Q.630.7 116c no. 1041 cop. 5

UNIVERSITY OF ILL AT URBANA-CHAMPAIGN ixICULTU

The person ^g?*j£\£$££ly ta» KfitS* wiSdr^on or before the

which it was w Kelow.

la,es. Dote stamped bow ^

•* -ssr-s s^r— - "•"•'•"' ,r,m

for disciplmory «"«■

the University. /.-_ter 333-8400

T„ renew cCTeiephone Cente. 3 URBAN^HAMFAIC*

L161_O-1096

Digitized by the Internet Archive

in 2011 with funding from

University of Illinois Urbana-Champaign

http://www.archive.org/details/productivityinde1041fehr

CIRCULATING COPY

LIBRARY

UNIVERSITY OF ILLINOIS AT URBANA- CHAMPAIGN COLLEGE OF AGRICULTURE COOPERATIVE EXTENSION SERVICE CIRCULAR 1041

CIRCULATING COPY

AGRICULTURE LIBRARY

PRODUCTIVITY INDEXES OF SOIL ASSOCIATIONS IN ILLINOIS

Developing productivity indexes at both basic- and high-management levels for the soil associations of Illinois allows ready comparison of the productivity of the general soil regions of the state. The difference between the basic- and high-management level indexes shows the responsiveness of a soil region to management. This infor- mation is useful in formulating public policies of land use and management, and in broad economic planning for efficient utilization of our soil resources.

Information from two sources was used to derive the productivity indexes (PI) for each soil association shown on the general soil map of Illinois published in Bulletin 725, "Soils of Illinois." These sources were Circular 1016. "Productivity of Illinois Soils," and Bulletin 735, "Soil Types and Acreages for Illinois."

Circular 1016 discusses productivity of individual soil types in the state and the factors affecting soil productiv- ity, and defines basic- and high-management levels. Bul- letin 735 gives the acreages of the various soil types in Illinois, summarized by slope and erosion conditions from the national Conservation Needs Inventor)'. These acre- ages exclude 2.9 million acres (about 8 percent) of the state that is in urban and built-up areas, federal land not leased for crops, and water areas.

Productivity indexes for each soil type were calculated for the slope and erosion combinations shown on page 12 of Circular 1016. These indexes were then weighted by the acreage of each mapping unit to obtain an average productivity index for each soil type in the state. In calculating the average productivity index for a given soil association, the average indexes of each soil type were weighted by their acreage in that association. The acreage of a few widely distributed soils was propor- tioned among the several soil associations in which these soils occur.

The basic- and high-management level productivity in- dexes for the various soil associations are given in the fol- lowing table. The soil associations are ranked according to the high-management productivity index. Average pro- ductivity indexes at the two levels of management, weighted by the acreages of the various soil associations, are given for the state and for the five soil groups shown in Figure 1. The table also gives the differences between

the two productivity indexes for each soil association, and for the three soil groups shown in Figure 2.

It should be remembered that the productivity indexes are estimates. The crop yields used in the calculation are based on longtime average yields for several benchmark soils on the Illinois agronomy experiment fields, and the acreages of the various soil types are based on a 2-percent mapping sample.

In general, the basic-management level includes inade- quate fertilization, plant populations, and erosion control practices, only partial drainage, and frequently a lack of timeliness in weed and insect control and tillage opera- tions. The high-management level includes high-input levels of those management practices based on present technology that are believed necessary for maximum profit.

In the preparation of Figure 1, soil association W, which includes a wide range of outwash soils, was pro- portioned into groups I, II, and III. Figure 1 shows the ranges in productivity indexes at both the basic- and high- management levels for groups I, II, III, IV, and V.

The differences between the high- and basic-manaji - rnent productivity indexes shown in the table indicate the degree of responsiveness of the soils in the various asso- ciations to management. In Figure 2 the soils are grouped into three classes — high response, medium response, and low response to management.

In general, the soils that were under a prairie vegeta- tion when Illinois was settled are in the most responsive soil group. The forested soils and those that are sandy oi shallow to gravel are intermediate in responsiveness, and those areas that contain a high proportion of soils that are shallow to bedrock are least responsive. The high pro- portion of rolling and eroded soils in the forested soil areas partially accounts for the fact that the average productivity of these associations is lower than that of the prairie soil areas. Within any soil association there may be a rather wide range in productivity among the various soil types present. Input costs needed to achieve high-level productivity differ among the various soil associations. and are not necessarily related to their responsiveness to management.

This circular was prepared by J. B. Fehrenbacher, R. T. Hendrickson, J. D. Alexander, and W. R. Oschwald, all of the Department of Agronomy.

Productivity Indexes and Response to Management of Soil Associations in Illinois

c7 Productivity indexes—

High Basic Difference

/ , , manage- manage- or

Soil associations— Total acres— ment ment response

Group I, Fig. 1; High response (H), Fig. 2

B Sidell-Catlin-Flanagan-Drummer 2,405,700 151 97 54

A Joy-Tama-Muscatine-Ipava-Sable 4,287,600 148 94 54

I LaRose-Saybrook-Lisbon 1,034,300 139 89 50

W Littleton-Proctor-Plano-Camden-Hurst-Ginat . . . 3,644,100 134 86 48

Total acreage and average PI of Group I . . . . 11,371,700 143 92

Group II, Fig. 1; High response (H), Fig. 2

J Elliott-Ashkum-Andres 1,279,000 130 81 49

D Harrison-Herrick-Virden 1,022,200 128 80 48

C Wenona-Rutland-Streator 90,700 127 82 45

Z Lawson-Beaucoup-Darwin-Haymond-Belknap 3,831,200 124 77 47

H Ringwood-Griswold-Durand 102,500 116 71 45

Total acreage and average PI of Group II . . . . 6,325,600 126 78 Group III, Fig. 1; High response (H), Fig. 2

K Swygert-Bryce-Clarence-Rowe 592,800 114 66 48

E Oconee-Cowden-Piasa 601,500 114 64 50

F Hoyleton-Cisne-Huey 1,751,000 112 59 53

TOTAL ACREAGE WITH HIGH RESPONSE 20,642,600

AVERAGE OF HIGH RESPONSE (H) , FIG .2 50

Group III, Fig. 1; Medium response (M), Fig. 2

M Birkbeck-Ward-Russell 478,700 105 61 44

G Warsaw-Carmi-Rodman 170,500 102 67 35

L Seaton-Fayette-Stronghurst 1,811,000 100 60 40

N Clary-Clinton-Keomah 2,128,200 95 57 38

Y Morley-Blount-Beecher-Eylar (Nappanee) 390,500 95 52 43

0 Stookey-Alford-Muren 491,500 91 53 38

X Hagener (Sparta) -Ridgeville-Bloomf ield-Alvin . . 980,800 91 55 36

Total acreage and average PI of Group III. . . 9,396,500 102 59 Group IV, Fig. 1; Medium response (M), Fig. 2

U Strawn-Miami 423,000 90 49 41

P Hosmer-S toy -Weir 1,435,400 87 45 42

Q Ava-Bluford-Wynoose 2,449,500 86 43 43

T McHenry-Lapeer-Pecatonica 335,800 84 48 36

S Fox-Homer-Casco 73,000 82 47 35

Total acreage and average PI of Group IV . . . 4,716,700 86 45

TOTAL ACREAGE WITH MEDIUM RESPONSE 11,167,900

AVERAGE OF MEDIUM RESPONSE (M) , FIG. 2 40

Group V, Fig. 1; Low response (L), Fig. 2

Y Channahon-Dodgeville-Dubuque-Derinda 597,400 62 35 27

R Grantsburg-Robbs-Wellston 455,200 55 25 30

Total acreage and average PI of Group V. . . . 1,052,600 59 31

TOTAL ACREAGE WITH LOW RESPONSE 1,052,600

AVERAGE OF LOW RESPONSE (L) , FIG. 2 28

TOTAL ACREAGE AND AVERAGES FOR THE STATE 32,863,100 117 71 46

From General Soil Map of Illinois, Bulletin 725, "Soils of Illinois."

' Acreages exclude about 2.9 million acres of the state in urban areas, water, and some federal land.

All indexes for soil associations are weighted by soil type acreages, and the average indexes of soil groups (I, II, III, high response, medium response, etc.) are weighted by soil-association acreages.

Fig. i. _ Soils Grouped By Productivity Indexes at Basic- and High-Management Levels.

CD

SOIL PRODUCTIVITY INDEXES

GROUP BASIC HIGH

86-100 133-151

71-85 115-132

51-70 36-50 21-35

91-114 73-90 55-72

Fig. 2. — Soils Grouped By High, Medium and Low Response to Management.

1 H 1 High -difference 45-54

Medium-difference 35-44 Low -difference 25-34

Issued in furtherance of Cooperative Extension Work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agricul- ture. JOHN B. CLAAR, Director, Cooperative Extension Service, University of Illinois at Urbana-Champaign. (8M — 8-71 — 18885)