. 
Furthermore, preliminary results in Zambia at least show that it may yet be possible to 
devise other methods of clearing which will reduce the overall cost. 


Laurie y M.V* Tree planting practices in African savannas* FAO Forestry 

1974 Development Paper No. 19* Rome, FAO* 

- 123 - 


T.Q. Allan 
Forestry Department, FAO, Rome, Italy 

E.C.C. Akwada 

Savanna Forestry He sear oh Station 
Samara, Zaria, Nigeria 



Definitions 124 

Int roduct i on 1 24 

Land Clearing and Preparation Operations 125 

Environmental Factors: Climate and Vegetation 126 

Investigation and Results 127 

Knockdown and stumping 127 

Single tractor knockdown 128 

Hand stumping 128 

Windrowing and hand piling 129 

P re planting cultivations 129 

Conclusions 130 

Appendix Ai Basis of costing tractors, equipment and labour operations in 

land clearing preparation 133 

Table 1: Estimated 1975 knockdown rates and costs in Nigeria 135 

Table 2: Estimated 1975 windrowing rates and costs in Nigeria 136 

Table 3: Estimated 1975 costs for pre-planting cultivation 137 

Table 4: Estimated operating cost per hour for selected mechanical equipment 138 

I/ Paper for Symposium on Savanna Afforestation 

- 124 - 


In relation to land clearing operation* the following terms and abbreviation* are 
uaed in the terfct 

(i) "Operating time 91 (O.T,) for a tractor unit operation in the total working 
time in minutes per specific area or unit, and is calculated by adding 
working y minor stop and turning times, 

(ii) "Basal area" (B.A.) of a tree is the area of the cross section of the stem 
at breast height (b.h.), or at 127 cm (4 ft 3 in) above ground level. 
The basal area of a crop or vegetation type is the sum of the cross sectional 
areas of its constituent trees and is often expressed as the total basal 
area per unit land area (e.g. square metres per hectare, m 2 /ha). 

(iii) In relation to costings, decimal currency based on the Nigeria ffaira 00 
was introduced w.e.f. 1 January 1973 and is used in the text. Rate of 
exchange as at 1 October 1975 *** 

V1 (Haira) - US $1.626 
10.615 - US $1.00 


Land clearing in the savanna region requires the removal of the natural woody vegeta- 
tion cover for a specific purpose. As the removal of woody vegetation constitutes a major 
ecological change, it is essential to carefully survey and plan the use of any site, so 
that only those areas which will be adequately developed within a reasonable time are 
cleared. Land liable to erode should be neither cleared nor cultivated without planning 
adequate measures to prevent soil damage* In forestry, the main reason for land clearing 
is to remove woody material which would obstruct or hinder site preparation cultivation. 
Except for a few small and special sites, successful establishment of forestry plantations 
in the savanna region requires clean weeding (FAO, 1974; lyamabo and Ojo, 1971)* Main- 
taining clean weeding regimes, except on a minor scale or where taungya is possible, 
necessitates a high input of mechanical cultivation. For efficient mechanised weeding, land 
should be free of all surface woody vegetation and of all roots and stumps to the maximum 
depth of penetration of the weeding implements. To achieve this state requires the stumping 
of all standing trees and the disposal of all stumps, roots and other woody debris from the 

For generally small-scale plantation development, land clearing using labour and hand 
tools is the oldest sad most common method in Vigeria. Initial studies of land clearing 
costs for a range of sites indicated that they were some 30 to 70 of total establishment 
cost, which represents a major initial investment. An early mechanised knockdown trial 
using crawler tractors and an anchor chain was completed at Afaka in the northern Guinea 
one in December 1965* The trial, which took place some two months after the end of the 
rains, showed up some of the initial problems of tractor operation but indicated that 

was possible and that further investigation should be considered. Further mechani- 

sed clearing and preparation work was recorded by Barret (1968 and 1970) at Himbia in 1968, 
where even with a high level of mechanisation, land preparation costs comprised 50J6 of 
establishment costs. He also noted that there was little difference between hand or 
mechanised clearing oosts at that time. Sinoe that exercise, however, labour costs have 
risen 340?C and tractor operating costs 40jf to 100J&, a tread that Barrot forecast although 
it is unlikely he anticipated the actual pace of increase. Land clearing is not difficult, 
given adequate labour or suitable tractor power, but the area requiring elucidation relates 
to that method or combination ef methods, which will give the best results under specified 

- 125 - 


Land preparation for plantations in the broad sense consists of the following main 
operations (Allan and Akwada, 1974; Caterpillar Traotor Co., 1970a)t 

i) Stumping or mechanised knockdown 

ii) Windrowing or hand piling 

iii) Cleaning up 

IT) Burning 

V) Laying out 

vi) Preplanting cultivation. 

Such activities as cleaning up, burning and laying out have not as yet been studied 
in detail. There is, however, a considerable range of techniques for carrying out the other 
operations enumerated. The following are the main methods studied for plantation develop- 
ment in Nigeria. 

Stumping is mainly by casual labour; the main tools are the native hoe and axe. The 
operation involves excavation, cutting of roots and felling of the main trees. Mechanised 
knockdown may be by single tractor or by a chaining unit. In the single tractor technique 
a crawler tractor uses a bulldozer blade to push over standing trees. There is little or 
no digging of soil. The method is adequate bat capable of improvement. Chaining employs 
two or three heavy orawler tractors with front mounted blades or rakes and a heavy anchor 
chain rear-hitched between two of the tractors. The chaining tractors advance in parallel 
15 to 25 m apart depending on the density of the bush y and the trailed chain pulls down a 
swathe of trees behind the tractors. In heavy bush the third, or back-up , tractor, equipped 
with a tree stinger, supports the forward tractors by pushing over any large trees which 
hold up the chain. In efficient operations the impact of the chain extracts a high pro- 
portion of the main and lateral roots. 

If the stumped or knocked down trees cannot be sold as firewood or processed as char- 
coal, then it is necessary to windrow or pile this woody debris on site for burning. Wind- 
rowing of the debris into linear heaps, commonly 40 to 50 m apart, is usually done by orawler 
tractors equipped with front end rakes. In undulating terrain the windrows are usually 
sited roughly on the contour. Hand piling necessitates cutting the debris into manageable 
billets and packing these into tight piles or heaps for burning. 

Cleaning up can be defined as an operation following windrowing or burning in which 
any stumps, roots or other woody debris which remain in or on the soil, are gleaned from 
the area and added to the windrows or are heaped separately. Burning of the debris is a 
straightforward activity requiring only consideration of timing relative to season and time 
of day. 

The operation of surveying, pegging and beaconing the plantation layout including 
roads, rides and compartment at ion is designated laying-out. 

Pre-planting cultivation consists of two main activities: pioneer ploughing and 
harrowing. Ploughing following clearing is designated a pioneer operation because it 
involves breaking-in land for the first time. Such newly cleared, sites are much harsher 
and more difficult to cultivate than developed agricultural land. A ploughing depth of 
23 cm is probably just adequate, but a depth of 30 cm or more is preferable. Heavy duty 
harrow ploughs and conventional mounted disc ploughs allow satisfactory ploughing cultiva- 
tion. The object of pro-planting harrowing is to create a favourable environment for 
planting, which it should immediately precede. Such harrowing creates a tilth which 
facilitates planting and tends to level the land. Qy clearing the area of all weeds and 
vegetation there is greater latitude in planning subsequent weeding and the number of first 
season weedings should be reduced. This cultivation requires only 15 cm penetration and the 
operation can be effectively executed by a range of heavy and light harrows. Timeliness is 
often of greater consequence than economic efficiency in these cultivations. 

- 126 - 


There are many variables which affect land clearing and preparation investigations 
and without numerous replications it is difficult to measure the effect of, or allow for, 
such factors as soil, topography, labour or operator efficiency. The two main environ- 
mental variables to which work must be related are climate and vegetation (Allan and Akwada, 

Climate affects many facets of land preparation. Pry season mechanised knockdown 
tends to result in numerous above-ground tree breakages and the subsequent removal of broken 
stumps can be an expensive operation. An investigation in northern Guinea savanna to re- 
late tree breakages to rainfall, indicated that after some 100 mm of rain had fallen at the 
beginning of the rains, breakages ceased to be significant. At the end of the rains after 
the last significant recorded rain, there remains some twenty daya when effective knockdown 
free ef breakages is possible. Hand stumping outputs also tend to be greater during the 
rains when excavation is easier in moist soils; this factor also has a significant effect 
en adequate ploughing and penetration. Rainfall and temperature affect the timing of wind- 
row burning* Climate is critical to the whole land clearing and preparation cycle, and the 
following is an outline of the sequence of operations, assuming that land cleared during 
one wet season will be planted up at the beginning of the next. 

Season Operation Relevant month at 

Afaka Forest Reserve 

Start of rains after Commence knockdown or stumping. early June 
100 mm recorded Windrowing, oleaning-up and 

ploughing between windrows may also 

begin during this period. 

20 days after end of Stop knockdown. Complete windrowing. mid Hovember 
rains Clean up between windrows. 

Etad of dry season Burn off windrows. March 

Beginning of rains Complete ploughing. Harrow before April/key 


Start of rains after Commence planting. Commence knock- early June 
100 ami recorded down and ploughing for following 

year's planting area. 

The first column indicates the timing of operations relative to rainfall for any part 
of the ligerian savanna and the third column simply converts this data to calendar months, 
in this instance, for Afaka Forest Reserve, but similar conversions could be made for any 
other station with adequate rainfall records. 

In the savanna, density of woody vegetation is variable not only between climatic 
ones but even within a rone or ecological type. The density or volume, including the main 
root system of vegetation, is the faster critical to land clearing productivity. Outputs 
expressed as time per unit area (minutes/hectare) do not give sufficient indication of true 
performance unless the vegetation in the area is markedly unifoxn in density. Accurate 
determination of volume is difficult and time consuming. Investigations, however, have 
shown basal area (BA, expressed in m 2 ) to be a useful, aad relatively easy to determine, 
unit for measuring productivity or comparing efficiency between different types and densities 
of bosh cover* As laad clearing records are built up and given basal area per hectare, 
average tree height and type ef vegetation for a particular area, it should be possible to 
give aft estimation of the rate ef productivity for a particular clearing technique. 

- 12? - 


Following studies of past records and current methods of land clearing and prepara- 
tion up to 1971 1 a subsequent series of trial* and investigations waa set up to determine 
tho relative efficiency of a range of method*. These triala covered knockdown, stumping, 
wiadrewingt piemaer ploughing and pro-planting harrowing. 

To determine tho oomparatiTo ooonomioa of tho various mothoda investigated, ooata 
have boon applied. Tho basis of costing ia indicated in Appendix A and in greater detail 
in Allan and Jaokaon (1972) f Allan (I973a and 1973*) and FAO (1965). Tho ooata aro valid 
for comparison, but where more relevant data ia available, auoh figures may bo fod into 
ooat calculation* to make tho reault more meaningful to local condition*. Tho ooata aro 
baaed on reasonably efficient government operation ooata excluding management overhead* 
or equipment movement charge*; to u*e tho data for commercial typo operation*, oatimatoa 
for inauranoe, licencing and profit margin* would nood to bo added. Tho fact that all ooata 
aro hiatorio ia particularly evident in tho proaont inflationary era. To render tho 
evaluation* comparable and up to date, all ooata in tho text have boon recalculated on tho 
baaia of 1975 labour rate* and machine ooata in Nigeria. In relation to tractor*, thia ooat 
concept doe* not allow for tho fact that 1975 equipment tend* to bo more powerful with 
greater production potential than paat model*. Labour contract ratoa have boon doubled on 
tho baai* of tho 100 riao in direct labour ratoa but thia may not prove to be the oaae in 
practice* The main object of theae coat evaluation* i* to indicate management optiona and 
provide a reasonable baae for planning and budgeting. 

Knockdown and 3t itm ping 
A number of knockdown and atumping investigation* were aet ups 

(a) In the northern Guinea zone 

(i) To evaluate hand atumping and aingle tractor knockdown 
(Allan and Jackson, 1972; Allan and Akwada, 1973); 

(ii) To evaluate chaining and aingle tractor knockdown (Allan, 197 3a; 

Allan and Akwada, 1974*; Savanna Forestry Reaearch Station, no date); 

(iii) To evaluate a range of equipment for mechanised knockdown (Allan 

and Jaokaon, 1972; Allan, 1973a; Allan and Akwada, 1974a and 1974b) and 

(b) In the aouthern Guinea zone 

(i) To evaluate chaining and contract hand clearing in heavier buah 
condition* (Allan and Akwada, 1974b). 

Table 1 sets out ooata and operating time* (O.T.) per hectare and per square metre 
of baaal area (nrBJL.) for a aeleoted range of triala. 

In chaining, trial 1 at a unit ocat of 90.47/m represent* a high level of efficiency, 
whereaa trial 2 with unskilled operators and leaa serviceable tractor* gave poorer efficiency. 
A reasonable cost efficiency would be in the order of sT0.62/u 2 . Trial 3 attempted to lower 
power range and cost by using lighter tractors. Excessively wet 'conditions at the time cf 
this trial caused flotation and traction difficulties, which adversely affected the results. 
The trial showed that a lighter chaining unit could clear the bush but that there was no 
saving in costs the trial requires repeating under more favourable climatic conditions. 
Trial 4 took place in heavier aouthern Guinea vegetation with average basal area 21% greater 
and average tree height 5056 more than that of the first trial in northern Guinea vegetation. 
The trial was of median efficiency and the unit cost of 90.99/n compares with the average 
ef that of tho first two trials if a factor of 1.5 is applied to allow for the greater 
volume of woody debris. All of these results compare favourably with the introductory 1965 
trial, where the estimated unit cost would be in the order of M330/m 2 . 

- 128 - 

Single Tractor Knockdown 

The single tractor knockdown trials 5, 6 and 7 gave comparable results with variation* 
mainly attributable to difference* in operator efficiency; an anticipated average cost 
efficiency would be H1.50. Trial 8 using a larger tractor reduced oort efficiency lay 28$, 
indicating that by the nature of the operation the additional power could only affect oort 
efficiency adversely . Barret's 1968 trials gave figures of 926 to V10l/ha but are not 
directly comparable as density of vegetation was not calculated. The general quality of 
stump extraction was high. 

Trial 9 showed that hand stumping in northern Guinea vegetation required 7*7 man-days 
per m or 65 man-days per hectare with an average basal area of 8.55 m^/ha. The work was 
hard and the unskilled labour found it arduous and tiring* The tools used were adequate to 
the skill of the operators but try no means ideal for the job. The unit cost efficiency of 
914.66/m 2 could be considered average* Trial 10 with a cost efficiency of M22.86/m 2 in 
southern Guinea vegetation, is comparable with the previous trial if the factor of 1.5 is 
again applied. 

When comparing the mechanised techniques with hand stumping in the northern Guinea 
zone, it is obvious that chaining is the most efficient, the unit cost being 4.2$ that of 
hand labour and single tractor knockdown 10.2$ of hand labour. Similarly, in the southern 
Guinea, chaining costs are only some 4*3$ of hand stumping costs. Expressed as area per 
unit cost, the same data indicates that for the cost of clearing 1 ha by hand, 10 ha may be 
cleared by single tractor or 27 ha by chaining in light savanna; the ratio is 1:23 ha in 
southern savanna. It should also be noted that mechanised operations tend to extract a 
greater volume of root and the general quality of stumping is greater than hand operations. 

These figures indicate the cost efficiency of options open to management and for a 
particular project should be related to scale and timeliness of operation. To justify the 
setting up of a chaining unit, there would have to be a large scale clearing programme for 
a number of years. Even very large programmes can be done by hand labour, but (1) the 
labour and supervision must be available when required and (2) the social benefit of pro- 
viding employment has to be weighed against the oost benefit of using more economic alterna- 
tives. For smaller scale programmes, when the oosts of moving equipment are considered, 
there are occasions when hand or single traotor clearing may prove the less expensive 

Timely completion of clearing is important as it affects such subsequent operations 
as windrowing, ploughing and planting. It has been observed that planting as early as 
possible in the rains improves and expedites establishment. Timeliness in clearing depends 
on the rate of productivity, which is itself dependant on available working time and the 
resources which can be applied to the work. For example, from Table 1 the following produc- 
tivity rates provide a basis for determining options on how work might be completed relative 
to time and resource st 

In an average 6.5 hour working day in northern Guinea savanna 
(i) 65 labourers can stump 1 ha; or 

(ii) a 65 horsepower crawler traotor can knockdown 2*95 ha when a 
time loss is allowed for rest and maintenance; or 

(ill) a .< -tfl unit oan knockdown 33*2 ha when allowing a similar 

time loss. 

Similar figures can be readily calculated for other operations and cones. It should 
be noted that the mechanised peratienal day may readily be extended whilst maintaining a 
go+d rate of productivity; whereas hand labour productivity tends to fall off when the normal 
work period is extended. 

- 129 - 

Windrowing and Hand Piling 

The arias of windrowing trials, which used a range of available equipment, under- 
lined the superiority of the front end rake over the bulldozer blade (Allan and Jackson, 
1972; Allan and Akwada, 1974b). The front end rake causes little aoil disturbance and con- 
sequent ly windrows contain less soil and burn more freely. In the heavier savanna bush an 
investigation was set up to compare the efficiency of linear windrows or irregular heaps. 
In the latter, the debris is stacked round the larger trees, theoretically reducing the 
volume of debris to be moved. Any difference in cost efficiency was negligible, although 
on the credit side the heaps appeared more tightly packed for burning, whilst on the debit 
side cultivation in the irregular pattern created by heaping was difficult but is readily 
feasible between windrows (Allan and Akwada, 1974b). The general optimum spacing for wind- 
row* was 50 m apart. 

Table 2 records the rates and oosts for selected windrowing and hand piling trials. 
In lighter savanna, trials 1 and 2 using different makes of tractor, record similar results 
and indicate an average unit cost of 11.44/m 2 . Trial 3 showed that in this vegetation, 
increased tractor power did not improve cost efficiency. In the heavier southern Guinea 
vegetation using a heavy tractor, the increased volume of debris, as would be anticipated, 
increased the unit cost to 11.98/is . 

In all oases mechanised windrowing was considerably more cost efficient than hand 
stacking and mechanised oosts were between 92jf to 11. 7^ of corresponding hand oosts in 
different densities of vegetation. Thus, for the cost of stacking 1 ha by hand, some 8 or 
12 ha may be windrowed by tractor in the southern or northern Guinea zones, respectively. 

Pre-planting Cultivations 

Total cultivation by hand labour is possible in small scale plots, but observations 
indicate that oosts are so high and, perhapa of greater importance, the quality of cultiva- 
tion is so poor as to preclude large scale hand cultivation as a reasonable possibility. 
Trials have shown that oxen may be successfully used to cultivate small scale plantations 
but the practical development of oxen power for plantation cultivation would take consider- 
able application and time. The main practical cultivation alternatives lie in different 
types and powers of tractor and a range of ploughs and harrows. Table 3 records unit oosts 
(V/ha) for a selected number of ploughing and harrowing trials. Some of the productivities 
recorded are averages from extensive investigations (Allan, 1973b; Savanna Forestry Research 
Station, no date). 

With reference to pioneer ploughing, trials 1 and 2 using medium wheeled tractors show 
considerably different productivities, which may be attributed mainly to variability of 
operators and of soil conditions. The average unit coat is 110. 55A*. Trials 3 to 6 employed 
crawler tractors and heavy duty Rome disc harrow plough*. Trial 4 was a skilled operation 
with a high level of efficiency and is directly comparable with trial 6, where efficiency 
was less and the tractor was at the limit of its power pulling the TICK 12-30 plough; perhaps 
an average unit cost between M11 and H4/ha would be readily attainable in practice and 
would leave some room for improvement. Trial 5 illustrates once again that additional power 
does not necessarily yield greater cost efficiency, with the unit cost at 121.56 being more 
than double that of the comparable trial 4 

The wheeled tractor/disc combinations are slightly more cost efficient than the crawler 
units, but quality and depth of cultivation is less. In the heavier ploughing units the 
TACH 12-30 harrow gave the best penetration and effectively severed any remaining roots or 
stumps. Although the heavy duty harrow plough gives a quite different cultivation from that 
of a disc plough, results have shown that this type of soil working is generally adequate 
for plantations. For larger soale ploughing operations a 70 to 80 horsepower crawler tractor 
with the matching TACH harrow is reoonmended. A small trial employing a large 100 hp wheeled 
tractor as power unit to a TOR harrow, showed this to be a feasible ploughing unit and further 
trials are recommended. 

- 130 - 

When pioneer ploughing ha* been adequately completed and the land is largely free 
of all impediments, than pro-planting harrowing ia a at raight forward operation, Triala 7 
and 8 in Table 3, at aomo 18,17/ha, record aimilar unit ooata for different harrow of 
2* 1m oultiration width* There ia no great difference between theae implementa although the 
34/20 haa proved alight ly more durable in praotioe. Both harrowa by adjuatment and reduc- 
tion in number of diaoa can be adapted for inter-row weeding* Trial 9 uaing the M/F 28 
harrow with a 3 cultivation width and a unit coat of M3*57/ha,is economically efficient 
and givea a high rate of productivity offering an acceptable option where the aoale of 
operation justifies having an implement apecifioally for harrowing* Similar observations, 
relative to aoale, apply to the trial 10 pulvariaing harrow TOW 40/24 which produced quite 
the beat tilth or aeed bed; indeed the cultivation waa ao good aa to require the greateat 
care in uaing thia implement in areaa liable to eroaion. 

With reference to ratea of productivity during a 75$ effective 6.5 hour working day, 
the 3 diao plough would cultivate 2*4 ha and the heavy TA.CH harrow plough between 2*9 and 
5*0 ha; pro-cultivation harrowing ratea vary between 3*2 ha for the 34/20 and 8.0 ha for 
the TOW 40/24 harrow. 


i) There ia a well eatabliahed need for plantation development in the Nigerian aavanna 
(Allan and Ojo, 1974)* The need to accelerate thia development continue a to require 
atudy and inveatigationa to aacertain the more efficient teohniquea for main opera- 
tiona and to provide a Bound baae for plantation planning and budgeting. 

ii) Initial plantation development generally require* the clearing of the indigenous buah 
and cultivation of the aoil prior to planting. Land clearing ope rat i one are not 
particularly difficult but require careful forward planning; firstly, to enaure that 
only aui table land ia cleared and, secondly, to enaure a timely sequence of ope r at i one, 
With information on vegetation density and rainfall for a particular area, the pre- 
paration of a sound calendar of operationa ia the basis of good planning. 

iii) The costed results of a series of investigations to determine the efficiency of 
different techniques for clearing and cultivation indicated that: 

a) Chaining coat efficiency ia lesa than 5$ that of the coat of comparative 
hand stumping operations; 

b) 3imilarly f single tractor knockdown is only some 10$ of hand operationa; 

c) Meohaniaed windrowing costs are only 9 to 12$ of comparative hand piling costs; 

d) The mechanised clearing operations offer faat ratea of productivity and the 
possibility of expediting development; 

e) Pioneer ploughing with a light agricultural tractor and mounted disc plough 
unit is 4 to 32$ more cost efficient than using heavier crawler units. The 
heavier crawler diao harrow plough unit, however, improves the quality of culti- 
vation and can double the rate of output; 

f ) For pro-planting harrowing, the unit cost for the most efficient implement is 
only some 43# that of the leaat efficient unit cost recorded and the heavier 
crawler unit cultivates at more than double the rate of the lightest agri- 
cultural unit a* 

The results from these triala indicate acme of the optiona open to management, but 
decisions require consideration of the resources available, the scale of operation 
and the period during which the work haa to be completed* 

- 131 - 

IT) Far large scale plantation, meohaniaed operations hare considerable advantage over 

other less economic alternatives. Dae consideration, however f vast be given to cone 
of the constraints to efficient mechanisation which are common in a number of devel- 
oping countries (Creese, 1974). Such problems may be lack of spare parts, shortage 
of skilled operators, poor servicing facilities and lack of incentives. Unless these 
problems are eliminated by the planning and provision of an adequate infrastructure, 
successful mechanisation is unlikely to eventuate. 

v) If the considerable economic advantages of mechanisation over stumping and hand 
piling could be ignored, then mechanisation of such operations might be seen as 
erasing an opportunity for large scale employment. These economic advantages cannot 
be ignored, however, and the application of selective mechanisation to a marginal, 
labour intensity project may firstly make the project economically feasible and, 
secondly, the application of budget savings could allow the undertaking to be accel- 
erated or expanded. It is suggested that a soundly based, selective, mechanised 
plantation project will, in the longer term, provide more permanent direct employment, 
as well as indirect employment in processing industries than a marginally economic 
labour intensive undertaking (Oluwasanmi, 1975)* 

Allan, T.Q. 

Allan, T.Q. 

Allan, T.Q. and Akwada, E.C.C, 

Allan, T.O. and Akwada, E.C.C. 

Allan, T.G. and Akwada, E.C.C. 

Allan, T.Q. and Jackson, J.K. 

Allan, T.d. and Ojo, 0.0 .A. 

Barrot, H.N, 

Barret, H.H. 


Land Clearing and Preparation Trials using Caterpillar, 
Fleco and Rome Equipment (1972). Research Paper 17 
(Savanna Series) Fed. Dept. Forestry Research, Samara 

Mechanised Cultivation Trials for Forestry Plantations 
in the Savanna Region of Nigeria. Research Paper No. 18 
(Savanna Series) Savanna Forestry Research Station, 
Samara 1973. 

Land Clearing and Preparation Trials at Afaka Forest 
Reserve using Nassey Ferguson 400 Crawler Tractors and 
Rome Ploughs (1972). Project Working Document FOiNIR 
64/516 Samaru 1973. 

Land Clearing in the Savanna Regions of Nigeria. Paper 
presented 2nd Nat. Conf. Agric. Engineering Nig. Zaria 
Aug. 1974. 

Land Clearing Trials at Mokwa Forest Reserve, North 
West State 1973/74. Paper presented 5th Ann. Conf. 
Forestry Assoc. Nigeria, Jos 1974* 

Land Clearing Trials at Afaka Forest Reserve. Paper 
presented at 3rd Ann. Conf. Forestry Asscc. of Nigeria 
Benin Nov. 1972. 

Prospects for large scale mechanised plantation develop- 
ment in the savanna regions of Nigeria. Paper presented 
5th Ann. Conf. Forestry Assoc. Nigeria, Jos. 

A Mechanised Timber Plantation in the Derived Savanna 
Region of Northern Nigeria. 

The Nimbia Timber Plantation Project, pp. 304-313 
Proceedings Inaugural Conference Forestry Assoo. 
Nigeria, Ibadan. 

Caterpillar Tractor Co. 

Caterpillar Tractor Co* 

Creese, W. 




lyamabo, D.E. and jo, G.O.A. 

Oluwasanmi, H.A. 

- 132 - 

Land Clearing. Printed in U.S.A. 

Caterpillar Performance Handbook. Edition 2, Pub. 
Caterpillar Tractor Co. U.S.A. 1970. 

An Enquiry into the Serviceability and Failure Rate of 
Machinery in Tropical Developing Countries. Interim 
Report Nigeria Int. Dev. Research Centre Ottowa 1974. 

Forestry Equipment Note C 14-56. PAO, Rome. 

Tree Planting Practices in African Savannas, by 
M.V. Laurie. FAO Forestry Development Paper No. 19 1 

Plantation Establishment Techniques in the Savanna 
Areas of Nigeria. Research Paper 10 Savanna Series, 
Samaru 1971* 

Effect of Farm Mechanisation on Production and Qnploy- 
ment in Nigeria. Invited Paper. Expert Panel on 
Effects of Farm Mechanisation. Rome, February 1975* 

Savanna Forestry Research Station Unpublished records and reports. 

Indigenous vegetation such as this Isoberlinia doka in 
the northern Guinea savanna must be cleared away prior 
to plantation establishment* Mechanised clearing with 
two crawler tractors and an anchor chain is the most 
coet-^fficient method for these conditions. 

- 133 - 



Costing Crawler Tractors and Matched Equipment 

The costing method im mainly baaed on FAO Forestry Equipment Notes C 14-56 (FAO, 
Operating rates per hour are based on costs to Nigerian Government agencies as at 1975* 

The basis of tractor cost calculations 

I Estimated irreducible costs are based on the number of hours assuming: 

a) Annual interest at 6% averaged and 

b) Garaging cost at BO. 02 per hour. 

Insurance and road tax are omitted as Government equipment is free from such charges. 

II Estimated depreciation and repair costs are based on the estimated operating hours 
(H) in the lifetime of the tractor (standard life). Standard life spans of 10 000 
hours over 8 years have been assumed for crawler tractors and 5 000 hours over 5-6 
years for wheeled tractors. 

a) Depreciation is calculated on the straight line method by dividing the net 
1975 purchase price of the tractor (A) by the estimated life in hours or A. 
Scrap value is taken as nil. H 

b) Estimated cost per operating hour for repairs is expressed as a fraction (r) of 
the depreciation per operating hour. Based on experience, the index of 1.0 is 
used for standard lives. 

III Tractor costs directly incurred when working are taken as follows: 

a) Cost per operating hour for diesel oil consumption is based on average per- 
formance figures, diesel being oosted at 90.46 per gallon; 

b) Cost for lubrication is also based on handbook data (Caterpillar Tractor Co., 
197 Ob) and current costs for materials; 

c) Additional cost for maintenance and cleaning is estimated as HO. 10 and can be 
considered a non operative cost against the tractor operator. 

IV Wages and associated expenditure are based as follows: 

a) Wages per hour of machine operators are based on the Federal Tractor Driver 
1975 award at the top of the scale, i.e. 13.75 Pr 6.5 hour day. Allowing that 
only 75# of time will be operational and assuming that total hours should be 
charged to tractor work, this gives an hourly operating rate of 10.77. It is 
further assumed that when a tractor driver is on other work his time will be 
charged to such work; 

b) Estimated expenditure for pension, paid holidays and sick pay is taken as 15# 
of IV a) i.e. 10.12. Estimated hourly tractor and implement costs are detailed 
in Table 4. 

V Implements are oosted as per tractor calculations under items I and II. 

- 134 - 

Cog-ting Labour Operations 

The ooste for hand labour stumping are baaed on actual 1975 rates assessed aa 

a) Daily labour ia baaed on a baaio V2.02 per man day with working hours of 

7 houra per day Monday to Thursday, 5 houra on Friday and 6 hours on Saturday 
giving a total of 39 hours and an average of 6.5 hours per day over a six day 
week. An allowance of 10J6 to reflect leave and public holidays and other 
benefits makea the total coat of labour per man day 2.22; 

b) The coat of hand toola has been excluded. 

- 135 - 












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- 137 - 



Operation Equipment and Ref. Ho. 

Tear of 




Cost / ha 



Pioneer Ploughing 






1 x wheeled tractor 50 hp 1 
with 3 disc plough 

1 x wheeled tractor 50 hp 2 
with 3 dieo plough 






1 x 65 hp crawler with 3 
Rome TNR 10-30 diec harrow 






1 x 70 hp crawler with 4 
Rome TACH 12-30 






1 x 180 hp crawler with 5 
Rome THE 16-30 






1 x 65 hp crawler with 6 
Rome TACH 12-30 

Pre-planting Harrowing 






1 wheeled tractor 50 hp 7 
with M/P 34/20 harrow 

1 wheeled tractor 50 hp 8 
with H/R 35/70 harrow 






1 wheeled tractor 50 hp 9 
with M/P 28/26 harrew 






1 x crawler 70 hp with 10 
Rome TCW 40/24 harrew 






- 138- 

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- 139 - 


T.Q. Allan 
Forestry Department, FAO f Rome, Italy 


Spacing and Pegging 139 

Spacing 139 

Pegging squares method 141 

Planting 141 

Time of planting 141 

Transport of plants 142 

Planting method 143 

Weeding 144 

Complete hand weeding 145 

Mechanised weeding 145 

Chemical weeding 147 

References 148 

This discussion is based on Chapter 12 of Tree Planting Practices in African 
Savannas (FAQ, 1974); the following notes supplement the relevant sections, 


Recommended spacings in savanna have usually been determined from silvicultural in- 
vestigations largely based on rates of growth and form, but they can influence plantation 
profitability. The costs of planting, beating up, weeding, pruning, harvesting and yield 
are affected by spacing. 

The closer the plant spacing, the greater the number of plants and the larger the 
actual planting input required per unit area. Both these factors can considerably increase 
planting costs* With a larger number of plants per hectare, however, losses become less 
critical and it may be possible to dispense with beating up, whereas at wider spacing 
making good any losses could be essential. The closer the initial plant spacing the earlier 
canopy closures oan be anticipated and this in turn affects the oluration of the weeding 
regime. The suppression of ground vegetation by oanopy closure also reduces fire hazard. 
Wider spacing is likely to induce heavier branching with consequent higher pruning costs, 
but on the other hand there are fewer trees to be pruned. Plantation revenue is dependent 
on the volume and timing of production; spacing obviously oan influence both factors. 

- 140 - 

If it is assumed that plantation weeding will be mechanised, then the first constraint 
is that the spacing must be sufficient to allow a tractor and implement between the planted 
trees. Specialised small or narrow tractors are not a reasonable possibility at this point 
in time so use is made of the normal agricultural type tractor which requires a minimum 
spacing of 2.8 m. Accepting this constraint 9 the main objectives in selecting a spacing 
are to achieve an economic establishment and to close canopy (or take over the site) as 
early as possible. 

Planting may be on the square allowing mechanised weeding in two directions at right 
angles f on the diagonal or with reduced spacing in the lines allowing mechanised interrow 
weeding in one direction only. Table 1 gives some cost indications of the effect of spacing 
on establishment costs for the following options: 

Option 1, Planting eucalypts on the square at3mx3m(l111 plants per ha) 

with one year's spot weeding and two way mechanised interrow weeding. 

Option 2. Planting euoalypts in lines at 3 m x 1.5 m (2222 plants per ha) 

with one year's line weeding and one way mechanised interrow weeding. 

Table 1 
Indicative Establishment Costs 


Costs per hectare 

Option 1 

Option 2 

Planting stock 


US $ 


ITS $ 










Hand spot weeding x 4 





Hand line weeding x 4 





Mechanised interrow 










(a) 6 mechanical weed ings t 3 in each direction at K 3.31/ha 

(b) 4 mechanical weedings Y all in one direction at M 3.31/ha 

- 141 - 

In this example, by reducing the spacing from 3mx3mto3mx1.5m the selected 
first year ocsts are increased by some 83$. The benefits of closer spacing such as elimin- 
ation of beat'ing up and increased selectivity for thinning should also be quantified. 

The optimum spacing clearly depends on a number of factors that do not allow general 
conclusions to be drawn. In the first instance, it is often necessary to choose that 
spacing which within the given environment and with the available knowledge and resources 
will generally meet the objectives, whilst research gives consideration to the effect of 
other variations in spacing and their interaction with other factors. 

Having decided on spacing, the marking for planting by pegs has to be related to the 
plantation and compartment layout. In undulating country it may be necessary to use con- 
tour planting, but in savanna the general pattern is square or rectangular. Marking for 
planting may be done by tractor with a tool-bar and tines, but this requires a skilled 
operator; pegging by hand is more commonly the method used. Pegging may range from marking 
each individual planting spot to pegging squares and subsequently using marked chains to 
indicate planting spots in the squares. At 3 m x 3 m spacing the former method requires 
1111 pegs/ha and the latter slightly under 3 pegs/ha. 

Pegging Squares Method 

Assume a plant spacing of 3 m x 3 m on clean harrowed ground with a ready supply of 
6 pegs. The pegging is based on 60 m 2 . (The length of the sides of the squares must be 
a multiple of the plant spacing.) 

Equipment Prismatic compass or right angled prism, 
2 mallets or hammers. 
Pegs (allow 3 per ha), and 

1 x 60 m chain. 

Manpower 1 supervisor and a minimum of 4 labourers consisting of 

2 ohainmen, 2 carrying pegs and mallets, 


Method Prom the starting point, lay out and peg an exact 60 m using 

the prismatic compass or optical square. Prom these pegs lay 
out two base lines at right angles with pegs at 60 m intervals. 
From the initial square using the chain sigfrt in the corners 
of other 60 m 2 f until the entire area is squared. 

It is important to carry out periodic checks to ensure that pegs 
are exactly 60 m apart. The chain should be checked for stretch- 
ing during the exercise. When pegging, it is important firstly 
to leave a margin around the compartment for weeding and secondly, 
at compartment ends with stretches of less than 60 m, pegs should 
be put in at the multiple of 3 m that can be fitted in. 

Outputs Nigeria 4 to 5.0 ha/hr clear areas. 

Zambia 2.25 ha/hr in areas with anthills. 

Timing of Planting 

Planting should be completed early in the rains in as short a time as possible, to 
allow the trees to become well established prior to the severe dry season. The importance 
cf timely and good quality planting should be stressed. The Zambian method of commencing 
planting when the soil is moist to 30 cm is a good rule of thumb. 

- 142 - 

Kowal (1975) worked out planting dates based on the start of the rains according 
to the following definitions: 

(a) the first ten day period (deoade) during the year having at least 
one inch of rainfall with subsequent two decades of at least half 
evapotranspiration (calculated by Penman's formula using a 25 % 
reflection co-efficient) 

(b) the ten day period during which the cumulative annual rainfall is 
at least 100 mm, with falls of less than 10 mm in any decade 

The following are Nigerian samples. 

Table 2 
Start of rainy season for selected stations in northern Nigeria 


date of start of rains 

Estimated Target 
Planting Date 

method (a) 

method (b) 






7 June 

29 June 

22 June 

10 July 

1 July 


22 May 

14 June 

5 June 

23 June 

14 June 


12 May 

4 June 

26 May 

14 June 

5 June 


4 May 

26 May 

17 May 

5 June 

26 May 

I/ The latest likely date of the start of the rains at a confidence limit 1:9; i*e. only 
once in 20 years is the start of the rains likely to be later than the dates. 

Such data give a planning date for planting and for such associated operations as ground 
preparation and nursery production. For plantation planting, the object should be to 
complete the planting programme within a period of four weeks from the starting date. 

The effect of timely planting is related to and can affect the results of such other 
factors as fertiliser application, weeding regimes and consequent growth, but measuring 
suoh interactions is not easy. Research into this aspect has been done in savanna agricul- 
ture and for maize it was found (Baker, 1975) that planting at the optimum time gave some 
50 % to 84 % increased yield over planting one month later under specific conditions. 
Similar trends oould be anticipated with plantation crops. 

Transport of Plants 

One of the important factors related to transport and distribution is the weight of 
full plant-carrying boxes; trials in Nigeria used the following types: 

- 143- 

Table 3 
Weight of plant-carrying boxes and different types of poly pots 

Type of Box 

Weight empty 


Weight full 
with 15 
large pots 

Weight full 
with 15 
medium pots 

Wire tray 
41 x 29 x 10 om 




Wooden boxes 
39 x 24 x 10 cm 




Metal boxes 
41 x 28 x 5 om 




Large pots: 
Medium pots: 

25 om x 7.5 cm diameter 
15 om x 7.5 om diameter 

The weight of over 28 kg of the boxes with large pots proved to be a strain for lifting 
and carrying during a working day. The wire basket with medium pots proved the more success- 
ful in use. For drier areas where larger pots are essential the use of smaller boxes 
holding 9 or 10 plants should be considered. 

Planting Method 

When using polypots, the plant and its growing medium are transferred to the field, 
and as long as the plant has been hardened-off there is no severe shook in changing the 
environment. Mechanised planting is possible, but the well organised use of labour is 
generally preferable in savanna areas. The adequate and timely distribution of plants to 
the site is of critical importance to planting efficiency. 

Planting comprises the following activities: 


Distribution of plants on site, 


By pre-plant ing harrowing and using specific hand tools it is possible to combine these 
separate activities so that they are mainly carried out as a single operation by one man. 
This type of combined operation can considerably improve productivity. 

- 144 - 

The following section gives an outline planting method for specified assumptions, 
but requirements and productivity can be readily recalculated and measured when these 
assumptions are varied. In describing this planting method the following assumptions are 

(a) that the land has been harrowed and pegged in 60 m squares; 

(b) plant spacing is 3 m x 3 m;and 

(c) that medium sized polypots 15 cm high by 75 m diameter are 
used; and that there is an adequate supply of full planting 
trays on site. 

Ecrui pmerrb : 60 m planting chain with 3 m tags, 

300 to 600 plant carrying trays of 15 poly pot capacity, 
19 planting trowels with spares, and 
a tractor with plant carrying trailer. 

Manpower : 1 supervisor, 1 tractor driver, 27 labourers consisting 
of 2 chainmen, 19 planters and 6 distributors. 

Method: Distribute plants for line planting 20 seedlings at each 

peg. Using chain and 20 planters, plant in parallel lines 
6*0 m apart. When this line planting is complete, just 
over one twentieth of the area is covered. These plants 
serve as markers for full planting carried out at right 
angles to and between the planted lines. 

Between marker trees on the base line, and at each inter- 
val of 16 trees, lay out 19 full planting boxes 3 m apart. 
To start planting, the chain is placed between the base 
line tree markers to indicate the 3 m planting spots where 
planters with trowels pit and plant. The chain is advanced 
3 m to the next markers and the process is repeated. After 
planting 15 trees each, the empty trays are discarded and 
full ones are picked up by each planter and the planting 
operation is continued to the end of the area. Empty trays 
are collected and full trays are distributed in advance of 
the planting gang. Stretching of the chain is possible 
and requires checking. 

Output: 8.5 to 9.5 ha/day initial instructional trials in Nigeria. 

15 to 16 ha/day based on standard times for Zambia using 
mini pots. 


Except at higher altitudes or in areas where moisture is plentiful, it is generally 
better to start plantation development with a clean weeding regime, whilst research deter- 
mines what degree of tolerance to weeds the selected species might have. It is of equal 
importance to clean weed species trials and early research plots, as the presence of weeds 
often affects or negates the results obtained. Under most conditions, even outside the 
savanna region, clean weeding will produce faster growth and increased yields, but it is 
necessary to have some indication that the value of the increased growth is greater than 
the cost of the weeding inputs. It is of consequence to maintain a weeding cycle that does 
not allow the weed cover to become heavily established, as heavy weed is often difficult 
and extremely costly to eliminate. 

- 145 - 

The main methods or combinations of methods of eliminating weeds are hand, mechan- 
ised or ohemioal weeding, 

Complete Hand Weeding 

Hand weeding in savanna implies cultivation of the soil by hoe or a similar imple- 
ment* Scraping only severs roots and can produce undesirable soil capping. Cutting back 
of weeds generally stimulates growth and does not reduce competition for soil moisture 
(Chapman, 1973). 

The main constraints to hand weeding, particularly in large scale operations, are 
the size and cost of the labour inputs. Zambian data indicate that in very light weed 
cover weeding takes 1.2 man-days per ha, and that in heavier weed this rises to 25 man- 
days/ha. Task weeding in heavy grass in Nigeria required 32 man-days/ha. Assuming 1000 ha 
and that it is necessary to carry out a heavy weeding every 5 weeks, the figures indicate 
that a labour force of between 800 and 1100 men is required during the weeding season. At 
1975 rates each weeding would cost W 55 ($89) to W 70 ($113) per hectare. In general, hand 
weeding seldom produces as intense a cultivation as mechanised cultivation. 

Mechanised Weeding 

Mechanised weeding covers only the interrow area and requires supplementary hand 
weeding of the area adjacent to the trees left uncultivated in the mechanised operation 
(Baker, 1975) To avoid damaging the plantation crop, initial mechanised weeding should 
be kept fully 30 to 45 cm from the trees, and as the crop grows this distance should be 
increased. Interrow weeding may be by oxen or tractor power. 

When evaluating different types of mechanised equipment the comparative unit measure 
is the "cultivated plantation hectare 11 (C.P. ha), which is a measure of the area effectively 
cultivated excluding the area to be supplementary hand weeded, i.e. one C.P. ha is 
10 000 m 2 (length x width) of effectively cultivated plantation land. For management pur- 
poses, however, the "gross plantation hectare" is the unit measure used and refers to a 
hectare of trees i.e. when the number of trees including blanks treated equals the number 
of trees per ha planted, the area is a G.P. ha. The G.P. ha includes the area to be hand 
weeded, but that actual area will vary with the width of the implement used for the inter- 
row weeding. 

Investigations employing oxen with Ariana spring tine cultivators have indicated 
the feasibility of interrow weeding with this combination in the Nigerian northern Guinea/ 
Sudan zones (Allan, 1972? Makin-Taylor, 1974). A two oxen team averaged some 94 to 141 min 
to weed a G.P. hectare, which in a 4 to 6 hour day indicates outputs of 2 to 3 ha. On the 
assumption that costs will have doubled since 1971 f costs per ha would be of the order of 
V 3 ($4.80) to W 4 ($6.40). (The capital cost of the oxen will have more than doubled 
during the period, but the salvage, or meat, value will have risen in slightly more than 
compensatory fashion.) The setting up of oxen units requires considerable application and 
training and has not so far been implemented at other than the investigatory level. 

A number of trials to evaluate a range of weeding implements have been carried out 
in Nigeria and Zambia (Allan, 1973? Deveria, 1972? Forestry Department Zambia, 1971). 
Columns 7 and 8 of Table 4 indicate the greater cost efficiency of harrows compared to 
rotavators, and of the harrows the M/F 34/16 is marginally the best. Similar conclusions 
were reached in Zambia. The average trial output of the medium wheeled tractor and harrow 
is indicated as 1.58 G.P. ha/hr (column 3) but for practical purposes a standard time would 
be of the order of 1.0 to 1.2 G.P. ha/hr. mechanised interrow weeding may be done in one 
direction with supplementary line weeding, or in two directions at right angles with supple- 
mentary spot weeding. Referring back to Table 1 shows that a complete weeding in one 
direction would cost V 18.30 ($29.65) whereas spot weeding and two mechanised weedings at 
right angles would cost V 12.60 ($20.41 ); and the cost difference over a season is 6? %. 
These are not directly comparable because the two-way weeding gives double cultivation to 
60 % of the area and, as Deveria (1972) points out, cross cultivation can put a strain on 
the tractor and implement. 


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- 147 - 

Considerable studies of supplementary hand spot weeding have been completed in 
Zambia (Forestry Department Zambia, 1971) The vegetative weed cover is assessed by the 
number of hoe strokes required to weed around each tree as: 

Extra light - less than 10 hoe strokes 

Light - 10/20 hoe strokes 

Medium - 20/30 hoe strokes 

Heavy - 30 or more hoe strokes per spot . 

Table 5 
Standard times and outputs for spot weeding 

Item A Unit 

Weed Cover 





Standard time in 





Time per ha in 
minutes (3na x 3m) 





Output in man days/ 





taken as a Nigerian 6.5 hour man-day. 

The data in Table 5 are based on Zambian work study (forestry Department Zambia, 
1971) but initial studies in Nigeria indicate that with adequate supervision and some 
allowance for higher temperatures similar outputs could be anticipated. Estimated line 
weeding outputs can be readily calculated from this data. Spot weeding costs would vary 
from ii 1.76 ($2.85) per ha in sparse weed to W 6.11 ($9-90) in heavy weed cover. 

Chemical Weeding 

The use of herbicides or arboricides have been curtailed in many countries, due in 
some measure to fear of the danger in using such chemicals, in particular health hazards 
to operators and adverse ecological effects. Many of the dangers have been exaggerated 
(see Dost e al, 1975, on 2, 4, 5 - T and T.C.D.D.) but discussions have become emotional, 
and though clearance investigations have been run and proved it is not always easy to 
change public opinion. It is vital, therefore, to make a careful study of the background 
information and correct usage of any chemical weedicide before introduction into planta- 
tion practice (Barring, 1974) 

The main reasons for trying out chemical weeding are: 

where labour is in short supply, 
where present weeding methods are inefficient , 
where the land is liable to erosion, or where rooks or 
outcrops preclude mechanised weeding, 
(iv) as a supplement to hand or mechanical weeding. 

- 148 - 

There is a need for an extensive research programme which would offer an opportunity for 
co-ordinated work between savanna countries. Use should be made of agricultural results 
as many of. the problems are common to both disciplines. One basic silvicultural question 
is whether chemical weeding will give the same benefits in growth and yield as have been 
observed from cultivation weeding. 

Allan, T.G. 

Allan, T.G. 

Baker 9 E.F.I. 

Barring, U. 

Chapman, G.W. 

Beveria, N. 

Dost , et a 1 


Forestry Department Zambia 

Kowal, J. 

Makin - Taylor, D.C. 


Trial Use of Bullocks for Cultivation in the Establishment 
of Small Scale Plantations or Woodlot^ in Nigerian Savanna 
Areas. Proceedings third ann.. conf, Forestry Assoc. Nig. 
Benin 1972. 

Mechanised cultivation trials for forestry in the savanna 
region of Nigeria. Research Paper (oavanna Series) No. 18 
Samaru 1973. 

The effects of five inputs and their interaction on yield, 
and labour demand of field crops. Experimental Agric. 
Vol. 11 (295-304) published by the Cambridge University 
Press. 1975. 

Treatment of young stands, chemical weed control. Appendix 
Div. 3 status paper. IUFRO Sym. on Stand Establishment. 
Wageningen 1974. 

A manual on establishment techniques in man-made forests. 
Working Paper FO:MISC/73/3 FAG, Rome 1973. 

Plantation Mechanisation in Industrial Plantations. Proj. 
Working Doc. FO:SF/ZAM 5. PAD, Rome 1972. 

Statement on 2,45 - T and TCDD. Journal of Forestry Vol. 73 
No. 7 PP. 411 July 1975. 

Tree planting practices in African savannas, by M.V. Laurie. 
FAO Forestry Development Paper 19 rtome, FAO. 

Provisional Standard Times for Industrial Plantations. 
Cyclostyled handbook Ndola 1971. 

Report on research proposals for the soil physics and soil 
chemistry sections of the oavanna Forestry .Research Station. 
FO:DP/NIR/73/007. Rome, FAO. 

Trial Use of Bullocks for Cultivation of Forestry Plantations 
at Misau N.E. State. Paper presented 5th ann. conf . For. 
Assoc. Nig. Jos 1974. 

- 149 - 


J.B. Ball 

FAD /UNDP High Forest Development Project 
Ibadan, Nigeria 



Features of chemical weed control 150 

Nursery weed control 150 

Weed control in the establishment phase 150 

Woody weeds 151 

Methods of application 151 

Further information 151 

- 150 - 


1. Risk of erosion reduced through the mulching effect; 

2. Generally specific to one type of weed and 

3. Effects generally longer lasting than mechanical methods. 


1. Generally (but not always) more costly than mechanical weeding; 

2. Timing of application is usually important; 

3* Large quantities of diluent must be carried into the field (but this is being 
overcome by ultra low volume applications) and 

4. Toxicity. 

Sterile Seed Bed Technique 

Using paraquat (trade name Gramoxone), the beds are made up before transplanting and 
watered to encourage the weeds to germinate before they are sprayed. Paraquat is an overall 
herbicide that kills all green tissue. It is not translocated to the roots; therefore the 
weeds must be young (no more than 5 ora high). 

Rate: 1 litre product /ha. Can also be used on nursery paths. 

Cost: Approximately V0.20 (about USJt0.32) per 30 x 1 m bed, generally cheaper than 

hand weeding* 
Toxicity: Very high if ingested, but quickly inactivated in most soils. 


Methyl bromide is used. It kills weed seeds and pathogens y but also kills nitrifying 
bacteria; therefore a soluble fertilizer must be used. It is applied in gaseous form before 

Toxioity: Very high. 


Dalapon is specific to grasses. Best kill is when the grasses are freshly shooting. 
It can be mixed with 2,4-D to control broadleaved weeds as well. 

Rate: 6 - 10 kg active ingredient/ha in 100 litres water. 
Cost: About Ml5/ha (about U.S. $24/ha) 
Toxicity: Low. 


Simazine f atrazine, etc., act on emerging seedlings principally through root uptake. 
Some of the newer formulations are more soluble and also act through the leaf, but generally 
good soil preparation is necessary to remove the existing vegetation. Triazines give overall 
weed control of most species except maize (physiological selectivity). 

Rate: 1 - 3 kg active ingredient per ha. 
Cost: About B15/ha (about U.S. *24/ha) 
Toxioity x Low* 


Although most savanna plantations will be established by complete clearing, some woody 
weeds may still arise from roots or seed. The usual chemicals for their control are 2,4-J> 
and 2,4,5-T or more recently, picloram. They may kill through foliar or bark sprays, but 
they may also affect many of the species (especially broadleaves) used in savanna afforesta- 

Where stumping has not been done, coppicing may be prevented b.v these chemicals, or 
ammonium sulphamate or sodium arsenite. The last is very poisonous. Generally, chemicals 
diluted in oil give better bark penetration* 


1. Hand. Knapsack sprayer, often with guards to prevent drift. Cheap to buy , but 
slow ( 1 - 2 ha per day)* 

2. Tractor. Faster, but ground may be too wet at the best time for application. 
Dangers of drift. 5 - 10 na P er day. 

3. Aeroplane. Very fast, but need runways and support facilities close at hand. 
Independent of soil condition. Considerable dangers of drift. 100 ha per day. 


A useful source of further information on chemical weed control is the Weed Control 
Handbook. The full references to this are: 

Fryer, J.D. & Evans, S.A. Weed Control Handbook. Vol. 1 Principles. Blackwell, Oxford. 

Fryer, J.D. & Makepeace, K.J. Weed Control Handbook. Vol. II Recommendations. Blackwell, 
1972 Oxford. 

- 152 - 


J. K. Jackson 

Mae Sa Integrated Watershed and Forest Land Use Project 
Chiang Mai , Thailand 



Introduction 1^ 

Estimation of fertilizer need 1V. 

Response of different species to fertilizers 154 

Eucalypts 154 

Pines 154 

Teak ( Tectona grandis) 15^ 

Gmelina arbor ea 1^ 

Neem (Azadirachta indica) 15^ 

types of fertilizers 155 

Methods of application of fertilizers .So 

References 1^6 

Table 1: Effect of fertilizers on Eucalyptus carnal dul ens is 1S7 

Table 2: Effect of fertilizers on Eucalyptus citriodora 1S / 

Table 3s Effect of fertilizers on Eucalyptus tereticornis '^ 

Table 4s Effect of different forms of nitrogen on Pinus caribaea 1 C H 

Table 5 : Effect of superphosphate on growth of Pinus caribaea 1Sy 


It is only in the last two or three decades that the use of fertilizers 

in forest plantations has become widespread. Before that it was assumed that the expense 
of fertilizers was too great if they were used for a relatively slow-maturing crop like 
forest trees. Nowadays it is realized that if the diminishing area of land available for 
forestry is to meet the needs of a world population which is both increasing in numbers 
and demanding a higher standard of living, this land must be managed to produce the 
maximum economic yield* This is being achieved by improved cultural practices y selection 
and breeding of higher yielding trees , and f in appropriate circumstances, by the use of 

- 153 - 

There are two main situations in which fertilizers are needed, thougi there are 
borderline cases between the two. The first is where a species of tree cannot be grown 
satisfactorily on certain sites without the use of fertilizers. Examples are eucalypts t 
which need boron on many African savanna sites f and pines, which will not grow satisfactorily 
on some Nigerian soils without added phosphate. Here the choice is simple: apply fertilizer, 
or do not grow these species on such sites. The second case is where fairly satisfactory 
plantations can be established without the use of fertilizers, but where the yield is 
increased if they are applied. In this case the decision is an economic one; do the increased 
yields compensate for the extra cost, compounded appropriately? 

The work of the Savanna Forestry Research Station in Nigeria included a series of 

experiments on the use of fertilizers in plantations. These are covered in fair detail 

by Jackson (1974). Work elsewhere in the savanna region of Africa is dealt with by Laurie 
(1974) PP. 37, 104-105. 


A number of techniques are available for estimating the need for fertilizers. 
Shortage of certain plant nutrients will show up in visual symptoms, such as discoloration 
and deformation of leaves and stems. With experience it is often possible to know which 
nutrient is lacking, but even if this can be done with some certainty the amount of the 
nutrient required to correct the deficiency is unknown. Frequently, also, plants show no 
outward signs of nutrient deficiency, but still give greatly increased yields if fertilizers 
are applied. 

Soil analysis is useful to give an indication of what additional nutrients are 
likely to be needed. It can be misleading, however, as certain nutrients may be present 
in abundance, and yet be unavailable to plants. An example is certain soils on the Mambilla 
Plateau, which have a high phosphorus content; yet trees on these soils show a marked 
response to phosphate fertilizers. Also different species of trees vary in their nutrient 
requirements, and a soil which has adequate supplies for one species may have insufficient 
for another. 

Studies of nutrient content of plant tissues can be valuable, but before they can 
be used the levels of nutrients found need to be calibrated against those found in trees 
of known health and growth rate so that optimum levels can be determined. 

Pot experiments can give valuable indications of likely nutrient deficiencies, but 
it is rarely possible to extrapolate directly from the results of such experiments to field 
practice. For one thing the volume of soil available in a pot is much less than the 
volume available to the roots of a growing tree. 

Thus the basis of estimation of fertilizer needs must eventually be field experiments. 
When these have been established, results of soil and tissue analysis can be correlated 
with them, and used for further estimations. 

In field experiments, factorial designs with nutrients at, if possible, at least 
three levels each, are to be preferred. This method not only shows what nutrients are 
needed, but also enables the optimum levels of each to be estimated. Unfortunately the 
large areas needed for field trials of fertilizers in forestry often preclude the use of 
more than three levels of say three nutrients in a single trial. 

- 154 - 


Boron deficiency is a common cause of poor growth of eucalypts in many parts of the 
savanna region of Africa. It was first described from Zambia by Savory (1962). Its 
symptoms are distortion and discoloration of the leaves , followed by die back of the 
leading shoot; this die back may be repeated for several years, until in the end all that 
is left is a densely branching bush* In less severe cases repeated dieback causes the 
stem to become crooked, reducing its value. 

The remedy is to apply fertilizer borate (14 percent B) soon after planting. In 
Nigeria 5^-60 g per tree has been found to be adequate, but in Zambia "at least 57 g 
are required on shallow soils in low rainfall areas, and 144 g on the deep sands or in 
areas of high rainfall" (Laurie, 1974 ) 

Caution must be used in applying borate to very sandy soils of low buffering 
capacity y as in these conditions boron toxicity is very likely. Considerable damage 
was caused to Eucalyptus trials in the area north of Kano by application of borate. In 
such circumstances very light doses, repeated a number of times, should be tried. 

Eucalypts generally also respond to other fertilizers, especially phosphate, but 
quite often to nitrogen as well. There is also quite often a strong interaction, in 
that nitrogen without phosphate has little effect, and to some extent vice versa, but 
when the two are combined the effect is much greater. Particularly with nitrogenous 
fertilizers, too much can be as harmful as too little. 

Tables 1-3 give some results from fertilizer trials on eucalypts in Nigeria to 
illustrate some of these points. 

In Zambia, Laurie (1974) reports that standard practice is to apply an NPK 
fertilizer, with the proportions of 11:22:11, at the rate of 57 g per plant. This is 
equivalent to 14 g of urea (or 35 & ammonium sulphate), 70 g of superphosphates, and 
about 12 g of muriate of potash (KCL) per tree. 


In Nigeria phosphate has been found to be the most commonly limiting nutrient, and 
on many soils it is essential to add phosphatic fertilizers to obtain satisfactory 
survival and growth. Phosphate-deficient pines are typically stunted, with little 
branching, and needles which tend to turn brown at the tips. These axe very similar to 
the symptoms of nqycorrhiza deficiency, and it is possible that the effect of the phosphate 
acts through stimulating njycorrhiza development. 

effect of nitrogenous fertilizers is much less, and some forms have been found 
to be injurious, especially urea. For examples see Tables 4 and 5. At Mokwa, even with 
the phosphate, growth is unsatisfactory, but the striking difference in mortality should 
be noted. 

Boron deficiency has been recorded from pines in various parts of Africa, but so 
far there are no records of trials in the savanna region. 

- 155 - 

Teak (Teotona grandis) 

In Nigeria, on good sites, the general effect of applying fertilizers to teak has 
been an improvement in growth during the first three or four years, after which the 
unfertilized plots caught up with the rest. On poor sites fertilizers had a marked effect, 
but even with their use growth was unsatisfactory; growth of fertilized trees was poor, 
that of unfertilized trees even poorer. 

As teak is a relatively slow growing species, considerable increases in growth would 
be required to cover the cost of the fertilizer if compounded to the end of the rotation* 

Gmelina arbor ea 

Results from trials in Nigeria showed a considerable variation from site to site. 
In some cases there was a response to urea but not to superphosphate, and in others the 
reverse, while elsewhere there was a marked interaction between the two. The proportions 
which, on the whole, gave the best results, were NiP 2 Oc 5*4t when the nitrogen was applied 
as urea. In one group of trials this combination considerably increased height growth in 
the first year, but caused a marked colour change in the leaves, the lamina turning bright 
yellow while the veins and a narrow strip along them remained bright green. TCiis is 
presumably due to a trace element deficiency, and is an example of how, when one limiting 
factor is removed, the effects of others may become apparent. 

Neem (Azadirachta indica) 

Some trials were made north of Kano on a very poor sandy site. Although nitrogen 
and phosphate stimulated growth during the first two years, this increased growth was not 
maintained, and it was clear that the main obstacles to good growth were the very poor 
physical conditions of the site, a very freely draining, almost pure, sand. Some 
encouraging results were obtained during the first two years by incorporating animal 
manure in the planting holes at the time of planting. 


There are many types of commercial fertilizers on the market, and often the decision 
on which one to use will depend on what is available locally. A large proportion of the 
cost of fertilizers is freight. If a certain fertilizer is widely used in a country it is 
likely to be imported by the ship load (if not manufactured locally), and will be much 
cheaper than if a load of a few tons is specially imported. This effect of freight costs 
also means that, in countries remote from a port or source of manufacture, highly concen- 
trated fertilizers may be considerably cheaper in use than less concentrated ones. For 
instance it may be cheaper to use triple superphosphate (45 percent P^) "than single 
superphosphate (18 percent), although the initial cost of the former is higher. 

The nutrient content of commercial fertilizers is usually expressed as percentage 
nitrogen, percentage phosphorus pentoxide (? 2 0) or its equivalent, and percentage 
potassium oxide (lUO) or its equivalent in potassium. (Pp5 con<tains 42 percent P, and 
K 2 contains 70 percent K). Thus a compound fertilizer with the formula 11:22:11 will 
contain the equivalent of 110 g nitrogen, 220 g phosphorus pentoxide, and 110 g of potassium 
oxide per kg. This allows the cost of the nutrients in different fertilizers to be 

Sometimes local sources of fertilizers can be located. For instance in the north 
of Thailand locally produced rock phosphate costs $67 per ton, with 25 percent P 2 5 , 
while superphosphate (18 percent P 2 0c) costs about $270 per ton. Per unit of phosphorus 
the superphosphate costs over 5 times as much as the rock phosphate. 

- 156 - 

Book phosphate is a "slow release" fertilizer, in that its phosphate is only converted 
into a form usable by plants over several years (though it can be released more quickly if 
the finely ground rook phosphate is mixed with sulphur)* This is sometimes an advantage 
for forest trees, and in different parts of the world other slow release fertilizers as 
sources of nitrogen 9 boron t and other elements, are being experimented with quite widely y 
though little has been done in the savanna zone in Africa* 

Some fertilizers have side effects which may be harmful* The harmful effects of 
urea on pines have been already mentioned* Ammonium sulphate if used over a number of 
years increases the acidity of the soil; this might not be important for some species of 
trees, but can be harmful to agricultural crops* Not harmful, but in some circumstances 
beneficial, is the fact that superphosphate contains a high percentage of sulphur in the 
form of calcium sulphate; sulphur is known to be deficient in some savanna soils* 


The simplest method of application is to apply the fertilizer in two small patches 
on each side of the tree, 1530 cm from the stem, and hoe it in* (if the plantation is 
mechanically cultivated by disc harrow, the harrow will turn the fertilizer in during 
weeding operations)* Especially with bo rate and potassium chloride, care should be 
taken that the fertilizer does not come in direct contact with the foliage of the tree* 

The fertilizer should be applied a few weeks after planting, preferably during a 
relatively dry period, if this is possible. 


Jackson, J*K* 

Jackson, J*K* 

Laurie, M.V. 

Ojo, G*0*A* & Jackson, J*K, 

Savory, B.M. 

Some results from fertilizer experiments in plantations. 
Savanna For. Res. Stn. , Samaru Res. Paper 21 

Savanna Forestry Research Station, Nigeria Silviculture 
and Mensuration. FO/SF/NIR 15 Tech. Rep. 7 

Tree Planting Practices in African Savannas. FAO For. 
Dev. Paper 19. Rome, pp. 7, 37, 104-106. 

The use of fertilizers in forestry in the drier tropics. 
FAO/IUFRO Internat. Symposium on Forest Fertilization, 
Paris, December 1973. 

Boron deficiency in eucalypts in Northern Rhodesia. 
Etapire For Rev., 41 * 118-1 26. 

- 157 - 






Bo rate 


28 e 

57 e 




57 e 




113 e 









Least significant difference means within table 2.25 
Least significant difference marginal means 1.30 

No significant effects from urea in this experiment 




Ammonium Sulphate 

Superpho a phat e 

113 g 

227 g 




113 g 




227 g 







Least significant difference means within table 2.98 
Least significant difference marginal means 1.72 

No borate added* No effect from potassium chloride 



- 158 - 





Ammonium Sulphate 


100 g 

200 g 




100 g 




200 g 








Least significant difference means within table 32 
Least significant difference marginal means i 18 





Phosphate absent 

Phosphate present 

... _ 1 




Deaths height 
% m 

Deaths height 
% m 

Deaths Height 
% m 


12 1.17 

6 2.45 

9 1.81 


30 1.04 

33 2.45 

31 1.74 


16 1.10 

5 2.77 

10 1.94 



34 1.14 

5 2.62 

20 1.88 


23 1.11 

12 2.57 

18 1.84 

Least significant difference of 2 mean heigjhts in table i 0.29 

- 159 - 


Soil Series 

Superphosphate, g/tree 

Kulfo sandy loam 

Takumah loamy sand 



















Least significant 
di f f erence 



Boron deficiency is a common cause 
of poor growth of eucalypts in many 
savanna soils, and without addition 
of berate fertilizers plantations 
such as this Eucalyptus tereticornis 
(three years old and beginning to 
close canopy) at Afaka f Nigeria, 
would not be possible. 

- 160 - 


J.C. Delwaulle 

Centre Technique Forest ier Tropical 
Nogent-sur-Marne, Prance 


Establishment of Village Woodlots 

Arousing public consciousness 

Site selection 

Land clearing 

Pegging out 

Soil working 

Fishbone water catchment pattern 




Acacia albida 

Acacia albida and the farmer 
Acacia albida and stockraising 

Acacia Senegal 

Organization of gum gathering 
Safeguarding natural stands 
Man-made gum-tree stands 
The Sudanese system 







Ehiphasis in this paper will be on village woodlots and the role of Acacia albida and 
A Senegal in Sahel-zone forestry. 


A village woodlot is a small area, usually less than 5 hectares in size, to be planted 
to trees by villagers with the technical assistance of the forest service. 

Arousing Public Consciousness 

The first step in creating a village woodlot is to interest the local population by 
explaining the intended goals, how they will be expected to participate, and who will own 
the woodlot (as a rule it is the village). For an operation of rather large scope, this 
phase calls for the participation of administrative cadre, the customary chiefs, forest 
agents and rural extension officers. 

- 161 - 

Site Selection 

The problems of selecting a site is particularly difficult because successful estab- 
lishment of woodlots can only be accomplished on farmland, whereas the villages naturally 
prefer to donate only poor land for woodlots. It is absolutely necessary to refuse such 
land and to seek a compromise, even being prepared to use a smaller plot of land than 
initially anticipated. 

Land Clearing 

Clearing of land for village woodlots is done by hand. The following steps are usually 
followed (unless the land had been cultivated previously): 

1) felling of all trees on the plot; 

2) extraction of stumps; and 

3) removal of roots and cutting up into eteres. 

Obviously, the time required for clearing will depend on the type of vegetation. On 
savanna sites moderately densely covered with Combretaceae and below the 600 mm isohyet, 
roughly 85 man-days per ha will be required. 

Pegging Out 

It is not absolutely necessary that staking out be highly accurate, but trees should 
be spaced approximately 4 m apart. It is, therefore, advisable that this operation be done 
under the supervision of a forester. 

Soil Working 

In establishing village woodlots, it is best to work the soil manually, as there is 
no justification for the use of machinery for small-scale operations; furthermore, a 
purpose of establishing these woodlots is to involve the villagers in the operation. 

Two types of tasks have to be done: 

1) initial ploughing of the entire area for the sole purpose of improving the 
catchment of the first rains; this should be done with traditional farm implements; 

2) digging of holes on the land where the plantation is to be set out. 

Many trials of manual soil working have been conducted in the Sahel in order to find 
out which techniques are most effective. In particular, techniques devised for the arid 
zones of North Africa (mounding, ridging, etc) were tested and did not prove good. Following 
is a brief description of one such trial: 

Place of trial: Niger 

Total annual rainfall: 281 mm 

Treatments, corresponding to five soil working techniques: 

A. control plot (holes of pot size) 

B. digging of holes 60 x 60 x 80 cm 

C. digging of holes 40 x 40 x 40 cm 

D. burrowing 

. furrowing and ridging 

Design: 1 species of tree, 250 replications, or 1250 plants spaced 3*50 x 3.50 m apart. 
Species used: Eucalyptus camaldulensis 8411 
Date of planting: 11 and 12 July 1972 

- 16? - 

Results by end of November 1972: given in table below. 







Percent survival 






Height (cm) of live 






Prom this trial, as well as others, the following conclusion is drawn: In arid zones 
the best results are obtained by the method of large holes ("grand potet"). 

The cost and time involved in digging holes vary greatly depending on the kinds of 
soil. On soils of average difficulty, from 10 to 25 holes of 60 x 60 x 60 cm dimensions 
can be dug by one man per day. The holes are then immediately filled in; it not being 
necessary to wait for the first rains. 

Fishbone Water Catchment Pattern 

In the arid zone most of the water that falls on the plot has to infiltrate into the 
soil; losses due to runoff must be reduced to a minimum. It is also advisable, if possible, 
to concentrate the water around the plants, as this can especially help them withstand a 
drought period. To that end a so-called "fishbone" pattern or design has been worked out. 
On sloping ground (no matter how slight the slope) a slight ridging 10 cm high is required 
below the plants, forming for each plant a curved water retention basin. Two furrow-drains 
for each basin lead off to two other basins below. In a quincunx plantation pattern, one 
obtains the following design: 


This has proven to be a perfectly efficient design, as it effectively concentrates the 
water around the plants. 

Measurements have been taken in such an arrangement to determine the soil water content 
around the plants and between two plants* The following average figures were obtained one 
month after the end of the rainy season: 

- 163 - 

soil water content around the plant: 4.92% 
"between two plants: 4.11$ 

These notable differences are maintained for up to 6 months following the end of the rains. 

Construction of the fishbone pattern is done entirely by hand and requires only a few 
man-days: 15 to 20 per hectare. However, careful instructions may need to be given before 
the work is started. 


For any plantation in the arid zone, fencing is absolutely essential and, indeed, is 
decisive for success. Where there is no fencing or if the fencing is poorly made or not 
kept up, livestock quickly penetrate and can ruin the plantation within a few hours. 

There are several possible types of fencing, including barbed wire, grillwork and 
live hedges. The simplest and most rustic type, requiring no investment of funds, is the 
"zeriba 11 . By zeriba is meant an entanglement of spiny or thorny branches kept erect by 
wooden stakes. If well made, it is fully efficient as a fence but it has to be kept in good 
condition. About 180 man-hours are required to erect a 1 000 m long zeriba. 


Although termite damage in the arid zone is generally rather limited and termites are 
often incorrectly blamed, as they often appear to devour deadwood of plants of the previous 
season, whenever possible it is necessary to give the soil an anti-termite treatment, 
usually with dieldrin, prior to planting. In such cases, the technical assistance service 
must be called on to help. 

An absolute rule is that planting must be done after the rains have started. From 
experience it is known that this is generally around 15 July in the Sahel. It is always 
too risky to plant in June and it is too late to plant in August, the best planting season 
being, in at least 90 cases out of 100, between 15 and 30 July. 

In the arid zone it is always necessary to set out potted plants (see also paper 
entitled "Soil mixtures, use of containers and other methods of plant raising 11 , page ). 
Depending on the nature of the soil, one should use either neem (Azadirachta indica) , 
Cassia siamea, Prosopis chilensis, Parkinsonia aculeata or certain African acacias 
^A. nilotica var. adansonii, A. seyal, A. nilotica var. nilotica, A. tortilis, etc.). 
These plants will be furnished by the nearest forest tree nursery. Planting is an easy 
task but it may require certain preliminary explanation (especially regarding the cutting 
away of the bottom of the pot). It is relatively rapid, requiring a maximum of 8 man-days 
per ha. 


Unfortunately it often happens in the Sahel that plantations set out under good con- 
ditions are not well maintained, usually for lack of funds or follow-up of the operation. 
Even if such plantations are not ravaged by fire, their growth is very poor because of the 
tremendous competition from grasses, causing the forest trees to suffer and die for lack of 
water for which they are obliged to compete. 

During the first year after the plantation is set out maintenance work has to be done 
twice - once during the rainy season before the grasses go to seed, that is in the second 
half of August, and again at the end of the rainy season, during the first half of October. 
The maintenance work done at the end of the rainy season needs to be repeated in the second 
and third years. In subsequent years such maintenance seems desirable but is not absolutely 
essential. Maintenance is done with traditional farm implements (the hoe or 'daba 1 and 
'hilaire 1 in particular). 

- 164 - 


Acaoia albida has many local names - it is called f gao f by the Haouseas, 'cadde 1 by 
the Wolofs, 'balanza 1 by the Bambaras, 'zaanga* by the Mossis and 'tchaski' by the Peuls. 
It is a common tree in many farming areas of the Sahel -Sudan zone. 

It is a valuable tree for farmers because it enriches the soil and, being decidious, 
loses its leaves during the rainy season so that it does not interfere with crops. This 
characteristic has long been recognized and it deserves the name of "miracle tree" Jven it. 

The following sections on A. albida will provide some succinct information, in annotated 
outline form, which shows the value of this species and indicates planting costs in French- 
speaking arid countries of Africa. 

Acacia albida and the Farmer 

Research in Senegal by I.R.A.T. demonstrated the beneficial effect of Acacia albida 
on soils* Increases in soil properties under A. albida were: 

- clay content 

- assimilable phosphorus 
60$ - total carbon content 

43$ - equivalent moisture, consequently, water retention capacity 
100$ - total nitrogen 
100$ - exchangeable calcium content 

- exchangeable magnesium content 

In Niger, O.R.S.T.O.M, measurements showed that the increase in the contents of certain 
minerals in soils under Acaoia albida corresponds to the following quantities of fertilizers 
and soil amendments: 

synthetic fertilizer - 50 to 60 t/ha (300 kg of organic nitrogen) 

potassium chloride - 50 kg/ha (24 kg of potassium) 

bicalcium phosphate - 80 kg/ha (31 kg of soluble ?20s and 25 kg of Ca) 

dolomite - 125 kg/ha (15 kg of Mg and 25 k of Ca) 

lime - 100 kg/ha (43 kg of Ca) 

The reasons for the beneficial effect of A. albida on the soil are the following: 

1. very active decomposition of leaves when crops are starting to sprout; 

2. fertilization by livestock which finds shade under the acacia; 

3. diminution of dessication by wind, and of evapotranspiration during the dry 
season, as well as of leaching by rain, and of fluctuations in temperature 
at all seasons; 

4. possibility of fixing atmospheric nitrogen; 

5 bringing fertilizing elements up to the surface from very deep in the soil 
(in relation with point 1). 

The fertilizing and improving action of A. albida on soils is beneficial to crops. 
In experimental plots of I.R.A.T, in Senegal mean yields of millet were: 

a. 600 kg not under A. albida (traditional millet growing); 

b. 1 000 kg at a distance of 5 m from A. albida stems and 

c. 1 700 kg at less than 5 m from the tree. 

- 165 - 

Planting under A. qlbida it is possible to obtain millet yields three times greater 
than those in open fields were there are no Acacia, 

Acacia albida and Stockraising 

A. albida is valuable as forage and fodder crop. The leaves are edible and assimilable, 
As regards protein content, they provide an excellent forage or fodder. 

As for the pods f a yield of from 400 to 600 kg may be obtained from a stand of 60 
acacias per ha, equivalent to the fodder consumed between two over-wintering periods. 


The planting of one hectare of Acacia albida at the rate of 100 stems spaced 10 x 10m 
apart, preferably in quincunx, costs about 30 000 CFA francs. Spacing of 10 x 10 m is opti- 
mum. Even when reduced to 50 trees per hectare due to gaps, failure to take, natural 
selection or artificial thinning, the trees still cover the soil, yet without interfering 
with the use of draught animals in crop farming. 

Operation Cost (CFA F) 

Raising of 100 nursery plants in polyethylene wrappings 3 500 

Marking out the plantation area, soil preparation and 
staking out 

10 man-days at a rate of ^JOO CFAF/man-day 4 000* 

2 man-days at a rate of 600 CFAF/man-day 1 200 

Transporting of nursery plants to the plantation grounds, and 

distribution on the ground (using an all-purpose vehicle) 5 100 

Actual planting 

3 man-days at a rate of 400 CFAF/man-day 1 200* 

Small implements 1 000 

Surveillance and protection against livestock 

1st year 5 000* 

2nd year 5 000* 

3rd year jHXW* 

TOTAL 30 000 CFA F 

These costs are distributed as follows: 

1st year 21 000 CFA F 

2nd year 5 000 CFA F 

3rd year 4 000 CFA F 

* These prices may possibly be reduced if, as is desirable, the local population 
is directly involved in the operation (bonuses awarded for good plant survival). 

- 166 - 


As for Acacia albida, it would be possible to discuss A. Senegal, the gum-tree, at 
great length. Here only certain ideas will be expressed relative to the various possibili- 
ties for its use offered foresters in the Sahel - that is, the establishment of groves of 

Organization of Gum Gathering 

Nomadic, pastoral peoples generally collect gum, provided a market for it exists. 
To illustrate, little more than 20 years ago the production of gum in a country like Chad 
was insignificant, certainly less than 100 tons per year. Then in the geographic departments 
of Ouaddai and Biltine a publicity campaign was launched and an agency was set up to pur- 
chase the gum at a price fixed annually. This caused a considerable increase in the annual 
production in Chad, to about 2 000 tons in the years 1965 to 1968. 

Sinoe then there has been a spectacular decline in the production of gum in Chad, now 
running from 200 to 300 tons annually. Certainly the drought in recent years was largely 
responsible for this decline but it was accelerated by the almost complete stoppage of 
publicity and a purchase price that offered no incentive whatsoever; in fact, a good portion 
of the gum produced had to be sold in the Sudan. 

Wherever natural stands of gum trees exist, the first step to be taken is therefore 
to make the population aware of the value of this commodity, to be followed by organization 
of the market and setting of good incentive prices. 

Safeguarding Natural Stands 

The gum-tree is a pioneer species that gains a foothold on abandoned land, especially 
former cropland. Gum-trees grow in virtually pure, even-aged stands and start to produce 
at about five years of age, continuing up to 25 years of age; they then grow old and die 
off at from 40 to 50 years of age. As a rule, no natural regeneration occurs under gum- 
trees. Consequently where there were gum trees in full production, around the years 1940 
to 1950f there are now dying stands on land which bear no other trees. This is what was 
observed during a study tour on the gum-tree in 1972 in Niger, in the 'manga' country, 
where the only large stands of gum-trees that were seen were outside classified forests. 

Spots where regeneration is occuring, sometimes large ones, do appear almost every 
year on abandoned land. These regeneration spots will turn into future gum-tree stands but 
they are exposed to three hazards, especially during the first 3 years, namely: fire, live- 
stock browsing and renewed crop growing. 

It seems that a well thought out gum-tree policy should have among its goals, and 
before any planting work is undertaken, the safeguarding of such naturally regenerated 
stands. Also forest laws should give foresters the authority to protect young gum-tree 
stands discovered in this way so long as they continue to produce. This solution, which is 
being developed in Niger, seems far preferable to establishment of man-made stands, 

Man-made Gum-tree Stands 

The planting of potted gum-trees om land that has been worked is easy from the techni- 
cal standpoint but a heresy in economic terms because of the high cost of working the soil 
and planting. 

It was thought that it would be possible to establish man-made gum-tree stands by 
direct seeding after harrowing of the soil. This is technically possible but definitely 
raises the question of protection. However, from results obtained with the gum-tree project 
now underway in Chad in the Chari Baguirmi (a European Development Fund - EDF project), 

- 167 - 

this in a technically feasible solution only if the soil is harrowed after the first rains. 
It appears that it is impossible to work large areas by machines because they can be used 
for only 15 days to one month, it being necessary to have a rainfall potential of 250 mm 
after seeding* Such a solution is therefore only possible if done by the local farmers, 
as in the Sudanese system. 

The Sudanese System 

The Sudan supplies 80 to 90$ of the world market for gum, this being due to the fact 
that the gum-tree is included in the normal crop rotation. In that part of the Sudan where 
gum-trees are grown, the farmers practice the following rotation: 4 to 5 years of millet 
growing and about 20 years of gum-trees. The soils are appropriate for this purpose. Gum- 
trees are grown and gum collected by farmers; this makes possible the practice of tapping 
the trees | a practice which is almost impossible to develop in countries where nomadism is 
usual, nomads not being gum gatherers. 

It is in those parts of the Sahel where there is a settled farm population and which 
lie within the natural range of the gum-tree and in its production area, that this solution 
is advisable. The matter of production area is particularly important because the gum-tree 
yields little or no gum when it grows on sites which get too much water (500 mm). Apparently 
the trial development of gum-trees in Assale, Chad, failed to take this particular aspect of 
the ecology of the gum-tree into account. 

- 168 - 


J*K* Jackson 

Mae Sa Integrated Watershed and Forest Land Use Project 
Chiang Mai, Thailand 



Introduction 168 

The Suian Gezira 168 

Later developments in the Sudan 170 

Some general aspects of irrigated plantations 170 

Water requirements 170 

Quality of water 171 

Methods of application of water 171 

Choice of species 171 


Irrigated forestry plantations have been established in the drier parts of Asia for 
many years; the famous Changa Manga plantations in the Punjab were begun in 1866* In the 
savanna region of Africa, on the other hand, there has been relatively little development 
of irrigated plantations. The most important area in which they have been established is 
in the Gezira area of the Republic of the Sudan* This paper, therefore, will begin with a 
description of the plantations in the Qezira, and then go on to discuss some more general 
problems of irrigated plantations* 


The Suian Gezira is a vast plain, of alluvial origin, lying between the Blue Nile and 
the White Nile south of Khartoum* The rainfall ranges from about 150 mm near Khartoum to 
about 550 mm in the south* The soils are mostly dark cracking clays, or vertisols, with a 
high pH (over 8*5), and high clay content* During the dry season they are divided into a 
network of deep and wide cracks* When the soil is moist these close, and further penetra- 
tion of water into the soil becomes very slow, so much so that no matter how much water is 
applied to the surface of the soil, moisture movement below two or three metres is 
negligible* The original vegetation was probably mainly open grassland in the north, 
Acacia mellifera scrub in the centre, and open Acacia seyal-Balanites aegyptiaoa woodland 
in the south. 

- 169 - 

The Oezira Irrigation Scheme oame into "being in the years immediately following the 
First World War. It was based on the cultivation of long^-staple ootton as a oash orop and 
sorghum as a subsistence crop for the farmers* The scheme was originally a partnership 
between the Sudan Government, the tenant farmers, and a private company, the Sudan 
Plantations Syndicate, who shared the proceeds of the ootton crop in the ratio of 40 per 
oent, 40 per cent, and 20 per cent respectively. Other crops, including the sorghum, 
were entirely the property of the tenant farmers. The Government constructed the dam at 
Sennar and the major irrigation works, and was responsible for supplying the irrigation 
water; the company took care of technical supervision of agriculture in the field, and of 
marketing the ootton crop; and the tenant farmers provided the manpower. A few years 
before The Sudan attained independence in 1955, "the Government bought out the Sudan 
Plantations Syndicate whose functions were then taken over by a quasi-Government organiza- 
tion, the Sudan Gezira Board. 

The amount of water which could be used in the Gezira was regulated by the Nile Water 
agreement with Egypt. This has since been amended several times, but originally allowed 
free use of water between August and December, when the Blue Nile was in flood; between 
January and Ifeiroh water use was restricted to the amount which could be stored in the 
Sennar reservoir; while from March onwards water supplies were severely restricted to the 
drinking water needs of stock and people, and very limited irrigation of orchards and 
other perennial crops. 

In the early years of the Gezira scheme the Sudan Plantations Syndicate was strongly 
opposed to the establishment of forestry plantations, on the ostensible grounds that the 
trees migjit harbour ootton pests. However in the mid-1930 f s it was possible to begin 
irrigated plantations on a small scale, partly on land allotted for resettlement of the 
people who were moved from their homes when the Jebel Aulia dam was established on the 
White Nile (to help regulate water supplies in Egypt) , and partly on land managed by a 
smaller company, the Kassala Cotton Company. This company had been formed to grow ootton 
in the Gash delta, near Kassala, but local opposition prevented this and they were given a 
concession in the Gezira area instead, on similar terms to those enjoyed by the Sudan 
Plantations Syndicate. After the formation of the Sudan Gezira Board irrigated plantations 
were extended to other parts of the Gezira. 

The original irrigated plantations were of two types, village woodlots on a veiy small 
scale to provide firewood and small timber for individual villages, and larger areas of 
plantation, usually on land relatively unsuitable for ootton. The village wood lots were 
on the whole a failure, as it was difficult to protect these small scattered areas, 
especially from the depredations of goats and other domestic livestock. The other areas 
were more successful. 

A number of species were tried initially including neem (Azadiraohta indioa) t sunt 
(Aoaoia nilotioa) , sissoo (Palbergia sissoo) and various euoalypts. Sunt was disliked as 
it provided a refuge for grain-eating birds, and neem was susceptible to moderate salinity. 
Sissoo never did very well. The most promising species was found to be Eucalyptus 
miorotheoa F.V. Mull, (including E. ooolabah Blakely and Jacobs). This is a species 
occurring near seasonal wate recourses in dry regions of Australia. Its form is not very 
good, and, for a eucalypt, its growth rate is not very rapid; however it has the supreme 
advantage of being able to withstand the long, hot period between .Msirch and August when no 
irrigation water is available and there is very little rainfall. 

Originally the Eucalyptus seedlings were raised in metal containers 25 om long by 
7.5 cm in diameter, made from old petrol tins. They were slit up one side, and provided 
with tabs so that they could be removed when the seedlings were planted and re-used. 
Nowadays these containers have been replaced by polythene tubes. The potting mixture was 
river silt mixed with sand, and the seed was sown direct into the tubes. No anti-termite 
treatment was used. 

- 170 - 

Before planting, the area was ploughed with a very large plough to produce a series of 
low ridges, separated by channels, the ridges being 2.4 to 2.7 metres apart, and 60 om to 
1 m vertically from crest to hollow. The plantations were irrigated by letting water into 
the channels between the ridges. 

In theory the plantations were irrigated at 15 day intervals from August to Iferoh. In 
practice this was not often attained. During periods of water shortage cotton and other 
crops had priority, and so one or more waterings might be missed at times of high water 
demand, particularly in September and October. On the other hand, the plantations were 
often used as dumping grounds for surplus water and some suffered from waterlogging. Thus 
increment rates have been very uneven, ranging from just over one to nearly 10 nH/ha/year. 
A good average yield from fairly regularly watered plantations would be about 6 nvi/ha/year 
for first rotation trees, with about 25 per cent more from subsequent ooppice rotations. 
The normal rotation is 8 years for the first rotation, and 6 years for subsequent ooppice 


In the early 1960 ! s work was begun on the establishment of an irrigated "Green Belt" 
to the south of the city of Khartoum. The first part was irrigated by purified effluent 
from the recently installed Khartoum sewage works; later extensions received their water 
from a canal. In this area year-round watering was possible, and thus a much wider range 
of species could be grown. Among the more promising are ConooarpuB lancifolius, Eucalyptus 
cans Idulen sis, and E. teretioornis (especially the %sore provenance) . 

The Khartoum Green Belt included some areas of very saline soils, and there were 
doubts on how these would behave under irrigation. However, in the early stages at any 
rate, although there was considerable deposition of salt at the soil surface in some 
places, it was still possible to grow satisfactory tree crops. 

Water Requirements 

Water needs will vary with the climate, the type of soil, the species of tree to be 
grown, and the method of application. Obviously in hot, dry climates where there is a 
high rate of potential evapo-transpiration the amount of water needed will also be high. 
A very permeable soil, which allows much of the water applied to percolate to beyond the 
rooting depth of the trees, will need more water than a less permeable soil; in permeable 
soils there will also be greater losses in canals, unless these are lined. Drought tolerant 
species will need less water than more mesophytic species. Water requirements can be 
reduced by special methods of application (see below). 

In the Sudan Gezira reasonable growth of Eucalyptus microtheoa has been obtained from 
the application of about 1100 mm of extra water, by irrigation per year, but Peggie (196?) 
considers about 1700 mm is necessary to obtain optimum growth. In the Central Gezira the 
total amount of water received, including rainfall, would be about 1550 and 2050 mm 
respectively. In Pakistan the optimum water requirements of five year old Dalbergia sissoo 
were estimated at 1200 mm, but rates as high as nearly 2000 mm were applied (Siddiqui, 
1967) In Iraq, GVLlgur and Nouri (1975) estimate water application in existing plantations 
at between 200 and 800 mm annually, but suggest that optimum water requirements might be 
considerably higier (1200-1360 mm). All this data is from furrow irrigation. 

- 171 - 

Quality of Water 

The lower the salt-content of the water, the more suitable it is for irrigation. In 
this respect the Sudan (Jezira is fortunate, in that the Blue Nile water has a low salt 
content and is of high quality. However in other countries, especially Kuwait and Abu 
Dhabi, water of a fairly high salt-content has been successfully used for irrigating tree 
crops. If saline water is used, larger quantities must be supplied, to leach the salts to 
depths where they will be harmless to the threes (Wormald, undated). 


The most common method is by furrows, either very large furrows as used in the Sudan 
plantations, or in smaller trenches for instance 30 cm deep, as in Pakistan. In the 
Khartoum Green Belt, where furrows 2 m wide by 60 cm deep were used, Bosshard (1966) 
found some advantages in applying water to every second or third furrow only once the 
trees had established their root systems (one year or more after initial planting). The 
use of very large furrows, as in the Sudan, will tend to increase losses of water by 

Flood irrigation, of level land, has generally been found to be impracticable for 
tree crops, as it is very difficult to obtain uniform distribution of water using this 

Of more sophisticated methods of irrigation, rotating sprinklers were used at Msilam 
Fatori on the shores of Lake Chad in Nigeria, to establish a provenance trial of 
Eucalyptus oamaldulensis. This was on a permeable lacustrine sand, and irrigation was 
applied for one year only, until it was considered that the tree roots had reached the 
water table. Over most of the area results were very good, the trees of the best 
provenance producing an average of 8? m3/ha (solid volume) at the age of 4 years. On a 
small area of slightly higher ground, more distant from the lake, growth was poorer and 
there were some deaths from drought. This method, although needing a fairly heavy capital 
outlay, is worth considering in areas where there is a high water table, and only 
temporary irrigation is needed. 

Drip irrigation, developed originally for fruit trees, has been used for establishing 
forest plantations in Abu Dhabi (Wormald, undated) and experimentally in Pakistan (Sheikh 
and Masrur, 1972). In Abu Dhabi the water is pumped from wells to a control head and 
filter. Prom the control head it is piped through polyvinyl chloride laterals 10-15 in 
diameter, which are provided with nozzles at intervals. These nozzles are designed so , 
that, provided a constant pressure is maintained in the drip lines, a fixed quantity of 
water per hour is delivered through each nozzle. One nozzle serves each tree. This is 
again a method requiring a high capital outlay, but is the most economical in the use of 
water: in the experiments in Pakistan, drip irrigation used only 22 percent as much water 
as trench irrigation, and 15 percent as much as flood irrigation. 


Here it is impossible to generalize. The use of Eucalyptus microtheoa in the Sudan 
Oezira was dictated by the peculiar circumstances there, in the soil type and in the times 
at which water was available. For most other areas it is probable that better species can 
be found. Some further references to choice of species for irrigated plantations, and on 
irrigated plantations generally may be found in Laurie (1974) pp. 44-47, 49 f 52 f 114-115? 
and 141. 

- 172 - 


Bos shard, WC. Irrigation Methods in Khartoum Greenbe It * Forestry 

1966 Research and Education Project, Sudan* Pamphlet no* 21. 

Foggie, A* Forestry and Forest Policy in the Gezira Area. Rome. FAO, 

1967 TA 2411- 

Gttlc,ur, M. and Nouri f A. Planning of Irrigated Tree Plantations in Iraq. UNDP/FAO 

1975 Baghdad. FO: SF/IRQ 518, WS/15. 

Laurie, M.V. Tree Planting Practices in African Savannas. FAO Forestry 

1974 Development Paper No. 19. Rome. FAO. 

Siddiqui, K. M. Irrigated Forest Plantations in West Pakistan. Prooeedinge 

1967 of World Symposium on Forests. Canberra, 


Sheikh, M.I. & Mstsrur, A. Drip Irrigation - A new Method of Irrigation Developed at 

1972 Pakistan Forest Institute Peshawar. Pakistan J. For. 

22: 446-462. 

Wormald, T,J. Some Notes on Nursery Practice in Abu Dhabi. (Mimeo.) 


- 173 - 


J.C. Delwaulle 

Centre Technique Forestier Tropical 
Nogent-sur-Marne f Prance 



Live hedges 174 

General remarks 174 

Tree species that can be used 174 

Proeopis 174 

Acacia 175 

Parkinson i a aculeata 175 

Ziziphus 175 

Bauhinia refescens 175 

Planting of live hedges 176 

Windbreaks 176 

Winds 176 

Effect of wind 176 

Windbreaks 1 76 

Windbreaks as mechanical obstacles 176 

Effect of windbreaks on microclimate 177 

Planting of windbreaks 177 

Environmental forestry 178 

Formation and development of sand dunes 178 

Sand dune fixation techniques 179 

Planting of sand dunes with trees 179 

J/ Paper for Symposium on Savanna Afforestation 

- 174 

The term shelterbelts will be used to embrace live hedges and windbreaks This 
paper is confined to arid tropical Africa* 


General Remarks 

Prom experience in recent years one can make some very positive statements on certain 
points pertaining to the growing of live hedges in the Sahel-Sudan zone, viz: 

a) Any planted stand not protected during the first three years of life is doomed 
to failure. 

b) No live hedges are absolutely impenetrable to livestock, particularly goats, 
either because of failed spots or because the lower portion of plant stems 
become more or less bare in time* 

c) Not even barbed wire fences will keep livestock out; a common sight is goats 
forcing their way on the run into areas protected with five rows of barbed wirel 
Fencing of this type moreover never resists the assault of large animals very 
long (by large animals is meant cows, camels, antelopes, giraffes, etc*). 

d) The combination of live hedges plus barbed wire fencing provides almost complete 
protection against invasion of protected areas by animals. Prom the above it 
follows that live hedges should be planted inside enclosed areas up against the 
fencing which delimits them. 

Tree Species that can be Used 

The main reason for planting live hedges is to protect certain areas against 
intrusion by animals. The species to be used must therefore form a continuous shield that 
is difficult for animals to break through because of entanglement of branches and/or the 
presence of thorns or prickles. The species used should be of limited height and pruning, 
clipping or cutting should be possible. 

If it is possible to make a choice between several species, other possible uses of 
live hedges should be looked into, namely, supplying forage or fodder, or producing edible 
seed, nuts or fruit. 

Pro so pis 

Prosopis juli flora (= P. chilensis), or mesquite, is a spiny deej>-rooted tree or shrub 
of southwestern USA, Mexico, Venezuela f Peru and Colombia. This is the species most commonly 
used as live hedges due to its rapid growth, ease of producing nursery stock, the high rate 
of "take" on appropriate soils and its ease of clipping* Disadvantages are its small 
spines, which make it not entirely impenetrable, and its tendency to shoot up in height so 
that frequent topping is necessary. 

Seeds* Prosopis seeds number from 20 000 to 35 000 per kg. Fruiting occurs around 
the month of March. When old seeds are used it is necessary to dip them in boiling water 
and then let them cool for 24 hours before sowing* 

Additional uses* Prosopis is also used for fuelwood and stakes bearing inscriptions* 
The leaves yield an excellent forage or fodder and their shoots are relished by animals. 
There are 0*70 forage units per gross kg containing 75 grams of digestible protein per gross 
kg* The dry matter yield per hectare may amount, in irrigated plantations, to twelve tons 
per year. 

- 175 - 

Soil* Prosopis adapts well to many types of soil except those that are two sandy or 
in bottomlands so wet as to asphixiate it. 


There are about 24 species of Acacia in Africa but only a few of them have been 
experimented with as live hedges* 

Acacia nilotica var. adansonii. This species is particularly well adapted to arid 
lands and can also grow fairly well on sandy soils. Its rate of growth, although less than 
that of Prosopis is fairly rapid. The size (from 6 to 10 cm) of its very hard, straight 
white thorns makes it a species that is highly recommendable as a live hedge. 

Seeds are collected in December in stands along watercourses and near stagnant ponds. 
The seed has to be scarified in boiling water before being sown. It is sown directly in 
pots in March, with an 80 percent germination rate. 

Acacia seyal. This Acacia is usually grown on loam or sandy clay soils that are 
flooded during the rainy season. Sometimes however it is found on hill crests that remain 
dry all year round f so there could be several races. When grown as live hedges it gives 
good results | and this is probably also true of its close relative, Acacia ehr en ber gi ana , 
which is suited to drier soils. 

Acacia ataxacantha. We have had only limited experience with this sarmentous or 
rambling species which, because of the intertwining of its branches and its big thorns, 
should be excellent for live hedges. The plants are easily grown in nurseries but we have 
always found that when it was planted out in the field the "take 11 was not good. We do 
know of one instance of a successful planting of a live hedge of this species. 

Parkinsonia aculeata 

This sarmentous bush has terrible thorns, but if not pruned quickly it tends to 
become barren at the base. This species succeeds better on heavy than on sandy soils. 
Paradoxically, the finest specimens that we know of are found at far northern latitutes 
(Agad&z, Niger, 17N) with a rainfall of 150 mm. 

The seeds have to be emersed in boiling water prior to sowing. The seeds are 
gathered from November to February and sown in pots or in beds from January to February. 
When planting in pots care has to be taken to move them occasionally because of the taproot 
which tends to grow out of the pot quickly. 


There are in the Sahel several species of Ziziphus, the most common being Z._ 
rnauritiana and mucronata. The seeds have to be sown in pots because pricking out is a 
very delicate matter. Sowing is done toward mid-February. Raising in nurseries and 
plantation is easy, and the live hedges are particularly thick and inextricable, although 
once they have been set out in plantations growth is rather slow. 

Bauhinia refescens 

This species produces one of the best live hedges we know of. There is virtually 
no problem with it in the nursery (sowing is done in January or February) and it adapts 
well to a wide range of soil types. Take is not always excellent however. 

- 176 - 

Planting of Live Hedges 

Planting should be done as soon as the rainy season starts, usually about 15 July. 
A good live hedge consists of two f or even better three f rows of plants spaced 80 cm apart 
in quincunx formation* Prior to planting subsoiling should be done or else 50-cm deep 
trenches should be dug and re-filled. Topping the plants in the nursery (cutting 5 cm from 
the top when the plants have reached a height of about 20 cm) favours the growth of low 



There are two wind regimes in the continental Sahel - dry season winds and rainy 
season winds. The harmattan dry season wind blows very regularly each morning from about 
9 to 13 hours from November to March. It is a hot, dry wind usually from the northeast. 
Rainy season winds are much more regular and may blow in real squalls from May to 
September, generally from the south or southwest. 

Windbreaks aligned in the NW to SE direction will therefore be of maximum effectiveness 
against either the harmattan or the rainy season winds. 

Effect of the Wind 
Winds affect both soil and vegetation in several ways: 

a) by causing soil erosion; 

b) by mechanical impact on vegetation; and 

c) by affecting evapo transpiration. 


Here we shall discuss only live windbreaks consisting of trees or bushes or even 
simple rows of annuals such as millet, sorghum and certain grasses (Pennisetum pur pur e urn ) . 

Windbreaks as Mechanical Obstacles 

A windbreak separates two zones: the windward one, that is, the one on the side from 
which the wind blows, and the leeward one, that is, the one on the side where the wind 
passes. As a rule it is said that a windbreak protects a distance up to its own height on 
the windward side and up to 10 to 12 times its height on the leeward side. 

The effectiveness of the windbreak depends on its permeability. Low permeability 
lessens the speed of the wind but because it creates turbulence, the protected area is 
smaller. Optimum permeability is that with 40 to 50 percent of space (i.e. 50 to 60 percent 
density of vegetation). Gaps in the hedge are particularly dangerous because the wind 
rushes violently into them; therefore, windbreaks must be continuous. The thickness of 
windbreaks is of little importance and, provided that there are no gaps in theory, a single 
row of trees suffices. 

Windbreaks should be at least 12 times as long as they are tall in order to eliminate 
turbulence along the sides* 

- 177 - 

Maximum protection is afforded when the windbreak runs perpendicular to the direction 
in which the wind blows, so it is very important before planting windbreaks to make a thorough 
study of local winds and make a graphic representation showing the relative strength of the 
winds blowing from different directions. 

The length of the protected zone (10 to 12 times the height of the windbreak) is 
lessened as the speed of the wind increases so it is almost always necessary to plant 
several parallel successive rows in order to protect large areas.' Optimum spacing between 
rows is from 10 to 20 times the height of the windbreak. Closer spacing increases air 
turbulence and diminishes the effectiveness of the system, 

Effect of Windbreaks on Microclimate 

Windbreaks in addition to presenting mechanical obstacles also affect the microclimate, 
and the importance of this is no less great than that of reducing wind speed. Generally 
speaking, windbreaks diminish evapo trans pi rat ion. Experiments conducted in the USSR in 
1953 enable certain authors to state that water losses due to evaporation are reduced by 
at least 20 percent in the shelter of windbreaks. This reduction of evapo trans pi rat ion 
leads to increased photosynthesis in the vegetation, the stomata remaining open for a 
longer part of the day. In arid zones, however, windbreaks cause increased evapotranspi- 
ration due, in particular, to the fact that they themselves evaporate large quantities of 
water; to compensate for this water deficit it is necessary to irrigate. 

On the other hand, as a rule windbreaks even out extremes of temperature, raising 
the lowest temperatures and lowering the highest, which helps provide better growing 
conditions for vegetation. 

The result of these changes in microclimate is markedly increased yields of the 
protected crops. 

Yields decrease slightly in close vicinity to windbreaks due to the effect of 
shading and to competition of the plant roots, but this competition occurs only on a strip 
of land not more than half the height of the windbreak in width while yields of cereal 
grains on the entire plot may be increased by as much as 40 percent. This increase is 
higher in dry climates with plants whose roots do not penetrate deep, such as prairie 

Summing up, windbreaks are always beneficial to crops not only because of the pro- 
tection they afford against the mechanical impact of the wind but also due to their 
influence upon the microclimate due to a marked increase in photosynthesis of the plants 
that is translated into a higher crop yields. In arid zones the use of windbreaks should 
however be confined to protection of irrigated districts. 

Planting of Windbreaks 

The most usual type of windbreak consists of one or several rows of trees. 
Theoretically, one row should suffice because windbreak width is to little importance, 
but it is always possible that several trees will die leaving a gap which spoils the 
effectiveness of the entire windbreak. Furthermore, when the trees are cut it is necessary 
to be able to leave at least one row standing in order for the windbreak to continue to 
perform its function. Finally, young trees are better protected against violent winds if 
planted more thickly. Experience has shown that the most effective windbreaks are those 
consisting of at least four rows of trees, that is, those from 10 to 12 m wide. 

If the windbreak reaches 10 m in height and protects a strip of land 12 times that 
height, windbreaks 10 m wide should be set out every 120 m. The maximum amount of land 
that they occupy with their roots is 20 m (10 m for the windbreak proper plus 5 m of roots 
extending on either side), all together 16 percent of the cropland. This seems to be a 
reasonable proportion considering that crop yields may be increased by as much as 40 percent 

- 178 - 

because of the combined mechanical and physiological effect of windbreaks on the vegetation; 
but it is best not to exceed this size of windbreak. 

The species used for windbreaks should insofar as possible have the following 
characteristics! adequate heigjvt, rapid growth, evergreen foliage, compact form, limited 
root competition and resistance to windfall and wind breakage* 

Planting should not be too close in order to allow sufficient air permeation of the 
windbreaks* Trees should therefore be spaced not less than 1*50 m apart* 

For the rest, the manner of soil preparation and planting are the same as those in 
conventional reforestation work (subsoiling or digging of holes 50 x 50 x 60 cm). However, 
since in this case what one is dealing with are row plantations usually cutting across 
grassland or cropland where animals are allowed to pasture on stubble or straw, special 
attention should be paid to the protection of crops or plantations, lest the success of the 
operation be jeopardized* To that end it may be advantageous to plant thorny vegetation 
along the edges of the windbreaks to protect forest tree species from livestock. 

Finally, no matter what species is used, the correct planting dates must be respected 
(cf Prosopis). 

Maintenance of the windbreaks is indispensable in order to: 

a) make sure that they remain continuous (obviously replacement of any failed 
trees is necessary) and 

b) prevent them from becoming too thick and consequently absolutely impervious to 
wind; the branches therefore have to be clipped or trimmed frequently. 

It is best not to top the trees, since the size of the protected zone depends on the 
height of the windbreak. 


Under this heading one could discuss planting of woodlots inside or around the large 
towns of the Sahel and even the growing of ornamental trees. We shall not elaborate on 
these points, however, except possibly during the discussion, considering it preferable 
here to speak of the role of trees in sand dune fixation, a very important matter for 
maritime countries. Senegal, for instance, is at present taking new steps along these 

Formation and Development of Sand Dunes 

Whenever regular violent winds blow over vast expanses of sandy desert, sand dunes 
are formed. There are continental dunes, particularly in the Sahara, but more often such 
dunes are formed along the sea coast, on the sandy shores at sea level swept by regular 
winds (in Africa and Madagascar, usually the trade winds). 

When sand dunes are not covered with vegetation or when, for any reason whatsoever, 
whether it be repeated passages over the land, pasturing or grazing of herds and flocks, or 
cropping, whatever vegetation once covered them has been destroyed, they start to move in 
the direction of the wind at a speed which may attain as much as 10 m per year. When this 
happens they cover everything as they move along - crops, plantations, roads and railways 
and sometimes even houses and villages; all the inhabitants can do is to abandon land 
invaded by moving sand dunes. 

To prevent this from happening and in order to protect engineering works and crops 
against being covered with sand, the vegetative cover has either to be established or 
re-established, this being the most effective protection against soil erosion. However, 

- 179 - 

in order to establish vegetation on moving sand dunes, it is necessary first of all to fix 
them using techniques that are both delicate and costly. 

Sand Dune Fixation Techniques 

One technique for fixing coastal sand dunes was devised in Europe in the last century; 
it can be applied without great change in Africa and Madagascar except of course as regards 
the plant species to be used. 

The first operation consists of constructing as close as possible to the sea an 
artificial sand dune, called the coastal cordon, in order to stop the piling up of more 
sand on the dunes. The way to start is by erecting along the coast a 0.75 to 1 m high 
wattle fencing; this wattle fencing is composed of wooden stakes driven into the sand and 
tied together by branches sufficiently closely matted to form an obstacle to the sand 
blown against it by the wind. The grains of sand pile up behind this palisade and when the 
little hill thus formed reaches a height of 0.50 to 0.75 m, a second wattle fencing is 
built up on top of it and so on until one has a dune of a slope and of a height such that 
it is impossible for the sand to be blown up over it. For a 30 to 40 percent slope this 
equilibrium soil profile is reached in 2 or 3 years. If the sea coast runs obliquely to 
the direction of the prevailing winds, it IB necessary in addition to construct transversal 
spurs that will prevent the formation of "whistle holes 11 into which the wind penetrates. 

It then is possible to fix the sand dunes behind the coastal cordon by planting 
either slips or seed of plant species that provide good ground cover and are able to 
withstand being at least partly buried in sand. Ammo phi la arenaria, which is very useful 
in Europe and North Africa, does not give good results on the sand dunes south of the 
Sahara or in Madagascar. There one must preferably use local, rapid-growth species with 
creeping roots which make it possible to get a hold on the sand quickly; in Madagascar the 
best is a plant of the Convolvulaceae family, Ipomea pescaprae, which sprouts very easily 
and quickly covers the soil. Certain grass species can also be tried under the same 
conditions, namely Sporobolus spicatus. Aristida stipoides, Panicum turgidum. . ^ dune 
fixation trials have also been conducted in the Adamaoua ( Northern Cameroon) with Stylosanthes 
gracilis . Melinis tenuissima. Digitaria unifolozi, Cynodon dactylon and Pennisetum. 

Such vegetation has a threefold purpose: the aerial portions act as a windbreak at 
ground level; the debris consisting of leaves, stems, pods etc. provides a dead cover which, 
as it decomposes, enriches the sand with humus; and, finally, the creeping roots hold the 
sand and help stabilize the dunes. 

Despite the rapidity of growth of the plants used for sand dune fixation it sometimes 
happens that the seeds or the slips are either exposed by the wind or buried in sand, so 
in regions where the winds are particularly violent it is neoe -W to keep tte sand down 
by means of cover materials before undertaking any sowing or planting of slips. The 

are generally plant debris - branches, palm leaves, etc ., gathered in the 

or woods. Since several tons are required per hectare, their transport 

a difficult problem and considerably increases cost prices of such fixation 


On the areas most exposed to wind it is also possible to dt> some dense checkering, 
that is sei ott sJuareiTof wattle fencing dug into the sand. Obviously plants will 
grtw mucJ bettfr if protected by such wattle fencing than without. 

Planting of Sand Dunes with Trees 


- 180 - 

The species most commonly used are: 

a) Arborescent species 

Acacia cyanophylla, A. ataxancantha 
Casuarina e cruise ti folia (filao) 
Pro so pis africana and JP. juliflora 
Eucalyptus spp. ; E. carnal dul ens is 

b) Bush species 


Euphorbia balsamini f era 

At ri pi ex halimus 

Gymnosporia Senegal ens is 

So Ian urn sp. (tsingivy of Madagascar) 

It is necessary to set out fairly large f nursery-grown plants very close together, 
that is to say 1 x 1 m on the side exposed to the wind and 2 x 2 m on the sheltered side* 
Such planting is customarily done at the onset of the rainy season* 

In arid climates , it is much more difficult to plant trees on sand dunes already 
colonized by grass vegetation than on barren sand dunes because of the considerable 
competition of the roots for water and because the presence of already well developed root 
systems hampers the "take" of young plants. It is therefore preferable to plant the trees 
at the same time as the grass vegetation; this always gives a definitely better take. 

Plantations must be well maintained, as always in the tropics; this must be done by 
hand to avoid having machinery criss-cross the sand dunes. In fact as a rule, all traffic 
on sand dunes must be prohibited and especially all movement of livestock, as this again 
destroys the vegetation, the sand then becomes mobile and the dunes begin their march once 
again. If it is absolutely necessary to allow livestock to cross the sand dunes, they 
should do so by routes marked ahead of time where constant surveillance is practised. These 
routes should, as much as possible, run obliquely to the slope and to the direction of the 
winds; they should be protected and delimited on either side by hedges of bushes, whether 
thorny or not, viz: Euphorbia balsamini f era , Opuntia, Fagara xanthoxlo ides and Acacia 

- 181 - 


A.V. Pox 

Forestry Division, North-Eastern State 
Maiduguri, Nigeria 


Introduction and Background 1 81 

Species/Growth/Provenance Trials ^? 

Fertilizer Trials 18 4 

Site Planning and Layout 1^5 

Plantation Establishment 1 86 

Hillside and Afforestation Management 187 

Summary and Conclusion 1 88 

References 1 $8 


The Mambilla Plateau, situated on the eastern border of Nigeria and at the southern 
extremity of the North-Eastern State, forms part of the Cameroon Highlands geographically 
and is an extension of such. The plateau occupies an area of approximately 1 500 square 
miles (388 500 hectares) with a high proportion of it topographically gently undulating to 
steep slopes. Afforestation started in the early 1940 f s with introductions from the 
Cameroon Republic (Fox, 1973), and continued on a local moderate scale until 192 when the 
Mambilla Afforestation Scheme was first started under the First National Development Plan. 
This plan has been enlarged through successive plans, and a Hillside Afforestation Scheme 
has also been added to the present Forestry Development Programme, which was initially in- 
troduced in the Second National Plan 1970-74. 

Land use allocation on such a potentially productive area results generally in for- 
estry being given the steepest slopes. Although there is a need for the afforestation of 
the steep slopes, there is also a need for large scale mechanised plantations which require 
relatively gently sloping areas. A large part of the government and local authority Affor- 
estation programme, however, has been confined to the steep, eroded hill slopes, and has been 

thTflattet areiB^r B bya^l means on the steeper, eroded slopes. 

_!/ Paper for Symposium on Savanna Afforestation 

- 182 - 

The altitude of the main stations on Mambilla varies from 1 524 m to some 1 981 m. 
The annual rainflall at Oembu is 1 981 mm with some slight variations over the rest of the 
plateau. The mean monthly temperature is probably 85F (Kemp, 19^9) and minimum monthly 
temperatures are generally around 50F. There is a heavy oattle population in the area and 
the soils are subject to over grazing and annual burning and consequently there are signs 
of accelerated erosion in some of the steeper areas. These steeper sites for afforestation 
are f therefore, shallow highly acidic lithosols with a silt loam texture and free drainage, 
developed under a temperate, high rainfall climate. 

Provenance trials can indicate the best species/ provenance for a particular site. 

Replicated species elimination trials of pines and eucalypts were started on the 
plateau in 1966 at Maisamari, Nguroje and Gembu. Of all the Eucalyptus species/provenances 
tested in the programme, none is as successful as the long established Eucalyptus grandis 
hybrid. Of the pines, . caribaea, . kesiya and . oocarpa were selected for further 
testing after the initial elimination trials. The results of a species elimination trial 
at Nguroje, planted in 1966 on basalt soils, Number SM2/66/1 is as follows: 

Table 1 

Mean height and survival of coniferous species trials planted in 1966 



Mean height (m) after 

Survival % after 

32 months 

46 months 

32 months 

46 months 

Cupressus lusitanica 






Pinus ayacahuite 






P. caribaea 






P. kesiya 






P. mas s on i ana 

Hong Kong 





P. montezumae 






P. oocarpa (I. 1136) 






P. oocarpa (l. 1157) 






P. pseudostrobus 






P. teocote 






Species growth trials commenced in 1967 with mainly four pine species which were 
planted in four large replicated blocks per species and at the normal plantation espacement 
of 3 m by 3 m Further development of species/ provenance testing was limited by the avail- 
ability of seed, and thanks must be recorded to the Federal Department of Forestry, Ibadan, 
Nigeria and to the Commonwealth Forestry Institute, Oxford, U.K. who provided all of the 
seed for the further trials. 

- 183 - 

Table 2; Summary of mean height, maximum height and survival, 
% of 4 year old P. caribaea and P. keaiya, 
provenance trial7 Maisamari, Mambilla. 



Basalt Site 

Basement Site 

ht (m) 

ht (m) 



ht (m) 

ht (m) 


P* caribaea 

Gt. Abaco, 
















Puerto Cabezae y 







P. kesiya 

Baw Luang, 








S. Vietnam 
















Khasi Hills, 















Table 3t Summary of mean height, maximum height and survival % of 

3 year old P. oocarpa provenance trial, Nguroje, Mambilla, 


ht (m) 

ht (m) 



K1 1/70 Nicaragua/Came lias 




K7 7/70 Honduras/San Marcos 




K9 9/70 Guatemala/Canas 




K34 3/71 Ouatemala/Bucaral 




K35 4/71 Honduras/Angeles 




K36 5/71 Honduras/Zamorano 




Oxon 1.2326 Guatemala/El Lobo 




K44 27/71 Nicaragua/Rafael 




- 184 - 

Two provenance trials of . oaribaea and P. kesiya were planted on the soils derived 
from basalt and granite at Maisamari in 1971 In 1972, 113 g of superphosphate was applied 
to eaoh plant and after 4 years, . kesiya from Dalat, South Vietnam, was dominant on both 
sites. The mean height on the granite soils was 5*7 m and on "the basalt soils 6*3 m. For 
the trial results see Table 2. 

A P. oooarpa provenance trial was planted at Nguroje in 1972 on a soil derived from 
basalt* Tfter three years, the provenance from Rafael, Nicaragua, was superior with mean 
and maximum heights respectively of 4*9 and 7.2 m, whereas the poorest provenance was one 
from Guatemala with mean and maximum heights respectively of 2.8 and 4.6 m. Both Nicaraguan 
provenances were superior to the rest* For full results see Table 3* In any plantation 
development programme it is essential that selected seed should' be available in commercial 
quantity and that a local programme be designed and implemented to produce future seed 


In 1966, McComb, Ojo and Jackson (1970) conducted a laboratory experiment of the 
Fertilizer Response of IS. grand is grown in a basaltic soil from the Mambilla Plateau 1 . 
The results suggested that it would be virtually impossible to grow JE. grandis from seed on 
subsoil exposed by erosion, unless fertilizers were applied. Phosphate was indicated as 
the principal limiting element, but boron was also indicated as being necessary. 

Also in 1966, Jackson (1973) conducted experiments with borate and superphosphate 
on E^. grandis at Maisamari, Nguroje, on fairly level sites derived from basalt and at Gembu 
on an eroded steep slope derived from granite. At Gembu the fertilizers were applied to 
a two year old plantation which had been beaten up in the year prior to the application of 
the fertilizer. Borate was applied atQ f 57 and 113 g per tree and single superphosphate at 
O f 85 and 170 g per tree. At Gembu 113 g of borate gave a response but not 57 g. The in- 
crease due to super ph osphate was not significant. Generally, the application reduced ter- 
minal shoot die-back and leaf discolouration, thus improving the health and shape of the 
crown and hastening canopy closure. 

In 1972, Fox conducted three experiments at Maisamari on steep, shallow soils derived 
from granite. In the first trial in a fairly steep part of the P. 71 compartment, approxi- 
mately 123 kg/hectare eaoh of borate, borate and superphosphate and borate and sulphate of 
amonia were applied by a rear tractor mounted mechanical spreader. There was a significant 
difference between the untreated and treated areas. There appears to be no difference be- 
tween the formulations and the implication is to use the least costly treatment. The results 
are shown below in Table 4. 

Table 4: Correllation of height growth of IS. grandis 
hybrid and fertilizer applications" 1972. 

Treat ment 
On application 

Heights (m) 




Borate <k superphosphate 




Borate & ammonium sulphate 












- 185 - 

In trial 2, in the P. 72 oompartraent, ammonium sulphate and single superphosphate 
were applied by hand around the trees and below ground level at 0, 114 and 228 g per tree 
and borate at three levels of 0,57 and 114 g per tree in a single replioated experiment on 
a poor soil in a steep rooky area. Sixteen months after application the greatest responses 


Mean height 5.2 5.3 5.3 5.8 1.2 

increase (m) 

After 27 months, there appears to be a substantial response to N f although there is little 
difference between the two rates. There is some, though rather less, evidence of a positive 
effect of applying B. There is also some difference between plots receiving no P and those 
treated with 114 and 228 g per tree. 

In trial 3, boron was applied at two levels and in two forms as a granular fertilizer 
in a drill below ground level and as a foliar spray. All plots also received 114 g of 
single superphosphate. Twenty-seven months after application there were few statistically 
significant differences, although there was an indication that granular borate around the 
tree may be more lastingly beneficial than the foliar spray. 

Generally, any fertilizer application should be done in the year of planting and as 
soon as possible after planting to accelerate height growth, crown development and canopy 
closure. Hand application, preferably into the soil, is all that is possible on the steep 
slopes. Whereas on the gentler slopes, mechanical application is possible. 


Once suitable species and techniques have been evolved for the site through species, 
fertilizer and other trials, then the acquisition of larger sites can commence. Sufficient 
land must be obtained above and below the steep slopes for afforestation. Above the steep 
slopes, land must be obtained for roadways for access, plant distribution at the time of 
planting and for extraction of produce whenever necessary. Sufficient land must also be 
obtained above the slopes to arrest the surface flow of water down the slope by land use 
techniques and to promote ground water percolation. Contour ploughing and contour bunding 
are useful controls. Below the slopes, land is required for access at the time of planting 
and throughout the life of the plantation to the time of exploitation. 

The average slopes normally allow ready upper and lower access. However, on longer 
slopes, roads will be required at intervals along the contours. These roads are normally 
put in by mechanical means before planting starts while visibility in layout is easiest. 
The gradients should be enough to allow for the extraction of the produce throughout the 
life of the plantation. Natural features should be used where available, especially in the 
siting of the joining roads. Prom experience, it is of great advantage to have a road 
system throughout the plantation from the very start rather than making the roads when re- 
quired, often through young plantations. 

Some site grading is occasionally required on the over-hanging slopes and this should 
be done before planting starts to allow the site to resettle and to reduce site disturbance 
down the slope. Fencing against animals should be done as soon as possible and before 
planting on the current year's planting site. On Mambilla, use is made of natural features 
where possible and the steep sided streams make excellent boundaries where fencing is un- 
necessary. It is generally cheaper to fence the entire area initially than to fence only 
current planting areas. However, on the Mambilla Plateau it is good policy to allow cattle 
to graze over unplanted areas so long as they are attended by a herdsman. It is also good 
for public relations since the herdsmen see forestry as an acquisition of land lost to the 

- 186 - 

original cattle owners. Cattle are useful in controlling the grass growth, reducing both 
the fire hazard and the amount of cultivation required prior to planting. They also con- 
tribute manure to the site. They should be at all times controlled and kept out of the 
plantation areas and off the steepest slopes. 

Fencing and the exclusion of animals allow for the rapid recovery of the site if fire 
is also excluded, but is only a temporary solution, since degradation will follow when cattle 
are again allowed to utilise the site. A more permanent solution is to put the area under 
forestry with maintenance of canopy for the maximum period tinder the chosen silvicultural 

Nurseries should be sited within the plantation area and near to water. On long 
slopes over several kilometres it may be better to use temporary nurseries for each year's 
planting as long as water and labour are available nearby. For eucalypts, a three month 
nursery season from early March to early June is adequate for potted stock. After germina- 
tion in March much of the watering is from precipitation, since the rainy season normally 
starts in April. 

Labour shortage can be a much more serious problem, since hillside afforestation on 
Mambilla is a very labour intensive operation. It is worth trying to encourage labour to 
settle close to plantation developments since transport and labour availability are con- 
straints to such developments. At present most of the available labour reside in larger 
towns and villages and only limited numbers are available in more remote areas. The cattle 
owners do not generally contribute to the labour force, only the Mambilla farmers. 


Nursery techniques for Eucalyptus spp. are based on Fishwick (1966) with modifications 
to the semi -temperate climate of the area. Local humus and soils are used together with 
fertilizers and dieldrin in the potting mixture to produce strong trees of 0.3 m in height, 
balanced in root and shoot growth, with a reservoir of nutrients in the pot at planting time 
to encourage initial establishment. Tall plants are a disadvantage on the plateau due to 
the strong winds and occasionally have to be cut back after planting. For pine seedlings, 
an addition of ammonium sulphate and superphosphate to the potting mixture is recommended, 
but urea and potassium have been found to have harmful or negative effects. 

Site clearance, either mechanical or manual, of the grass cover norrrally occurs in 
April when fire can be used carefully to reduce the heavy grass. If fire happens to enter 
the area earlier, then grass regrowth can form a heavy sward by the time of site cultivation. 
It is, therefore, best to leave the clearing as late as possible to reduce the amount of 
labour involved. On the steep slopes, the site clearing should be done along the contour 
using heavy hoes to upturn the turf placing roots uppermost to dry in the hot sun. On 
gentler slopes, complete cultivation is carried out, but on the steep slopes cultivation is 
restricted to minimum contour lines about 3 metres apart. It should be noted, however, that 
grass not killed during the pre- or post-planting operation will survive throughout the ro- 
tation and responds as soon as the canopy is opened. Since grass is the main retardant to 
eucalypts, the question of the duration and periodicity of cultivation for successful estab- 
lishment is a matter of experience. 

The problems of plant distribution vary with the degree of slope, but mechanical 
means should be used to convey the pots as near as possible to the planting site. On the 
steep slopes, much on site distribution has to be manual. The seedlings are planted at 
about 3 m by 3 m and the whole of the pot is removed. Normally, the holes are prepared by 
a separate labour force and only a few labourers actually do the pot removal and planting. 

- 187- 

Approximately 4 weeks after planting, fertilizer can be applied to the plants. The 
area should be weeded first to reduce the competition for rooting space and available nutri- 
ents and then the fertilizer is applied manually in a slit below the surface, or by mechani- 
cal techniques on flatter sites. Afterwards, the area should be weeded as and when required. 
This is where experience is an essential asset. It is necessary to retain some weed cover 
to reduce the danger of accelerated erosion, but grass should be prevented from hindering 
the growth of the trees. 

Inadequate weeding causes trees to quickly show signs of ill health on the steep 
slopes but appreciation of such indications are often too late to rectify the situation that 
same season. As much as possible should be done in the year of planting to achieve a healthy 
vigorous tree which will continue to grow over the dry season and take advantage of the early 
rains for maximum growth opportunity in the second year. The weedings should be continued 
along the contour when required. On good sites canopy closure can be obtained 16 months 
after planting, i.e. just before the onset of the second dry season. Eucalyptus grandia 
hybrid will continue to grow throughout the dry season on good sites where fertilizers have 
been applied. If the technique is not correct, however, terminal die-back and leaf dis- 
colouration occur which require expensive treatment to return the crop to healthy growth. 
The use of selective weed killers has been tried on the plateau employing mechanical appli- 
cators. Such trials have been unsuccessful due to the high cost of the weed killer, the 
slow rate of application and the quick recovery of the grasses. Herbicides, however, are 
worth further trials. 

Modern technological advances are tending to overcome the inherent difficulties of 
species utilisation (Hardie, 1974? Alders, 1975) an d at present for the steep slopes on the 
plateau, E. yandis hybrid can be recommended for rapid site coverage and for the production 
of large volumes of wood as a utilisable resource. 


Protection should always be the prime consideration on steep slopes, but once a large 
wood resource is available there is likely to be a demand to utilise tbiu basic raw material 
for some industry. 

End use will no doubt influence what system is to be used in the management of the 
established forest. For small size fuel, poles and timber, a coppice system will be suffi- 
cient and has several advantages for steep slopes. If larger size timber is required, a 
selection or clear felling system will be employed according to the requirements of the 
species used. Coppice systems have the advantage of rapid site recovery and are suitable 
for the management of . grandis hybrid on steep slopes. However, experiments conducted on the 
plateau, indicate that~maximum coppice regeneration is obtained at the height of the rains 
when forest produce is not normally required in any quantity locally. Such forest produce 
as poles and firewood is normally required in the dry season when coppice regeneration 
results in up to 2?fo stump mortality. On high rainfall areas greater site protection is 
necessary during the exploitation period but this is to some extent counteracted by the 
faster growth and speedy site recovery. 

Although most of the silvicultural and management problems in the selection and 
establishment of the best species for particular sites have been dealt with, research on a 
local scale should continue to select superior breeding material and to produce superior 
seed. Infact, such a programme which would confer benefits both locally and nationally 
might be a matter of some priority. 

- 188 - 


The afforestation of steep and eroded slopes free of tree vegetation and with shallow 
soils requires the selection of a fast growing tree species employing establishment tech- 
niques giving speedy establishment. Local species should be studied first but if no local 
species are suitable, a much longer process of species and provenance trials has to be tried. 

After initial selection, there is room for further improvement through more advanced 
provenance trials and trials of establishment techniques. A research arid development pro- 
gramme is required to further improve the selected species, and in the longer term to pro- 
duce the estimated requirements of improved seed. 

Having selected the species, for a large afforestation scheme where protection is the 
primary requirement, there is always the risk that demand for woody raw material could have 
an adverse influence on the silviculture and management of the plantation. Where possible, 
such demands may be aocomodated within the programme, but the primary protection objective 
should not be sacrificed. 

Fortunately on the Mambilla Plateau the species E. grand is hybrid was established and 
suited the forestry requirements, but even so f for the past 10 years species, growth, proven- 
ance and fertilizer trials have been conducted to try and improve efficiency and economy of 
establishment. With E. grandis hybrid, the fertilizer trials have been the most directly 
productive. Other Eucalyptus species and growth trials have not produced a comparably pro- 
ductive tree. However, with the introduction of the pines, two Nicaraguan provenances of 
Z* oocftTPQ' an d- "the southern Vietnam provenance of JP. kegiya, have shown promise for further 
development. At present a provenance trial of Cupressus lusitanica is required to try out 
the new canker resistant strains and to select provenances with finer and less persist ant 
branches. Such a selection might then be suitable for development. The improvement of 
species and techniques is a long term programme and requires continuity of supervision and 
well defined long term management objectives. 

Alders, L. 

Bawden, M.G. & Tuley, P. 

Fishwiok, R.W. 

Fox, A.V. 

Goodman, K. 

Hardie, A.D.K. 


New Zambian mill saws plantation Eucalyptus with gangsaw, 
circle saw lines. World Wood, July 1975 Vol. 16, 
No. 7. 

The Land Resources of Southern oardauna and Southern 
Adamawa Provinces, Northern Nigeria. Land Resources 
Study 2. Directorate of Overseas Surveys, Tolworth, 
England . 

Irrigated Nursery Practice Instruction. Ministry of 
Animal and Forest Resources, Kaduna, Nigeria. 

First year post planting assessment of Pin us kesiya^/Pinus 
oaribaea provenance trial, Mambilla, Nigeria. Tropical 
Provenance and Progeny Research and International Co- 
operation, Edited by J. Hurley & D.J. Nikles, 1973 C.F.I., 
Oxford, England. 

Baptist Mission, Gembu Mambilla, Nigeria, 
c ommunicat i on . 



Zambia. Commonwealth Forestry Review, Vol. 53 (4) 
No. 158, December 1974. 

- 189 - 

Hepper, F.N. 

Hepper, F.N. 

lyamabo, D.E., Jackson, J.K. & 

Ojo, G.O.A. 


Jackson, J.K. 

Kemp, R.H. 

McComb, A.L. f Ojo, G.O.A. <fc 

Jackson, J.K. 


Mould, A.W.S. 

Nash, C.A.M. 

Pryor, L.D. 

A botanist in Adamawa: Part 1, Mambilla Plateau. 
Nigerian Field, 27:100-122. 

Outline of the vegetation and flora of Mambilla Plateau, 
Northern Nigeria. Bulletin de 1'I.F.A.N. T. /CKVIII, 
ser. A, n1, 1966. 

Pine Trials in the Savanna Areas of Nigeria, Research 
Paper (Savanna Series) No. 11. Federal Department of 
Forest Research, Ibadan, Nigeria. 

3ome Results from Fertilizer Experiments in Plantations, 
Research Paper (Savanna Series) No. 23 Federal Depart- 
ment of Forest Research, Ibadan, Nigeria. 

Trials of exotic tree species in the savanna region of 
Nigeria. Part 1. Research Paper No. 4, Savanna Forestry 
Research Station, Samaru, Zaria, Nigeria. 

Fertilizer response of Eucalyptus grandis grown in a 
basaltic soil from Mambilla Plateau, Nigeria, oavanna 
Forestry Research Station, Samaru, Zaria, Nigeria. 
Research Leaflet 2. 

Report on a Rapid Reconnaissance 3 oil survey of the 
Mambilla Plateau. Bulletin No. 15, Soil ourvey Section, 
Regional Research Station, Ministry of Agriculture, 
Samaru, Zaria, Nigeria. 

Notes on a visit to the Mambilla Plateau during 
January, 1965- Ministry of Animal fc Forest. Resources, 
Zaria. (Unpublished) . 

Report on the Present Performance and Prospects of 
Future Development of Forest Plantations of Eucalyptus 
in Nigeria, for Savanna Forestry Research Station Samaru, 
Zaria, Nigeria. 

- 190 - 


M.O. Orode 

Savanna Forestry Research Station 
Samara, Zaria, Nigeria 

B. Adeka 
Forestry Division, Jos, Nigeria 

T.G. Allan 
Forestry Departmenx, FAO f Rome, Italy 



Introduction 190 

Plateau Climate, Weather and Vegetation 191 

Restoring Tin Mining Land 192 

Site preparation and fertilization 192 

Species of trees planted 193 

Problems and Future of Mine Reclamation Areas 193 

Conclusion 195 

References 195 

Table 1} Growth of Eucalyptus on mining spoil and on undisturbed soil 194 


There has been extensive open-cast mining on the Jos Plateau for the past 60 years. 
The mining operation leaves a desolate landscape of earth mounds, dried out mud ponds, tin 
tailings and reservoirs which render the land unproductive for agriculture, forestry or 
grazing, without expensive rehabilitation programmes. 

A recent (1972) aerial photography of mined areas indicates that the tall steep- 
sided earth dumps cover a relatively small area of a mining lease and that the network of 
paddocks and tin tailings covers a much larger area. 

The 1973 - 1974 estimate of the Government of the Federal Republic of Nigeria puts 
the total revenue from mining at M 336 872 264 -2/ Of this value, the greater part came 
from the Jos Plateau. At present the area of land held under mining leases for tin and 
other minerals on the plateau exceeds 81 000 ha. A conservative estimate of the area 
actually disturbed by active mining is in the region of 26 730 ha. As Howard (1974) has 
pointed out, the rehabilitation of the mining spoil areas is important for a number of reasons: 

J/ Paper for Symposium on Savanna Afforestation. 
2/ 1974 exchange rates 1 - US* 1.62. 

- 191 - 

(a) Land is at a premium because of the high population and low yields in 
the existing agricultural system. 

(b) Erosion is caused by the mining scars because the base level of a 
stream is often lowered, thereby causing gulley erosion higher up the 

(c) The plateau is virtually treeless and trees are needed for firewood 
and poles for house building. Areas of tin mining spoil may be suit- 
able for extensive tree plantations, because Eucalyptus will grow on 

(d) The plateau is heavily grazed in both the wet and dry seasons. If 
palatable grasses or legumes could be established on the mining spoil, 
this would provide valuable additional grazing. 

(e) The extensive network of deep reservoirs is a valuable water resource 
providing possibilities for dry season irrigation, not at present 
utilised on any large scale for agricultural production. 


The Jos Plateau is situated between latitudes 9 50 f and 10 50 1 N and longitudes 
8 and 9 E at an elevation of about 1 200 m and covers an area of 4 662 sq km. Weather 
conditions are controlled by moist south-westerly winds during the summer, and dry north- 
easterlies during the winter months. 

The highest temperature recorded since 19^4 is 100 F (38 0) while the minimum is 
41 F (5 C); average temperatures are around 70 F (21 C) . The mean annual rainfall is 
approximately 1 270 mm, the total decreasing from the southwest part of the plateau to the 
north and east. On average, the rains occur during eight months of the year and thunder- 
storms of high intensity are frequent especially at the beginning and towards the end of 
the wet season. The variation in rainfall from year to year is considerable. Tree felling 
and overgrazing on the plateau have tended to reduce the efficiency of the rainfall by 
allowing a more rapid runoff. Relative humidity on the plateau is seldom uncomfortably high. 

The plateau has been an enclave for surface mining for many years. The area consists 
of undulating grassland dotted with granite outcrops and occasional flat -topped hills of 
lateritic ironstone. During the rainy season, May - September, grain crops such as "Aoha" 
Digitaris excilis, millet, Eleusine ooraoana ,are extensively grown on the open plain by the 
Birom people, whilst numerous herds of cattle owned by nomadic Fulani graze during the wet 
months. When the grass is exhausted they descend to the Benue plain for the duration of 
the dry season. 

Native smelting of tin and iron in past centuries must have caused a great deal of 
woodland destruction, but the present treeless state of the plateau has resulted from the 
development of the tin mining industry. The influx of people from the rural areas to tin 
mining locations suoh as Bukuru and Jos resulted in large increases in population and con- 
sequent demand on land for cultivation of food crops. The Birom practice of digging out 
tree stumps on terms does not allow coppice regeneration. Only afforestation could provide 
for an ever-increasing demand for firewood and poles. In the 1940's firewood became so 
scarce that the activities of the mining companies became threatened and it was necessary 
to transport firewood from Jema'a, 

Thus, early recognition of the need to conserve and supplement indigenous wood species 
ld to the development of an afforestation programme under the Mines Reclamation and Affor- 
estation Unit. There is a great demand on land for farming and mining and it is difficult 
to have additional land set aside for communal tree plantations. One possible solution to 
the problem lies in planting up land which mining has rendered useless for farming. 

- 192 - 

Modern tin-mining on the plateau oalls for the use of heavy earth moving equipment 
involving the removal of up to 12*20 m of earth to reaoh the tin bearing ground which lies 
underneath. The larger companies, e.g. the Amalgamated Tin Mines of Nigeria (ATMN) f 
normally use draglines for excavation which pile the earth in great steep-sided mounds or 
dumps around the rim of the excavated "paddock", as the pit is called. 

Site Preparation and Fertilization 

In 1948 a trial was made on the mine dumps planting Eucalyptus oamaldulensis, and 
this proved successful at little expense. Shortly afterwards, the Ministry of Agriculture 
followed up with land restoration experiments involving levelling the dumps, using bull- 
dozers and crawler tractors. Night soil compost from Jos town was spread thinly over the 
levelled surface at the rate of 50.18 tonnes per hectare and cover-crops such as elephant 
grass Penisetum purpureum "gp-mba 11 grass (Andropogon gayamus) and Stylosanthes gracilis, were 
sown. It was intended that after a few years under cover-crops the restored mining land 
could be returned to the native owners for normal cultivation. In 1955 an d. 1956 experi- 
mental growing of 'acha' Pi git aria exoilis and other local staple crops on reclaimed mining 
land was further undertaken by the Ministry of Agriculture. These experiments indicated 
that normal yields of staple crops on restored mining land could only be attained using 
large application of organic compost and fertilizers. It was considered to be beyond the 
means and capability of the local farmers to procure fertilizers on the scale required to 
enable staple crops to grow. 

The satisfactory indications obtained from the 1948 experimental tree planting 
suited in more areas being planted. In 1959> a central forest nursery was built at Bukuru 
to replace the 19 scattered non-irrigated nurseries in Jos Division. Funds for the develop- 
ment of the nursery were jointly provided by the Ministry of Agriculture and the Jos Local 
Authority. Seedlings raised in the nursery were for both mine reclamation areas and com- 
munal forestry areas. 

In 1959 observation plots were set up to determine if the practice of establishing 
Eucalyptus trees, with a headpan (18.2 kg - 22.7 kg) of compost added to each planting hole, 
was the most efficient . 

The following treatments were included: 

(a) One headpan of (18.2 kg - 22.7 kg) compost per planting hole; 

(b) 1/4 headpan of (4.5 kg - 5 .4 kg) compost per planting hole; 

(c) 1/4 headpan followed by 112 g of sulphate of ammonia applied 
one month after planting} 

(d) Nothing applied to the planting hole and 112 g sulphate of 
ammonia applied to the seedling one month after planting; 

(e) No treatment . 

Subsequent trials in 1960 and 1962 applied nitrogen and compost at different rates. 

As a result of the above trials, when the Mine Reclamation Unit took over complete 
responsibility for rehabilitation and afforestation of mineland, a new method was started 
which employed a shovelful of organic compost and 84 g of ammonium sulphate mixed with the 
soil from eaoh planting hole before planting. The results were promising and trees attained 
heights of 3*05 m to 3*66 m in the first year. In subsequent years, the use of compost was 
dropped as the distance and cost of transport from the depot to some of the planting sites 
became too great* Nevertheless, measurements taken in such plots eight years after estab- 
lishment, averaged 9 m - 14 m height which is reasonable on disturbed soils. 

- 193 - 

In the first planting season, planting holes were dug either by hand or by post-hole 
digger mounted on a Ferguson 35 tractor. In the subsequent year, the planting lines were 
cultivated by heavy ripper or sub-soiler (powered by a D-8 caterpillar) which had the heavy 
tines set at a suitable planting distance. Experience has shown, however, that better 
results are achieved by planting trees in the same year as that in which the levelling oper- 
ation is completed. Due to soil compaction, it was considered that heavy sub-soiling was 
necessary to allow the tree roots to penetrate to some depth. Growth of Eucalyptus and of 
grass improved on areas so treated. 

Species of Trees Planted 

The main species used in planting on the plateau both in. mine reclamation areas and 
communal forest areas are as follows: 

(i) Eucalyptus camaldulensis; This is the main species for af f oreatation of 

restored mining land and is used extensively in communal forest area 
plantat i ons . 

(ii) E. punctata; This species is now being used in preference to Ei. rostrata 

on coarse-grained quartz soils, which generally have a low clay content 
and are consequently well drained. It forms a dense canopy at 2 years 
of age 9 suppresses grass and has a straight stem. It has been found 
necessary, however, to apply borate fertilizer (approximately $6 g per 
tree) in the first year to prevent leading shoot die-back. 

(iii) E. robust a; This species has one great advantage over E_. rostrata and 
E_. teret icornis; it will readily form a closed canopy and can greatly 
minimise weeding costs and also reduces the danger of damage by fire. 
It is susceptible to termite attack and it a use has been mainly on the 
red basalt soils in areas of high rainfall. 

(iv) E. rostrata;-' This species haa proved to be generally reliable, being 

easy to raise in the nursery, able to stand a good deal of rough treat- 
ment in transport and planting, is adaptable to most soils and sites 
(except very wet sites), and is fast growing and not liable to die back 
in the first year. It yields good firewood and poles and after felling 
coppices strongly. It is considered to be the beat all-purpose short 
rotation plantation species on the Jos Plateau. 

(v) E saligna (hybrid): A fast growing species with a straight stem capable 

of forming dense canopy. Due to hybrid swarm there is a proportion of 
misshapen or dwarf trees. It grows successfully only on deep soils in 
the heavy rainfall areas of the plateau (south and west). 

(vi) E. tereticornis: This species appears to be similar t o E^. rostrata but 
is generally straight er in form. It is being planted extensively on the 
same sites as E^. rostrata. 

All the foregoing species are classed as commercial timbers in Australia, E^. robust a 
and 12. saligna in the joinery class (e.g. window frames, doors and furniture) and 
JE. roVbrata and . tereticornis in the construction class (e.g. beams, railway sleepers, 
bridge timber, etc.). Thus they have some potential beyond fuel and building poles if they 
can be grown on larger rotations. 

Table 1 shows growth rates of Eucalyptus on mining spoil (Howard f 1974) According 
to Howard, Du CFA (D 345) and D 346 are situated on an undisturbed ironstone gravel soil. 
MRA 25 (D 348) and MRA 33 (D 353) are compacted mining spoils. 

J/ eyn. IS. oamaldulensis. 

- 194 - 



Plot No. 




Trees/ ha 




B 346 

MRA 25 

E. camldulen 8 is 


1 300 




B 347 

MRA 25 

IS. oamaldulensis 


1 525 




B 348 

MRA 25 

E. oama Idul ens i s 






B 349 

MRA 33 

E. multiflora^ 


1 150 




B 352 

MRA 33 

E. camaldulensis 


1 420 




B 353 

MRA 33 

JE. oamaldulensis 






B 344 

MRA 11 

E. camaldulensis 


1 300 




B 339 

Ryom CPA 

JE. mult /oama Id. 


1 025 




B 338 

Vwang CFA 
No. 4 

IS. oamaldulensis 


1 100 




B 345 


IS. oamaldulensis 


1 000 




ayn.IS. robust a 

- 195 - 


The afrea of restored mining land which has been planted since 1960 is 1 336.5 
hectares of which more than 202.5 hectares were established immediately after restoration. 
A further 202.5 - 243.0 hectares were established on land restored some years previously 
and sown with cover-crops of grass and legumes. It may be noted that little land has been 
surrendered for reclamation between 1968-1975. 

Mining companies are reluctant to surrender their mining title after the ground has 
been worked for tin. Check-drilling of the ground, which is always done before restoration 
begins, often reveals the presence of small values of tin. To. larger companies these values 
may not be worth recovering, but they may be economically exploited by small private miners 
who use simple hand methods and have low overhead expenses. There is always some optimism 
that a rise in the market value of tin or minerals in general might make it profitable for 
the recovery of the remaining tin, or even other minerals not presently capable of economic 

Since 196? the Forestry Division has been attempting to persuade the Jos Local 
Authority to have plantations on reclaimed mine lands constituted into either forest reserves 
or communal forestry areas to afford some security of tenure. The prospects for agricultural 
development on such areas are not good and there is little doubt that afforestation, 
which not only improves the environment, but also provides much needed firewood and poles, 
is a sound form of land use. 


Most of the Eucalyptus species so far raised on the mine reclamation areas have some 
wood potentialities but unless there is some security of tenure of existing arid future 
plantations, it will not be possible for the Forestry Division to carry out the essential 
long term research on improvement of the environment, on wood production and on possible 
soil improvement potentialities of Eucalypti us and other species. This mine land reclamation 
project has assumed a small but important place in shaping the land-use pattern on the Jos 
Plateau and further soundly based development is essential if land deterioration and erosion 
is to be controlled. 


Adeka f B. The Establishment of Vegetation on Waste Lands with particular 

1974 reference to the Jos Plateau. Paper prepared for the Forestry 

Association of Nigeria Conference. 

Anon. Annual Report of the Mines Division, Ministry of Mines and Power, 

1960-1961 Nigeria 

Anon. Notts and Memoranda on Mineland Reclamation, Jos Plateau 

undated (collated from files). 

Grove, A.T. Land Use and Soil Conservation on the Jos Plateau. Geological 

1952 Survey of Nigeria. Bulletin No. 22 

Howard. W.J. Rehabilitation of Tin Mining Areas on the Jos Plateau. Paper 

1974 prepared for the Forestry Association of Nigeria Conference. 

Wimlmsh, S.H. Afforestation of Restored Tin Mining Land in Nigeria. 

1963 Cow. For. Rev. f 42 (3) No. 113. 

- 196 - 


W. Boss 

Industrial Plantations Project 
Ndola, Zambia 



Fire protection 197 

History 197 

Degree of hazard 197 

Damage by fire 197 

Cost of fire control 197 

Fire prevention 197 

General 197 

Control burning 198 

Firebreaks 199 

Fire warning system 200 

Fire towers 200 

Fire control centres 200 

Frequency of fires 200 

Fire empress ion 200 

General organization 200 

Types of fire 201 

Hand equipment 201 

Mechanical equipment 201 

Fire weather information 202 

References 202 

Paper for Symposium on Savanna Afforestation 

- 197 - 


The present system of fire protection in Zambia is based almost entirely on the work 
in 1970, of Mr. N.P. Cheney, a summary of whose report (Cheney. 19^1) appears in Appendix 
7 of Tree Planting Practices in African Savannas (Laurie, 1974;. This led to the setting 
up of a Fire Control Section to get the organisation going; work is now sufficiently 
advanced to bring it under the control of line management from the beginning of this year. 

Degree of Hazard 

The long dry season with increasing temperature, decreasing humidity and often 
strong winds, especially in September, combined with plentiful fuel, give conditions for 
severe fires. The exotic trees grown are inherently fire prone and there is a considerable 
build up of fuel from pruning and thinning wastes under the trees, especially pines. 
Large blocks of even-aged trees, sometimes unavoidably orientated along the prevailing 
wind, give a potential, according to Cheney, of fires up to 1 600 ha. 


Gfae population traditionally uses fire for land clearing and hunting and is only 
slowly becoming aware of the need for avoiding fire in plantations. 

In 1975 f the worst season to date, a total of fifty six fires occured, eighteen of 
them originating outside and thirty- eight inside the plantation. 

A total of 602 hectares were involved, of which 120 ha were killed and 225 ka 
suffered severe scorch. 

Damage by Fire 

Pines are most susceptable to death and severe damage up to year twelve, and 
euoalypts throughout the rotation. Damage is by leaf scorch and destruction of the 
cambium. Overall scorch normally leads to death, whereas cambial damage is usually only 
partial and leads to degrade of timber. Because of their thinner bark, eucalypts can 
suffer cambial damage very readily, and for this reason fuel reduction by burning cannot 
be practised. 

Cost of Fire Control 

Ofce approximate cost of establishment per hectare of pines is K 3 985-' and eucalypts 
K 670 calculated at 7 percent compound interest to the end of the rotation (based on 1975 
costs). Fire control costs are about 5 percent of this figure. 


Fire prevention within the pine plantation only becomes a problem after the sencond 
year when weeding normally ceases. Some third year weeding is carried out in dangerous 
locations, but this tends, owing to the work load, to be just a rolling down of the grass. 
Past fires indicate that it will be possible to burn this off early in the season with only 
minor damage; this is preferable to severe damage at a later date, ttie heavy grass growth 
normally found in young pine plantings makes for an extremely fast moving fire, especially 
if there is any Wind. 

J/ 1 K - US$ 1.56. 

- 198 - 

Pruning to 2.2 metres is carried out when the mean top heigjht is 10.5 m (at approxima- 
tely 5 years of age), which leads to a considerable increase in the fuel on the ground. 
This is perhaps the most dangerous stage in the life of the tree from the point of view 
of fire. A programme of control burning after pruning has been carried out since 1971, 
It should be noted that slash is scattered as evenly as possible and no of piling branch 
wood must take place as this leads to hot spots and consequent damage. 

Control Burning 

The object is to reduce the amount of fuel on the ground to keep damage by scorch 
to a minimum. It has been found that trial fires can only give an indication of rate of 
spread and name height and that when fires join up both are increased, flame heights being 
almost doubled. As scorch height is approximately five times flame height it is necessary 
to keep flames as low as possible. The fuel which causes difficulty is the dry needles 
on pruned branches not lying flat on the forest floor; it may be necessary to burn these 
off in one operation and burn again later to reduce the compact needle litter remaining. 

Practical application 

Burning is carried out in March/April when the rains are tailing off and in the 
late afternoon when there is little or no wind. Lighting is done on a grid pattern using 
the lines of trees as a guide. A trial fire gives the rate of spread and as a result of 
this lifters are spaced out along the side of the compartment and given a track along 
which they must walk, counting lines of trees as they go. Bepacement is generally between 
30 and 40 metres, and men must be cautioned only to light one spot of fire at the prescribed 

When lighters emerge on the other side of the compartment they are assembled and 
again sent off in the opposite direction till the area is completed. General direction of 
advances is into the prevailing wind. Detailed directions for carrying out control burning 
are given in Cheney's report, and persons interested in this work should study these 
carefully. Caution is necessary in the use of fire as once lighting up has taken place 
it is usually too late to put out the many spots burning in one compartment. While 
isolated cases of crowning have occurred, damage is usually minor, but this should not be 
confused with trees with persistent needles which occasionally flare up in an alarming 
fashion, but seem to suffer no damage as a result. Weather conditions must be taken into 
consideration and any cumulonimbus clouds in vicinity treated with suspicion as they can 
cause severe turbulence. In case of doubt a weather forecast for the locality should be 

Successive burns 

There is no doubt that control burning reduces danger of damage from wild fire and 
gives supression forces a better chance of success, but this is dependent on the amount 
of fuel removed. It is therefore recommended, as a result of 1975 experience, that fuel in 
dangerous edge compartments exposed to the prevailing wind be kept to an absolute minimum. 

Normally in other compartments additional control burning should be carried out when 
there is a significant increase in the fuel on the ground. Poisoning of unproductive 
thinnings has been successfully carried out. This allows the trees poisoned to remain 
standing and gradually disintegrate instead of encumbering the forest floor as they would 
do if felled. This is of course better from the fire point of view, but has now been 
abandoned owing to a change in thinning schedules which delays the first thinning to age 
nine when more ut ill sable material can be obtained. 

Effect on increment 

Measurements carried out in a series of nine plots in three compartments and burned 
yearly since 1972 indicate that so far there is no significant effect on increment. 

- 199 - 

Understory species 

At Chichele Plantation infestation by Lantana camara is extensive, and it has been 
found that the stocking of this has been considerably reduced by repeated control burning. 
It is unlikely that complete eradication lay fire will be possible due to infested anthills, 
but lantana can be kept sufficiently in check to allow almost unrestricted access* This 
is important in allowing forest operations to take place and for fire control, especially 
as lantana burns severely later in the dry season 

cost of the operation using an average gang of eight men and two vehicles is 0.30 K- 
per hectare* This does not include the cost of one forester, and one forest ranger who 
are also normally in attendance. About 80 ha can be burned in one night by this force. 

Internal firebreaks 

In the past a number of different firebreaks have been tried, but now the leaving 
of large areas of un planted land, with a high work load for no return, and of doubtful value 
for stopping high intensity fires, has been discontinued. It is considered that graded 
compartment roads combined with control burning and compartments of thick barked eucalypts 
strategically placed across the prevailing wind to break up large pine areas will be 
adequate. The graded roads will stop low intensity fires and allow speedy access, and 
control burning will provide areas of low fuel loading. The species favoured for planted 
firebreak compartments is Eucalyptus cloeziana which can be safely burned at about age 
four and is useful commercially. 

Etternal firebreaks 

Boundaries axe protected by a graded strip five metres wide immediately alongside 
the plantation. In addition between this and the indigenous woodland a ten metre wide 
strip is rolled and burned off at the end of the rains. On certain dangerous boundaries 
where there is much foot traffic, there is a further graded stri^ outside this. 

There are obvious advantages in streamlining boundaries and this is being done in 
new areas even thougfc it may mean the inclusion of some poorer planting land. 


Ifce adjacent woodland is intensively early burned as the grass dries out, and again 
after leaf fall, care being taken to avoid damage to the canopy. Anthills in the fire- 
break and on the edge of the woodland have in the past provided a spring-board for fire 
to jump into the plantation so these are now being systematically cleared of vegetation. 
Bead and dangerous trees on the woodland edge need to be felled and cleared away. 


Grading with a caterpillar 120 Grader costs K 15-^per kilometre and rolling a 
further K 15/knu 

I/ 1 K - USS 1.56 

- 200 - 


Fire Towers 

Fire warning is based on a series of steel towers strategically placed throughout 
the plantation at rougily 10 km intervals. Advantage is taken of any suitably placed 
hills to reduce the height of towers at these points. 

It is important in locating towers that good cross bearings can be obtained. 

Towers are fitted with a bearing indicator with a simple sighting device reading 
horizontal angles to the nearest degree. These are set up to coincide with protractors 
marked on the plotting map in the fire control centre. Communication is by means of a 
portable radio powered by a heavy duty 12v battery kept in a locked steel box at ground 
level. Batteries last on an average three weeks before having to be brought in for 
charging. Look-outs are provided with binoculars , water bag, protective clothing and a 


As fire danger progressively increases, tower manning is increased from a single 
shift at the beginning of the season to three eight hour shifts on strategic towers. Only 
five fires were recorded as having started between 22.00 hours and 06.00 hours during the 
1975 season; these did little damage and were readily controlled. 

Fire Control Centres 

Basch plantation group has its own control centre manned by a radio dispatcher on 
an eight hour shift basis. This man is responsible for plotting smoke reports from the 
towers and taking appropriate action. He maintains a log book, checks vehicles and 
towers in the field hourly, changes batteries and takes meteorological readings. Much 
of the radio time is occupied by administrative messages, but in case of fire these can be 

Frecruency of Fires 

In 1975 at the two main plantation centres, 2 721 smoke reports were received of 
which 691 were investigated and 47 fires were suppressed. 

Normally | fire watoh begins in Nay. There is a build-up of fires until June when 
the total remains fairly constant. It starts falling off in October, with the fire 
season ending towards the end of November. 


General Organisation 

Every employee is liable to fire fighting duties, but initial investigation and 
suppression is carried out by trained teams normally consisting of two gangs of six men 
plus supervisor stationed at each plantation centre and travelling in fully equipped vehicles. 
It is only when conditions warrant that the larger organization is called into service, 
as detailed in the fire plan. Full-time fire teams are backed up by stand-by gangs. It 
is hoped that the whole labour force will eventually become versed in the elements of fire 

- 201 - 

Types of Fire 

( 1 ) Grass fires in young plantations spread rapidly, but vehicles using water 

can usually be driven into the compartments. Knock-down can be accomplished quickly, but 
there is need for efficient follow-up by men on foot to ensure that the fire does not 

(2) In older compartments trees reduce the wind, and rate of spread is less, 
especially if control burning has been practiced, but here vehicles are confined to roads 
and so are mainly useful in stopping spread from one compartment to the other. In this 
case control must be achieved by hand methods as detailed in Cheney's report. 

Hand Equipment 

McLeod tools imported and fitted with bamboo handles locally, are excellent for fire line 
construction in litter fuels. 

Shovels are used nosed, fitted with long handles and sharpened. 

Brush hooks are used for clearing branches and light growth ahead of fire line construction. 

Axes are useful when larger material such as trees felled in thinnings, is encountered. 

Knapsack sprayers An excellent design has been imported from Australia consisting of a 
sixteen litre plastic tank with pump and hose clipping neatly round the outside. 

Drip torches are very efficient when quick lighting up is required. 

Mechanical Equipment 

For Zambian conditions experience indicates that a fast (at least 100 km/hour top 
speed) 4^-wheel drive vehicle of about 3 tons capacity is best. Tnis should be fitted with 
an internally baffled steel tank capable of holding about 1 400 litres of water, pump, 
hose reel and hand tools. At least one larger tanker should be available in each area. 

Water pumps 

A centrifugal pump producing a pressure of at least 10 bars with a good filling 
rate at low pressure and hand or other priming facilities is recommended. 

Other equipment 

Hose reels should be of the vehicle type supported at both ends and capable of 
carrying~up to 60 metres of 20 mm rubber hose. 

Branch pipes should have spray and jet facilities and positive shut off. 

Hose Strong fabric reinforced rubber hose of 20 mm and 25 mm is used. Canvas 
hose is mainly used for tank filling, but a few lengths of 38 mm are carried on the large 
tankers for use in case of a sawmill or other static fire. Generally, vehicles fight 
fires while on the move so it is undesirable to have them anchored to long lengths of hose. 

Slip-on units can be useful on conventional lorries or light trucks, and should 
consist of light steel, internally baffled tanks with a small pump and hose reel mounted 
on the top. These are loaded empty and then filled with water. Hand tools and all other 
equipment necessary should be kept at the loading point. 

- 202 - 

Wheeled bowsers towed by tractor or land rover can be useful* 

Fire Weather Information 

Generally speaking, fire weather in Zambia gets progressively worse as the dry 
season progresses , though there are days when conditions can be more severe than expected* 
With this in mind forecasts are obtained form the Meteorological Department each afternoon 
for the following day of: (l) maximum wind speed, (2) wind direction, (3) maximum 
temperature and (4) minimum humidity. 

This gives a chance to plan activities ahead and to alert any extra forces which 
may be necessary* 

In addition, local weather information is collected at fire control centres at 
09iOO and 16:30 daily consisting of air temperature, wet bulb and maximum and minimum 
temperature* Hind direction and speed are recorded hourly* Any rainfall is measured 
and a thermohygro graph makes a seven day chart of temperature and humidity* 

Weather information is used in compiling fire reports, calculating the drought index 
figure (see Cheney, 1971 ) and computing the fire danger rating using the McArthur Forest 
Fire Banger Meter. 


Cheney, N*P, Fire protection of industrial plantations. Forest 

1971 industries feasibility study, Zambia. Rome, FAO. Technical 

Report 4 

Laurie, M.V. Tree planting practices in African savannas. FAO Forestry 

1974 Development Paper No, 19* Rome, FAO. 

- 203 - 


Z.U. Momoh 

Federal Ministry of Industries 
Lagos, Nigeria 

M.O. Akanbi 

Forest Research Institute of Nigeria 
Ibadan f Nigeria 


Introduction -Q^ 

Major insect pest problems ->Q^ 

Ma,jor disease problems ->0g 

Conclusion OQ^ 

References 097 


The savanna occupies between 75-80% of the entire vegetational area of Nigeria. Thus, 
of the total forest reserve area of about 96 000 km 2 , the savanna covers about 76 000 km 2 . 
However, much of the savanna reserves are low value forests with a lot of grasslands. On 
the other hand, the estimated 20 000 km 2 of high forest reserves which have considerable 
industrial potential may be unable to sustain the extremely heavy demand to which timber is 
put . 

At present, about 1-i million cubic metres of wood is consumed annually in Nigeria, At 
this rate, the high forest would be used up in not more than 30 years. It is therefore 
essential to find means of augmenting the supply of timber in the country, partly through 
rehabilitation of the savanna. Besides, ready availability of timber for immediate local 
consumption is also desirable for the savannas. 

In these circumstances, the vast savanna needs to be converted into productive forests. 
Such massive efforts to establish man-made forests require intensive research and large- 
scale management techniques. No doubt, the resulting artificial 1 forests would conspicuously 
lack the biological balance which is obtainable in natural forests. Subsequently, this has 
given rise to a number of forest and timber diseases and insect problems, some of which have, 
on occasions, assumed epidemic dimensions in monocultural practices. Some of these have 
either directly seriously discouraged the successful establishment or the management of 

J/ Paper for Symposium on Savanna Afforestation 

- 204 - 

certain tree species, or have adversely influenced the morphogenesis of nursery and planta- 
tion stands, resulting in very poor yield. 

There has been very little research conducted on forest and timber insect pests in "">he 
savannas of Nigeria. Roberts (1969) conducted the first general forest insect studies in 
the savanna beginning in 1962, which was in the form of a forest insect survey. This was a 
continuation of a similar work initiated in Nigeria by Eidt (1963), but which was then 
restricted to insect pests of indigenous tree species of onlv the lowland rain forests. 
Earlier, the West African Timber Borer Research Unit ( WATBRU) , with its main activity 
centre in Ghana, also extended its timber insect research to Nigeria but on a relatively 
smaller scale. However, detailed biological studies on some important timber insects, 
mainly beetles, were carried out (WATBRU Reports 1953-58, 1959, 1-960, 1961-62). In 
addition, effective methods of control of termite in young Eucalyptus plantations were 
initiated by Lowe in 1960. Further experiments were also carried out by Sands (1962 a, b) . 
It is now the normal practice to treat Eucalyptus seedlings for termites before they are 
planted out in the field. 

The forest disease survey of Parker (1964) noted a number of plantation and nursery 
diseases in the savanna areas of Nigeria. Most of these were at that time causing only 
minor damages, notable exceptions being damping off diseases in some nurseries and the 
root rot of E. oamaldulensis at Okene caused by Poj.yporus sp. 

As teak planting became extensive in the savanna areas, the root rot of the genus 
became so significant that much attention was devoted to it (Momoh, 1973 and 1974)* Other 
disease problems relating to plantation establishments in the savanna have also been 
recorded and studied briefly or in detail (FAO, 1970) . 


The savanna forests have had less frequent serious outbreaks of insect pests compared 
to the rain forests. The major reason for this is probably climatic. Nonetheless, there 
have been sporadic insect problems of major dimensions. 

Perhaps one of the major serious insect problems is found on the mahogany. The 
mahogany is a composite name embracing the group of trees in the Meliaceae family. This 
family represents some of the most prized and popular indigenous tree species of local and 
export value. In Nigeria, all members of one subfamily, the Swietenoideae, are attacked 
by the well-known "Mahogany Borer 11 Hypsipyla f a pyralid, and closely related species. They 
attack the shoot, stem, bark, flowers and fruits of the host trees. The impact of this 
pest generally discourages the establishment and successful management of the susceptible 
species. However, in the savanna Khaya senega lensis, aptly called the savanna mahogany, is 
the more widely planted (as shade trees) particularly in the northern Guinea and Sudan 
zones. In the derived savanna, K. ivorensis and K. grand if olio la are examples of the other 
common plantation mahogany specie's. All these are" similarly severely attacked, although, 
according to Roberts (1969)1 there are usually fewer generations annually than in the rain 
forests of the south. 

There are a number of other insect pests of the mahogany, but the impact of these is 
much less severe than that of the Pyralid borers. A few important defoliators and borers 
include: Paohypasa dentioula Bethune-Baker (Lasiooampidae) ; Pseudobuneae epithyrena 
(Mstasen <fe Weyding) , Lobobuneae ohristyi Sharpe, Nudaurelia dione '( Eabricius^ (Saturniidae) ; 
Cryptoblabes ghidielia CMilliero)7 Pyralis manihotalis (Guenee) (Pyralidae) , the oalliphorid 
fly Luc ilia ouprina (Wiedmann) and a host of others, including some beetles. Some of theae 
pests have a wide host range. For example, Roberts (1969) found P. dentioula to occur 
throughout most of the savanna and was recorded on Eucalyptus carna Idulen s is , the favoured 
host, E. deglupta t E. microtheoa and E. tereticomis. The larvae of this species attacked 
eucalypts of between 3-16 years old, while they attacked as much as about 18$ of older 
stands measuring 14-20 m high. 

- 205 - 

The major insect pests of Paniellia spp. are some of the beetles whioh attack felled 
timber and lumber. Others are those which attack wood and feed on cambium of plantation 
and natural trees. However, much of the infestation is apparently secondary because often 
predisposing factors such as reduced vigour or mechanical darrege, play important roles. 
Among the beetle timber borers of D. oliveri are the longhorn beetle (Cerambycid) 
Plooaederus viridipennis (Hope) which attacks felled as well as living trees, and 
Paohydissus came run icus Aurivillius. In the latter case, a heap of dust under a severely 
attacked tree is diagnostic, and occasionally heavily attacked trees are killed. The con- 
dition of predisposed trees may be worsened by the following insects: Xyloperthella 
orinitarsis Imhoff a common polyphagous species, Sinoxylon ruficorne Pkbricium 
(Bostrychidae) 5 and certain colydid and ourculionid species. 

Isoberlina doka is another common indigenous savanna species which is attached by a 
host of insects, major among which are certain Lepidoptera. Two of these, Elaphrodes 
duplex (Oaede) and the prooessionary Epanaphe molpney, (Druce) (Notodontidae) are 
defoliators of I. doka, the former to such a serious level that attacked trees are often 
completely stripped. The lasiooampid G. rufesoens is also a serious defoliator, but such 
heavy defoliation is usually localized. 

The noctuid Crypsotidia conifera Hampson severely defoliates certain Acacia spp., 
especially A. albida. It is capable of causing up to 50$ defoliation on large trees. 
Among the other numerous insect pests of the Acacias is the noctuid Pandesrre, anysa Guenee, 
whose habit on its host is similar to that of C. conifera t and Characome nilotica Hmp., 
whioh attacks fruits of A. nilotioa; and the p'sychid Crypto the lea ^unodi (Heylaerts) , 
which is a widespread defoliator of the Acacias. Recently a new, undescribed insect 
species was reported severely attacking Aoac ia nilotica. The weevil, Pachyonx sp. bores 
the shoot of the host and forms galls. It is considered to be a potentially dangerous 
pest which has affected about 150 acres of plantations. Other important hosts of . .^unodi 
include the exotics Eucalyptus oamaldulensis f E. deglupta t the particularly favoured 
E. t orel liana; and the native Anogeissus leiooarpus and Bauhinia rufescens. Certain 
species of eucalypts also suffer attack by Bunea alcinoe Cram, a saturniid defoliator whose 
wide host range also includes some species of mahogany, Balanites aegyptioa and Cuss on ia 

Other insect pests also occur on the eucalypts and these include defoliators, miners, 
rollers, and case bearers, apart from the damage done by wood and cambium coleopterous 
borers as well as girdlers. The former group is of more importance during the production 
stage as it affects the condition of the hosts to various degrees. More serious however 
is the damage done to Eucalyptus spp. by termites. Usually, eucalypts have to be treated 
at the nursery or early plantation stage against termite infection. A lack of treatment 
might lead to excessive losses J/. 

Termite attack also occurs on some other exotics but is normally less significant or 
only secondary on species like pines, neem and Acacia. According to Lowe (1960), termite 
attack had been a deterrent to the establishment of eucalypts in the savannas, although 
some treatments against termites have considerably improved the situation. Thus, the 
impact of termites on forestry development, especially in the savanna, cannot be over- 
stressed, not to belittle their role in the biodeteri oration of wood in storage, transit 
and use. 

I/ See Laurie (1974) for use of insecticides dieldrin and aldrin for protection against 

- 206 - 

The widespread orthopteran Zonogerus variegatus L. (Pygomor Phidae) feeds on pines, 
but with no severe effect. Generally, the pines f Gmelina arborea and Azadiraohta jlndioa, 
among others, are attacked by only few insects. Dalbergia sissoo and the eucalypts, on the 
other hand, suffer attack by the Diaorisia lute seen s (Wet Ike r) . This arctiid is found in 
murseries and plantations. Also Tectona grandis harbours some insects but the damage done, 
though sometimes to a significant dimension, has not often caused serious concern. In 
general, numerous other insects have been recorded on various tree hosts in the savanna, but 
apparently most of these have been within tolerance levels and have so far been contained 
by the respective hosts. 


The most economical plantation disease that has been recorded in Nigeria is the root 
rot of teak (Teotona grand is Lin. F.) caused by Rigidoporus lignosus (Klotzsch) Imazeki. 
The disease occurs widely in the derived savanna areas of Nigeria, except in Nimbia. The 
percentage death due to this disease varies from one locality to another. A loss of about 
30$ has however been recorded (Momoh, 1974) at age 5 in Egabada (idah area). 

The disease is more severe on poorly drained sites, although it is capable of occvrring 
over a wide range of geological formations. The first visible signs of the disease are 
normally yellowing leaves which tend to drop premature ly These visible symptoms however 
only develop after a severe infection of the root system and the host is on the verge of 
death (Momoh, 1973)- Sporocarps may or may not develop on the affected host. 

Teak trees have also been found to die in some localities from a die-back disease 
caused by S t e^mphy 1 1 ium sp. The pathogen is closely followed by Be It ran ia . 

Although Eucalyptus spp. are widely grown in the savanna zone of Nigeria, its diseases 
have been few. A Ce rat ocv st ig sp. has been found to be associated with water stress in the 
death of E. robust a in a few areas. Such deaths only occur at the peak of the dry season. 
Unidentified bacteria have also been found to cause necrosis of leaves on E. oamaldulensis. 

In some parts of the southern Guinea savanna there has been sporadic occurrence of the 
root rot of gmelina ( Gme lina arborea) raised from stumps. Such infections also sometimes 
occur on stumped teak and are normally due to fungi of a wide host range such as Geotrichum 
and Gloesporpides. 

Species of Pest a lot ia and Pestalotiopsis are frequently associated with the die-back 
of a number of plantation trees. They have also been found to be associated with the 
necrosis of ageing needles of various pines. Nigeria (and the rest of West Africa) has so 
far not suffered from the notorious Dothistroma blight of pines, but Pestalotia is known in 
East Africa to be sometimes associated with such blights on Pinus radiata which is not an 
important plantation species in West Africa. Nevertheless, the common occurrence of 
Pestalotia in West Africa gives food for thought and vigilance. 

At the nursery level, damping off disease is experienced to varying degrees in a few 
localities. The disease is no longer significant in many nurseries which have developed 
valuable techniques and which use container "pots 11 rather than germination beds or boxes 
for raising seedlings. The common damping off fungi include Rhizoctonia so Ian i and Fusarium 

Timber harvest is currently done only in areas of the derived savanna. The harvested 
species include various light coloured timbers that are susceptible to the blue staining 
fungus Bo t ryod ip lodift theobromae. Infection is more severe in the wet season than the dry 
season (Momoh, 1966). It can be controlled by quick extraction followed by rapid 

- 207 - 

conversion and drying. As infection can occur within a few days, chemical treatment 
immediately after felling is desirable if logs are to be left in the green state for up 
to a week or more. Different chemicals can be used for spraying or dipping (Momoh and 
Oluyide 196? f Momoh and Akanbi, 1969). 


Although preliminary diseases and insect pest surveys have been carried out in the 
savanna areas of Nigeria there is a need for constant vigilance and further periodic 
surveys to ensure that any disease or insect pest outbreak is cited and curbed before 
extensive damages are done. The root rot disease of teak and the Pachyonyx attack on 
Acacia are clear indicators of the necessity of a continuous survey. Such sudden out- 
breaks of diseases or insect pests have also been noted in savanna areas of other parts 
of Africa. The 1972 outbreak of Phoraoantha recurva in Zambia f a sporadic outbreak of 
Plagiotriptus pivinorus in Malawi and the root rot of Eucalyptus caused by Phaeolus 
manihotis in Ghana are other notable examples. 

Thus it is desirable to have a periodic routine survey for diseases and insect pests 
in forest nurseries and plantations. These natural human enemies know no political 
boundaries. A close cooperation between the pathologist s and entomologists of different 
nations is therefore essential. 

Eidt, D,C. 


Laurie, M.V. 

Lowe f R.O. 

Momoh, Z.O. 

Momoh, Z.O. 

Momoh, Z.O. 


Momoh, Z.O. & Akanbi, M.0 


A Survey of Insect Pests of Indigenous Trees in 
Plantations and Nurseries. FAO Report no. 1775- 64 pp. 

Savanna Forestry Research Station Nigeria. Interim Report. 
FO: SF/NIR 16. 18-1Q. 

Tree Planting Practices in African Savannas, FAO Forestry 
Development Paper 19. Rome. FAO. 

Control of termite attack on Eucalyptus citriodora. Emp. 
For. Rev. f 40(1): 73-78. 

Blue stain in Antiaris africana. Technical Note no. 36. 
Dept. of For. Res. Ibadan. 10 pp. 

The root rot of teak (Tectona grand is) and its control. 
Research Paper (Savanna SeriesJ no. 15* S.F.R.S. Fed. 
Dept. of For. Res. Samaru, Zaria. 17 pp. 

Studies on the butt rot disease of Teak (Tectona grand is 
Linn. F.) . A thesis submitted to the Acuity of Agriculture, 
Forestry and Veterinary Science in partial fulfilment of 
the requirements for the degree of Doctor of Philosophy of 
the University of Ibadan. 

The efficacy of sodium pentachlorophenol against blue- 
stain infection of timber. PANS 15(4). 574-7. 

- 208 - 

Momoh, Z0. & Oluyide, A.O. An attempt to control blue stain by the use of chemicals. 

196? Tech. Note 38. Dept. of Forest Research, Ibadan. 10 pp. 

Parker, A.K. Diseases of Forest Nurseries and Plantations. Report to 

1964 the Govt. of Nigeria. FAO no. 1883. 40 pp. 

Roberts, H. Forest Insects of Nigeria, with notes on their Biology 

1969 and Distribution. Comm. For. Inst., Paper no. 44 206 pp. 

Sands, W.A. Observations on termites destructive to trees and crops. 

1962a Tech. Rep. no. 26. Regional Research Sta., Win. of Agric. 

Northern Nigeria. 18 pp. 

Sands, W.A. The evaluation of insecticides as soil and mounds poisons 

1962b against termites in agriculture and forestry in West 

Africa. Bull. Ent . Res. 53: 179-192. 

- 209 - 


Alhaji Hamza Turabu 
Kano State Forestry Department 
Kano , Nigeria 



Fencing 210 

Mass propaganda ? 11 

Cultivation 211 

Keeping of watchmen ?11 

Cost analysis for fencing 100 acres of plantation ?1? 

Cost analysis for fencing 1 mile of shelterbelt 213 

I/ Paper for Symposium on Savanna Afforestation 

- 210 - 

In recent times sufficiently successful methods of establishment of forest stands in 
the savanna areas of Nigeria have been developed. 

During plantation establishment and maintenance , foresters met with many problems, 
dangers and various bottlenecks before achieving their desired objectives* The most difficult 
problem that has plagued foresters in savanna regions has, however, been the protection of 
plantations against the bio tic elements of the environment. For this reason, various methods 
of protection have been devised over the years, all with varying d grees of success. Of the 
biotic factors, man and animals present a special type of problem. This paper deals with 
some aspects of the methods presently in use to protect plantations against man and animals 
in Kano State in particular and the savanna zones in general. 

The general methods of protection include fencing, mass propaganda, cultivation, and 
keeping of watchmen. 


This method is found to be equally successful in keeping away both men and animals 
from plantations. The presence of a fence impresses upon any individual the fact that the 
area fenced is out of bounds, as this practice is even common among indigenous people as a 
means of protecting their private properties. 

In Kano State, forest plantations are fenced using 4 feet (l.2m) high cattle fencing 
wires supported by 6 feet (1.8m) high azara (Borassus aethiopium) posts spaced 10 feet (3m) 
apart with one strand of barbed wire about 4 inches (10 cm) above the fencing wire. Alterna- 
tively, four strands of barbed wire spaced horizontally about 2 feet (60 cm) apart up to a 
heigrt of 5 f *t ( 1 5 m ) on Boraasus posts is sometimes used in the absence of cattle wire. 

These methods have been found to be effective only in keeping off man. 

A slight modification of the first fencing method described above has been found to 
be effective against cattle. 

Fencing a plantation by using 4 feet (l.2m) high cattle fencing wire attached to 6 
feet (1.8m) azara posts spaced 10 feet (3m) apart and putting only one strand of barbed wire 
in the middle is highly effective in preventing cattle damage. Since cattle do not feed on 
Azadiraohta indioa (Neem), Eucalyptus species, and Cassia siamea (Kashiya), unless in extreme 
drought conditions, in a plantation of these species the fence could be removed two to three 
years after stand establishment or when the species close canopy. But in case of Khaya 
senegalensis (Madaci), Dalbergia sissoo (Dalbegia), Acacia nilotica (Bagaruwa), Acacia albida 
(Gawo), etc., fences should not be removed until the planting stocks reach a height of up to 
15 - 20 feet (4.5 -6m). Also, if exploited the coppice should be fenced until they reach 
the sane height before the fence is removed. 

The goat is readily the most notorious animal causing damage in plantations. It feeds 
on almost anything green. The thorns which characterize the Acacia species do not deter 
this animal from browsing freely on shoots of the species* Also, because of its size, it 
can easily squeeze through small openings which can keep away man or cattle. Effective 
fencing against goats consists of using 4 feet (1.2m) high pig or cattle wire attached to 
6 feet (l.8m) higjh Borassus posts spaced 10 feet (3m) apart but with two strands of barbed 
wire. One of the strands of barbed wire should be on top, while the other is in the middle 
of the wire netting. In addition, earth mounds are made at the base of the wire netting to 
cover the first two horizontal strands of the wire netting. This is to prevent the goat from 
lipping underneath the wire at ground level. Openings or entrances should be minimized along 
the, fenoe* It is advisable to use ladders looated at convenient points along the fence as a 
is of gaining entrance into the fenced area. 

- 211 - 

The above method im equally effective in keeping out sheep. 

One or two strands of barbed wire alone have been found effective in keeping off 

Except in remote forest reserves, damage from wild animals is not likely as the areas 
in which forest plantations are located are generally in localities that have been continuously 
under cultivation for decades. It is thought, as of now, that the fencing method used for 
keeping out goats will be sufficiently effective in keeping out some wild herbivors. 


This could easily be one of the most important methods of protecting plantations 
against man if well organised. However, experience has shown that this method does not work 
in sparsely populated areas. This system usually involves the broadcast of instructions in 
public places such as markets, festival squares, churches, and Friday Mosques, etc., that 
specific areas have been declared out of bounds. It is usual to stipulate a penalty of 
either a fine or term of imprisonment or both for offenders. 

Sometimes radio discussions on the reasons for protecting these areas are held in 
local languages. Documentary films are also shown on mobile cinemas to get the message 
across to the population. 

However, people are still known to trespass without being caught in spite of the 


This is a method of protecting plantations against incidental activities of man. In 
the savanna areas of Nigeria, various species of grasses are commonly used for thatching of 
roofs, mat-making and as fodder. People therefore go about collecting these grasses in 
plantations and very often set fires to the grasses intentionally as a means of promoting 
their active regrowth. Sometimes the fires are set maliciously. Clean cultivation is 
normally carried out in August and January in newly established plantings to keep off the 
grass. In Kano State, cultivation, is done mechanically. 


In addition to a fence, a watchman (locally known as a maigadi) should be employed in 
an area with over 100 acres (40 hectares) of forest plantation. It has been found that in 
a plantation with over 100 acres (40 hectares), fencing alone could not suffice unless a 
proper watchman is employed to look after the area. 

The main duty of a watchman is to cater for the general welfare of the plantation. 
This includes the repair of fences, reporting any out-break of diseases, pests, fires, etc. 
His main attri"butes should be high influence among the entire people of the area, fearlessness, 
devotion to duty and knowledge of the area or beat he is watching.' 

Experience has shown that putting a watchman in an area is much better and more economical 
than fencing a whole area with chain links if it comes to the protection against man's atroci- 

It is important to mention that protection is an expensive item in forest plantation 
establishment in the savanna areas (especially in the Sudan zone). Cost analyses of fencing 
in Kano State are shown in Tables 1 and 2 following. Cost figures shown do not include 
supervision. Fencing cost alone is known to account for about 70# of the oost of establishing 
plantations in the Sudan zone in Kano State. 

- 212 - 



1. Shape of plantation: rectangular (40 x 25 chs) 

2. Perimeter: 130 chains (8580 feet; 2574m) 

3. Azara interval: 10 feet (3m) 

4. Strands of barbed wire used: 2 

5. Number of bindings against azara posts: 3 

6. Length of fencing wire: 165 ft (50 meters) 

7. Length of barbed wire: 660 ft (220 meters) 

8. Length of binding wire: 1000 ft (333 meters) 

9. Length of azaras: 6 ft (2 meters) 

10. Cost of cattle fencing wire: M30 (about U.S. $43) 

11. Cost of cattle barbed wire: K20 (about U.S. $32) 

12. Cost of cattle binding wire: K20 (about U.S. $32) 

13. Cost of cattle asara posts (12') - U1.20K (about U.S. $1.92) 
14 Labour for fencing: 3 man-days/acres (7-5 man-days/hectare) 

15. Labour for trench making: 5 man-days/acre (12.5 man-day s/hect are) 




coar PER 


(100 acres) 

Cattle fencing wire 




Barbed wire 



640.00 2 strands 

Binding wire 




Azara posts 
Cost of materials 


Ml. 20 

516.00 (to be cut into 2) 


Labour for fencing 


Labour for trenching 



Grand Total 


Cost per acre B41.76 (about U.S. $67) 
Cost per hectare K 104*40 (about U.S. $167) 

- 213 - 


Specif ioat ions 

1. Shape: linear, 1 mile by 110 feet (1.6 km x 33m) 

2. Perimeter: 10780 feet (3593 meters) 

3. Azara intervale: 10 feet (3m) 

4. Strands of barbed wire used: 2 

5. No. of bindings against azara posts: 3 

6. Labour for fencing: 60 man-days 

7. Labour for trenching: 100 man-days 






(i MILE) 


Cattle fencing wire 



M 19 50. 00 

Barbed wire 




2 strands 

Binding wire 




Azara posts 
Total for materials 
Labour for fencing 




(to be cut 

into 2) 

M4 063. 6*0 


Labour for trenching 
Grand Total 


(about U.S 

. $6980) 


N.B. Number of acres 

(hectares) for 

the above dimension 

- 13 acres (5.2 


Average cost per acre - M33566 (N839.15 P er hectare) 


Cost per acre (hectare) of agricultural land protected at interval of 700 feet (210m) 
between belts - 48^00 (11120.00 per hectare) 

N.B. With reference to the tables of cost analysis, it could easily be seen that it is much 
cheaper to fence a plantation with more or less equal dimensions. Wherever possible f 
the shape of plantation should not be linear unless the desired objective is shelterbelts 

It is found that very good cattle fencing wires could continuously be used up to ten 
years. Also, black and matured azaras could be used for about six to ten years. Except 
in extreme cases, barbed wire could be used for well over two decades. 

- 214 - 


A.M. Oseni 

Federal Department of Forestry 
Ibadan, Nigeria 




The need for planning ;>id 

The national development plan ^15 

Planning in the forestry sector P1^ 

Plantation planning 217 

Implications of a national plantation programme ^1^ 

References and further sources of information ^1 


Foresters have for many years realised the need for planning because the long 
rotation of their crop meant that mistakes were both time-consuming and costly. The 
framework of their planning was the working plan, which gathered together information on 
a particular area and from this prescribed the action that was to be taken over a period 
of years to achieve the objects of management of the plan. At its simplest the working 
plan might prescribe no more than that records should be kept, but it is often from this 
repository of information that modern plans are made up. 

The traditional working plan did not, however, take into account the interactions 
with other sectors, nor even between working plan areas within the forestry sector. The 
plan period was generally 10 years, but if conditions changed during that time it was 
necessary to get sanction from the highest authority to change the prescriptions. Although 
annual records were maintained, performance was not always compared with the plan targets. 

Paper for Symposium on Savanna Afforestation 

- 21 5 - 

Modern planning seeks to take into account the needs of the country and to set 
objectives for supplying them. Planning is the means of forecasting how those directives 
may be achieved, but also retaining sufficient flexibility so that the plan can be altered 
to meet changing circumstances quickly. For this to be done, there must be a constant flow 
of accurate information from the project or sector which can be readily analysed. 


Most countries have a national development plan whose objectives are the outcome of 
political processes. In the long term the objectives may be unquantified and generalised, 
e.g. "to improve the standard of living of the people", but in the short term the objectives 
may be quantified, e.g. "to produce enough pulpwood to meet the country f s requirement before 
the end of the five year period". The task of the planners is to formulate the methods by 
which the objectives will be achieved, and some of the objectives may in fact become 
constraints in certain sectors. 

Forestry will have an important place in the national development plan of many countries 
Demand for forest products is increasing rapidly and there is also the attraction that 
development takes place in rural areas. 


Regardless of the structure of the forestry sector (i.e. the division between State 
control and private enterprise) there must be an overall policy. This is a statement of 
the objectives laid down for the forestry sector. 

Within the forestry sector, a planning unit should be set up to determine the means 
of achieving the objectives of the policy. In order to do this, the organisation should be 
capable of: 

1) collecting and analysing the data; 

2) formulating alternative courses of action for attaining the objectives; 

3) evaluating the choice available according to various criteria; and 

4) monitoring the implementation of the plan and taking the necessary action to 
correct it as conditions change. 

The planning unit must first identify the services and products demanded by the 
sector. Table 1 illustrates this for Nigeria, and similar trends are apparent in other 
African countries. 

- 216 - 


Projected Demand for Forest Products in Nigeria 






Sawn wood 





'000 m 3 

11 per oaput 





m 3 






! 000 m 3 

11 per caput 





m 3 

Other panels 





'000 m 3 

11 " per caput 





m 3 

Paper and particle board 





'000 m 3 

11 lf per caput 






Roundwood Conversion 





'000 m 3 











Total m 3 





Source: PAO High Forest Development Project, 

Federal Department of Forestry, Ibadan. 

In addition to the demand for products, there will be a considerable demand for 
services, such as shelterbelts, erosion control, etc., which will be mainly supplied by 
plantations because there is unlikely to be any natural tree cover where these services 
are required. Plantations are likely to be preferred for the supply of products too, 
because industrial uses require that the raw material is of uniform size with little 
variation in quality. 

An estimate of the forest areas required to meet the likely demand can next be 
made. This should take into account future improvements in the efficiency of conversion, 
the effect of substitutes and the increased use of so-called secondary species. Present 
areas of natural forest and plantations are generally well knwon through the records that 
are maintained in working plans, etc. It is, however, important to ensure that these 
figures are obtained by physical survey and are not estimates of doubtful accuracy. 

- 217 - 

Yields of natural forest types and plantation species must next be determined. In 
the natural forest, low sampling intensity inventories have been carried out in most countries, 
supplemented by high intensity stock-mapping undertaken by, or for, the logging companies. 
There is thus a good idea of the present yields, but future yields may be less easy to 
predict because secondary species have not been included in the past. A further disadvantage 
of previous inventories is that they often made no allowance for defect or grade of log. 
Both of these points need to be incorporated into present day inventories to allow for 
technological changes that will in the future permit more complete exploitation of the 
natural forest. 

Yields of the main plantation species have been studied in many countries, and sample 
plots have been laid down to obtain data for the construction of volume and yield tables. 
Preliminary volume tables for the smaller sizes have been produced in several countries for 
the main plantation species planted in the savanna, but often yield tables await the 
acquisition of more data as the crops are usually fairly young. The importance of 
establishing permanent sample plots as a routine in all plantation axeas cannot be over- 
stressed; besides providing data for volume and yield tables, they will provide estimates 
of compartment yield (supplemented by temporary plots) and they will monitor the performance 
of the crops through the first and subsequent rotations, an important consideration in view 
of findings with some exotic crops that production falls off in the second rotation. 


Although it may be necessary to meet much of the demand for services and products 
by the creation of plantations, they must always be seen as part of the whole integrated 
forestry sector and not be considered in isolation. The time, the location, the size, the 
species and the technology to be used in the establishment of the plantation must all be 
considered, and in evaluating the benefits there must be knowledge of the product, the 
quantity, the type, the price and the date that it will be available. 

The planning body for the forestry sector must identify projects which will be the 
means by which the plantation programme will be carried out. It is important that this 
body is not seen as the sole source of ideas for projects, because often line managers 
may have a better idea of the sort of projects that are possible within certain constraints 
of site, staff capabilities, etc. Close contacts should be maintained too with the 
organization responsible for forestry research so that promising lines of study may be 
developed at any early stage. In fact, planning, research and management services (such 
as inventory) should all be part of the same organization. 

After possible projects have been identified and a preliminary screening has been 
done, project proposals must be drawn up for each. Watt (1973) has listed the essentials 
of a project design for presenting to decision makers. They include studies of technical, 
commercial, financial, economic, organizational, social and political aspects and the way 
in which the project would be financed. The criteria for selection between projects have 
been summarised by Adeyoju (1975) as: maximum volume, employment, balance of payments, 
profits, net discounted revenue (NDR), internal rate of return (IRR), value added, output, 
capital ratio, social marginal product, benefit /cost ratio, marginal per capital reinvest- 
ment and net social benefit. 

NDR and IRR are the criteria most generally quoted, and sufficiently accurate data 
on costs and returns can usually be collected to make the figures obtained reasonably 
reliable. Criteria based solely on direct economic returns such as NDR, IRR, profits, 
value added, etc., present only part of the picture, and may lead to a choice of project 
which conflicts with government social policy. Other benefits are therefore also calculated, 
and two of the most frequently used are employment and net social benefit. Employment may- 
be measured as the number, the type or the location of new jobs created, or in terms of net 
value added, cost per new job or the effect. on the re-distribution of income. The saving 
of foreign exchange is frequently quoted as a criterion for the evaluation of pulpwood 
projects in particular, but in fact it may be illusory, for in such a capital intensive 


industry the benefits of home production may be more than outweighed by the cost of imported 
machinery or raw material and the cost of servicing loans. There is increasing world shortag 
of pulp which makes it necessary for Nigeria to satisfy this need in the rapidly expanding 
home market and perhaps also for the export world. Inflation makes it better to invest now 
rather than to delay into the future. 

In order to select between projects, they may be ranked according to several of the 
criteria, but even then the final choice may be influenced by other factors. These include 
interactions with other projects within or outside the sector and the flexibility of the 
project to adapt to unforeseen circumstances, in particular inflation. 

The monitoring of the performance of the project against its targets will largely be 
done within the project as will much of the adaptation of the methods or targets to meet 
local conditions. There will, however, be a need for monitoring at the national level for 
continuing interactions between projects, reactions to national policies and evaluation of 
the performance of the project. The sectoral planning unit will also be responsible for 
co-ordination between projects. 


Where it is decided that all or part of the national requirements of forest products 
and services may best be met at some future date by the creation of plantations, there 
may be implications far outside the forestry sector. 

The first is that forestry may be an excellent means of implementing government plans 
to raise the rural standard of living and check the drift to the towns. For example in 
Nigeria, it is hoped to achieve this through rural forestry development projects such as 
agri silviculture, promotion of the development of farm wood lots and communally owned 
forest plantations. Large labour forces will be required near the plantation, and it will 
be necessary to house the workers and offer various social services if a permanent, skilled 
labour force is to be retained. But full time employment of labour will remove them from 
subsistence farming where they worked mainly to feed themselves and their families and to 
sell surplus foodstuffs. 

Labour forces are still likely to grow a small portion of their food requirements 
outside working hours, but in order to supply their total needs and to produce more food 
for the rest of the population, large agri-si Ivicultural schemes will have to be developed, 
based upon the proper planning of the potential of the land for growing various crops. 
The savanna and derived savanna are potentially suitable for this as they have high rainfall 
during the growing season and high sunshine hours during ripening and harvest of grain 
crops. This will require some degree of mechanization for the following reasons: 

1) Scale. Manual methods on the scale of most large plantation schemes would impose 
an enormous administrative and managerial burden. 

2) Timing. Several operations, such as the sowing of crops, have to be done in a 
very short period. 

3) Cost. 

Compared to most developed countries, however, the labour component will still be 
high, especially in nurseries, for planting and in some maintenance and harvesting operations* 

It will be necessary, too, to integrate the present timber industry more closely with 
the plantation schemes to get the most suitable areas of high forest harvested at the right 
time. More coercion may be necessary to force the industry to take more of the secondary 
species in order to clear the land more thoroughly. 

- 219 - 

More training in managerial techniques for graduate staff will be required, possibly 
with a reduction in biological studies* More specialists will also be required, and there 
will be a need for retraining staff at frequent intervals to update their skills. In 
order to speed up reporting, it is likely that the traditional line of command may be 
short-circuited in order to produce figures for speedy monitoring. 


Adeyoju, S.K. Forestry and the Nigerian Economy. Ibadan University Press. 

Anon. An introduction to planning forestry development. FAO/SWE/TF 1 1 8 

1974 FAO, Rome. 

Fraser, A.I. A manual on the planning of man-made forests. Working Paper, 

1973 FO:MISC/73/22. FAO, Rome. 

Johnston, D.R. , Forest planning. Faber. 
Grayson, A.J. & 
Bradley, R.T. 

Watt, G.R. The planning and evaluation of forestry projects. Institute 

1973 Paper No. 45. Commonwealth Forestry Institute, Oxford. 

- 220 - 



T.G. Allan 
Forestry Department, FAO, Rome, Italy 



Introduction 221 

The outline project 221 

The detailed project 221 

Objectives, constraints and criteria 222 

Collection of data 223 

Resource data 23 

Operational data 226 

Market and yield data 226 

Socio-economic data 227 

Institutional data 227 

Appraisal and decision 227 

The planting plan 228 

Detailed prescription of activities 229 

Marshalling resources 229 

The "budget 230 

Records and control 230 

Conclusion 230 

References 231 

Appendix A: An outline of equipment and materials for an afforestation 

project 233 

Paper for Symposium on Savanna Afforestation 

- 221 - 


Foresters are long established as planners and managers. The traditional "working 
plan" provided a basis for effective continuity, and by collecting records a reasonable 
base for future planning was built up. Modern planners (Johnson, Grayson and Bradley, 
1967) have suggested that these plans have three main deficiencies: they lack flexibility? 
there is no definition of criteria by which to judge the relative success of alternatives; 
and the planning was generally only at the forest level. 

Planning is used to describe anything from a series of arbitrary decisions to a 
critical and sophisticated investigation into the whole range of possible choices open 
to an enterprise. The planning of a savanna afforestation enterprise will be considered 
in the following sequence: 1) the "outline project", 2) preparation of the "detailed 
project" and 3) preparation of the "project planting plan". 

Subsequent to the planting or establishment plan it would be necessary to incorporate 
or prepare a plan for exploitation, but that consideration, which increases the complexity 
of planning, lies outside the scope of this discussion. 

The main reason for planning a project is to maximise efficiency, so that the plan 
will represent the most efficient courses of action to achieve the stated objectives. The 
final form of a sound plan results from a process of successive approximations, and many 
possible activities may be repeatedly analysed with different data, but in the final 
analysis that what is planned on paper should be realised on the ground. 


The outline project may be generated by a forest department or by the national 
planners. One of the first essentials in identifying a project is a measure of the supply 
and demand for forest produce which should indicate where priorities for development might 
occur. For instance in Nigeria, Thulin (1966 and FAO, 1970) prior to 1970 carried out 
a survey of the general consumption of wood products in the savanna region and of possible 
trends in the aggregate levels of consumption for such products in the future. More 
recently Ehabor (1971 ) examined the position on a national basis. Such estimates of 
future consumption provide a useful framework for examining resource allocation and research 
needs for the forestry sector in relation to the national economy. Supplemented by input 
and output data, these estimates form the main basis of outline projects but are insufficient 
for the detailed planning and analysis of a particular development project. 

From such data, the national or development planners should be able to indicate on a 
national or sectoral basis the extent and priority for forest development. This project 
generation and selection should form a preliminary process prior to detailed project 
planning. From a possible selection of outline projects or proposals the forest planners 
in turn will allocate priorities and select those which merit immediate planning in greater 
detail. Such projects should be technically feasible and commercially viable. This choice 
of outline projects represents selection and priority at the national level. 


On the assumption that the national planners have agreed on the need for afforestation 
and have broadly outlined a savanna plantation project, the next task is to prepare the 
detailed project. An afforestation project may vary in size from the planting of a few 
hectares for shelter or soil protection, to a large-scale scheme extending over 10 to 30 
years and involving considerable investment. It is with this latter type of large-scale 
project that this paper is mainly concerned. It is obviously impossible to implement on 

- 222 - 

an ad hoc basis a large-scale planting programme involving complex establishment systems 
without plunging the enterprise into chaos To make such an enterprise efficient requires 
planning, and the objects of planning are: 

1) to minimise costs in achieving specified ends; 

2) to ensure that aims are likely to be achieved in practice by anticipating 
constraints ; 

3) to provide continuity; and 

4) to provide estimates of the resources needed and the time sequence in which 
they will be required. 

The detailed project is essentially a document setting out objectives , recording 
whatever data relevant to the project are available, considering alternatives and indicating 
what programme should be completed and when, and putting values on inputs, outputs and the 
project as a whole. At an early stage of development it is essentially a paper exercise 
based on the best available information, indicating the economics of the enterprise under 
specified assumptions and conditions. It provides the evidence which allows higher authority 
to decide whether and on what basis the project should be approved and financed. Once 
approved, it provides the basis for operational planning, budgeting and implementation. 
The more sound the planning the easier the subsequent implementation. Planning the detailed 
project falls into three main phases: 1) objectives, constraints and criteria, 2) data 
collection and 3) appraisal and decision. 

ObjectiveSf Constraints and Criteria 

The outline project may have broadly based and possibly multiple objectives which 
require clarification in the detailed stage. Objectives have to be attainable, clearly 
defined, consistent and quantitative (PAO, 1973) The refinement of generally stated 
objectives for detailed planning purposes, can reveal limitations in the original concept 
requiring adjustments. Again, having determined objectives, subsequent preliminary 
calculations may result in further changes of priority or modification of aims. For 
example, the project objectives may be: 

1) to produce x m per/annum of wood for local industry; 

2) to be labour intensive; and 

3) to earn y percent on capital invested. 

Subsequent study might show that as supervision is limited, the required labour force 
cannot be employed and the rate of planting required to attain objective (l) cannot be 
achieved. Or it may prove impossible to earn the required rate of interest and be labour 
intensive simultaneously. Such conflicts would require a re planning of the objectives and 
consideration of the more efficient alternatives. 

Constraints are limitations imposed on the activities of a project and are generally 
inflexible, although in certain circumstances it is possible to remove or adjust a constraint 
when so doing materially improves the project. It is convenient to consider constraints 
in the following categories: 

1) Technical : These are constraints which impose restrictions on the methods used 
or products created - for example, the mosaic pattern of pi an table land affecting 
layout or technique, or the unsuitability of certain eucalypts to sawing or 

- 223 - 

2) Financial i These may be represented by restrictions on the financial resources 
available, or obligations to meet repayment of interest and/or capital, or 
erratic provision of funds. 

3) Social and Economic: These can be related to opportunity costs, in that the 
resources being used for the project are not available for use elsewhere* 

4) Institutional: These are limitations imposed by the organisational and managerial 
ability of the agency executing the project, by the legal framework and by the 
social patterns and attitudes of the local people. 

Criteria are used to ascertain the ability of a project to achieve its objectives. 
They also provide a measure against which alternative methods of achieving the objectives 
can be compared and evaluated. A good criterion is applicable to all alternatives and 
should be readily calculable to provide in a single figure, all the information needed for 
decision making. One of the better known economic criterion for measuring the profitability 
of a project is "net discounted revenue" , or the "present worth" of the future benefits 
created net of the capital and operating costs. Other criteria which might be applied are 
measurements of employment created, rate of loan repayment or, on a technical base, the 
rate of tree growth and the area planted annually. Where expertise is limited and where 
the availability of management is restricted, it is advisable to limit as far as possible, 
the number and complexity of objectives and criteria. 

Collection of Data 

Much of the background data such as methods, costs and yields required for the 
formulation of a project have to originate from established plantation research or 
development in the area. Information on demands, and value of produce requires a market 
study. Although it is necessary to have a reasonably clear idea of what the aims of a 
project are before collecting data, it may not be possible to specify attainable objectives 
until after certain data have been gathered. 

Data are collected from best available sources to allow the construction of a 
realistic plan. Such data may indicate possible alternative courses of action which can 
be evaluated to facilitate decision making. Where data are lacking, it may be necessary to 
postpone planning and design systems to collect necessary figures. Any sectoral or outline 
planning which has occurred prior to defining projects will contain some relevant data but 
often too generalised for detailed planning. Data for project planning, in addition to 
being detailed, tend to be of a more technical nature as they will serve to specify 
operations in practice. 

The data required for a plantation project may be classified into five categories: 
1) resource data, 2) operational data, 3) market and yield data, 4) socio-economic data 
and 5) institutional data. 

Resource data 

The main resources to be considered are land, planting stock materials and equipment, 
human and financial. The required information on each is availability, productivity and 

Land resources: The first essential is sufficient plantable land to accommodate 
the project planting programme; indeed, excess land is required to allow for unforseen 
problems and possible future expansion. Where tribal or other legal rights affect the use 
or availability of land, such matters require clarification before further planning is 
undertaken . 

- 224 - 

In the early stages of development it is not possible to assign site quality classes 
to soil types, but a simple pi ant ability classification can indicate the better areas for 
planting* The assessment of plantability requires a soil survey of the type outlined by 
Barrera (1969 and 1976) for Nigeria or Sanders (1967) for Zambia and the preparation of 
maps showing soil types, vegetation types and plantability. At the same time as the 
vegetation is recorded the tree cover should be sampled for basal area to give a measure 
of tree density, a major factor in land clearing* 

Established growth trials of plantation species should indicate the productivity for 
the range of plantable sites. There is some merit in planning to plant the better sites 
whilst research and growth trials produce further data on secondary or marginal sites. If 
no growth data are available, a full project is premature and a 'well planned pilot project 
is a reasonable alternative. Where forest reserve land is available there are no direct 
costs for the resources , but where land is acquired by purchase or compensation f such costs 
are recorded and debited. The annual planting land requirements should be allocated using 
the plantable land map. 

Planting stock resources: The primary requirement is an adequate and sustained 
supply of seed of the selected species and provenances. Selection of species is a major 
subject but it is presumed that species and provenance trials have been extensively 
evaluated prior to the preparation of a large-scale project. Seed supplies often prove 
major bottlenecks to the proposed rate of development. Sources of supply and storage 
facilities should be thoroughly determined. If importation represents a risk then local 
seed production and methods of expediting this must be given priority. Availability of 
seed must necessarily have some influence on the planting rate of species previously 
selected for silvicultural and utilisation reasons. Seed is readily raised to planting 
stock provided that the nurseries and expertise are available to produce sufficient 
quantity of adequate quality seedlings at the required time. When purchasing seed it is 
the cost per plantable seedling and not the cost per unit weight which is of consequence. 
The annual requirements of seed and seedlings and costs should be detailed. 

Material and equipment resources: These fall into three main categories: those 
required for the administrative organisation, for operational activities or for 
maintenance and support. Administrative requirements include offices and buildings and 
minor items such as office equipment and stationery which are common to any enterprise. 
Operational materials and equipment are specific to plantation development and a general 
outline is listed in Appendix A. Maintenance and support items include workshop equipment, 
transport and spare parts. The critical factors with reference to stores, are firstly to 
select those items suited to the particular work and scale of the project and to ensure 
that such equipment or materials, together with spares, are available on site when required, 
which necessitates the provision of ample storage. 

Equipment offers a considerable range of options, and past experience shows that 
operational data and selection of methods are required before the field of choice can be 
narrowed. Land clearing, for example, if by hand requires extensive supplies of hand tools. 
If, however, for reasons of efficiency this operation is to be mechanised, then clearing 
should commence one year before planting, and the order for clearing equipment would 
require to be placed at least two years before planting. If only mechanised clearing is 
feasible and the scale of operation does not merit purchase of a chaining unit, then such 
alternatives as sharing this activity with another project or projects, employing a 
different mechanised technique, or hiring equipment need to be considered and evaluated. 

The productivity of equipment is critical to the efficiency of a project. Evaluations 
of the output of equipment may be of little value unless allowance is made for variables 
and the basis of measurements is stated (Allan and Akwada, 1976). Good productivity 
requires as full an annual or seasonal utilisation of equipment as possible. Scale of 
operation and operational data are required before any stores or equipment requirements 
can be set out* When the types of equipment and materials have been finalised, an 
assessment of the total requirements by years should be drawn up for the full period. 

- 225 - 

The purchase or capital cost of all project materials and equipment is the true cost 
and is required for estimates, budgets and costing the total project requirements. Fbr 
comparative evaluations the planner requires the equipment hourly operating cost, which is 
largely a hypothetical calculation, and from which a unit productivity cost can be calculated. 

Human resources I Man is the most important resource in the project, and due considera- 
tion of his abilities and reactions is required in deciding on possible courses of action. 
The possible sources of labour and staff require study, as they determine the need for 
additional investment in transport or housing. Etoployees benefit from a plantation project 
not only in cash wages but also from training, improved housing and security. Hastie and 
MacKenzie (196?) point out the benefits of employees living in mixed communities rather 
than exclusive project settlements or villages. A plantation project involves many skills 
and requires managers, supervisors, mechanics, machine operators, administrative and 
clerical staff, medical staff and both skilled and casual labour. In particular, if a 
project is to be selectively mechanised then the provision of a suitable infrastructure 
employing skilled mechanics and operators is mandatory; and where numbers are limited 
training will be necessary. 

The productivity of labour is variable and often reflects the quality of management 
and control. Work study, method study and training all contribute to labour efficiency. 
Initial hand weeding studies in Zambia (Allan and Ehdean, 1966) increased output by up to 
300 percent, and planting studies in Nigeria showed increases of the order of 200 percent 
to 500 percent. In the early stages of a project there is scope for very large increases 
in productivity, but even at a later stage improved methods in Zambia (Allison, 1972) were 
giving 30 percent increases in output which is not insignificant. Productivity can also 
be improved by the payment of incentives. This is not always easy under government fiscal 
regulations, but where benefits are significant, sanction for such payments should be 

The cost of human resources is the sum of salary or wages, social and fringe benefits, 
leave and sick time. The manpower requirements of the project should be set out for staff 
by years, categories and responsibility and labour is similarly recorded, but operations 
replace responsibility. To calculate the annual labour force, a calendar of operations and 
labour inputs not only gives the necessary data but also allows fluctuations in requirements 
to be smoothed out to provide more regular employment. Information on the productivity 
and unit costs of labour may be extracted from operational data. 

Financial resources: Generally some indication of the finance available for the full 
project, or a development plan phase of the project, will have been given at the outline 
stage. The detailed project should be planned to fit this financial framework, but where 
finance proves to be a critical constraint, the case for an additional allocation should 
be made. The total costs of the other resources, plus contingency, represent the alloca- 
tion required, and these figures should be set out as annual requirements for the entire 
project period. 

It is important that the financial authority should understand that a plantation is 
a dynamic enterprise not readily accommodated in the fiscal year concept. Plantation 
operations such as land clearing, nursery and weeding are interrelated in time, in that 
this year's programme can affect both last year f s and next year's.. This means that delays 
in funding or erratic allocations will not only effect the year of occurrence, but also 
past and future investments. Two possibilities of overcoming this problem are either to 
have the financial authority consider the project as a capital investment until normality 
is achieved or to make funds available on a three or five yearly allocations. The ready 
availability of funds, however, does not preclude carefully planning their investment. 

- 226 - 

Operational data 

The data to be recorded in this section for all plantation operations are: 

1) unit of measurement - ha y km or '000 plants; 

2) input - man-days, machine operating time, materials; 

3) output - units per hr, per day, etc. and 

4) cost - cost of each resource per unit 

These data allow a ready estimation of the productivity of men and machines and of the total 
requirements of such resources for particular project operations. Where management considers 
that two or more techniques offer a reasonable choice of operating method, data for each 
should be recorded to allow comparative evaluation. The collection of operational data is 
critical and fundamental to the planning process. The information must be the best 
available. It may be extracted from costing records where available, but when lacking, 
sampling work outputs as recorded for Ferguson (1973) in Nigeria, provides indicatory 
data* Operational data provide a basis for appraisal, for estimating resource requirements, 
and budgeting; consequently it is vital that the source and reliability of all such data is 
recorded. A project or plan is only as realistic and workable as the data used in its 

Market and yield data 

The project planner requires information on markets, outputs and the value of 
different categories of plantation produce. To obtain market data in the probable project 
catchment area it is necessary to study: 

1) the current consumption of different wood categories; 

2) the current price level for the different categories; and 

3) population trends in this area. 

A survey to determine such data is more detailed and specific than a national wood 
consumption survey. A relevant example is the survey made by Grut (1972) of the market 
for firewood, poles and sawn wood in the major towns and cities in the Nigerian savanna 
region. This survey covered eigfrt cities and although sampling was from only 3*5 percent 
of the population in the area, this sector of the population represented the main cash 
market in the areas of most rapid economic development. 

In addition to recording costs, which may be applied to the different categories of 
produce, the market survey gives a measure of demand at a particular point in time which, 
with information on population trends, allows a forecast of demand to be made. Such a 
forecast identifies factors which may cause changes in demand, and allowing for these 
possibilities, predicts future demands over the project period. 

Data are also required on the estimated yield of different categories of produce 
from the selected species, noting a specific silvicultural system and rotation 
for each. The yields axe estimated by category and year to the end of the project period. 
Bty applying the market survey prices to these yields, the yearly revenue accruing to the 
project is estimated. In the early stages of a project some of the growth and yield data 
may be based on minimal evidence and where only young trial plots are available it may be 
necessary to extrapolate data from elsewhere on the assumption that later growth will be 
comparable. Where growth data is plentiful, a supply forecast can be made noting possible 
changes in method, which might alter yields, quantifying the effect of these changes and 
predicting potential supply under different specified conditions* 

- 227 - 

To check on the commercial viability of the project the supply and demand forecasts 
should be reconciled. If the balance suggests a shortfall, then either the project will 
have to be expanded or produce will need to be imported or substituted. 

Socio-economic data 

Estimated costs of resources and estimated project revenue give the financial 
composition of the project but do not fully account for the real cost and the real benefit 
to the community as a whole. Socio-economic factors attempt to assess these real costs 
and benefits, but they are difficult to quantify and economists are still developing 
improved techniques to measure these factors. 

The project is essentially a joint production by the practising forest manager with 
his support services and the forest economist, and it is in determining and calculating 
socio-economic data that the latter comes into his own. The main socio-economic data 
required are: 

1) shadow costs of labour; 

2) opportunity costs of land; 

3) discount rate to be used; 

4) shadow price of produce; and 

5) value of non marketable benefits. 

For an indicative approach to deriving socio-economic data, refer to Ferguson (1973)| who 
completed preliminary studies of the economics of selected savanna plantation enterprises 
in Nigeria. Socio-economic factors may often seem to be of little consequence to 
practising foresters, but when projects are in competition with others for limited capital, 
it is just such factors that can transform a marginal forestry project into a feasible and 
viable one. Spears (196?) stresses the importance of presenting forestry economic data in 
the best possible light. 

Institutional data 

Institutional factors to be noted are mainly of a political nature, but include the 
project legal framework and the commitment of the supervising agency in other fields, such 
as training, which might influence the acceptability of the project. Other factors on 
which information should be collected are the interrelationship of the local community and 
the project, facilities for multiple land use and information on plantation research in 
progress but insufficiently advanced for appraisal. 

Appraisal and Decision 

Having compiled all available information relevant to the project, the appraisal stage 
consists of the following steps: 

1) identifying different courses of action which will achieve the objectives and 
analysing these for inputs, outputs and costs; 

2) testing courses of action against identified constraints; 

3) comparing alternatives, using project criteria to determine the better 
ones; and 

4) making final project decisions. 

- 228 - 

With large quantities of reliable data, appraisal and analysis may be complex and 
possibly time consuming, although where efficient computing facilities are available the 
time required for analysis can be greatly reduced. The number of factors which can be 
varied in the execution of a project and the number of alternative courses of action are 
almost limitless. Project planners usually operate against target dates and time pressures 
which necessarily limit the number of alternatives that may be considered. The forest 
planner restricts the alternatives for analysis to those which are feasible and might give 
some significant benefit when judged by the project criteria. More obvious areas where 
different courses of action might significantly affect project results are: 

1) planting rate and rotation; 

2) spacing and thinning; 

3) intensity of management; 

4) distance from markets or processing plant; 

5) degree of mechanisation; and 

6) insurance factors related to timeliness or using a range of species to reduce 
disease hazard t or selecting species with alternative utilisation possibilities. 

At an early stage in the development of a plantation project, with the main criteria 
being the financial and social net present values per hectare, the following analytical 
processes | incorporating alternative data where necessary, should indicate firstly the 
better alternatives and secondly the feasibility of the project: 

( 1 ) Financial analysis* Using the national development plan rate of interest, the 
project "net present worth" is calculated by deducting the discounted costs from 
the discounted revenues. Net present worth per hectare is derived by dividing 
by the number of hectares in the plantation area. Data for different courses 

of action may yield significant differences in this unit value. 

(2) Social analysis. This is similar to the financial analysis but the input and 
output data are revalued to determine social cost benefit. The process for 
social revaluation is best defined by the central government to ensure uniformity 
in project evaluation, but might include shadow rates for labour, the social 
opportunity cost of net capital expenditure, foreign exchange factors and a 
social discount rate or social rate of time preference. 

The application of sensitivity testing to both types of analyses to gauge the effect 
of changes in such assumptions as cost and revenue, can provide useful information and 
indicators. When the net unit worths from financial and social analyses exceed those of 
a comparable best alternative use of the land, the project is indicated as being financially 
and socially beneficial. 

With the quantified results of analysis senior management should be able to decide 
whether the project will be undertaken and which specific course of action will be adopted. 
When the detailed project is approved the next stage is the planning and implementation 
of the initial phase which is mainly concerned with plantation establishment. 


On the assumption that the detailed project is approved and the necessary finance 
authorised, the next stage is planning initial implementation by preparing a planting plan* 
The planting plan can be considered the operational planning section of the detailed project. 
It reoords for the plantation manager what is to be done over a period. Assuming a 30 year 
project, the initial planting plan should cover five years, although circumstances may 
vary this period. The remainder of the project time will be implemented by similar periodic 
plans* At this stage in development the object should be to allow some flexibility and to 

- 229 - 

keep the plan as simple as possible. Jbr complex projects or problem areas, network 
analysis is a useful technique that may be used by management* 

The 5 year planting plan forecasts all of the project requirements annually over the 
period. This annual data may be extracted and set out as the annual programme of work for 
all project activities and represents an instructional plan for assistant managers and 
supervisors. If annual financial allocations cannot be avoided, the budget section may 
submit annual estimates of funds required. The main sections of the plan are the detailed 
prescription of activities, marshalling of resources, the budget and records and control. 

Detailed Prescription of Activities 

Detailed prescriptions of work set out the method, quantity, estimated inputs and 
outputs for the following main operations: 

Plantation operations 

Allocation of land and surveys 

Establishment of nurseries and raising planting stock 

Land clearing and preparation 

Laying out and construction of access 


Beating up 





Pi re protection 

Road maintenance 

Other works 

Allocation of staff and definition of responsibilities 

Training of staff and operators 
Maintenance of transport and equipment 
Maintenance of building and general services. 

If management has a handbook of plantation techniques as in Zambia (Allan and Ehdean, 
1966), reference to this may reduce the length of the prescriptions and the plan. Laying 
out, item d), which includes the design and delineation of compartments, blocks, roads, 
rides and fire traces, constitutes an important management decision, and other than topo- 
graphy and national features, two of the main considerations influencing design are fire 
protection and probable logging methods. Thinning, item j) f which will undoubtedly occur in 
the next project period, is included in the initial planting plan for contingency reasons. 

Marshalling Resources 

The general resource requirements for the period are in the detailed project and 
these should be up-dated and adjusted as necessary to the planting plan. The prescription 
in this section will require the manager to requisition where cecessary and acquire by 
given dates: 


staff and labour, 

machinery, transport and equipment, 

building materials or buildings, 

project materials and seed, and 

essential spares. 

- 230 - 

The detailed requirements will include timely ordering of specified resources for the start 
of the next project period. It is advisable to seek specialist advice in ordering certain 
of these resources. 

The Budget 

The budget is the estimated costs of all the resources to be used in achieving the 
detailed prescriptions, and is usually set out for the plan period by years and main 
operations. Much of the information for the budget may be extracted from the project 
financial resources data section. For convenience the budget may be set out under functional 
heads f such as: 

Land preparation Road construction 

Nurseries Maintenance 

Plantation operations Administration 

Protection Services 

The approved budget is the authority for the allocation of funds for the enterprise and 
when subsequently compared with actual expenditure for the same period, is a measure of 
planning and management efficiency. When release of funds is requested allowance must be 
made for inflation, changes in methods and increased efficiency in plantation operations* 

Records and Control 

Complex recording methods will inevitably cause problems and fail, so it is essential 
to keep systems simple whilst recording only essential data. Compartment, or block records 
if areas are uniform, will provide basic information on the area and note what treatments 
are applied and when. A simple type of report may be in map form showing the area treated 
by shading and with operational data recorded on the back. 

Control of a project concerns keeping the work completed and the expenditure within 
the limits set by the programme of work and budget for the year. Periodic progress 
reports give simultaneous information on work completed and expenditure. It is necessary 
to train supervisory staff in completing these reports and to advise on the reasons for 
submitting such data. Equally it devolves on management to check such reports and to 
inquire into the reasons, firstly for major deviations from budget estimates and secondly, 
for widely variable outputs from different supervisors for the same operation. 


This paper attempts to encompass a very wide subject in a very short presentation 
which follows the outline of the FAO Manual on the Planning of Man Made Forests (PAO f 
1973) Brevity has undoubtedly introduced some imprecisions and omissions. The outline 
covers planning from project initiation to point of implementation, and although this 
terminates the defined discussion it does not end the planning process. As has already 
been pointed out, the project is a dynamic conception. Experience gained, problems solved, 
changes in the economic climate, and data gathered when implementing the planting plan will 
initiate changes and modifications in subsequent plans and plan periods. 

-231 - 

Allan, T.G. & Qidean, F. 

Allan, T.G. & Akwada, E.C.C. 

Allison, C.E. 

Barrera, A. 

Barrera, A. 

Ehabor, E.E. 



Ferguson, I.S. 

Ferguson, I.S. 

Grut, M. 

Hastie, W.F. & 
MacKenzie, J. 

Johnston, D.R., Grayson, A.J. 

& Bradley, R.T. 


Manual of Plantation Techniques. Dept. Instruction. 
Zambia Forest Dept. Ndola, 1966. 

Land clearing and site preparation in the Nigerian 
savanna. Paper for the Sjyraposium on Savanna Afforestation, 
Kaduna, Nigeria. 

Work study in industrial plantations. Forest Ind. 
Feasibility Study Project Working Document. FO:SF/ZAM 5 
FAO, Rome. 

The use of soil survey in assessing sites for forestry 
potential in some areas of the northern states of 
Nigeria. Technical Report No. 5. FO:SF/NIR 16. 
FAO, Rome 1969. 

Soil and site selection. FAO/DANIDA Training Course on 
Forest Nursery and Establishment Techniques for African 
Savannas . 

Forecasting potential consumption requirements for 
Nigerian forest products. Nig. Journal For 1(1). 
Ibadan 1971. 

Wood requirements in the savanna region of Nigeria. 
Technical Report No. 1. FOR/SF:NIR 16. FAO, Rome 1970. 

A manual on the planning of man-made forests. Working 
Paper FO:MISC/73/23. Rome 1973- 

Costing and economic aspects of plantation establishment 
in the savanna region of Nigeria. Project Working Doc. 
FO:SF/NIR 16. FAO, Rome 1972. 

The economics of plantation forestry in the savanna 
region. Savanna Forestry Research Station Project 
Working Doc. FO:DP/NIR/64/5l6. Samaru 1973. 

The market for firewood, poles and sawn wood in the 
major towns and cities in the savanna region. Technical 
Report No. 6 FO:SF/NIH 16. FAO, Rome 1972. 

Planning an integrated forest programme. Symposium on 
Man-made Forests. Canberra 1967. 

Forest Planning. Faber and Faber, London 1967* 

- 232 - 

Spears, J.S. 

Sanders, M. 


Thulin, S. 

Feasibility studies and financing man-made plantation 
forests. Symposium on Man-made Forests. Canberra 

Soil survey and site selection in Zambia. Symposium on 
Man-made Forests. Canberra 1967- 

A Forest Plantation Programme for the savanna region of 
Nigeria: need, justification, cost. Savanna Forestry 
Research Station. Roneo. 

Weeding is one of the cultural operations with which 
savanna plantation planners and managers must reckon. 
The good growth of this 4-year old Pinus oocarpa stand 
at Afaka, Nigeria, is in part the result of regular 
mechanical wee dings in one direction, supplemented 
occasionally by manual spot weeding. 

- 233 - 


An Outline of Equipment and Materials for an Afforestation Project 




land clearing 

ground preparation 

nurs ery 


Maintenance and 

road making 

survey equipment 

tractors, crawler 

anchor chains 

tree dozer blade 


front end rake 

root plow 

tractors, 5O-1OO HP 
ploughs, disc 
angle dozer blade 

wheel tractor 


loader attachment 

sprinkler equipment 

soil mixer 

hand tools, spades, 

forks, hoes 

tractor, 50-1 OO HP 

tractor, 50-100 HP 

soil cultivators 

pruning saws 

fire towers 

fire engines 

water pumps and hoses 


tipping trucks 



rollers, rubber tyred 

fuel and oil 
hand tools 
aerial photographs 

fuel and oil 
hand tools 






fuel and oil 

hand tools 

fencing stakes 
fencing wire 
hand tools, spades, 

fuel and oil 
tree carrying 


fuel and oil 
hand tools 

fuel and oil 
road ballast and 


bridge materials 
cement gelignite 

- 234 - 


J.B. Ball 

FAO/UHDP High Forest Development Project 
Ibadan, Nigeria 



Objectives of cost account ing 235 

General principles 233 

Operations 235 

Estimation of quantities 235 

Labour component 236 

Allocation of labour time to operations 236 

Calculation of labour cost per man-day 236 

Calculation of the labour cost of operations 236 

Materials component 236 

Plant and vehicle component 237 

Log book 237 

Calculation of unit cost 237 

Calculation of plant or vehicle component 237 

Overheads 238 

Items included as overheads 238 

Allocation of overheads to operations and costings heads 238 

Reconciliation of expenditure and costings 238 

Other records 239 

Compartment history 239 

Other works 239 

Distinction between records and correspondence 239 

Sampling methods of obtaining cost figures 239 

Glossary of terms 240 

Literature 240 

Appendix 1: Flow chart of cost and other works 241 

Appendix 2a: Worked example of labour abstract, Iperu Charge 242 

Appendix 2b: Worked example of labour abstract, Iperu Nursery 243 

Appendix 2c: Worked example of calculation of cost per man-day 244 

Appendix 2d: Worked example of calculation of labour cost of operation 245 

Appendix 2e: Worked example of summary of labour cost of operation 246 

- 235 - 


The objectives of cost accounting are: 

1. Budgetary control, 

2. Estimates, 

3 Labour control, 

4. Calculation of financial returns and 

5. Identification of those components that would show the greatest return 
from improved methods. 

These objectives are applicable at all levels of responsibility. 


Six general principles are involved in cost accounting: 

1. All expenditure must be included; 

2. Expenditure must be allocated to an operation, either directly (e.g., labour wages) 
or proportionately (e.g., overheads); 

3. The costs must be capable of being reconciled with the total expenditure to check 
that all expenditure has been included; 

4* The components of the unit cost are added at different levels of responsibility, 
and the system must be capable of extracting the components (see diagram in 
Appendix l) ; 

5. It must also be possible to extract information for other purposes from the costing 
system (e.g., for compartment histories) and 

6. The scheme must be simple to allow its use at the lowest levels of responsibility 
and to ensure that the cost figures are speedily produced. 


Operations must be rigidly defined to enable comparisons to be made between years and 
between plantations. 

A code number should be given to each operation to enable easy identification and for 
computer processing. 

Operations can be grouped together under costings heads. For example, in the nursery 
the operations of sowing, making transplant beds, transplanting, weeding, watering, etc., 
could all be added together under the nursery head to give a nursery unit cost per planted 

All jobs should be definable as operations; there should be no "miscellaneous" costings 
head. But one of the heads should cover general management costs, such as inventory, publicity 
research, training, etc., and these costs may be apportioned to quantifiable operations in 
the same way as overheads. 


In order to obtain the unit cost of an operation, the total quantity of work done in 
a particular place must be known. Area is the quantity in which most costs are expressed. 
Accurate maps to show net afforested areas are therefore essential. Areas should not be 
estimated by eye, except for 1 ha or less, nor should they be estimated from the number of 
blocks cleared, or trees planted. 

The definition of each operation should also contain an explanation of the relevant 
quantity Pbr example, if a weeding is necessary only in a small part of a compartment, 

- 236 - 

should it be coated to the actual area weeded or should it be oosted to the total area of 
plantation of that age? The latter io usually the course adopted, as it is with fire 
protection, insect control, etc* 

The place that an operation is carried out should also be indicated with the quantity, 
both to explain anomalies and for extraction for compartment and other records. 

Allocation of Labour Time to Operations 

This is done by the man responsible for directing the work .in the field* At the end 
of each day he notes the number of men working on each operation in a labour abstract or dis- 
tribution book. The man days for each operation are totalled at the end of each month. 

Where a man works on two or more operations, hie time is usually charged to the 
operation on which he worked longest. 

Calculation of Labour Cost per Man-Day 

The details of the wages of the labour are generally maintained on a pay sheet or muster 
roll, separate from the record of the allocation to operations. 

Although labourers are paid at different rates depending on experience and responsibility, 
it is simplest to add all of the wages together and calculate an average cost per man-day. 
The alternative is to combine the pay sheet and the record of the allocation of labour to 
get a "true" cost, but this is time consuming and liable to error. 

Labour overheads should also be included in the calculation. These are mainly the wages 
of staff who are also paid on the pay sheet with the labour, but who are responsible for 
supervision or administration, such as headmen, storekeepers, etc. Their pay is added to 
that of the labourers, along with other overheads such as paid holidays, paid sick leave, 
allowances and the cost of food where it is included as part of the wages. The cost per 
man-day is then calculated in the following way: 

A. Total man-days worked (from the record of the allocation of labour to operations); 

B. Man-days paid, but not productive (labour overheads); 

C. Total man-days paid (A + B); 

D. Gross wages paid, plus allowances, to the men represented at C; 

E. Cost per man-day - D/A. 

Calculation of the Labour Cost of Operations 

The man-days per month worked on each operation are multiplied by the cost per man-day 
to get the labour cost of the operation, and divided by the quantity to get the unit cost. 

The calculation can be simply checked lay adding together all of the costs of operations, 
which should agree with the amount paid. 

Worked examples of the calculations for determining the labour component are in Appendix 2 


For most forestry operations, except building, the expenditure on materials is a fairly 
small proportion of the total cost. Approximations can therefore be made in the allocation 
to operations without great loss of accuracy. 

Ideally, all materials issued from the store should be charged to an operation* At 

- 237 - 

the end of the month, copies of the issue voucher* are used to allocate expenditure to opera- 
tions. This requires well-trained storekeepers with a knowledge of the cost oode and of the 
value of the materials that they are handling, and in the initial stages of projects they 
may lack the experience to do this* 

If the storekeepers are inexperienced, then the officer in charge of the accounts must 
allocate the expenditure to operations, and without a knowledge of the day to day running of 
the project he cannot do this entirely accurately. He will also tend to allocate the whole 
expenditure, when in fact only part of the materials may have been used* He must therefore 
have some means of finding out unused balances* 

In either case, approximations will have to be made in the case of small hand tools 
which may be used for several jobs* The allocation of the expenditure to operations should 
then be done in proportion to the labour expenditure on them. 

Although the expenditure on materials used for the operation of plant and vehicles is 
also usually charged to the same account, it should be kept separate for the easier calcula- 
tion of plant operating costs. 


Log Book 

Close control of plant and vehicles is essential, both for the allocation of expenditure 
to operations and to prevent abuse, particularly of vehicles. Every item of plant and every 
vehicle must have a log book which must be maintained to show the reason for its use for 
allocation to operations, which are then summarised in terms of hours or kilometres run at 
the end of each month. 

Calculation of Unit Cost 

Expenditure on operating plant and vehicles may be incurred under the following, which 
should be totalled separately for subsequent analysis: 

(a) Wages and allowances of the driver or operator. These must be kept separate 

from labour wages and not included as a labour overhead. 

Fuel and lubricants. The expenditure can be obtained from a materials sub-account. 

Spare parts, repairs. The expenditure can be obtained from another materials 

sub-account . 
(d) Depreciation or amortisation, insurance, etc. A record of the cost of each item 

of plant or of each vehicle and the date of purchase should be kept at a senior 

level, and the annual depreciation calculated. This is most easily done in equal 

annual amounts. 

Calculation of Plant or Vehicle Component, 

The simplest way to calculate the plant or vehicle component of operations costs is to 
do it annually, but if the costings are done on a computer, it may be done monthly. Unit 
costs are obtained by adding together expenditure on the items above and dividing by the total 
hours or kilometres run. Unit costs should be aggregated for vehicle types, rather than 
being assigned to individual vehicles. This evens out variations due to age. 

Another way of calculating the plant and vehicle component is to use a figure based 
on theoretical calculations or on the previous year's running. This makes the reconciliation 
of costs with expenditure less easy, and due to rapidly increasing prices reduces the useful- 
ness of the figures for estimates purposes. 

Provision must be made in the system for charging the cost of a vehicle working in 
another project, or hired from a central pool. Generally, the details are extracted from 

- 238 - 

the log book and notified to the officer to be charged, with the oost, at the end of the year. 
The officer who used the vehicle then allocates this oost to an operation. 

The unit cost of towed equipment must also be calculated, and its use identified on 
the log sheet for inclusion in the oost of the operation. 

It is possible to add even more information to the log sheet, for the identification 
of "lost time". This might include travelling to the job, minor or major repairs, time 
lost due to bad weather, lack of a driver, or the vehicle having no job to do. As projects 
become more sophisticated, this information is very useful for the control of vehicles. 

Quite often the time cannot be allocated to an operation - for example, taking a 
worker to hospital, or a senior officer's inspection. Then the cost is charged to a manage- 
ment oost head. 

Items Included as Overheads 

Overheads include the following: 

1. Staff salaries and allowances; 

2. Office rents, water and electricity charges; 

3 Transport of senior officers with project-wide responsibilities and 
4* Management costs. 

The calculation of overheads charges is done at the highest level and should include 
all expenditure not previously accounted for. 

Allocation of Overheads to Operations and Costings Heads 

Overheads should be divided between costings heads in proportion to the labour compo- 
nent. The reason for this is that most of the overheads are due to the supervision and 
administration of labour. Generally, it is of no interest to allocate overheads to opera- 
tions, and the only purpose of adding in overheads anyway is for the calculation of the 
rate of return per hectare. 

When, however, plantation projects reach the exploitation stage, it may not be correct 
that most of the overheads will be due to supervision and administration of labour. If 
exploitation is being done by contractors, then much of the time of senior staff 
is spent on planning, the control of harvesting and the collection of revenue. Allocation 
of their salaries may then be done in proportion to the time they spend on these jobs, which 
may be determined by means of diaries or by a system of sampling. 


The total expenditure should be checked against the total costs in order to ensure 
that all items of expenditure have been included. This is generally done at the end of the 
year, but a running check on sub-totals may be done each month. 

The equation for the annual reconciliation is: 

Total Expenditure - + Total Cost of Labour) 

+ Total Cost of Materials Used) 

+ Total Cost of Plant Operation on the Project) 

- Total Depreciation of Plant) 

+ Total Expenditure on Unused Materials) 

+ Total Cost of Vehicles, etc., Hired to other Charges) 

- Total (Cost of Vehicles, etc., Hired from other Charges) 

- 239 - 

This equation omits depreciation f staff salaries, etc., but includes management costs* 


The practice of scientific forestry depends upon the collection of accurate figures and 
the maintenance of accessible records 

Compartment History 

The details of work done in a compartment, with date and area covered, can be extracted 
from the costings system. Likewise the outturn records show the amount of each type of forest 
produce and the date that it was removed. It is usually not necessary to keep records of 
costs or revenue on a compartment basis, but they should be kept on some sub-division of the 
whole project such as a forest or plantation. 

The compartments should also be described, and such information as seed sources, 
inventory results, etc., recorded. A map must be included. Descriptions should be 
standardized to permit comparisons of outturn, etc., between compartments. An excellent 
series of forms suitable for compartment descriptions are given in Anon. (1974). 

Other Works 

Descriptions and details of other works such as buildings, roads, etc., with date of 
completion and a record of maintenance should also be kept. 

Distinction between Records and Correspondence 

It is most important to distinguish between records, which are permanent, and correspon- 
dence, which is generally ephemeral. Where correspondence contains information that should 
be retained, it must be extracted and put in the records - an annual review of the correspon- 
dence files is a useful way of doing this. Likewise, correspondence must not be allowed to 
clog the records and prevent speedy access. 


The system of cost accounting that has been described in this paper is the ideal, 
but until it has been in operation for at least a year, there will be no reliable figures 
for unit costs. In the meantime, data may be required for estimates or project evaluation. 
In this case, the cost of operations may be determined by sampling to estimate output per 
man-day or per machine-hour. The application of cost sampling in Nigerian savanna planta- 
tions is well described in Ferguson (1972). 

The sampling is carried out by one or more email teams who observe an operation over 
the whole day. They mark on the ground the point at which work starts in the morning, and 
note the number of men employed. At the end of the day, the output (generally area) is 
measured* For machines, the type of machine (including attachments), the work done, and 
the time taken are noted. Under Nigerian conditions, it woe found that for a standard 
error of 20J6 to 30$, it was necessary to observe an operation fdr a minimum of four days, 
and ten days were preferable. The operations observed should be those carried out on a 
reasonably large scale, say more than ten ha* 

The times per unit for each operation are then multiplied lay the cost per man-day cr 
per machine-hour to get the unit cost of the operation. The cost per man-day is estimated 
from the same items of expenditure that are described on page 236, and for machine costs 
the same as are described on page 237* If materials form a significant proportion of the 
cost of an operation, then expenditure on them must be estimated too. 

- 240- 

A sampling ays tern is useful for producing cost figures quickly, but it cannot act in 
the same monitoring role as the cost accounting scheme. There is no check on inefficiency or 
dishonesty, one has to accept a fairly large standard error, and there are difficulties in 
the calculation of labour overheads. A sampling system may therefore precede a cost 
accounting scheme, but it should not be an alternative. 


Costs: The expenditure attributable to an operation. 

Components of Cost; The items of expenditure that make up the total cost - labour, materials, 
plant /vehicle s, and overheads. 

Unit coat; The total cost of an operation divided by the total number of units 


Expenditure ; The money paid out on wages, materials, etc., from the accounts (or Vote 


Operation; A forestry job or process that is definable and distinct from other jobs, 

The smallest sub-division of the costing code. 


Anon. Essai de presentation uniformisee des conditions d' execution, des result ate et des 

1974 oouts des reboisements. FAD, Rome. FO:MIX/74/3. 

Ferguson, I.S. Costing and economic aspects of plantation establishment in the savanna 
1972 region of Nigeria. FAO , Rome. K);SF/NIR 16 (Project Working Document). 

Grut, M. Records of costs and revenues in forests. FAO, Rome. K) ; DP /TUR/7 1/521. 

1975 Working Document No. 5. 

- 241 - 


- 242 - 
























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- 243 - 























































































































































































































































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- 244 - 



Centre: Sbagamu Pulpwood Plant at lone Month: February, 1975 

A Total Man-Days Worked. Field 1186 

(from Labour Abstract) Nursery 266 

Total A 1452 

B Man-Days Paid but not Productive. Public Holidays - 
(from Pay Sheet) Sick 

Leave 63 


Headman 20 

Storekeeper 20 

Total B 103 

C Total Man-Days Paid (Total A + Total B) 15^5 
(This must agree with the man- day a paid on the pay sheet) 

D Gross Wages Paid (from pay sheet) 3445 

Labour Allowances: Bicycle allowance. 20 

Total D 

E Cost per Man-Day (Total D/Total A) 2.39 

- 245 - 



Centre: Shagarou Pulpwood Plantations Month ; February , 19 75 

Coat per Man-Day (from Job Coating Sheet l) 2.39 per roan-day. 






M. Days/ 






798 X 







3. '11 





























































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- 246 - 


Project: Lekki Lagoon Pulpnood Scheme 

Operation: Brushing 
Unit: Hectare 

Code: 1121 
















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- 247 - 


Part A: Pines 


G.O.A. Ojo 

Forestry Research Institute of Nigeria 
Ibadan, Nigeria 

The aims of establishment techniques for Pinus caribaea and P^ oocarpa are to establish 
the seedlings as quickly as possible and to provide optimal growing conditions* Existing 
vegetation is clear-felled, stumped and burnt and the site is mechanically cultivated. 
Planting is done during the rainy season, beginning when the soil is wet to about 13 cm, 
employing seedlings 20-30 cm high raised in polythene pots. The spacing used depends largely 
on the method of management adopted, with 2.8 x 2.8 m being usual where mechanical cultivation 
in two directions is foreseen, and 1.8 x 1.8 m where manual weeding is contemplated. Weeding 
is necessary about three times a year (four the first year) during the rainy season for three 
to four years. Hand weeding is practised around individual trees, followed by mechanical 
cultivation between the rows. On ferruginous tropical soils 11 g of phosphate fertilizer is 
applied around each tree about four weeks after planting and following manual weeding. Clean 
weeding is also an effective fire prevention tool, but fire tracing around plantations, fire 
patrols and brash ing to a height of four to five feet at age four are also employed. 


D.E. lyamabo 

Agricultural Research Council, Moor Plantation 
Ibadan, Nigeria 

M.A. Ogigirigi 
Shelterbelt Research Station 
Kano y Nigeria 

This paper discusses the results of height and girth growth studies of young Pinus 
caribaea and P. oooarpa in relation to environmental conditions in northern Nigeria. 
Successive measurements at three and four years of age showed that both species exhibited 
continuous height growth and apical buds active all year round, but the rate of apical growth 
and the rate and quality of foliage production were less in the dry season than during the 
wet season. Dry season needles of these species are generally smaller, shorter, thinner and 
greatly deformed as a result of having to force their way through the dried needle sheath. 

Girth growth is lowest during the dry season, but shows a gradual increase from May to 
June and is highest during the June to September wet season. The increase from May to June 
may be due to hy drat ion of stem tissue and bark, cambial activity or both. 

Some of the pine species included in elimination trials showed negative results. 
Following six months in the nursery at Zaria, P^ montezumae did not grow at all in plantations* 
Also at Zaria, P. roiohoaoana grew normally for nearly t% years and then wsnt into a prolonged 
period of dormancy, and at Afaka and Miango P.. pseudostrobus grew very irregularly producing 
long terminal and lateral shoots that had no needles. 

- 248 - 

NUTRITION OF PINES (Pinus oaribaea and P* oooarpa) 

0. Kadeba 

Savanna Forestry Research Station 
Samara, Zaria, Nigeria 

Nutritional studies on Pinus species being tried in the afforestation programme of the 
Nigerian savanna is a recent development. So far, attention has been focussed primarily on 
the three major nutrients N, P, and K* Work to date has shown that the establishment phase 
of pines in the field would be difficult and growth rate unsatisfactory if phosphate fertilizer 
is not used* Effects of nitrogen fertilizers varied depending on type of material used* 
Urea was found to be injurious to pines with or without supplementary phosphate application* 
Positive response to nitrochalk and ammonium sulphate could be obtained only when phosphate 
was simultaneously applied* In no case was there any favourable response to K fertilizer. 


0. Kadeba 

Savanna Forestry Research Station 
Samaru, Zaria, Nigeria 

B.S.K. Onweluzo 

Savanna Forestry Research Station 
Samaru, Zaria, Nigeria 

Analyses of soils under plots of Pinus paribaea, Pinus oocarpa and savanna woodland 
show some changes in the soil chemical properties* Acidity ie intensified with increasing 
age of the pines. The data provide evidence of an initial reduction in organic matter content 
of the mineral soil* However, with increasing plantation age and canopy closure, there is a 
gradual build-up of organic matter in the top soil. A similar trend is demonstrated by 
exchangeable K. Values of 14*70, 5*44 and 6*00 tonnes/ha are estimated as oven dry weight of 
accumulated and un-deoomposed litter under (i) 15-year Pinue caribaea (ii) 7-year Pinus caribaea 
and (iii) 7-year Pinus oooarpa plots respectively. 


J*0. Abayomi 

Forestry Research Institute of Nigeria 
Ibadan, Nigeria 

The growth and yield of three Pinus species, P^ caribaea, P. oocarpa and P^ kesiya are 
described and compared in different localities of the savanna zones of Nigeria* The best 
growth of the three Pinus species has been observed at Mi an go on the Jos plateau. P^ oaribaea 
appears to have the best growth on all sites, followed closely by P^ oooarpa. Some limitations 
in the comparisons made in the paper are mentioned* 

- 249 - 


0.0. Okoro 

Forestry Research Institute of Nigeria 
Ibadan, Nigeria 

Investigations were carried out to determine the rooting propensities of cuttings taken 
from various ages of Pinus caribaea trees and rooted under two environmental conditions: mist 
and temporary propagator. Better callusing was obtained under mist. Some cuttings from all 
ages of trees rooted under mist whereas only cuttings from seedlings and a few from ten-year 
old trees rooted in the temporary propagator. Under both environmental conditions, cuttings 
from six and 15 month old seedlings rooted best. When seedlings of these two ages were 
coppiced, the latter had better survival percent (100$) and those stumps which had 8-16 
sprouts produced more uniform shoots with reasonable growth. Stumps of ten year old trees 
did not coppice at all. 

Pinus oocarpa is one of the best 
plantation species for the northern 
Guinea savanna* This growth trial 
plot at Afaka f Nigeria, is 7 years 

- 250- 

Part Bi N 


M.A* Ogigirigi and F.Y. Adskiya 

Shelterb It Research Station 

Kano, Nigeria 

This paper review* the history of neem (Agadiraohta indioa) in the Sudan zone of northern 
Nigeria; gives a general description of the tree, its phenology, silvioal characteristics and 
ueee; and describes current nursery, planting and tending practices. 

Following its introduction into the Sudan cone in 1928, neem hae become the most important 
plantation spsciss in the sone with nearly 1500 ha planted by 1964* The major uses of the 
wood are for poles and fuel* 

The neem tree is deep rooting, has a large, heavy crown and is a prolific seeder from 
age five onwards. Planting is primarily with nursery stock raised in polythene tubes and 
Qutplanted at 2.4 z 2.4 m or 2.7 z 2.7 m spacing*. Two mechanical harrowings per year are 
necessary for the first three years to reduce weed competition. Around large towns where 
both farmland and wood products are in short supply, farming in the plantations is successful* 
Groundnuts, beans, and occasionally millet are raised. 

Direct sowing has also been shown to be a promising, simple and cheap method of enriching 
large areas of savanna. 


J.E. Ujah 

Shelterbelt Research Station 
Kano, Nigeria 

Measurements of particle size distribution, bulk density, particle density, total 
porosity and soil moisture content from four selected sites stocked with (a) five year old 
neem, (b) one year old neem, (c) only weeds, and from a site (d) where neem failsd after one 
year, showed no significant differences between sites where neem is growing well and where 
it failsd or was never planted. 

- 251 - 
Part Cx Eucalypt s 


G.O.A. Ojo 

Forestry Research Institute of Nigeria 
Ibadan, Nigeria 

Eucalypts used in plantation work in the Nigerian savanna are E^ camaldulensis, 
E^ teretioornis, E^ citriodora t ._ cloeziana and E^ "saligna" hybrid. 

Intensive management techniques are employed. The natural vegetation is felled, 
stumped and burnt and the site is ploughed. Planting stock is raised in polythene pots to 
a height of about 30 cm for outplanting early in the rainy season after the soil is wet to 
about 15 onu The species differ in their ability to withstand dry spells immediately after 
planting; whereas most can tolerate a week of unexpected dry weather, _ doe ziana must be 
planted in very wet weather* Spacings from 1.8 x 1.8 m to 2.8 x 2.8 m are used depending on 
the objective of management and the weeding method to be adopted. Three to four weedings, 
manually around individual trees and usually mechanically between the rows, are carried out 
the first year during the rains. Weedings are fewer in subsequent years but are required 
until canopy closes, often within one to two years, depending on species. E._ cloeziana gives 
a dense canopy, but E. citriodora is thin crowned and requires weeding for three to four 
years. Borate fertilizer applied to the soil a few weeks after planting at the rate of 56 g 
per plant is highly beneficial. On very sandy soils the application is made over a two year 

Owing to their ligfct crowns, clean weeding, fire tracing and fire patrols are required 
fire protection methods in savanna eucalypt plantations, 


D.E. lyamabo 

Agricultural Research Council, Moor Plantations 
Ibadan, Nigeria 

M.A. Ogigirigi 

Shelterbelt Research Station 
Kano, Nigeria 

Studies of the height and girth growth of Isorberlinia doka, Khaya senegalensis. 
Eucalyptus citriodora, E^ cloeziana. E.. deglupta, E^ propincrua t E._ robust a and E^ tereti- 
oornie showed the eucalypts to have growth rates and periodicities superior to those of 
species indigenous to the northern Nigerian savanna. Apical and lateral meristems, dormant 
for part of the year in both I doka and K^ senegalensis, remain active all year round in 
the eucalypts, enabling them to sustain appreciable levels of growth during the dry season. 
Accelerated height growth, however, begins in late April to early May after soil moisture is 
sufficiently replenished. Accelerated girth growth starts earlier - in March - but some of 
thie "growth" may be attributed to hydration of stem tissue following increasing atmospheric 

Starting at about the middle of the wet season and continuing into the dry season, 
there is a progressive decrease in girth growth rates in 1^ doka and all species of 
uoalypts. This oan apparently be attributed to the heavy leaching of nitrogen from the 
forest litter which accumulated during the dry season, rather than water stress. 

-252 - 


0. Kadeba 

Savanna Forestry Research Station 
Samara, Zaria, Nigeria 

Nutritional studies form part of the several integrated forest cultural practices 
employed in the establishment and management of exotic plantations of eucalypts in Nigeria. 

Boron | nitrogen and phosphorus are the three elements that may limit the growth of the 
different specie* of euoalypts that are being tried in the afforestation programme. Results 
of all the field experiments conclusively show that the incidence of dry season die-back of 
euoalypts is associated with boron deficiency; application of bo rate fertilizer at the rate 
of 50g per tree would correct this deficiency. Growth increases were obtained on some sites 
following application of nitrogen and phosphate fertilizers. A common feature is the positive 
interaction between nitrogen and phosphorus. There was no response to potassium. 


N.A. Ogigirigi 
Shelter-belt Research Station 
Kano, Nigeria 

Studies on the water relations of euoalypta in the northern Nigerian savanna demonstrated 
that "avoidance 11 is a significant component of drought hardiness in E^ cloeziana, E^ robust a t 
Hi Pilularig and E. propinqua, while "tolerance 11 is important in B^ oamaldulensis. Measurements 
of transpiration from excised leaves of four species showed that the stomatal mechanism of 
E. pilularis was most efficient in the control of water loss, followed by E. robusta, E^ tere- 
tioornis and E. oamaldulensis. The range of seasonal variation in leaf water deficit was also 
less for E^ robusta, E. proplnqua and E^ oloezinana than for E^ camaldulensis. 

Under conditions of high soil moisture stress, E^ oamaldulensie was more efficient in 
water use and put on greater height growth than Pinus oaribaea. E^ teretioornis and E^ robusta. 
E^ robusta showed high water use and good growth at intermediate to low levels of soil moisture, 
but heavy mortality occurred at the highest level of moisture stress. Water use by P^ caribaea, 
on the other hand, was high under conditions of high soil moisture , but low When soil moisture 
became limiting. 


0. Kadeba and B.S.K. Onweluzo 

Savanna Forestry Research Station 

Samaru, Zaria, Nigeria 

Analyses of soils under plots of Eucalyptus oloeziana, E^ to re 1 liana and adjacent savanna 
woodland provide evidence that organic matter and exchangeable potassium in the mineral soil 
are depleted more under the euoalypts than under woodland. No difference in calcium or magne- 
sium were evident. There is, however, much greater litter accumulation on the forest floor 
under euoalypts; dry weight values were 14-59, 14.20 and 6.60 tonnes per hectare, respectively, 
for 8 year old E^ oloeziana at Afaka, 9 year old E^ tore 1 liana at Mi an go and savanna woodland 
that had been fire protected for about 20 years. 

- 253 - 


J.O. Abayomi 

Forestry Research Institute of Nigeria 
Ibadan, Nigeria 

The growth and yield of some Eucalyptus species are described and compared in different 
localities of the savanna zones of Nigeria. The best growth recorded is that for Eucalyptus 
grandis at Ngoroji on the Mambilla plateau, while in the plains, Eucalyptus oamalduleneis 
(Pet ford provenance), E^ teretioornis and some stands of E^ grandis have produced relatively 
high yields. Afaka appears to be the most favourable experimental site on the plains for the 
establishment of Eucalyptus plantations. Some limitations in the comparisons made in the 
paper are mentioned. 

The excellent performance of the Pet ford 
provenance of Eucalyptus camaldulensis 
in the northern Guinea savanna creates a 
demand for adequate seed supplies. This 
6 year old seed stand, spaced 12 x 12 ft 
(3.8 x 3.8 m) at Afaka f Nigeria, began 
seed production after 4 years, but the 
tall, narrow crowns make collecting 

- 254 - 


A.C. Finch 

Division of Forest Research 
Kit we, Zambia 



1 Land Clearing 

2. Nursery Plants 

3. Planting 

(a) Pre-discing 

(b) All Other Planting Operations 
4 Fertilisation 

5* 1st Season Weeding 

(a) Hand 

(b) Mechanical 

6. 2nd Season Weeding 

(a) Hand 

(b) Mechanical 

7. 3rd Season Weeding 

(a) Hand 

(b) Mechanical 

8. Total Cost 

(K/ha) * 






(K/ha) * 






* Labour and direct field supervisory labour, their wages, social security contributions, 
clothing, leave and housing allowances, together with machinery used in operations and 
materials consumed. 

1 Kwacha - US$ 1.56 

- 255 - 


K/acre gross 

K/acre net 


11 .50 



Stump, Burn and Clear 




Glean and Plough 

1 1.50 


Total Cost per acre 



Total Cost per ha 



The total cost per acre net (K71.08) assumes an additional charge for plant movement 
of 6 per cent and that the net area is 85 per cent of the gross area. It is the intention 
of the Industrial Plantations Project to carry-over 50 per cent of the area to safeguard 
against land clearing contingencies in the following year. This places an average interest 
charge on the ground prepared for next year's planting of K1 .84 per net acre. 






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- 257 - 



Nursery Stock Input Units 

Estimated Cot 

per ha 

per ha 

Labour 2.423 man-days at 2.82 


7 ton Lorry 1-639 km at 0.13 


D-4 0.024 hours at 4-00 


Materials K1.189 

1 .1? 

Supervisory Ratio 1:10 


Based on 1490 plants raised for each hectare to allow for losses 

in nursery and 

beating up in field. 



(a) Frediscing 

Drivers 0.175 man-days at 3-72 


Tractor 1.198 hours at 1.75 



Supervisory Ratio 1:7 

(b) Other Operations including Staking, Plant Distribution and 

Plant i ng. 

Labour 3-356 man days at 2.76 


Drivers 0.361 man-days at 3*52 


Tractor 0.477 hours at 1.75 


Lorry 1.787 km at 0.13 


1 1 ,59 

Supervisory Ratio 1:18 


1st Season Weeding 

(a) Hand Weed (3 times) 

Labour 3-284 man-days at 2.88 


Transport 9-941 km at 0.10 



Supervisory Ratio 1:7 

(b) Mechanical Weed (8 times) 

Drivers 1.000 man-days at 3-75 


Tractor 7.910 hours at 1.75 


Transport 4-784 km at 0.10 



Supervisory Ratio 1:6 


2nd Season Weeding (4 times) 

Drivers 0.371 man-days at 3-75 


Tractor 2.965 hours at 1.75 


Transport 1.853 km at 0.10 


Supervisory Ratio 1:6 


3rd Season Weeding (2 times) 

Drivers 0.247 man-days at 3-75 


Tractor 1-977 hours at 1.75 


Transport 1.236 km at 0.10 



Supervisory Ratio 





-258 - 




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- 259 - 


Country! BBflN 


1.1 Area of country: 112 600 km 2 

1.2 Locations longitude 040 f - 034 5 'E; latitude 0615 ' - 1225'N 

1.3 Population: 3 250 000 inhabitants 

1.^ Main climatic and vegetative zonesj Equatorial climate with vestiges of semi- 
deciduous forests; continental climate with tree savanna formation; continental 
climate with savanna woodland formation. 


2.1 Area of high forests - km 2 

I/ ? 

2.2 Area of savanna ' 22 OOO knr 

2.3 Proportion of land under high forest -$; in savanna ' 20$, 

2.4 Does the country have a written statement of national forest policy? 
Yes m No / 7 

2.4.1 If a national forest policy exists, what are the main objectives 
stated in it? To safeguard the constitution and conservation of the 
national forest domain and to carry out reforestation ajnd rational 

2.4.2 If there is an official statement of forest policy for the savanna 
region, briefly outline its main points. Control of bush fires; 
authorization of early burning under state surveillance. 

2.5 Legislation available to implement policy Yes/ X / Ho / / 

I/For the purpose of this questionnaire, savanna is considered as including the full range 
of tropical vegetation types of which grass is a significant characteristic. At one end 
of the spectrum, closed forest and thickets are excluded; at the other end, desert is 
excluded. Between these extremes, savanna comprises the various types of savanna wood- 
land, savanna and steppe as described in Appendix 1 of Tree Planting Practices in 
African Savannas, PAO Forestry Development Paper No.l9 f by M.V. Laurie, 1974. 

- 260 - 

206 Ownership of forests and savanna High forests Savanna 

Under state control - % ?&/(-< 

Private ownership - % -f 

Community ownership - % - % 

No effective control - % - J., 

2.7 Principal forest products from all regions (e.g. fuel wood, charcoal, sa,wlos, 
gum, beeswax and honey, veneerlogs, logs for sleepers, poles, piling and 
posts, pulpwood). 

4 300 000 steres of fuelwood and charcoal; 
20 000 m^ of sawlogs; 
200 000 poles 

2.8 Forestry staff State Others 

Professional 6 - 

Subprofessional(with diploma 
or certificate of training) 10 

2.9 Gross annual budget for forestry 100,000 U3& 

3.1 Areas 

3.1.1 Total net area -/of plantations at the end of 1974: - ha 

3.1.2 Net area ' of plantations in the savanna a.t the end of 197/j: - ha 
3-1 3 Planned annual target area of af/ref orestation: - hn/yr 

3*1 4 Planned annual planting rate in savanna: variable 

3.2 Organization and administration of savanna planting schemes 

3.2.1 State forest services 100 / 

3.2.2. Others (specify) 

33 Intended principal end use (e.g. sawtimber, posts ana poles, pulpwood, fueldwood, 
protect ion, etc. ), species, growth and rotation of major savajma plantation. 

Mean annual increment 

End use Species 

- / (u.b.) at rotation age 
net area(ha)-/ Rotation (Yrs) (m-y ha/year) 

lumber teak 6 285 60 

lumber Cedrela spp. 250 under study 

pilinghposts teak 715 7-8 

pilingfposts Casuarina sp. 500 d-?0 

fuelwood Casuarina sp. 1000 8-10 

I/ Net area is the 07oss area of plantations minus the area in roads, rides, buildings 
and other non- stocked land. 

- 261 - 


4*1 Nursery types and capacities 

4*1*1 What is the total annual production capacity of existing permanent 
savanna nurseries? 1 000 000 plants, 

401*2 What is the actual annual production (average from last 3 years) 
from permanent savanna nurseries? 750 000 plants, 

4*13 What is the annual production (average from last 3 years) from 
temporary savanna nurseries? - plants, 

4,2 Planting stock 

42,1. Indicate the main types of planting stock (bare-rooted transplants, 
stumps, container stock, etc,) raised for the principal savanna 
plantation species, 

Species Type of stock 

teak stumps 

Gmelina, Cedrela bare-rooted transplants 

neem bare-rooted transplants 

Casuarina basket containers 10 x 30 cm 

42,2 If containers axe used, state type (polythene tubes or pots, "jiffy pots", 
etc,) and give dimensions (lay flat for polythene) 

woven palm baskets 30 cm deep and 10 cm in diameter 

4*2,3 Give average size (height) of savanna outplanting stock and length 
of time (weeks) required to raise it in the nursery, 

Species Outplanting size rteeks in nursery 

Casuarina 10-15 cm 6 

43 Savanna nursery methods 

43,1 Briefly describe the sowing methods used in savanna nurseries (bed 
sowing, pricking out, direct sowing into container s, et c, ) 
For teak, neem and Gmelina, seed is sown in lines about 10 cm apart 
in beds, Casuarina is broadest sown and pricked-out after 6 weeks, 

4.3.2 Briefly describe the soil mixtures and fertilizers (and quantities) 
usedt Manure is used, but quantities are not measured. No chemical 
fertilizers are used, 

4.3.3 Briefly describe savanna nursery watering methods and schedules (if mechanical 
irrigation equipment is used, indicate type). 

All nurseries are watered manually with watering cans, except the Casuarina 
nursery, which has a water tower and rotary sprinklers, 

434 Briefly describe the standard savanna nursery protection measures 
(against pathogens, insects, animals, environmental elements), 
Manure is treated with BHC or DDT to fjiard against attacks on Casuarina 
seed in nurseries, 


51 Site selection 

5,1,1, Are detailed vegetation maps available for most savanna regions? 

Yes / X / No /'" / 

5,1,2 Are detailed soil maps and soil survey descriptions available for 
most savanna regions? Yes AX / No / / 

- 26? - 

52 Land clearing and site preparation 

5*2.1 Briefly describe the main savanna land clearing methods used. 

Clear felling is done by axe; tractor clearing is envisaged and 
is under study, 

52.2 Briefly describe the principal site preparation techniques used 
after land clearing in the savanna* 

After felling, the site is burned and large holes are filled in. 
Pegging out follows. 

5*3 Savanna planting and direct seeding 

5*3*1 Is direct seeding used in savanna 7 Yes /\7 No j^_J 
If so, indicate for which species: Anacardium . 

532 Indicate the most common s pacings at which the main savanna plantation 
species are planted. 
5 x 5 to 6 x 6 m; later thinned to 10 x 10 or 12 x 12 m. 

533 Give the total number of hectares of plantations established to 
date in the savanna by means of taungya. 5 000 ha. 

54 Tending of savanna plantations 

541 Briefly describe the method and frequency of weeding. 

Two weedings per year for young teak, and after the fourth 
year one annual slashing and one singling. For Anacardium 
two weedings and one cultivation annually. 

542 If irrigation is used in plantations, give the area irrigated of 
each species, the frequency of watering and the qi;antity of water 
applied. None. 

5.5 Protection of savanna plantations 

551 Briefly describe protection measures against insects, pathogens and 

animals. No significant control measures but research is being done 
on rots, borer attacks to Khaya senef^ilonsis and Chlorophora alls. 

5.5.2 Is there a national fire danger rating system? 
Yes I 7 No /X/ 

553 Are fire breaks and fire lines allowed for at the time of savanna 
plantation establishment? Yes /X V No / / 

554 Is controlled (i.e. pr e s c r i be d or early) burning practiced in 
savanna plantations? Yes / / Wo 

Around plantations? Yes /X / No 


6.1 Is there a national tree seed coordinating centre? Yes ^ "/ No/ X / 

6.2 Is there a national tree seed certification system? Yes/ X / No/ / 

6.3 Are there facilities for storing seed at controlled temperatures? 
Yes/ 7 No flTJ 

6m4 Indicate the main source of seed supply for the principal savanna plantation 
species. Seed of teak, Anacardium , Cedrela and neem is obtained from 
selected seed trees within the country. 

- 263 - 

6.5 List the species being tested in comparative trials in the savanna* 

Indicate in parentheses the number of provenances being tested of each 


Only Cedrela odor at a and Gmelina arborea, introduced a long time ago, 

are acclimatized* 


List the main published sources of information on afforestation and nursery 
practice in the savanna regions of your country. 


Country: CONGO (see also Appendix 4) 


1.1 Area of country 342 000 km^ 

1.2 Location: longitude 1109 ! 04" - l6/)O f Ej latitude 03/}2 ' 30"K -0502 f 03"3 
13 Population 1 500 000 inhabitants 

1.4 Wain climatic and vegetative zones 

Equatorial climate with two seasons: dry season from May to September; 

wet season from October to April. Vegetation: high forest, mangrove forest, 

savanna and gallery forest. 


2.1 Area of high forests 205 tan 2 

I/ P 

2.2 Area of savanna - / 137 000 tan 

2.3 Proportion of land under high forest 60^1; in savanna ' 4&jv 

2.4 Does the country have a written statement of national forest policy? 
Yes /5T7 No I 7 

2.4.1 If a national forest policy exists, what are the main objectives stated 
in it? To contain monopolization of commercial forestry; reinforce 

and develop the state f s role in forest exploitation; increase the amount 
of wood which is processed within the country; conduct research to promote 
under-utilized tree species; carry out plantation programmes with eucalypts 
and pines. 

2./J.2 If there is an official statement of forest policy for the savanna region, 
briefly outline its main points. 

Carry out eucalypt and pine plantation programmes in accordance with the 
first national three-year plan. 

2.5 Legislation available to implement policy Yes ^ jC 7 No / / 

\J For the purpose of this questionnaire, savanna is considered as including the full 
range of tropical vegetation types of which gyass is a. significant characteristic. 
At one end of the spectrum, closed forest and thickets are excluded; at the other 
end, desert is excluded. Between these extremes, savanna comprises the various types 
of savanna woodland, savanna and steppe as described in Appendix 1 of Tree Planting 
Practices in African Savannas, FAO Forestry Development Paper No.l9 f by M. V.Laurie, 1974 

- 264 - 

206 Ownership of forests and savanna High forests oavanna 

Under state control 100^ 10C#. 
Private ownership - - 

Community ownership - - 

No effective control - - 

2.7 Principal forest products from all regions (e.g. fuel wood, charcoal, sawlogs, 
gum, beeswax and hondey, veneerlogs, logs for sleepers, poles, piling and 
posts, pulpwood). 

Puelwood, charcoal, posts. 

2.8 Forestry staff State Others 

Professional 13 

Subprofessional (with diploma or 

certificate of training) 17 

2.9 Gross annual budget for forestry - Uo$ 

3.1 Areas 

3.1.1 Total net area-/ of plantations at the end of 1974s 13 827 ha 

3.1.2 Net area ' of plantations in the savanna at the end of 19742 7 39''' ha 
313 Planned annual target area of af /reforestation: - ha/year 

3.1.4 Planned annual planting rate in savanna: 500 ha/year 

3*2 Organization and admin strati on of savanna planting schemes 
3.2.1 State forest services lOCtyc 

32.2 Others (specify) 

3*3 Intended principal end use (e.g. sawtimber, posts and poles, pulpwood, 
fuelwood, protection, etc.), species, growth and rotation of major 
savanna plantations. 

Kean annual 
increment (U. b.) 

, , ., . /i_\l/nj.j.-/vN a "t rotation 

End use bpecies Net ar ea( ha.)- 7 Rotation lYrsj / 3 / / N 

Construction Terminal ia superba 6 435 35 4 


pulpwood eucalypts 5 179 4-6 20-35 

pulpwood pines 2 213 8-12 10-20 

Net area is the gross area of plantations minus the area in roads, rides, buildings 
and other n on- stocked land. 

- 265 - 


4*1 Nursery types and capacities 

4.1.1 What is the total annual production capacity of existing permanent 
savanna nurseries? 2 000 000 plants 

4.1.2 What is the actual annual production (average from last 3 years) 
from permanent savanna nurseries? 630 400 plants. 

4.1.3 What is the annual production (average from last 3 years) from 
temporary savanna nurseries? - plants. 

4.2 Planting stock 

4.2.1 Indicate the main types of planting stock (bare-rooted transplants, 
stumps, container stock, etc.) raised for the principal savanna 
plantation species. 

Species Type of stock 

Eucalyptus platyphylla containers (polythene pots) 
E. XII ABL it 

E. urophylla it 

Pi mis caribaea 

P. oocarpa 

4.2.2 If containers are used, state type (polythene tubes or pots, "jiffy 
pots", etc.) and give dimensions (lay flat for polythene), 
polythene pots 17 x 21 cm 

4.2.3 Give average size (height) of savanna outplanting stock and length 
of time (weeks) required to raise it in the nursery. 

Species Out pi ant ing size rteeks in nursery 

eucalypts 10-15 cni 8 

pines 10 cm 12 

4.3 Savanna nursery methods 

4*3.1 Briefly describe the sowing methods used in savanna nurseries (bed 
sowing, pricking out, direct sowing into containers, etc.) 
Eucalypt seed is broadcast sown in irrigated seed beds; pricking 
out into polythene pots is done < wfeks later. Pines are line sown 
in seed beds and pricked out (also in polythene pots) 6 weeks later. 

4*3.2 Briefly describe the soil mixture and fertilizers (and quantities) 

used: Soil mixture is 505,'. black earth and 30^ sand. A complete fertilizer 
(10-10-20) and slag are used. 

4*3*3 Briefly describe savanna nursery watering methods and schedules (if 
mechanical irrigation equipment is used, indicate type). 
Manual watering is with fine rose watering ca.ns. Watering with rotary 
sprinklers is done twice a day when plants are young and once a day later. 

4.3.4 Briefly describe the standard savanna nursery protection measures 
(against pathogens, insects, animals, environmental elements). 
Insecticides (dieldrex Py or phytosol) are dusted around germination 
and plant holding beds. 

- 266 - 


5.1 Site selection 

5.1.1 Are detailed vegetation maps available for most savanna regions? 
Yes /T7 No / / 

5.1*2 Are detailed soil maps and soil survey descriptions available for 
most savanna regions? Yes /X / No^ / 

5.2 Land clearing and site preparation 

5.2.1 Briefly describe the main savanna land clearing methods used, 
In closed forest, clearing is done with axes and power saws; 
in the savanna crawler tractors are used. 

5.2.2 Briefly describe the principal site preparation techniques used 
after land clearing in the savanna. 

Clearing and burning followed by ploughing with a Cropmaster or 
Crop PulvSrisage with pulverizing discs. 

5.3 Savanna planting and direct seeding 

5.3.1 Is direct seeding used in savanna? Yes / / No /X ~J 
If so f indicate for which species 

5*3.2 Indicate the most common spacings at which the main savanna plantation 
species are planted. 
2.5 x 2.5 m and 3.12 x 3.12 m 

5.3.3 Give the total number of hectares of plantations established to 
date in the savanna by means of taungya: - ha 

5.4 Tending of savanna plantations 

541 Briefly describe the method and frequency of weeding 

Harrowing between the rows using a wheeled tractor equipped with a 
disc harrow or rotavator once every three months the first year (i.e. 
four times) and three times during the second year and manual hoeing 
around the trees. 

5*4.2 If irrigation is used in plantations, give the area irrigated of each 
species, the frequency of watering and the quantity of water applied. 

55 Protection of savanna plantations 

5.5.1 Briefly describe protection measures against insects, pathogens and animals. 

At the time of planting poison baits are placed around the base of each 
plant to protect against insect attack - particularly stem cutting crickets* 

5*52 Is there a national fire danger rating system? 
Yes I 7 No ffl 

5.5.3 Are fire breaks and fire lines allowed for at the time of 
savanna plantation establishment? Yes/ X / No / / 

5.5.4 IB controlled (i.e. prescribed or early) burning practiced in savanna 
plantations? Yes /X / No/ / 

Around plantations? Yes/ X / No/ / 

- 267 - 

6.1 IB there a national tree seed coordinating centre? Yes/X / No / / 

6.2 Is there a national tree seed certification system? Yes/ / No / X / 

6.3 Are there facilities for storing seed at controlled temperatures? 

Yes /XT No I 7 

6.4 Indicate the main sources of seed supply for the principal savanna 
plantation species: 

eucalypts: Australia, New Guinea and Congo (old plantations) 
pines: Central America and Congo (old plantations) 

6.5 List the species being tested in comparative trials in the savanna. 
Indicate in parentheses the number of provenances being tested of each 

Various eucalypts and pines: Eucalyptus urophylla, & tereticornis, 
Pinus caribaea and P. oocarpa. 


List the main published source of information on afforestation and nursery 
practice in the savanna regions of your count ry. 

Country: GHANA (see also Appendix 5) 


1.1 Area of country 238 539 km 2 

1.2 Location: longitude 1E to 3W; latitude 5 - 11N 

1.3 Population: 10 million inhabitants 

1.4 Main climatic and vegetative zones: The climate ie humid to dry tropical. There 
are three main vegetation zones namely the coastal thicket, the high forest and 


2.1 Area of high forests 82 258 km 2 

2.2 Area of savanna 150 497 km 2 

2.3 Proportion of land under high forest 34^; in savanna '6$% 

2.4 Does the country have a written statement of national forest policy? 

Yes /" X / No / / 

2.4.1 If a national forest policy exist r>, what are the main objectives stated in it" 
Creation of sufficient permanent forest resources by reservation to supply 
direct and indirect benefits necessary for the welfare of the people of Ghana 
and the management of the Forest resources by methods that achieve sustained 
maximum productivity and value. 

2.4.2 If there is an official statement of forest policy fdr the sa.vanna region, 
briefly outline its main points. 

Same as in 2.4*1 

I/ For the purpose of this questionnaire, savanna is considered as including the full range 
of tropical vegetation types of which ^rass is a si^iificant characteristic. At one end 
of the spectrum, closed forest and thickets are excluded; at the other end, desert is 
excluded. Between these extremes, savanna comprises the various types of savanna woodland, 
savanna and steppe as described in Appendix 1 of Tree Planting Practices in African 
Savannas , FAO Forestry Development Paper No. 19, by K.V. Laurie, 1974. 

- 268 - 

2.5 Legislation available to implement policy Yes / X / No / / 

2.6 Ownership of forests and savanna High forests Savanna 

Under state control - 

Private ownership - - 

Community ownership lOOji lOCty 

No effective control - 

2.7 Principal forest products from all regions (e.g. fuelwood, charcoal, sawlogs, gum, 
beeswax and honey, veneerlogs, logs for sleepers, pol^s, piling and posts, pulp- 

Sawlogs, veneerlogs, logs for sleepers, fuelwood, charcoal, poles, gum, export logs, 

2.8 Forestry staff State Others 


Subprof essional (with diploma 

or certificate of training) 

2.9 Gross annual budget for forestry 7 501 974 

3.1 Areas 

3.1.1 Total net area^ of plantation at the end of 1974: 23 206.00 ha 

3.1.2 Net area ' of plantations in the savanna nt the end of 1974s 3 331 && 

3.1.3 Planned annual target area of af /reforms tat ion: 7 3^8.00 ha/yr 

3.1.4 Planned annual planting rate in ssavemna: r c 176.00 ha/year 

3.2 Organization and administration of savanna planting schemes 

3.2.1 State forest services 1CX>/ 

3.2.2 Others (specify) 

3.3 Intended principal end use (e.g. sawtimber, posts and poles, pulpwood, fuelwood, 
protection, etc.), species, growth and rotation of major savanna plantations. 

End use Species 

Saw Log Teak + Mahogany 

Pulp Gmelina - Eucalyptus 


Poles Teak 

Charcoal all spp. 

Fuel wood all spp. 

Fuel Neem 

Net area(ha) 


60-70 years 
up to 10 years 

10-15 years 
10-15 years 
10-15 years 
10-15 years 

increment (u.b.) 
at rotation age 
(m-y ha/year^ 

\J Net areas is the gross area of plantations minus the area in roads, rides, buildings 
and other non-stocked land. 

- 269 - 


4.1 Nursery types and capacities 

411 What is the total annual production capacity of existing permanent 
savanna nurseries? 3 million plants. 

412 What is the actual annual production (average from last 3 years) 
from permanent savanna nurseries? Unknown 

413 What is the annual production (average from last 3 years) from 
temporary savanna nurseries? NIL 

4.2 Planting stock 

4*2.1 Indicate the main type of planting stock (bare-rooted transplants, stumps, 

container stouk, etc.) raised for the principal savanna plantation species. 

Species Type of stock 

Anogeissus stumps 

Teak stumps 

Eucalyptus potted 

Khaya senegalensis stripling and potted 

Neem stripling said potted 

4*2.2 If containers are used, state type (polythene tubes or pots, "jiffy pots 11 , 
etc.) and give dimensions (lay flat for polythene). 
Only polythene bags are used: 5x7 inches 

42.3 Give average size (height) of savanna outplanting stock and length 
of time (weeks) required to raise it in the nursery. 

Species Outplanting size Weeks in nursery 

Teak ! - 2 ft. 24-30 weeks 

Eucalyptus l - 2 ft. 18-24 weeks 

Anogeissus 1 - 2 ft. 24-30 weeks 

Khaya Senegal ensis 1-* - 2 ft. 24-30 weeks 

Neem 2 - 3 ft. ^-3< 

4.3 Savanna nursery methods 

4.3.1 Briefly describe the sowing methods used in savanna nurseries (bed sowing, 
pricking out, direct sowing into containers, etc.) 

(a) Teak, Khaya and Neem are sown on seed beds and pricking out is done 
immediately on germination either onto transplant beds or into con- 
tainers. (b) Anogeissus is sown direct on to seed beds. No pricking 
out is done. 

4.3.2 Briefly describe the soil mixtures and fertilizers (and quantities) used. 
No fertilizers are used. Normally the containers are filled with top soil 
from the nursery site. Also compost is used. 

4.3.3 Briefly describe savanna nursery watering methods and schedules (if 
mechanical irrigation equipment is used, indicate type). 

Where seedlings are raised in polythene bags, watering cans are used 
twice a day, morning and evening. Canal irrigation is also practised. 

4.3.4 Briefly describe the standard savanna nursery protection measures 
(against pathogens, insects, animals, environmental elements). 
Aldrex is used against insects. Fences are erected against animals 
and sheds are raised as environmental protection for shade. 

- 270 - 

5*1 Site selection 

5.1.1 Are detailed vegetation maps available for most savanna regions? 
Yes /~7 No /T7 

5*1.2 Are detailed soil maps and soil survey descriptions available for most 
savanna regions? Yes / X / No/ '"/ 

52 Land clearing and site preparation 

52.1 Briefly describe the main savanna land clearing methods used. 

The annual bush fires normally leave clumps of grass which is cleared 
either with hoes or cutlasses. After that the area is stumped* 

5*2*2 Briefly describe the principal site preparation techniques used 
after land clearing in the savanna. After stumping a two-disc 
plough is used to make ridges on which the seedlings are planted, 

53 Savanna planting and direct seeding. 

5 3*1* I s direct seeding used in savanna? Yes /X / No/ / 
If so, indicate for which species: Anogeissue (Nangodi; 

532 Indicate the most common spacings at which the main savanna plantation 
species are planted. 
3 x 9 ft. f 6 x 9 ft. 

533 Give the total number of hectares of plantations established to 
date in the savanna by means of taungya: - ha, 

5*4 Tending of savanna plantations 

5*41 Briefly describe the method and frequency of weeding 
Weeding on ridges twice a year, 

542 If irrigation is used in plantations, give the area irrigated of each 
species, the frequency of watering and the quantity of water applied. 
There are no irrigated plantations in Ghana. 

55 Protection of savanna plantations 

551 Briefly describe protection measures against insects, pathogens, and 

There have been no known severe insect or pathogenic attacks. Limited 
fencing has been practised against animals, 

5.5,? Is there a national fire danger rating system? 
Yes/ 7 No/jJr~7 

553 Are fire breaks and fire lines allowed for at the time of savanna 
plantation establishment? Yes / X J No / / 

554 Is controlled (i.e. prescribed or early) burning practiced in savanna 
plantations? Yes / 7 No /x7 

Around plantations? Yes /X / No / / 


6.1 Is there a national tree seed coordinating centre? Yes /X / No / / 

6.2 Is there a national tree seed certification system VYes/ / No /X_y 

- 271 - 

6.3 Are there facilities for storing seed at controlled temperatures? 
Yes /5T"7 10C No/~7 

6.4 Indicate the main source of seed supply for the principal savanna 
plantation species* 

Seeds for savanna species from Jexna and other places in the North. 

6.5 List the species being tested in comparative trials in the savanna. 
Indicate in parentheses the number of provenances being tested of each 

The only species being tried at the movement is Acacia Senegal. 
Seeds have been obtained from the Senegal, Mali and Ghana. 


List the main published sources of information on afforestation and nursery 
practice in the savanna regions of your country. 

Guidelines in the M.O.P. (Manual of Procedure) 


1.1 Area of country 32? SCO kn/ 

1.2 Location: longitude 0230' - 09W; latitude 04 - 13 h 
13 Population: 6 000 000 inhabitants 

1.4 toain climatic and vegetative zones 

Climates: Guinea (equatorial) arid Judan-Guinoa (tropioaJ ) 

Vegetation: humid evergreen dense forest; humid nemi deciduout; dense forest; 
pre-forest and savanna. 


2.1 Area of hi h forests 156 719 km'' 

2.2 Area of savanna ^ 165 781 km 2 

2.3 Proportion of land, under high forest /|8.6^.; in savanna-/ 51./i' A - 

2.4 Does the country have a wr 'it t en statement of notional forest policy': 

Yes /X / No / / 

2.4.1 If a national forest policy edicts, what are the main objectives stated in it? 

Preservation of the ecological "balance; oustained yield of wood through manage- 
ment and reforestation. 

2.4.2 If there is an official statement of forest policy for the savanna region, 
briefly outline its main points. 

Under study, but no particular statement for the sava,nna region yet. 

2.5 Legislation available to implement policy Yes /X / No / " '/ 

2.6 Ownership of forests and savanna High forests Jav^nna 

Under state control 10O// lOCfy. 

Forest reserves 2 89^ 55& ha 1 300 000 ha 

National parks 54& 000 ha 1 175 000 ha 

\f For the purpose of thie questionnaire, savanna is considered as including the full range 
of tropical vegeta.tion types of which grass is a significant characteristic. At one end 
of the spec tr UIL , closed forest and thickets are excluded; at the other end, desert is 
excluded. Between these extremes, savanna comprises the various types of savanna wood- 
land, savanna and steppe as described in Appendix 1 of Tree Planting Practices in 
African Savannas, PAO Forestry Development Paper No. 19, by K.V. Laurie, 1974. 

2*7 Principal forest products from all regions (e.g. fuelwood, charcoal, sawlogs, gum, 
beeswax and honey, veneerlogs, logs for sleepers, poles, piling and posts, pulpwood). 

For 1974: logs - 4 626 000 m 3 

sawntimber - 56/1 000 " 

other products - 70 000 " 

2.8 Forestry staff dtate Others 

Professional 53 

Subprofession (with diploma 

or certificate of training) 120 - 

2.9 Gross annual budget for forestry (1975) 6 031 956 UU3 


3.1 Areas 

3.1.1 Total net area ^/of plantations at the end of 197/1: 35 300 ha. 

3.1.2 Met area /of plantations in the savanna at the end. of 1974: 10 000 ha. 

3.1.3 Planned annual target area of af/ref orestation: 3 5^0 ha/year 

3.1.4 Planned annual planting rate in savanna: stopped after 1968 

Questions 3.2 - ^42 

For all practical purposes, reforestation in the savanna zone in the Ivory Coast was 
stopped in 1968 because the Government decided to concentrate its efforts in the high forest 
by launching an industrial plantations programme. 

From a beginning in 1929 and up until that time reforestation in the savanna and pre- 
forest zones reached a total of 19 700 ha., of which 15 400 ha. were in forest reserves and 
4 300 were on village lands. Of the 15 400 ha. of plantations in reserved land, 10 000 ha. 
are still regularly looked after. 

Anacardium was the species most used for village plantings; on forest reservea the 
following were used: 


9 300 ha 
2 350 " 
1 900 " 
1 750 " 
700 " 


neem and others 

The establishment techniques used were mechanical (in the Katiemba forest from 1964 
to 1966 for 950 ha of teak) and chiefly taungya. 

Anacardium was direct sown (2 seeds per planting spot); stumps were used for teak. 
an( ^ Gmelina; while for Cassia bare root seedlings were employed. 

Planting densities were 625 - 1000 trees/ha for Anacardium and 2 500 trees/ha for 
most other species. For mechanized teak planting, density was 2 000/ha. 

In addition to cashew nuts, fuelwood and general utility wood are produced as well 
as construction timber from Gmelina and teak. Expected commercial production for 1975 
from these plantations iss 

firewood 36 000 steres 

poles 32 000 units 

stakes 11 000 units 

posts 30 000 units 

J/ Net area is the gross area of plantations minus the area in roads, rides, buildings 
and other non-stocked land. 

- 273 - 

These plantations are old enough now not to require further tending and weeding other 
than fire protection and improvement cuts. 

The valuable plantations, that is the successful oneiof sufficient area, are under 
management. Exploitation is according to plans drawn up for each plantation, the total 
area being 10 000 ha. 

Although afforestation in the savanna zone ceased in 1968, agricultural industries 
are bringing rapid development to the region and management of rural space is becoming 
indispensible. Concerning forests and woodlots, the permanent state forest domaine will 
be consolidated and it is probable that an afforestation programme will be undertaken. 

To avoid certain errors which occurred in the past, this programme will involve the 
local populations concerned, and chiefly the farmers. Three types of schemes are envisaged: 
private plantations; village and communal plantations; and afforestation on state- con- 
trolled land. 

55 Protection of savanna plantations 

5.5.1 Briefly describe protection measures against insects, pathogens and 
animals. None. 

5*52 * s there a national fire danger rating system? 

r~i NO m 

553 Are fire breaks and fire lines allowed for at the time of savanna 
plantation establishment? Yes / X / No / ~ / 

5.54 Is controlled (i.e. prescribed or early) burning practiced in savanna 
plantations? Yes / / No / X / 

Around plantations? Yes / X / No / / 


6.1 Is there a national tree seed coordinating centre? 

6.2 Is there a national tree seed certification system? 

6.3 Are there facilities for storing at controlled temperatures? Yes / / No/ X 7 

6.4 Indicate the main source of seed supply for the principal savanne plantation 
species: See above note for questions 3 54? 

6.5 List the species tested in comparative trials in the savanna, Indicate in parentheses 
the number of provenances being tested of each species. None. 


List the main published sources of information on afforestation and nursery 
practice in the savanna regions of your country. 

- Etude de reboisement en zone de savane dans la region de Bouake* Cfrte d'lvoire 
(Nogent/Marne CTFT 1962) 

- La protection des sols et la restauration forestiere dans les regions de savane du 
Nord de la catS d'lvoire CTFT 1961 (La Llensbruge) 

- Les Essences de reboisement en savan*: colloque sur les Priorite"s de la recherche dans 
le deVeloppement e"conoroique de 1'Afrique, Abidjan les 5 - 12 Avril 1968 (G. de la 

- Lee experiences de reconstitution de la savane boise"e en Cfcte d'lvoire 
(Bois fer-Trop. 1953 No. 3? 

- RSsultats d f experience forest ieres entreprises a Bouake" (Nogent/Marne CTFT 1942). 

- 274 - 

Country: KiiflYA 


1.1 Area of country 569 252 km* 

1.2 Location: longitude 340 f - A 350'E; latitude 5% - 440'S 

1.3 Population: 13 000 000 inhabitants 

1.4 Main climate and vegetative zones 

i. Afro-Alpine: Moorland and Grassland 
ii. Humid-Dry Humid: Forests and derived grasslands 
iii.Dry sub-humid - Semi-Arid: Woodland - Hooded Grassland 
iv. Arid - very Arid: Dry Woodland and Grassland 


2.1 Area of high forests 17 077 km 2 

2.2 Area of savanna -' 405 343 tan 

2.3 Proportion of land under high forest 3^; in savanna-/?^ 

2.4 Does the country have a written statement of national forest policy? 

Yes /5T7 No 

2.41 If a national forest policy exists, what are the main objectives stated 
in it? To manage forests, develop and control forestry for the greatest 
common good of all. Objectives include Reservation of land for Forest, 
protection and management of forests, conservation, provision of timber 
and other forest products. 

2.4*2 If there is an official statement of forest policy for the savanna region, 
briefly outline its main points. 

The Savanna regions are mainly under Private Ownership. Farm Uoodlots 
and Afforestation are encouraged through a Rural Afforesation Scheme 
covering most of the country. 

2.5 Legislation available to implement policy Yes / / No /JL7 

2.6 Ownership of forests and savanna High Forests Savanna 

Under state control % ...../,' 

Private ownership % .% 

Community ownership ...... % % 

No effective control % .% 

For the purpose of this questionnaire, savanna is considered as including the full range 
of tropical vegetation types of which grass is a sigiificant characteristic. At one end 
of the spectrum, closed forest and thickets are excluded; at the other end desert is 
excluded. Between these extremes, savanna comprises the various types of savanna wood- 
land, savanna and steppe as described in Appendix 1 of Tree Planting Practices in 
African Savannas, FAO Forestry Development Paper No. 19, by M.V. Laurie, 1974* 

- 275 - 

2.7 Principal forest products from all regions (e.g. fuelwood, charcoal, sawlogs, gun, 
beeswax and honey, veneerlogs, logs for sleepers, poles, piling and posts, pulp- 

Sawlogs, pulpwood, fuelwood, veneer logs, poles, piling and posts, gum. 

2.8 Forestry staff State others 

Professional At least B. Sc. 45 

Subpr of es s i onal 

(with diploma _ _ , ^ ^^ ^ ^^ ^ 

or certificate Diploma 140 2OO Certificate 

of training) 

2.9 Gross annual budget for forestry - US$ 


3.1 Area I/ 

3.1.1 Total net-area /of plantations at the end of 1974:104 080 ha 

3.1.2 Net area ' of plantations in the savanna at the end of 1974 J NIL 

3.1.3 Planned annual target area of af /reforest at ion: 4 570 ha/year 

3.1.4 Planned annual planting rate in savanna: NIL 

3.2 Organization and administration of savanna planting schemes 

3.2.1 State forest services - 

3.2.2 Others (specify): 

Rural afforestation covers most districts in 

3.2 Intended principal end use (e.g. sawtinrber, posts and poles, pulpwood, fuelwood, 
protection, etc.), species, growth and rotation of major savanna plantations. 

Mean annual 

/ increment (u.b.) 

End use Species Net area (ha)-/ Rotation (Yrs) at rotation age 




4.1 Nursery types and capacities 

4.1.1. What is the total annual production capacity of existing permanent 
savanna nurseries? plants. 

4.1.2 What is the actual annual production (average from last 3 years) 
from permanent savanna nurseries?... .... .plants. 

I/ Net area is the gross area of plantations minus the area in roads, rides, buildings and 
other non-stocked land. 

- 276 - 

413 What is the annual production (average from last 3 years) from temporary 
savanna nur 3eri es? ......... plant s 

42 Planting stock 

4*2.1 Indicate the main types of planting: stock (bare-rooted transplants, 
stumps, container stock, etc.) raised for th * principal savanna 
plantation species. 

Species Type of stock 

/] .2. 2 If containers are used, state type (polythene tubes or potn, " jiffy pots" f 
etc.) and give dimensions (lay flat for polythene). 
Polythene tubes. 

4*2.3 Give average size (height) of savanna outplentine stonk and 
of time (weeks) required to raise it in the nursery* 

Species Out pi ant ing size ^eeks in nursery 

O V 


4.3 Savanna nursery methods 

4*3*1 Briefly describe the sowing methods used in savanna nurseries (bed 
sowing, pricking out, direct sowing into containers, etc,) 
Bedsowing and pricking out into containers. 
Bedsowing and pricking out into boxes. 

4*3*2 Briefly describe the soil mixtures and fertilizers (and quantities) 

4*3*3 Briefly describe savanna nursery watering methods and schedules 
(if mechanical irrigation equipment is used, indicate type) 

4*3*4 Briefly describe the standard savanna nursery protection measures 
(against pathogens, insects, animals, environmental elements). 


5.1 Site selection 

5*1*1 Are detailed vegetation maps available for most savanna regions? 

Yee /~7 NO nrj 

5*1*2 Are detailed soil maps and soil survey descriptions available for 
most savanna regions? Yes /X / No/ / 

5.2 Land clearing and site preparation 

3*2.1 Briefly describe the main savanna land clearing methods used 

- 277 - 

5.2.2 Briefly describe the principal site preparation techniques used 
after land clearing in the savanna. 

53 Savanna planting and direct seeding 

531 Is direct seeding used in savanna Yes / / 
If so, indicate for which species. .. . 

5*3.2 Indicate the most common spacings at which the main savanna plantation 
species are planted. 

2.75 m x 2.75 m 

5*3*3 Give the total number of hectares of plantations established to 
date in the savanna by means of taungya ha 

5.4 Tending of savanna plantations 

5.41 Briefly describe the method and frequency of weeding. 

5.42 If irrigation is used in plantations, give the area irrigated of 
each species, the frequency of watering and the quantity of water 


5*5 Protection of savanna plantations 

5*5*1 Briefly describe protection measures against insects, pathogens 
and animals. 

5.52 Is there a national fire danger rating system? 
Yes ZZ7 No /~X"7 

5.5.3 Are fire breaks and fire lines allowed for at the time of 
savanna plantation establishment? Yes /X 7 No f _J 

5.5.4 Is controlled (i.e. prescribed or early) burning practiced in 
savanna plantations? Yes / / No / X / 

Around plantations? Yes / X / No / '/ 

6.1 Is there a national tree seed coordinating; centre? Yes /X 7 No / / 

6.2 Is there a national tree seed certification system? Yes /X / No / _"/ 

6.3 Are there facilities for storing seed at controlled temperatures? 

Yes T7 No ~ 

6.4 Indicate the main sources of seed supply for the principal savanna 
plantation species. Local supply from established seed areas and orchards. 

6.5 List the species being tested in comparative trials in the savanna. Indicate 

in parentheses the number of provenances being tested of each species. 
Eucalyptus tereticornis, saligna, carnal dul ens is ' 
Pinus oaribaea .oocarpa, kesiya 


List the main published sources of information on afforestation and nursery 

practice in the savanna regions of your country. 

Technical notes, published for Department use. 

Technical Orders, prescriptions published for the Department. 

Forest Bulletins - occasional publications. 

- 278 - 

Country: SENEGAL 
1.1 Area of country 220 000 kn/ 



1.2 Location: longitude 1122' - 1732 W- latitude 12l8 ! - 1641'N 

1.3 Population: 4 320 000 inhabitants 

1.4 Main climatic and vegetative zones 

a) Sahel - Senegal climate, b) coastal Sahel - Senegal climate, c) oahel - Sahara 
climate, d) sanel-Sudan climate, e) Guinea climate. Vegetation types employing 
the same names corresponding to these climatic types. 


2.1 Area of high forests 500 km 2 

2.2 Area of savanna ^/ 110 000 km 2 

2.3 Proportion of land under high forest 0.?7$.; in savanna -/6C9fa 

2.4 Does the country have a written statement of national forest policy? 

Yes /XT No / 7 

2.4-1 If a national forest policy exists, what are the main objectives stated 
in it? 

a) Manage forest exploitation in the short run for the production of 
fuelwood, general utility wood and construction timber; 
EJnrioh the forest domain by introducing high value exotic species; 
Promote the protection of nature and wildlife conservation. 


2.4 2 If there is an official statement of forest policy for the savanna 
region, briefly outline its main points. 
Same as 2. 4.1 above 

2.5 Legislation available to implement policy Yes /X / No / / 

I/ For the purpose of this questionnaire, savanna is considered as including the full range 
of tropical vegetation types of which ^rass is a significant characteristic. At one end 
of the spectrum, closed forest and thickets are excluded; at the other end , desert is 
excluded. Between these extremes, savanna comprises the various types of savanna wood- 
land, savanna and steppe as described in Appendix 1 of Tree Planting Practices in 
African Savannas, PAO Forestry Development Paper No. 19, by M.V. Laurie, 1974 

- 279 - 

2.6 Ownership of for eats and savanna 
Under state control 
Private ownership 
Community ownership 
No effective control 

High forests 


2.7 Principal forest products from all regions (e.g. fuelwood, charcoal, sawlogs, 
gum, beeswax and honey, veneerlogs, logs for sleepers, poles, piling and 
posts, pulpwood). 

Sawnwood, construction timbers, veneer, stakes, props, poles, posts, and 
artisan wood. 

2.8 Forestry staff 

Subprofessional (with diploma 
or certificate of training) 




2.9 Gross annual budget for forestry 1 260 870 US$ 


3.1 Areas / 

3.1.1 Total net area-' of plantations at the end of 1974: - ha 

3.1.2 Net area ' of plantations in the savanna at the end of 1974:- ha 
313 Planned annual target area of af /reforest at ion:- ha/year 

3.1.4 Planned annual planting rate in savanna:! 700 ha/year 

3.2 Organization and administration of savanna planting schemes 

3.2.1 State forest services lOOJi 

3.2.2 Others (specify 

3.3 Intended principal end use (e.g. sawtimber, posts and poles, pulpwood, 
fuel wood, protection, etc.), species, growth and rotation of major 
savanna plantations. 

Net area(ha)^ 

End use 

Sawtimber and 


General utility 


Line plantings 





2 133 
1 266 

3 200 
1 900 

6 200 

Rotation years 




Mean annual 
increment (u.b.) 
at rotation age 


I/ Net area is the gross area of plantations minus the area in roads, rides, buildings 
and other non-stocked land. 

- 280 - 


4.1 Nursery types and capacities 

4.1.1 What is the total annual capacity of existing permanent savanna 
nurseries? 3-4 000 000 plants 

4.1.2 What is the actual annual production (average from last 3 years) 
from permanent savanna nurseries? 3 000 000 plants. 

4.1.3 What is the annual production (average from last 3 years) from 
temporary savanna nurseries? 500 000 plants. 

4.2 Planting stock 

4.2.1 Indicate the main types of planting stock (bare-rooted transplants, 
stumps t container stock, etc.) raised for the principal savanna plantation 

Species Type of stock 

teak stumps 

Gmelina striplings 

neem bare-root 

Casuarina polythene tubes 

eucalypts polythene tubec 

4.2.2 If containers are used, state type (polythene tubes or pots, "jiffy pots", 
etc.) and give dimensions (lay flat for polythene). 

Polythene pots 8 - 10 cm diameter and 25 cm long are used for some species 
(eucalypts and Casuarina) 

4.2.3 Give average size (height) of savanna out plant ing stock and length of time 
(weeks) required to raise it in the nursery. 

Species Out plant ing size Weeks in nursery 

teak stumps 52 - 104 

Gmelina striplings or stumps 5 2 
eucalypts 60 cm 17 

Casuarina 60 cm 25 

Belaleuca 40 cm 25 

4.3 Savanna nursery methods 

4*31 Briefly describe the sowing methods used in savanna nurseries( bed sowing, 
pricking out, direct sowing into containers, etc,). 

Teak, Gmelina and neem are sown in seedbeds; Casuarina t eucalypts , Nela- 
leuca and Acacia albida and A. Senegal are direct sown into tubes. 

4.32 Briefly describe the soil mixtures and fertilizers (and quantities) used. 
The quantities of fertilizers and soil mixture are not the same for all 
soils, some of which are rich with a high humus content while others are 
poor and sandy or clayey. For Ca>suarina in sandy soil 1 kg of NPK 
fertilizer is used per m3 of soil. 

4*33 Briefly describe savanna nursery watering methods and schedules (if 
mechanical irrigation equipment is used, indicate type). 

4*34 Briefly describe the standard savanna nursery protection measures (against 
pathogens, insects, animals, environmental elements). 

Protection methods against pathogens, insects and animals are almost always 
the same - knowledge of use of baits, anticoagulants and antiseptic products 
against rodents; insecticides dieldrin and BHC against termites; erecting 
fences against animals; and fire protection and surveillance. 

- 281 - 


5.1 Site selection 

5.1.1 Are detailed vegetation maps available for most savanna regions? 
Yes /T7 No I 7 

512 Are detailed soil maps and soil survey descriptions available for most 
savanna regions? Yes /~%. / NO / / 

5.2 Land clearing and site preparation 

5.2.1 Briefly describe the main savanna land clearing methods used. 

The principal land clearing method is manual and occasionally mechenieal. 
Agri-silviculture (taungya) is often practised, with farmers aiding 
in the land clearing, burning, planting, protection and weeding. This 
method is generally used for planting teak and Gmelina (with mountain 
rice ) Anacardium (with millet ) and Acacia albida (with millet and ground- 
nut s ) . 

5.2.2 Briefly describe the principal site preparation techniques used after land 
clearing in the savanna. 

Where rainfall is greater than 1100 mm, normal planting holes are prepared. 
In drier regions, large holes and subsoiling are used. On dunes fertilizers 
are needed if the soil is poor. 

5.3 Savanna planting and direct seeding 

5.3.1 Is direct seeding used in savanna? Yes /X / No f / 

If so, indicate for which species; Anacardium Occident ale, teak and 

5.3.2 Indicate the most common spacings at which the main savanna plantation 
species are planted. 

teak: 2.5 x 2.5 m eucalypts: 3 x 3 m Anacardium: 10 x 10 m 
Gmelina; 2.5 x 2.5 m Acacia: 4 x 4 m 

5.3.3 Give the total number of hectares of plantations established to date in the 
savanna by means of taungya: 12 000 ha. 

5.4 Tending of savanna plantations 

5.4.1 Briefly describe the method and frequency of weeding. Weeding is usually 
manual and is required only once after the winter and rarely in the dry 
season. Watering every two days during the first dry season is not always 

5.4.2 If irrigation is used in plantations, give the area irrifated of each species, 
the frequency of watering and the quantity of water applied. Irrigation is 
not used. 

5.5 Protection of savanna plantations 

5.5.1 Briefly describe protection measures against insects, pathogens and animals. 
Where means permit, firebreaks are maintained. Insecticides (BHC powder) are 
used; pesticides and anticoagulants are employed against rodents (especially 
the palm rat) and barbed-wire fences are erected to guard against animals. 

5.5.2 Is there a national fire danger rating system? 
Yes y5T7 No /"7 

5.5.3 Are fire breaks and fire lines allowed for at the time of savanna 
plantation establishment? Yes /JT7 No /~7 

- 282 - 

554 10 controlled (i.e. prescribed or early) burning practiced in savanna 
plantations? Yes / 7 No 

Arcmnd plantations? Yes ^ m _/ No X / 

VI * Swm* AND Tiffin TlffPRQV^MT^^ 

6.1 Is there a national tree seed coordinating centre? Yes / / No 

6.2 Is there a national tree seed certification system? Yes / X / No 

63 Are there facilities for storing seed at controlled temperatures? 
Yes fjf No /T7 

6*4 Indicate the main sources of seed supply for the principal savanna 

plantation species. Sufficient supplies of taak, Casuarina, eucalypts and, 
after 1976 Groelina, seed is available locally. 

6.5 Ijist the species being tested in comparative trials in the savanna. Indicate 
in paretheses the number of provenances being tested of each species. 
Eucalyptus carnal dul ensi s (100 Australian sources) 
Melaleuca sp. (8 provenances) among which the best are from Casamance). 


List the main published sources of information on afforestation and rureery 
practice in the savanna regions of your country. 

"L'arbre dans le paysage s&i&galais: sylviculture en zone tropicale seche 11 
by P.L. Giffard, CTFT f 1974* 

- 283 - 

Country: SUlJAN 


1.1 Area of country 2 506 800 kn 

1.2 Location: longitude 22 E - 37 E;latitude /] - 'c2 K 

1.3 Population: 16 000 000 inhabitants 

1.4 Main climatic and vegetative zones 
(i) Desert (ii) Semi-desert 

(iii) Low rainfall savanna ( iv) High rainfall 

Savanna (v) Montane vegetation (vi) Flood region 


2.1 Area of high forests / kr/ 

2.2 Area of savanna 4/15 000 km 2 , 

2.3 Proportion of land under high forest ...../... ..*/;; in savanna 40Ji- 

2.4 Does the country have a written statement of national forest policy? 
Yes /T7 No I 7 

2.4*1 If a national forest policy exists, what are the main objectives stated in it? 

1) To provide forest products to the population and to forest industries. To protect 
and conserve existing vegetation and catchment areas, 

2) To combat desert creep. 

2.4.2 If there is an official statement of forest policy for the savanna region, briefly 
outline its main points. 

(i) Levying of royalties (ii) to reserve 155-0 of the areas as forests (iii) prohibit 
overgrazing, overfelling and fires (iv) opening of fire lines 

(v) Establishment of shelter belts (2-4$-) in every agricultural scheme. 

2.5 Legislation available to implement policy Yes /X / No / / 

2.6 Ownership of forests and savanna 

High forests Savanna 

Under state control 100$ 

Private ownership 
Community ownership - 

No effective control - 

I/ For the purpose of this questionnaire, savanna is considered as including the full range 
of tropical vegetation types of which grass is a significant characteristic. At one end 
of the spectrum, closed forest and thickets are excluded; at the other end, desert is 
excluded. Between these extremes, savanna comprises the various types of savanna woodland, 
savanna and steppe as decribed in Appendix 1 of Tree Planting Practices in African Savannas, 
FAO Forestry Development paper No.19, ty M.V. Laurie, 1974- 

- 284 - 

2.7 Principal forest products from all regions (e.g. fuelwood, charcoal, sawlogs, gum, 
beeswax and honey, veneerlogs, logs for sleepers, poles, piling and posts, pulpwood). 
Sawn timber, fuel wood, charcoal, gums, beeswax, honey, poles, 

2.8 Forestry staff State Others 

Professional 38 


(with diploma ^-M 

or certificate * LL 

of training) 

2.9 Gross annual budget for forestry 2,500.000 US$ 

3.1 Areas 

3.1.1 Total net area \J of plantations at the end of 1974: 119735 ha. 

3.1.2 Net area I/ of plantations in the savanna at the end of 1974: 100352 ha 

3.1.3 Planned annual target area of af /reforestation: 10 ,000 ha/yr 

3.1.4 Planned annual planting rate in savanna: 20 , 000 ha/yr 

3.2 Organization and administration of savanna planting schemes 

3.2.1 State forest services lOOJb 

3.2.2 Others (specify) % 

3.3 Intended principal end use (e.g. sawtimber, posts and poles, pulpwood, fuel wood, protection 
etc.), species, growth and rotation of major savanna plantations. 

Mean annual increment 
(u.b.) at rotation age 

End use Species Net area ha ' Rotation (yrs) niVha/yr 

Fuelwood A. nilotica 29117 30-35 

Fuelwood A. mellifera 1600 

Gum arabic A. Senegal 36554 25-30 

Post+poles Euc. spp. 9860 8-10 

Sawn Timber Tectona grandis 9690 80 

Protection Prosopis chilensis - - 


41 Nursery types and capacities 

4.1.1 What is the total annual production capacity of existiing savanna nurseries? 
6 000 000 plants. 

4.1.2 What is the actual annual production (average from last 3 years) from permanent 
savanna nurseries? 2 $86 251 plants 

I/ Net area is the gross area of plantations minus the area in roads, rides, buildings and 
other non-stocked land. 

-285 - 

41*3 What ia the annual production (average from last 3 years) from temporary savanna 
nurseries? - Plant s, 

42 Planting stock 

4*2,1 Indicate the main types of planting stock (bare-rooted transplants, stumps, 
container stock, etc,) raised for the principal savanna plantation species, 

Species Type of stock 

A, Senegal Container stock 
A, nilotica _ 

Tectona grandis Stumps 

Eucalyptus sp. Container stock 

4.2.2 If containers are used, state type (polythene tubes or pots, M jiffy pots 11 , 
etc,) and give dimensions (lay flat for polythene). Polythene tubes 10 cm 
x 20 cm, 

4.2.3 Give average size (height) of savanna outplanting stock and length of 
time (weeks) required to raise it in the nursery, 

Species Outplanting size Weeks in nursery 

Euc, spp, 30 cm 32 

Tectona grandis 8 cm 40 

A Senegal 20 cm 40 

43 Savanna nursery methods 

431 Briefly describe the sowing methods used in savanna nurseries (bed sowing, 
pricking out, direct sowing into containers, etc.) Bed sowing is used for 
preparing teak stumps. Seedlings are transplanted directly after germination 
into raised beds 20 cm apart and after 40 weeks stumps are planted out, 
Bucalypt seeds are also sown into beds and then transplanted into tubes, 
Other species are already sown into containers, 

432 Briefly describe the soil mixtures and fertilizers (and quantities) used, 

Soil mixture is prepared by mixing sand and loamy soil in the ratio of ?:1, 
Fertilizers are not generally used| sometimes farm yard manure is added if deemed 

433 Briefly describe savanna nursery watering methods and schedules (if mechanical 
irrigation equipment is used, indicate type), 
1} Spraying transplants once daily, 
2) Flooding once (1-5 days) 
3; Rain nurseries (mainly in the South) 

4.3.4 Briefly describe the standard savanna nursery protection measures (against 
pathogens, insects, animals, environmental elements). 

1) Insecticides (e,g, Dieldrin)are used against insects, 

2) Thorn, barbed wire enclosures are used against animals and rodents. 
3; Shelterbelts are used in exposed areas, 


5,1 Site selection 

5,1,1 Are detailed vegetation maps available for most savanna regions? 
Yes T7 No * 

5,1,2 Are detailed soil maps and soil survey descriptions available for most 
savanna regions? Yes /X / No / / 

52 Land clearing and site preparation 

5,2.1 Briefly describe the main savanna land clearing methods used, 

- 286 - 

(i) Mechanical clearance ( in mechanised crop production schemes) followed 

"by fire, 
(ii) Axe - felling. 

5*22 Briefly describe the principal site preparation techniques used after land 
clearing in the savanna. 

(i) Soil working by ploughing, 
(ii) Ridge and furrow, 

53 Savanna planting and direct seeding 

531 Is direct seeding used in savanna? Yes /X / No [_ j 

If so, indicate for which species: Acacia nilotica 

532 Indicate the most common spacings at which the main savanna plantation species 
are planted. 2 m x 3 ni - Acacia Senegal; 4 m x 4 tn - Acacia mellifera; 4 m x /] m 

533 Give the total number of hectares of plantations established to date in the 
savanna by means of taungya: 40 000 ha 

5.4 Tending of savanna plantations 

5.41 Briefly describe the method and frequency of weeding. Hand weeding is usually 
carried out once in the first and second year. Another weeding if need arises 
is carried out in the third yenr. 

542 If irrigation is used in plantations, give the area irrigated of each species, 
the frequency of watering and the quantity of water applied. 

Eucalypts 30 000 ha 

Frequency fortnightly 

Quantity 10 000 cu.m./ha (approx. ) 

5*5 Protection of savanna plantations 

5*52 Is there a national fire danger rating system? 

Yes r~i NO m 

5*5*3 Are fire breaks and fire lines allowed for at the time of savanna plantation 
establishment? Yes /X~/ No / / 

5*5*4 Is controlled (i.e. prescribed or early) burning practiced in savanna 
plantations? Yes /X / No /"'/ 

Around plantations? Yes /X / No /. 7 


6.1 Is there a national tree seed coordinating centre? Yes J No /X / 

6.2 Is there a national tree seed certification system? Yes /X / No /"^7 

6.3 Are there facilities for storing seed at controlled temperatures? Yes / X/ No / / 

6.4 Indicate the main sources of seed supply for the principal savanna plantation species. 
Locally collected from mother trees. 

6.5 List the species being tested in comparative trials in the savanna. Indicate in paren- 
theses the number of provenances being tested of each species. 

i) Eucalyptus hybrid (Mysore) 

ii) Acacia Senegal (selected seeds from high yielding trees). 

- 287 - 

List the main published sources of information on afforestation and nursery practice 
in the savanna regions of your country. 

i) Badi, K.H (1972) Afforestation in the clay plains of Kassala province, For. 
new series No. 13 

ii) Booth, G.A. (155) Afforestation in Dueim Range While Nile 3ude,n tfilvr No.l. 

iii) Foggie, A. (1966) Forestry and forestry policy in the Oezera area,FAO, MTAP 

Rep, Soudan Govt. 

iv) Khan, M.A.W. (1966) Improved methods and devices in nursery practice, UNDP 
for Res. Ed pro Sudan 28. 

Country: TOGO 


1.1 Area of country 56 000 km^ 

1.2 Location: longitude - 1 40'K; latitude 06 - 11N 

1.3 Population: 2 000 000 inhabitants 

1*4 Main climatic and vegetative zonea: a) Guin^p climate in the south, corresponding 
to relatively dense tree savanna with some forest relics; b) Judan climate ir th^ 
north, with tree and shrub savanna, savanna woodlands ami steppes; c) i-,quHteria] 
climate in mountainous regions, with dry, d^nse forest formations and montftne lro<.- 


2.1 Area of high forests 1 680 km 2 

2.2 Area of savanna ^ 21 280 km 2 

2.3 Proportion of land under high forest 3/ ; in savanna ' 3^7 

2.4 Does the country have a written statement of national forr-st policy? 
Yes yT"7 No 

2.4.1 If a national forest policy exists, what are the main objectives stated 
in it? Immediate objectives: Reflate the flow of fuel wood and ^n^r;- 1 
utility wood from the main supply centres; ohort term objectives (1C) - 1^ 
years); a) establish plantations of fast -growing species ;"b) manage and 
exploit some forest blocks in order to reduce imports; l.*ciium and lon^ term 
objectives: supply wood from plantations to processing industries ben^fici^l 
to the country. 

2.4*2 If there is an official statement of forest policy for the wHvanii*. r-^inn, 
briefly outline its main points. The above* outlined policy is implemented 
on BCtfc of the savanna area with an annual rainfall of 1 000-3 i. 00 mm. In the 
north, in grass savanna and in denuded zones, the policy is still under study. 

2.5 Legislation available to implement policy Yes /X 7 No / ""7 

For the purpose of this questionnaire, savanna is considered as including the full range of 
tropical vegetation types of which grass is a significant characteristic. At one end of the 
spectrum, closed forest and thickets are excluded; at the other end, desert is excluded. 
Between these >extremes f savanna comprises the various types of savanna woodland, savanna 
and steppe as described in Appendix 1 of Tree Planting Practices in African Savannas , 
PAO Forestry Development Paper No.l9t hy H.V. Laurie, 1974 . 

- 288 - 

2.6 Ownership of forests and savanna 

Ownership of the 430 000 ha of officially classified forests in the savanna 
and high forest regions is not yet determined* 

2.7 Principal forest products from all regions (e.g. fuel wood, charcoal, sawlogs, 
gum, beeswax and honey, veneerlogs, logs for sleepers, poles, piling and posts, 
pulpwood). Puelwood, sawtimber, sleepers, posts, piling, gum, besswax and honey. 

2.8 Forestry staff State Others 

Professional 11 - 

Sub-professional (with diploma or 
certificate of training) 42 - 

2.9 Gross annual budget for forestry - US$ 


3.1 Areas 1 / 

3.1.1 Total net area -/of plantations at the end of 1974: 5 500 ha 

3*1.2 Net area 'of plantations in the savanna at the end of 197 / 1 : 4 5^0 na 

3.1.3 Planned annual target area of af/ref orestation: 1 000 ha/yr 

3.1.4 Planned annual planting rate in savanna: 600 ha/year 

3.2 Organisation and administration of savanna planting schemes 

3.2.1 State forest services 100 /Q 

3.2.2 Others (specify). Private plantations are rare. 

3.3 Intended principal end use (e.g. savrtimber, posts and poles, pulpwood, fuelwood, 
protection, etc.) species, growth and rotation of major savanna plantations. 

Mean annual 

Bnd use Species Net area (ha)^/ Rotation(Yr S ) increment (u.b.) 
-* 1 -../ * L a t rotation ae 


firewood eucalypts 300 10-1? 

general utility teak 

sawtimber Terminal ia 700 20-50 

veneer Cedrela 


4.1 Nursery types and capacities 

4*1*1 What ie the total annual production capacity of existing permanent savanna 
nurseries? 1 500 000 plants 

4,1.2 What is the actual annual production (average from last 3 years) from 

permanent savanna nurseries? ^00 000 plants. 
41.3 vrfhat is the annual production (average from last 3 years) from temporary 

savanna nurseries? 5^0 ^)00 plants 

I/ Net area is the gross area of plantations minus the area in roads, rides, buildings 
and other n on- stocked land. 

- 289 - 

4*2 Planting stock 

4.2.1 Indicate the main types of planting stock (bare-rooted transplants, 
stumps, container stock, -ate.) raised for the principal savanna 
plantation species. 

Species Type of stock 

eucalypts polythene pots 
teak stump B 

Gmelina stumps 

Cedrela stumps 

4.2.2 If containers are used, stato type (polythene tubes or pnts, 
"jiffy pots", etc,) and giv* dimensions (ic-.y fL-'t for polythene). 
Polythene pots: 25 cm lon^;, 8 - 10 cm diameter 

4.2.3 Give average size (height) nf savanna outplantin;; stock rtnc length 
of time (weeks) required to raise it in tlif nursery. 

Species Out p 1 ant in ^ n i ?, e . v oeks in nursery 

eucalypts 2.5 - 5 cm* ir - 15 

Cedrela 5 -10 ern* ?0 - ^4 

Gmelina 5 - 10 cm* 20 - 24 

4.3 Savanna nursery methods 

431 Briefly describe the sowing methods used in savanna nurseries (b^u 
sowing, pricking; out, direct sowing into containers, etc,) 
Sowing is into plastic or galvanised frames of 2 000 cm'" are; f need- 
beds, or for teak stumps into prepared open bods. Pricking-out is oone 
into polythene pots or bed a. 

432 Briefly describe the soil mixtures a^id feriilisera (arid quantities) 
used: Soil mixture is composed of 5^ fluvial sand and 5^- earth or 
sifted humus. Fertilisers are not used, 

433 Briefly describe savanna nursery watering methods and schedules (if 
mechanical irrigation equipment is used, indicate type): i^Yamed beds 
are mist irrigated; watering cans are used for other beds, 

4.34 Briefly describe the standard savanna nursery protection measures (against 
pathogens, insects, animals, environmental elements); For eucalypts, the 
soil/sand mixture is steam sterilised on metal sheets and Gifted, 

5.1 Site selection 

5.1.1 Are detailed vegetation maps available for most savanna regions? 
Yes r7 No /T7 

5.1.2 Are detailed soil maps and soil survey descriptions available for 
most savanna regions? Yes /X , J No / / 

5*2 Land clearing and site preparation 

* pricking-out size 

- 290 - 

521 Briefly describe the main savanna land clearing methods used t 
a) Manual clearing by eliminating understorey plants and the 
herbaceous cover followed by windrowing; bj Mechanical 
clearing using crawler tractors with or without windrowing. 
Note; Charcoaling is practised in some areas in conjunction 
with clearing 

5*2.2 Briefly describe the principal site preparation techniques used after land 
clearing in the savanna: Some mechanically cleared areas to be planted 
are worked with a heavy plough (Rome) pulled by a D-6 tractor; others 
are turned with a Massey-Ferguson and a 3-disc plough; while on lands 
to be planted by local people, traditional methods of cultivation are 

5.3 Savanna planting and direct seeding 

531 Is direct seeding used in savanna? Yes / / No /X / 
If so, indicate for which species. - 

5.32 Indicate the most common spacings at which the main savanna plantation 
species are planted. - 

533 Give the total number of hectares of plantations established to 
date in the savanna by means of taungya: about 5 000 ha 

5.4 Tending of savanna plantations 

5.41 Briefly describe the method and frequency of weeding: a) Clean weeding 

manually by hoe and machete twice a year for the first two years following 
establishment; b) Mechanical clean weeding with a rotavator twice a year 
in some stands. 

542 If irrigation is used in plantations, give the area irrigated of each 
species, the frequency of watering and the quantity of water applied. 


5.5 Protection of savanna plantations 

551 Briefly describe protection measures against insects, pathogens and 
animals: None 

5.5.2 Is there a national fire danger system? Yes / / No / X/ 

553 Are fire breaks and fire lines allowed for at the time of savanna 
plantation establishment? Yes /X"/ No L^.J 

554 Is controlled (i.e. prescribed or early) burning practiced in savanna 
plantations? Yes / 7 No /X 

Around plantations? Ye /, X/ No 


6 t l Is there a national tree seed coordinating centra ? Yes /X / No f~ / 

6.2 Is there a national tree seed certification system? Yes fi / No / / 

6.3 Are there facilities for storing seed at controlled temperatures? 
Yes /T7 No r~~J 

6.4 Indicate the main sources of seed supply for the principal savanna 
plantation species. Ghana, Nigeria, Venezuela, Prance, Costa Rica, 
Australia and local stands. 

- 291 - 

6,5 List the species being tested in comparative trials in the savanna* 

Indicate in parentheses the number of provenances being tested of each 

Afzelia africana 
Anogeissus leiocarpus 
Anthocephalus cadamba 
Araucaria cunninghamii 
Aeadirachta indica 
Callitris intratropioa 
Calophyllum sp. 
Casuarina equi set i folia 

Cedrela odorata E.citriodora 

Ceiba pentandra E. ferruginea 

Cordia alliodora E. grandis 

Dalbergia sp. E. microtheca 
Erythrophleum guineense E, nesophila 

Eucalyptus alba E* robust a 

E. brassii K. tereticornis 

K. camaldulensis E. torelliana 

Khaya grendifoliola 
K. senegalensis 
Pterocarpus angolensis 
Sterculia foetida 
Tectona grandis 
Triplochiton sclerexylon 


List the main published sources of information on afforestation and nursery 
practice in the savanna regions of your country. - 

Country: UGANDA 


1.1 Area of country ?35 ^90 km' 

].? Location: longitude r'930' 350 latitude, 13C" j / 

1.3 Population: 10 million inhabitants 

l./i Main climatic and vegetative zones: (l) ^:lorjfil forest (r ) Open fr-rct and 
Crass land (3) oteppe wnd grassland. Tropic?! climate with f punks pattern 
rainfall April/Kay and October /November 


2.1 Area of high forests 6 3^ 3 km^ 

I/ 2 

2.^ Area of savanna ' 7" 7 3 km 

^3 Proportion of land under hi^h fornst /I*/-; in savarina ' f^ fJ 

2*4 Does the country have a written statement of national i'orest policy? Yes J1CJ l. ; c 

2.4.1 If a national forest policy exists, what are tho main r/bjectivcs stated in 
it? (l) To reserve adequate land as forest estate so as to ensure a) a 
sustained production of timber arid other forest products for the needs of the 
country and export, b) Protection of water catchments, soil, wildlife and * 
amenity of land; (2} To develop that estate so as to obtain uaxinaxm economic 
returns to the country; (3) To ensure efficient conversion of wood and wood 
products so as to reduce wastej (4) Help people and organisations to row r nd 
protect their own treesj 5) Education of the public to the role of forestry 
and forest industries. 

2.4.2 If there is an official statement of forest policy for the savanna region, 
briefly outline its main points. Not officially stated but understood to be 

(l) Establishment of forest plantations, both softwoods and eucalypts, for 
building poles and fuel. (2) As in (l) above, i.e. protection soil, wildlife 
and amenity of land. ^_^ 

2.5 Legislation available to implement policy Yes A / No / / 

I/ For the purpose of this questionnaire, savanna is considered as including the full range 
of tropical vegetation types of which grass is a significant characteristic. At one end. 
of the spectrum, closed forest and thickets are excluded; at the other end, desert is 
excluded. Between these extremes, savanna comprises the various types of savanna woodland 1 
savanna and steppe as described in Appendix 1 of Tree Planting Practices in African 
Savannaflj PAO Forestry Development Paper No.l9t by M.V. Laurie^ 1974 

- 292 - 

2.6 Oimwafcip of fwMtfl and Muraana 

Under state control 
Private ownership 
Community ownership 
No effective control 

High farMta 




2.7 Principal forest products from all regions (e.g. fuelwood, charcoal, sawlog8,gum, 

beeswax and honey, veneerlogs, logs for sleepers, poles, piling and posts, pulpwood). 
Fuelwood 185 000 nH, Particleboard 5 5&4 nr f charcoal 600 000 m^ f plywood and block- 
board 635 m* f sawlogs 175 000 m^ poles 32 500 nA 

2.8 Forestry staff 

Subprofessional (with diploma or 
certificate of t reining) 

2.9 Gross annual budget for forestry 




000 000 USlt 

3.1 Areas 

3.1.1 Total net area -/ of plantations at the end of 1974:45 000 ha 

3.1.2 Net area =* of plantations in the savanna at the end of 1974: 35 000 ha 
313 Planned annual target area of af /reforestation: 3 $00 ha/year 

3.1.4 Planned annual planting rate in savanna: 2 000 ha/year 
32 Organization and administration of savanna planting schemes 
32.1 State forest services 955 y 

3.2.2 Others (specify) Tobacco Society Woodfuel Plantations 550 

33 Intended principal end use (e.g. sawtimber, posts and poles, pulpwood, fuelwood 
protection, etc.), species, growth and rotation of major savanna plantations. 

End use Species Net area (ha)-/ Rotation(Yrs) Kean annual 

increment (u.b.) 
at rotation age 





Protection others 

Cupressus lusitanica 

Pinus patula 

P. caribaea/oocarpa 

Euc, carnal dul en si s 
11 tereticornis 
11 grandis 

P.caribaea, P. sp. 

Euc . carnal dul ens i s 
11 tereticornis 
11 grandis 




I/ Net area is the gross area of plantations minus the area in roads, rides, buildings 
and other non-stocked land. 

- 293 - 


41 Nursery types and capacities 

411 What is the total annual production capacity of existing permanent savanna 
.nurseries? 20 000 000 plants. 

4.1.2 What is the actual annual production (average from last 3 years) from 
permanent savanna nurseries? 35 000,000 plants. 

4.13 What is the annual production (average from last 3 years) from temporary 
savanna nurseries? 1 500 000 plants. 

4.2 Planting stock 

4.2.1 Indicate the main types of planting stock ("bare-rooted transplants, stumps, 
container stock, etc.) raised for the principal savanna plantation species. 

Species Type of stock 

P. caribaea Container stock 

P. patula " 

P. oocarpa IT 

Cup. lusitanica " 

Euc. carnal dulensis) M 

Euc. tereticornis ) 

Euc. grandis " 

42.2 If containers are used, state type (polythene tubes or pots, "jiffy pots", 
etc.) and give dimensions (lay flat for polythene) . 
Polythene tubes and mill pot 8 /] lf lay flat and 7" for ornament als 

42.3 Give average size (height) of savanna outplanting stock and length of 
time (weeks) required to raiso it in the nursery. 

Species Qutplanting size Weeks in nursery 

Cypressus spp. 1 ft (30 cm) 36 v/eeks 

Pine spp. 1 ft (30 cm) 16 - 20 v/eeks 

4.3 Savanna nursery methods 

4.3.1 Briefly describe the sowing methods used in savanna nurseries (bed sowing, 

prihking out, direct sowing into containers, etc.). 
l) The seed is sown by broadcasting after mixing with sand and pricked out in 

containers when 0.5 - 1 cm tall. This is both in softwoods and eucalypts. 
' When containers are not available pricking out is done into Swaziland beds 
or boxes. 

4.32 Briefly describe the soil mixtures and fertilizers (and quantities) used: 
Soil mixtures vary site to site but normally forest or black soil together 
with cow manure are used. fertilizer is mixed thus: 1 ^QO gms/W of soil 
in heaps and 100 gms/nr for top dressing. 

433 Briefly describe savanna nursery watering methods and schedules (if 

mechanical irrigation equipment is used, indicate type) : l) Catering cans 
are used at least twice daily, morning and evening. 2) Overhead irrigation 
water-pumped by hand pumps. 

4.3.4 Briefly describe the standard savanna nursery protection measures (against 
pathogens, insects, animals, environmental element s)$ l) opraying and 
soil pre treatment with fungicides and insect icideB f 2) Clearing around 
nurseries discourages rats f 3) Ditch drains prevents floods and washout f 
4) Fencing prevents large animals from walking over plants. 

- 294 - 

5*1 Site selection 

5.1.1 Are detailed vegetation maps available for most savanna regions? 
Yes ^1 No /T7 

5.1.2 Are detailed soil maps and soil survey descriptions available for 
most savanna regions? Yes /X / No / / 

5.2 Land clearing and site preparation 

5.2.1 Briefly describe the main savanna land clearing methods used. 

l] Manual cutting of trees and grass slashing is followed by burning, 
2] Peasant farmers may be allowed to clear the bush and cultivate 

before planting, 
3) Poisoning of large trees with aboricide in more open grassland, 

5.2.2 Briefly describe the principal site preparation techniques used after 
land clearing in the savanna: (l) Lining out using a pre-marked rope at 
planting spacing intervals and pegging, 2)Pitting using hoes and 
marked pits ready for planting, 
5.3 Savanna planting and direct seeding 

5.31 Is direct seeding used in savanna Yes / / No /X, 7 
If so, indicate for which species. 

5.32 Indicate the most common spacings at which the main savanna 
plantation species are planted. 

For Eucalyptus - 1.8m by 1.8m f 2.1m by 2.1m and 2.4m by 2,4 m have 
been tried, but 2.1m by 2.1 m now predominates. For cypressus and 
pines 2.7m by 2.7 m is used, 

5*3*3 Give the total number of hectares of plantations established to 
date in the savanna by means of taungya, 

5*4 Tending of savanna plantations 

5.41 Briefly describe the method and frequency of weeding: In first rotation eucrlypt 
plantations, weeding is done 4 times the first year, twice the second year by c]eron 
hoeing,and once in the third year by slashing.Afrer felling only one line slashing 
is needed. In cypress and pine plantations, line alashing is done twice the 
year and once the second year, 

5*4*? If irrigation is used in plantations, give the area irrigated of each species 
the frequency of watering and the quantity of water applied, 

5*5 Protection of savanna plantations 

5.51 Briefly describe protection measures against insects, pathogens and 

animals: l) Insecticide treatment of plants before planting to control 
termite attack as well as fungus. r d} Clean weeding protects youn trees 
from rat attack, 

5*5* t0 Is there a national fire danger rating system': Yes / / No /X r / 

5.5*3 Are fire breaks and fire lines allowed for at the time of savanna 
plantation establishment? Yes /X / No / / 

5*5*4 Is controlled (i.e. prescribed or early) burning practiced in savanna 
plantations? Yes /X / No / / ^_^ 
Around plantations? Yes /X / No / / 

- 295 - 


6*1 Is there a national tree seed coordinating centre Yee /X / No / / 
6.2 IB there a national tree seed certification system? Yes /X / No / / 

6*3 Are there facilities for storing seed at controlled temperatures? 
Yes FT! No ~ 

6.4 Indicate the main source of seed supply for the principal savanna plantation species, 
l) For cypressus and pines most of the seed is imported mainly from Central America 

and the Caribbeans. 2) For Eucalyptus most of the seed used in our plantations 
is collected locally from chosen seed stands. 

6.5 List the species being tested in comparative trials in .the savanna. Indicate in 
parentheses the number or provenances being tested of each species* 

Pinus patula (3)f Cupressus lusitanica (2), Pinus caribaea (2), Pinus oocarpg 


List the main published sources of information on afforestation and nursery practice 
in the savanna regions of your country. (1) Uganda Forest Department Technical Notes 
nos. 78/59, 135/67, 138/67, 139/67, 144/67, 145/67, 146/67, 159/69, 179/71, 181/71, 
183/72, etc. (2) A Forest Resources Development Study Report by CIDA. (3) Uganda 
Forest Department Annual Reports. (4) Uganda Forest Departmental Standing Orderr 
revised Edition 1970. (5) Forests and Forest Administration of Uganda 1961. 

- 296 - 

Country: ZAMBIA 


1.1 Area of country 752 613 km 2 

1.2 Location: longitude 22E to 34Ej latitude 8S to 18S 

1.3 Population: 4t million inhabitants 

1.4 Main climatic and vegetative zonee: Tropical savanna* 


2.1 Area of high forests Nil 

2.2 Area of savanna =* 600 000 km 2 

2.3 Proportion of land under high forest: Nil; in savanna ' 

2.4 Does the country have a written statement of national policy? 
Yes /T7 No I 7 

2.4.1 If a national forest policy exists f what are the main objectives stated in it? 

Protection of forested areas and watersheds 
Provide forest produce for industry and rural users 

Research into indigenous and plantation wood 
Extension work and advice to public 
Training of staff 

2.4.2 If there is an official statement of forest policy for the savanna 
region, briefly outline its main points! No separate policy except 
"early burning". 

2.5 Legislation available to implement policy Yes /X / No / / 

2.6 Ownership of forests and savanna High forests Savanna 

Under state control Nil 8.9$ 

Private ownership Nil 2.4$ 

Community ownership Nil 88.7$ 

No effective control Nil - 

I/ Por the purpose of this quest ionnaire, savanna is considered as including the full range 
of tropical vegetation types of which grass is a significant characteristic. At one end 
of the spectrum, closed forest and thicke-tsare excluded; at the other end^.desert is ex- 
cluded. Between these extremes, savanna comprises the various types of savanna woodland, 
savanna and steppe as described in Appendix 1 of Tree Planting Practices in African 
Savannas. PAO Forestry Development Paper No.19, by M.V. Laurie, 1974. 

3.1.1 Total net area 'of plantations at the end of 197/Js 24 900 ha 

- 297 - 

27 Principal forest products from all regions (e.g. fuelwood, charcoal, sawlogs, 
gum, beeswax and honey, veneerlogs, logs for sleepers, poles, piling and posts, 
pulpwood)* Sa wlogs, si eeperSjpoles, fuelwood, charcoal, honey, beeswax* 

2.8 Forestry staff State Others 

Professional 44 17 

Subprofessional (with diploma or 

certificate of training) 222 336 

2.9 Gross annual budget for forestry 7 543 740 US$ (K4 804 930) 


31 Areas 

Total ne 

312 Net area /of plantations in the savanna at the 'end of 1974: 24 900 ha 
313 Planned annual target area of af/ref orestation:3 300 ha/year 
3.1.4 Planned annual planting rate in savanna: 3 300 ha/year 
32 Organization and administration of savanna planting schemes 

3.2.1 State forest services 99?c 

3.2.2 Others (specify) : Agricultural scheme 

33 Intended principal end use (e.g. sawtimber, posts and poles, pulpwood, 

fuelwood, protection, etc.), species, growth and rotation of major savanna 
plantations Meaii &nnual 

End use Species Net area (ha)' Rotation (yrs) increment (u.b.) 

at rotation age 


Sawlogs P. kesiya 13 000 30 15 

Sawlogs P. oocarpa 2 100 30 15 

Poles E. grandis 6 000 8 12 

Poles E. cloeziana 1 900 10 11 

Poles others 1 9OO various - 


41 Nursery types and capacities 

4.1.1 What is the total annual production capacity of existing permanent 
savanna nurseries? 4 million plants 

4.1.2 What is the actual annual production (average from last 3 years) 
from permanent savanna nurseries? 3 million plants 

413 What is the annual production (average from last 3 years) from 
temporary savanna nurseries? Nil 

4.2 Planting stock 

4.2.1 Indicate the main types of planting stock (bare-rooted transplants 
stumps | container stock, etc.) raised for the principal savanna 
plantation species. 

Species Type of stock 

Pinus kesiya Polythene tubes 

Pinus oocarpa ff tf 

Eucalyptus cloeziana " " 

Eucalyptus grandis fl " 

I/ Net area is the gross area of plantations minus the area in roads, rides, buildings 
and other non-stocked land. 

- 298 - 

4.2.2 If containers are used, state type (polythene tubes or pote f "jiffy pots 11 , 
etc,) and give dimensions (lay flat for polythene): Blaok polythene tubes 
12 cm x 10 cm. 

4.2.3 Give average size (height) of savanna out pi ant ing stock and length 
of time (weeks) required to raise it in the nursery. 

Species Out plant ing size Weeks in nursery 

Pines 20 cm 16 weeks 

Eucalyptus 13 cm 8 weeks 

4*3 Savanna nursery methods 

4.3*1 Briefly describe the sowing methods used in savanna nuseries (bed 
sowing, pricking out, direct sowing into containers, etc. ): Pines, 
direct sowing. Eucalyptus, seed beds and pricking out. 

4.3.2 Briefly describe the soil mixture and fertilizers (and quantities) 
used: top soil collected in woodland j fertilised with "Welgro" or 

4*3.3 Briefly describe savanna nursery watering methods and schedules (If 
mechanical irrigation equipment is used, indicate type)i Spray 
irrigated by perforated pipes or "rainbirds". 

4 .3*4 Briefly describe the standard savanna nursery protection measures 
(against pathogens, insects, animals, environmental elements). 
Watering with Zineb fungicide. Treatment of potting soil with 
methyl bromide watering of Eucalyptus with Aldrin as insurance 
against termites in the field. 

5.1 Site selection 

5.1.1 Are detailed vegetation maps available for most savanna regions? 
Yes /XT No f~7 

5.1.2 Are detailed soil maps and soil survey descriptions available for 
most savanna regions? Yes / / No /X / 

5.2 Land clearing and site preparation 

5.2*1 Briefly describe the main savanna land clearing methods used. 

Large areas cleared mechanically by contractors. Small rural areas 
stumped by hand. 

5.2.2 Briefly describe the principal site preparation techniques used after 
land clearing in the savanna: Ploughing and discharrowing. 

5.3 Savanna planting and direct seeding 

5*3*1 Is direct seeding used in savanna? Yes / / No / / 
If so, indicate for which species. 

5*3*2 Indicate the most common spacings at which the main savanna plantation 
species are planted: Pines and Eucalyptus 1 OOO per hectare. 

53*3 Give the total number of hectares of plantations established to 
date in the savanna by means of taungya: Nil 

- 299 - 

5*4 Tending of savanna plantations 

541 Briefly describe the method and frequency of weeding: Disc harrow 
between rows, in both directions. First year 6 times; for all 
species; second year twice for Eucalyptus and 4 times for pines; 
third year twice for pines. 

542 If irrigation is used in plantations, give the area irrigated of 
each species f the frequency of watering and the quantity of water 
applied: Not used. 

5*5 Protection of savanna plantations 

5 51 Briefly describe protection measures against insects, pathogens 
and animals: None in the plantation. 

5.5 2 Is there a national fire danger rating system? 
Yes I 7 No 7 """x7 

553 Are fire breaks and fire lines allowed for at the time of savanna 
plantation establishment? Yes /X / No f" ] 

5*5*4 Is controlled (i.e. prescribed or early) burning practiced in 
savanna plantations? Yes /X / No / / 

Around plantations? Yes /X / No / / 


6.1 Is there a national tree seed coordinating centre? Yes /X_7 No / / 

6.2 Is there a national tree seed certification system? Yes /X / No / / 

6.3 Are there facilities for storing seed at controlled temperatures? 
Yes /T7 No / 7 

6.4 Indicate the main sources of seed supply for the principal savanna plantation 
species: Locally collected from selected stands and seed orchards. 

6.5 List the species being tested in comparative trials in the savanna. 
Indicate in parentheses the number of provenances being tested of each 
species* All the tropical pines have been tried and all tho Eucalyptus 
from the East Coast of Australia. 


List the main published sources of information on afforestation and nursery 
practice in the savanna regions of your country: Methods developed locally 
by Forest Department. 

- 300 - 


Zinga Kanza 

Office Congolais des Forits 
Point e Ho ire, Congo 



Introduction 301 

Background - purposes 301 

Ecological conditions 301 

Soils and vegetation 301 

Climate 302 

Relief 302 

Afforestation methods used for euoalypts 302 

Species of euoalypts used 302 

Nurseries 303 

Ground preparation 304 

Planting and management 304 

Results and future prospects 306 

Afforestation methods used for pines 306 

Species of pine used 306 

Hurseries 306 

Soil preparation 307 

Planting and management 307 

Results and future prospects 307 

Table 1: Savanna plantations (pines and euoalypts) of the Office 

Congolais des Forits 308 

- 301 - 


The People's Republic of the Congo, which lies in Central Africa between 1*\ 9'W' and 
18 4O W East longitude and between 342'30 W North and 5 2 I 3" South latitude is 342 000 km 2 
in size* Poresta in the Congo occupy choice land, covering a little over 60J6 of the total 
area* The rest of the country is savanna, comprising some 137 000 km2 of relatively flat, 
unbroken land* 

Three types of savanna are usually distinguished, namely: 

baren savanna 

bush savanna 

and gallery forests* 

Because of these exceptional natural conditions, Congo foresters have for both 
economic and scientific reasons been drawn to work largely on savanna* 


Trial afforestation of savanna in the Congo dates back to 1930* Initially, trials 
were started with local species* The first man-made stands were laid out in association 
with food crops (maize, groundnuts /peanuts/ ) using mainly 'limba 1 ( Terminalia superba) 
teak, Ceiba pentandra* the iroko 1 iChlorophora exoelsa) , and Cassia siamea* 

Later on, research and studies were devoted mainly to the introduction, acclimatization 
and growing of exotic, fast-growing species - in 1953, eucalypts ( Eucalyptus saligna, 
E* robust a. E. alba* E, panioulata and E. carnal dulenais, E. 12 ABL and E, teretioornis) and 
toward 1959? pine (Pinus caribaea and pT oocarpa) . ~" "" 

These plantation operations were launched initially and simultaneously at the forest 
research stations of Loandjili ( Point e-Roi re) and Loudima (Bouenza) and subsequently at 
the km 45 station (Brazzaville) and at Malolo (Niari). 

The original purposes were: 

to provide timber and fuelwood to the inhabitants of the large urban centres of 
Pointe-Noire, Loubomo (Dolisie) and Nkayi (Jacob); 

to supply the Congo Ocean railway ( CFCO) with fuelwood (this line having used steam 
engines before its complete changeover to diesel engines) ; and 

- to supply pulpwood for a pulp and paper industry to be set up, 

Soils and Vegetation 
Trials were conducted on three types of savanna: 

- coastal savanna on sandy shores in the Kouilou area with poor, deep and highly 
filtering soil containing 5 to 8j6 clay and covered with short grasses and Annona 

- clayey savanna in the Niari and Bouenza valley, covered with shrub vegetation 
( Hymenooardia aoida. Annona arenaria, Bridelia ferruginea. Mauolea esoulenta) f 
oriss-crossed with gallery forests* The soils are clays, resulting from decalcifi- 
cation, rather poor in exchangeable bases and somewhat acid (pH: 4*7 to 5) but of 
good structure from the start; 

- 302 - 

- sandy savanna of the Pool and the Batifcfs plateau region, sparsely covered with 
shrubs and in spots with degraded gallery forests; the soils are poor sands 
containing a little organic matter, and are higjhly filtering* 


The tropical climate is characterised by moderate rainfall (from 1 200 to 1 TOO am), 
though with great fluctuations from one year to the next, and higfc atmospheric humidity 
that does not change much over the year* The rainy season runs from October to May, with 
short dry seasons of one month between 15 December and 1 March* The dry season is well 
marked and lasts for four months, from June to September* All this time there is no rain* 
The average annual temperature ranges from 24C to 26C (24.9 C in 1973 at Pointe-Noire). 

Table of Climatic Data 



( Point e-Hoi re) 

Km Rouge 





Altitude ( elevation) 

150 m 

80 m 

700 m 

Total annual rainfall 

1 150 mm 

1 318 mm 

1 513 mm 

Number of rainy days 




Average msrlmnm temperature of 
the hottest month 

27*0 April 

26* 9 March 

26.4 March 

Average "tin*"" 1 ? temperature of 
the coldest month 

22* (f July 

21.7 July 

21.6 July 

The topography is rather flat on all three types of savanna where the forest stations 

are located : 

Loandjilis coastal savanna at 100 m elevation, 

Loudima: savanna in the Niari valley at 150 m elevation, 

and Km Rouges savanna of the Batfkfs Plateau at TOO m elevation* 

Species of Euoalypts Used 

Eucalyptus 12 ABL 

This is a particularly excellent provenance derived from Eucalyptus teretioornis 
introduced in 1936 with seed from Madagascar* This species covers over 3 300 ha at Loudii 
and its growth on all forest sites is excellent* BuoaLvptus timber is fire resistant* 
Hinety- nine percent of the stems give off shoots* The main drawback of Eucalyptus 12 ABL 
is that it does not protect the soil well and is sensitive to competition of other 

- 303 - 

Eucalyptus platyphylla P1 

This is a hybrid, the mother stock of which was introduced into the Congo in 1957 
under the name 1. platyphylla of Java. Apparently the mother stock itself is a hybrid 
grophylla x'E. alba. The father stock is a euoalypt related to E. urophylla introduced 
under the name E. kirtoniana. This species gives higher yields than~the preceding one. 
All of the stems give off shoots. 

Eucalyptus saligna 

This was introduced very early at Loandjili (1953) using stock from South Africa, 
Madagascar and Brazil. However, it proved unsuited to ecological conditions along the 
Congo coast. One finds that the bark bursts, there is some gummatous tumor formation that 
causes death of the tree in most cases. 

Eucalyptus deglupta 

This species grows particularly well on the clayey heavy and wet soils of Loudiroa, but 
seems unsuitable for sandy savanna. 

Other Euoalypt s 

These are Eucalyptus urophylla, E. teretioornis, E. cloeziana, E. grand! e t E. 
citriodora, E. oalmadulensis, E. albaT E. urophylla, E. teretioornis, E. saligna and 
E. alba are now being used in propagation of hybrids. The hybrid E. saligna x 12 ABL has 
proved very promising and gives good yields. 

One of the most interesting species for the Congo seems to be E. urophylla. One trial 
with a few specimens of different provenance shows that at 2& years~of age at Pointe-tfoire 
and 1 year of age at Loudima average growth seems to be greater than that of E. platyphilla 
71 (provenance Portuguese Timor and the Sundra Islands). 



The fine seed of Eucalyptus is mixed with fine grains of sand before being sown to 
prevent them from being blown away by the wind. They are sown broadcast in irrigated beds 
at the beginning of September. 

The seedbeds at these stations in sandy areas are double-walled boxes, 300 x 70 cm, 
the space between the two walls forming the irrigation canal. 

The soil of these seedbeds is a mixture of 2/3 black earth and 1/3 sand (200 and 
100 litres), freed of insects by powdering with 25 g of 'dieldrin' or 'aldrin' per 

Rigit after having been sown, the seedbeds are covered with shades and are irrigated. 
Watering is begun immediately after sowing through the irrigation canals around the edges 
of the seedbed, the moisture content of the soil being kept constant in depth, combined 
with a system of indirect watering using a fine spray. The plants germinate about 8 days 
after the seed has been sown. 

Careful hand-weeding of the seedbeds is necessary. 

- 304 - 

Pricking out 

Four weeks after sowing, toward the end of September or the beginning of October, the 
plant* t which by then are about 5 cm tall, are pricked out with bare roots in polyethylene 
pots, 17 * 21 on in size on the average. These pots are filled with a sifted mixture of 
black earth and sand in the sane proportions as the soil in the seedbeds, to which is 
added 0.8kg of Thomas slag per m to ensure a good start* 

The pricked out plants are then placed in a storage area f 1 000 plants per board. 
Instructions regarding shade, watering and weeding must be followed meticulously up to 
planting time at the beginning of November, right at the start of the rainy season. A 
minimum of one week's cover is desirable. 

Ground Preparation 
Stump Removal 

In the bush savannas on clayey soil of the Niari (Nalolo) and Bouenza (Loudima) valleys 
stumps can be removed by machine y whereas on the sandy coastal savannas (Loandjili) and on 
the Batfkl Plateau (Km Rouge) it has to be done by hand labour. 

Mechanical extraction of stumps is done by two 70 hp caterpillar tractors with an old 
caterpillar chain tied between; both tractors pull at the same speed and the chain clears 
all brush as it moves across the ground. 

This work is done during the rainy season from December to Nay of the year preceding 
actual planting. 

The brush and tree stumps are stacked in piles. 
Destruction of Grass 

Grass has to be destroyed just before the dry season, in May. For this purpose one 
can use either a rail pulled by draught animals, an 80-hp wheel tractor, or a small cater- 
pillar tractor ( f chenillard 1 ) . This rail flattens the grass as it moves along; the grass 
is killed off by two passages of the tractor, first in one direction and then in the 


The flattened grass dries rapidly and then the piles of wood and the grass over the 
entire area to be worked are burnt. 

Breaking the Ground 

Two methods can be used to break the ground} ploughing with a plough, followed by 
disk ploughing; and hoeing ( of the main crop or cover crop) followed by disk ploughing. 

Planting and Management 
Peggings-out and Digging of Holes 

Ground that has been broken as described above is then marked out in small 50 x 50 m 
squares. Stakes are then set out at a spacing of either 2.50 x 2.50 m or 3.12 x 3*12 m. 
(With the heavy equipment, which is coming more and more into use, the 3.12 x 3*12 spacing 
is better.) 

- 305 - 

As soon as the stakes have been set out, holes are dug using semi-oiroular shovels* 
The holes should have a diameter of 20 on and also a depth of about 20 cm. The digging of 
the holes must be completed at the latest by October. 

Setting Out of the Plants 

In October, one month before planting, 150 g of fertilizer (complete, 10-10-20 ferti- 
lizer or potassium fertilizer) are applied to each hole in sandy soils. In the Bouenza and 
Niari valleys, there is no need for fertilizers. 

Starting at the beginning of November the plants are set in place. Before removal 
from the nursery, the plants are watered heavily and the polyethylene pots removed. By 
that time, the plants are from 10 to 25 cm in size. There is about a 98$ "take" and no 
need to fill in failed spots. 


A dusting of the holes with either 4$ Dieldrex or Phytosol prior to planting eliminates 
termites. To combat stem-cutting crickets in plantations, poisoned bait is applied 
(mixture of 1/3 flour, 2/3 bran with Dieldrin CE 20) . 


After planting, maintenance work has to be done. Initially this can be done by 
machinery - with either a stubble-plough ( scarifier) or a rotary plough ( rotavator) - at 
least three or four times during the first year after planting and once or twice during the 
second year. Manual weeding by hoeing around the plant completes the maintenance work each 
time the stubble-plough is used. 

Protection Against Fire 

Usually brush fires sweep across the savannas in about the month of June. They occur 
earlier on sandy savanna than on clayey savanna. 

Prevention of brush fires is accomplished by breaking up the 25 ha plots into 500 x 
500 m plots separated by 10 m wide firebreaks. These firebreaks have to be maintained 
regularly especially just before the start of the dry season in May and June. The bare 
firebreak strips around the sites or stations also have to be kept up at the same time. 
After the rail has been dragged across the ground, an early preventive and controlled 
burning of the bare firebreaks is done, prior to the start of the usual brush fires. 

Cutting of Stands - Rotation 

Eucalyptus is cut at the age of 4 to 6 years. The first rotation comprises the cut of 
fully grown trees derived from seed. At Loandjili, the rotation cycle takes from 7 to 10 
years and at Loudima, from 5 to 7 years. Theoretically this first cut is followed by two 
coppice cuts. 

Financial Information 

The average cost of one hectare of Eucalyptus was estimated in 1973 to amount to about 
95 000 CFA francs. 

- 306 - 

Results and Future Prospects 

In the People's Republic of the Congo 9 Eucalyptus stands cover almost 5 200 ha of 
savanna, the main speoies being the hybrids Eucalyptus 12 ABL and B. platyphylla (PP1) 

Volume increment is about 20 n^ /ha/year at Loandjili and 35 m^ /ha/year at Loudima for 
the higfc-yielding speoies y E. F71 Average annual increment in height is about 3*60 m at 
Loandjili and 4.60 m at Loudima. Annual growth in girth is 7.5 cm at Loandjili and ^ cm at 

Initial trials with propagation by cuttings installed since 1973 at tl 
earch station of Loandjili CPointe Noire) are particularly encouraging. 

Future Prospects 

Such propagation by cuttings is expected to give much higher productivity of stands as 
a result of both the intensity of selection of plus (+) trees for propagation purposes and 
due to the homogeneity of the stands (pure stands). It is believed that starting from very 
specialized silvi culture , adapted not merely to the species but to the clone, it will be 
possible to attain mean annual increments 40 m^ /ha/year at Loandjili - 30 nH /ha /year at 

Paper Pulp Project 

The aim of this project is to establish an ensemble of plants producing 230 000 tons 
of bleached pulp annually for the making of kraft paper. The raw materials for this paper 
plant would consist of a mixture of eucalypt and pine wood. 

Plantations to feed this paper plant would consist of 27 500 ha of Eucalyptus estab- 
lished at the rate of 5 300 ha per year, and 22 000 ha of pine established at the rate of 
2 200 ha per year. 

Charcoal Making Project 

This project calls for the cutting of approximately 630 ha of Eucalyptus per year for 
the making of 10 000 tons of charcoal for export. 

Speoies of Pine Used 

Both Firms oaribaea and P. oooarpa were introduced into the Congo in 1958 after the 
Eucalyptus. They have proven~entirely satisfactory and well suited to local ecological 
conditions. Other species tried were P. kesiya t P. merkueii, P. hondurensis. 


Germination beds are prepared starting at the beginning of May. These are actually 
3*00 x 0.70 m boxes filled with a mixture of -fr black earth and i sand to which fertilizers 
have been applied. The seed is sown in these boxes between 15 May and the end of June, in 
rows, using a plank with screw nuts for alignment and spacing of the seed (1x1 cm) 
After sowing, the boxes are covered with a layer of chopped pine needles. They are left 
open and not irrigated, but watered frequently. Weeding has to be done continuously. 

- 307 - 


Germination occurs within about a week. Six weeks after owing, the plants already 
reach a heigit of 1 cm and are then pricked out into polyethylene pots filled with a mixture 
of sand and black earth containing fungi (myoorrhiza) , the earth being obtained from old 
pine plantation*. It is absolutely necessary to use complete fertilizers (10-10-20) when 
prickings-out the plants. 

In pricking-out | care has to be taken to keep the taproot straight by enclosing it in 
a pellet of liquid mud. Subsequently, the instructions regarding applications of fertilizer, 
watering and weeding have to be followed carefully. 

Soil Preparation 
This is the same as for eucalypts. 

Planting and Management 

This is the same as for euoalypts. 

The technique is the same as that used for euoalypts. During the first year mechanical 
and manual maintenance work has to be done 3 to 4 times, in the second year at least 2 to 
3 times, in the third year twice, and once again in the fourth year. 

Fire Control 

Again brush fire control here calls for the division of the area into small 6.23 na 
plots. Four such plots are grouped together (making 25 ha in all) and between each set 
10 m wide, bare firebreaks are opened. Between each set of four plots (25 ha in all) there 
is laid out a peripheral firebreak, usually consisting of Eucalyptus t ore 1 liana* 

Management of the Stand; Pruning and Thinning 

Tropical pines can be used for two purposes: either for making paper pulp or for 
lumber. In the first instance, no thinning will be done. In the second case, once a 
plantation has been set out with trees at a spacing of 2.5 * 2.5 or 3*12 x 3.12 m, it is 
absolutely essential that when the trees are 4 or 5 years old they be thinned out. 

In both oases pruning with a lumberjack's saw is necessary when the stands reach 4 or 
5 years of age. 

For the production of paper pulp, the rotation cycle is from 10 to 11 years, whereas 
it is from 20 to 25 years for the production of lumber. 

Results and Future Prospects 

M&n-oade pine stands already cover almost 2 600 ha in the People's Republic of the 
Congo. The increment is from 8 to 10 m 3 /ha/year at Pointe-IToire and from 15 to 20 m3/ha/ 
year at Loudima for rapid growth tropical pines that adapt well. 

-308 - 

Future Prospects 

Plan* for genetic improvement and tested seed orchards started in 1975 should make it 
possible to increase the production of these species. 


The Congo's Development Plan includes industrial planting of pine and euoalypts on 
the savannas to feed a factory with an annual capacity of 230 000 tons. About 22 000 ha 
are to be planted to pine at an annual rate of 2 200 ha* 

Finally y steps are being taken to set out plantations of Arauoaria hunsteinii and 
A. OH*!*!* nghMH i t trials with which have shown them to be promising species capable of 
producing excellent timber on savanna* 

Table 1 


Tear of 


LOUDIMA (Bouenza) 

MALOLO tNiari) 

KM ROUGE (B/city) 

































































































































































Total for the 

savannas 7878.78 hectares, pines - 2652.32 hectares, Eucalyptus - 5226.46 hectares 

- 309 - 


A* Yawo Komla 

Forestry Department 

Bolgatanga, Ghana 



Introduction 399 

Staffing 310 

Afforestation and reforestation 310 

Savanna nursery practice ^-j-j 

Establishment techniques for savanna plantations 311 


Ghana has an area of 23d 539 square kilometers and lies between longitudes 1 East and 
3 West and latitudes 5 and 11 North. The current population is estimated at 10 million* 

The country has a tropical climate which ranges from humid to dry, the southern portion 
receiving the greatest amount of rainfall* 

There are four main vegetation zones: the coastal strand with mangrove swamps, 
followed by a narrow belt of thicket, the high forest, and the savanna zone* The high 
forest covers approximately an area of 82 258 square kilometers or 34*48$ of the country, 
while the savanna covers 150 497 square kilometers or 63.09$, the remaining 2.43$ being 
taken by the strand, mangrove swamps and thicket* 

There exists a written National Forest Policy which has as its main objective the 
creation of sufficient permanent forest resources by reservation to supply direct and 
indirect benefits necessary for the welfare of the people of Ghana and the management of 
the forest resources by methods that achieve sustained maximum productivity and value* The 
other objectives of the forest policy include research into all branches of scientific 
forestry, emphasis being laid on silviculture, ecology and utilisation; the training of 
both professional and field staff and the provision of technical advice to non-Government 

In order to implement the forest policy successfully, a Forests Ordinance was passed 
on the 30 Haroh 1927, and in 1949 the Trees and Timber Ordinance was passed* Under the 
powers conferred on the Governor, later President of Republic, a number of regulations were 
made and a series of acts were also passed* Among the regulations are the Forests 
( Si Ivi cultural Works) Regulations, 1958; the Trees and Timber, Property Marks Regulations 
1950; the Trees and Timber (Control of Cutting) Regulations 1958; the Trees and Timber 

- 310 - 

(Measurement) Regulations 1958; the Trees and Timber (Control of measurement) Regulations 
I960} and the Trees and Timber (Control of Export of logs) Regulations 1961* Acts passed 
under the Forest Ordinance to give effect to the forest policy include the Protected Timber 
Lands Aot, 1959; the Forest Offences (Compounding of Fines) Act 1959 and the Forest 
Improvement Fund Aot 1960, to mention a few* 

In Ghana the bulk of the land (high forest or savanna) is held in trust for the stools 
(chiefs and people) by Government* The portion of land under purely state control is 
exceedingly small* 

The principal forest products from the high forest zone are sawlogs , veneer logs, logs 
for sleepers, charcoal, poles and export logs, and in the savanna zone, poles, charcoal 
and gum* 


There exists a Forestry Training School in Ghana which turns out sub-professional 
officers who are mainly field officers* In the past years the intake of students was small 
but recently with the inception of the reforestation scheme, the intake has been appreciably 

The current serving sub-professional staff number 500. The number of serving pro- 
fessional officers now stands at 22, the bulk of them having been lost to the educational 
institutions! the research institutions and industry* 

The gross annual budget for forestry for the financial year 1975/76 amounted to 
US$7 501 774* Babodied in this amount are the recurrent expenditure, reforestation 
expenditure (development) and forest improvement expenditure. 


As a result of the massive exploitation of timber from the high forest and the 
increased requirement of timber and timber products in the savanna areas, a decision was 
taken in 1972 to plant certain areas both in the high forest and savanna zones* Up to the 
end of 1974, the total area of plantation for the whole country stood at 23 208 ha. Out 
of this total 9 3 330*8 ha have been planted in the savanna zone* The planned annual 
target area of afforestation and reforestation is 7 328 ha, of which 2 176 are for the 
savanna area* The reforestation/afforestation schemes are controlled by the state, there 
being virtually no private forestry organizations in Ghana. 

The species currently being planted in the savanna zone include teak ( Teotona grandis) 
mahogany (Khaya senegalensis) Gmelina arborea, Anogeissus leiooarpus t neem (Azadiraohta 
indioa) and Dalbergia sissoo. The growth rate varies for the various species 
in the different parts of the savanna zone. In areas where the savanna borders on the high 
forest and where rainfall and soil conditions are favourable, and where teak is the main 
species being planted, the intended end use is lumber. In areas where the soil and rain- 
fall conditions are not so favourable, teak, Anogeissus, neem and Dalbergia are grown 
mainly for poles and firewood. The Gmelina is intended for pulp. For most of the species, 
no rotation has been fixed. It is estimated however that in 60 - 70 years the teak may 
reach sizes capable of being sawn. Species grown mainly for firewood and poles are ready 
for use between 10 and 15 years. 

- 311 - 

Savanna Nursery Practice 

The selection of permanent nursery sites in the savanna area is limited mainly by the 
availability of water. In the past, deep wells were dug and the water from these wells was 
used to water. the plants* In recent years however emphasis is being shifted onto irrigated 
nurseries. The irrigated nurseries are situated near dams. Water from the dams is brought 
to the plants either through pipes driven through the earth work of the dam or through 

The total annual nursery stock production capacity of the permanent savanna nurseries 
is in the neighbourhood of three million plants. Figures are however not readily available 
for actual annual production, as the records are not up to date. The types of planting 
stock vary according to the species. Teak and Anogeissus are stumped before planting. 
Khaya and neem are planted either as striplings or as potted plants. In recent years, most 
of the seedlings are raised in polythene bags which measure 5" ^y 7" or approximately 
13 cm by 18 cm. Seedlings are normally transplanted after they have attained an average 
height of between 30 - 45 om. This height is attained between 24 - 30 weeks. 

The methods used in savanna nurseries are: 

a} Broad-casting on germination beds 

b) Bed sowing (single or in drills) 

c) Direct sowing into containers (polythene bags). 

Seeds broad- cast onto germination beds include teak, neem and mahogany. Pricking-out 
is carried out as soon as germination starts. These species may also be bed sown, or sown 
direct into containers. Species with tiny seeds e.g. Anogeissus are sown into drills and 
thinned out when germination is completed. Seeds, whether they have been broad-cast on 
germination beds or sown into containers, are watered profusely twice daily early in the 
morning and late in the evening. Watering continues after germination, and in the absence 
of rainfall until the plants attain a suitable size for planting. No direct watering is 
carried out in the irrigated nurseries. 

Shade is always necessary to protect the young seedlings from the heat of the sun. 
Grass mats raised on poles provide adequate protection. 

Nurseries in the savanna zones are often disturbed by domestic animals. In such oases, 
strand-toarbed wire fences are erreoted to keep the animals out. There have not been many 
complaints about insect attack. The termite attacks which have been reported were treated 
by Aldrex 40* 

Establishment Techniques for Savanna Plantations 

In the savanna zone, the grass burns invariably during the dry season. In many cases, 
the burning is quite thorougi and the few trees left standing are stumped. After stumping, 
a two disc plough is used to make ridges on which the young trees are planted. S pacings 
commonly used are 3 V x 9 1 or 6 1 x 9 f , approximately 1mx2mor2rax3m. 

Little direct sowing is practised. 

No severe insect attacks in savanna plantations have been recorded. Fire, however, 
poses a serious threat, several plantations being affected each year. It is suspected that 
most of the fires in the plantations are deliberately set, as measures are always taken at 
the beginning of the dry season to forestall the out-break of fire. Some of the measures 
adopted to forestall fire out-break include the maintenance of internal and external fire 
traces and early burnings which are carried out around the plantations. 

- 312 - 

At the height of the dry season, twenty four hour fire patrol* are organized* Forest 
guards and labourers are detailed to keep watoh, detect and control fires before they get 
out of hand* In sosie oases y these patrols have been very effective and in one particular 
instance no fires were reported in the plantation for a period of 10 years* 

I I