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VERTICAL
FARMING

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GILBERT ELLIS BAILEY, A.M.«E.M.,Ph.D.

PROF. OF GEOLOGY
UNIVERSITY OF SOUTHERN CALIFORNIA

COPYRIGHT, 1915

E. I. DU PONT DE NEMOURS POWDER CO.

WILMINGTON, DELAWARE

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VERTICAL FARMING

PART I

The Origin and Character of Soils

Soils Are Rock Waste. — Soils were not originally a part of
the earth's surface, but have been formed slowly by the crum-
bling and breaking up of the surface rocks into fine particles,
such as clay and sand. Sometimes this breaking up occurred
where the soils are now found, and the character of the soil is
governed by the kind of rock that was left on the surface,
while in other cases the rocks and the soil that came from them
have been carried thousands of miles and mixed with other
material, forming a conglomerate mixture from many sources.
The highland and mountain soils in this country have, as a rule,
been formed very near the places where they are now found,
while the soils in the larger valleys, and along most of the
coast line, have resulted from material washed down from the
hills and deposited along the level stretches near the sea.
Much of the soil of the more northern states has been brought
down from Canada by the movement of ice along the surface.

This breaking down of the rocks and formation and moving
of the soil has taken a long time; but this work is yet going
on, and the exposed rocks, boulders and ledges in our fields and
mountains are yearly being attacked by the different forces,
and are slowly yielding up material to help replenish the older
soil. Different natural and artificial processes are also going
on in the soils that may either improve or injure them. Most
of these processes can be controlled by man and made to be his
servant, so that he can become a great factor in the formation
of profitable soil.

2 S^\:lA>^'&irttA^ FARMING

The breaking down of the original rocks has been accom-
pHshed by very simple means, the action of which has been very
powerful.

Work of the Atmosphere. — Everyone knows how a piece of
iron is attacked and falls into a powdery iron dust, which is
nothing but iron combined with oxygen taken from the air to
form a different substance called iron oxide. The oxygen,
carbon dioxide and other gases of the air attack the iron, lime
and other elements in the rocks, forming new substances and
causing the particles to fall apart, as is the case of the iron

u. s. G. s.

EFFECT OF WIND ACTION ON ROCKS

rusting. Rocks are also carved, eroded and worn away by the
cutting and sawing action of the wind, especially when it carries
with it any considerable amount of dust or sharp sand particles.
In this way large rocks are sometimes entirely worn away. In
some localities in this country the sand is swept across the level

VERTICAL FARMING 3

stretches so severely as to smooth off the rough places on brick
walls, and to scar the glass in windows.

U. S. G. S.

L[ME STONE AFTER EROSION

The Part Played by Water. — Much rock material is slowly
dissolved out and carried away by rain water. This is usually
carried long distances before being thrown back into a solid
state by the evaporation of the water, or by coming into con-
tact with some other substance that causes it to be precipitated.
Often this reforms into another rock that may be harder than
the original one.

A much greater effect of water, however, is in the formation
of ice, which expands and acts as a powerful wedge in splitting
off small fragments. You will often notice along the foot of a
cliff, or at the base of a large rock, a mass of small splinters of
stone that have been pried off the parent rock in this way.
Running water also slowly wears away even the hardest rocks,
reducing their close material into finer particles.

ENTRANCE TO THE GARDEN OF THE GODS
A BEAUTIFUL EXAMPLE OF EROSION

RUNNING WATER SLOWLY WEARING AWAY HARD ROCK

VERTICAL FARMING 5

Glaciation. — During the glacial age vast sheets of ice, carry-
ing with them boulders and everything else that was movable,
passed over much of the United States and Canada, and ground

BOULDERS WORN SMOOTH BY GLACIAL ACTION

up the rocks into soil. Large areas of the richest soils were
formed in this way. Smaller movements of ice occurred in
the valleys of the Northwest and resulted in the formation of
some wonderful soil areas there. These movements of ice
leveled down the rough surfaces of mountain ranges and
scoured out wide valleys.

Variations of Heat and Cold. — The variations of tem-
perature from day to night and from summer to winter have
also been busy in grinding out soil meal. When it is warm
the rocks expand slowly, and contract under lower temper-
atures. The different minerals in the rocks expand and con-
tract unequally, causing cracking which flakes off the outside
of the rock and permits of its being attacked much more easily
by other agents of destruction, or perhaps, better said, of
creation. The effect of these changes of temperature are more
noticed in some of the higher and drier regions where the hot
evening gives way quickly to cold night. It has been reported
that this action is at times so violent as to split large pebbles in
half so quickly that a noticeable report, like the bursting of a
percussion cap, is made.

VERTICAL FARMING

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ROOTS OF TREE WIDENING A CRACK IN A ROCK. WHEN GIVEN

FISSURES TO GROW THROUGH ROOTS WILL PENETRATE HARD

MATERIAL TO GREAT DEPTHS

Plants Render Assistance. — Just as soon as a little powder
is formed from the rocks by the action of these agencies, minute
plants, some of which can be seen only by means of a micro-
scope, fasten on the rock meal and begin to grow. As they
mature and die, their tiny bodies add the first organic matter
to the newly formed soil and help prepare it for larger and
more vigorous plants. The study of this action is very inter-
esting,' and a short search into any stony place will reveal many
examples. Mats of short moss will be found growing on what
seem absolutely dead and impervious stone. Trees can be
found sending their roots into the smallest fissures in the rocks
and bursting them wider. It is a hard life for these plants,
and their growth is slow and stunted, but it is one of their
missions in nature and they go on with the heavy work, giving
to man at the same time a wonderful revelation of what he can

VERTICAL FARMING 7

accomplish in the way of improvement by giving cultivated
trees and smaller plants a suitable place to grow, rather than
force them to combat all the adversities of a resistant soil.

Animals Help. — Tiny worms and bugs soon begin to burrow
into the weaker points of the rocks, and as the work goes on
much larger cousins follow them. Their action is to open
channels through which water can reach more effectively the
harder rock within. They also do large amounts of grinding
and mixing on their own part. Their excretions and their dead
bodies add more organic matter to the soil and help pave the
way for a good garden or a fruitful field.

U. S.G.S.

SOIL GROUND AND MIXED BY ANTS

Each Force Helps the Others. — These forces in their slow
work of grinding up the rocks into earth meal do not work
separately, but each helps the other. When one worker has
opened a way into the rock, his success is immediately fol-
lowed by activities on the part of the others. The roots and
worms open channels to permit the entrance of more water,
which may mean more freezing and more cracking, and there is
more room for roots, An expansion crack works the same
way. The pits made in the face of the rock by the action of
the air make suitable homes for the mosses and other plants.
It is a big job, and the work is accomplished only by all hands
keeping busy.

VERTICAL FARMING

The Formation of Humus. — The rocl<: powder or meal does
not of itself make a desirable soil, and other matter must be
added. Microscopic plants must flourish to help in the work of
crop production ; water must be present, and as a rule, the more
humus the better the crops. This humus is not a strange sort
of stuff at all, as it is only rotten trash from dead plants or
animals. Mention has already been made of how its first start
is made. This is later augmented by the growth of larger
plants which have more leaves, twigs and roots to rot. In
increasing the amount of humus in a soil the work of man,
when intelligently applied, can be made to do wonders.

^^"^^^^«i^^?-

GREEN MANURE CROP FOR INCREASING HUMUS

How Soils are Moved. — After the agencies just described
have ground out the rock powder, nature keeps right on at
work in moving and sorting out the soil particles. This work
is done by the action of :

Gravity. — The soils formed on the mountains and cliffs fall
to the base forming a heap of debris which is called '' tallus."
Where the slope is steep, this falling is immediate ; but where
the land is more level, the movement is slower and is more of a
slide than a fall. Gravity is ever at- work moving soils from
high to low levels.

VERTICAL FARMING

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US.GS.

THE MOVEMENT OF SOIL FORMING MATERIAL BY GRAVITY.

Water. — Every drop of water that falls on the earth can
move a particle of soil at least a little distance. These drops
of rain run together to form rivulets, each with its little load
of soil. Rivulets meet to form streams, and these join to form
creeks, and the creeks unite to form rivers. A creek or river
in flood-time is a stream of soil moving down from the factory
to be spread out over distant valleys and plains, or to fill up the
bottom of the sea so that it can finally be used by man to grow
food and raiment.

Glaciers. — The great sheets of ice that have already been
described moved great distances, and carried with them large
amounts of soil and soil material. Some of them moved from
Canada into what is now the United States, and brought fertile
material far within our borders to make some of the richest
land in the world.

Winds. — The housekeeper knows how fast dust accumu-
lates over everything, and how it thickens on furniture and
carpets if left undisturbed for even a short time. The winds

VERTICAL FARMING 11

have been busy, not for days but for centuries untold, picking
up soils in one place and dropping them in another — sorting
and arranging them until it is probable that any given section
of land anywhere contains particles contributed by every other
section in that district.

Residual Soils. — Not all soils are moved in these ways. In
places, sometimes large, sometimes small, the original rocks of
the locality have weathered down into soils that remain just
where they were formed. These are known as " residual soils,"
and embrace a great variety, some of which are fertile, while
others are not so well favored. The proportion of residual soils
to transported soils varies greatly in the different parts of the
v/orld.

Some of the Physical Characteristics of Soils. — Soils have
a number of marked physical characteristics, some of which are
of interest only to the exact scientist, but many of these char-
acteristics are of the greatest interest to the poorest farmer.
The greatest advances made in the Science of the New Agri-
culture have been due to the study of these physical character-
istics of soils, and the application of the discoveries along this
line have tended toward a better and more profitable agriculture.

Soil Texture. — One of the most noticeable differences in
soils is the variations in the size of the grains of rock powder of
which they are made. The fineness of a soil is spoken of as its
" texture." The sizes of grains most discussed and best under-
stood both by the student and farmer are: clay, silt, sand,
and gravel. It is well known that sand, loam, and clay soils
will not raise the same crops equally well. There are good
reasons for this. In a sandy soil the particles are relatively
large and do not pack so closely together. No matter how
tightly packed a soil may be, there are always small openings
and cavities between the particles. These are called " pores."
The sandy soils do not pack so closely together as do the clays,
and the pores are therefore larger and permit a much easier
movement of water and air in the soil. The clay soils pack
more closely together and reduce the size of the pores so that

12 VERTICAL FARMING

both the water and air move more slowly. The silts and loams
are intermediate between the sands and the clays. Loam soils
are made up of mixtures of fine and coarse soil particles. If
the loam carries a large percentage of sand it is known as a
sandy loam; if the clay particles predominate in amount, it is
known as a clay loam. The presence of gravel among the other
particles materially affects the texture of a soil and often the
fertility as well. When a considerable amount of these particles
are present in a loam soil it is usually called a gravelly loam, the
difference in clay and sand being maintained as before. The
intermediate textures, such as fine sandy loam, silt loam, and
the lighter clay loams are usually considered the best, as they
tend to be light, well drained and easily cultivated.

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COMPARATIVE SIZES OF SAND AND CLAY PARTICLES ( ENLARGED)

When the percentage of fine gravel and coarse sand is high,
the soil is likely to be too loose, too easily drained, and not
likely to withstand drought well. Such a soil, especially in the
rainy regions, is likely to be deficient in one or more of the
chemical elements needed for the production of plants. Where
the percentage of fine silt and clay is high, the soil is likely to
be cold, heavy, and sour. Such a soil, unless well tilled to con-
siderable depths, resists the ready movement of air and moist-
ure.

Soil Structure. — Another important physical characteristic
of soils is the way the particles arrange themselves as they lie
in the field. A coarse sand is found to have every particle
lying separate, and alone with no attachment to the particles
which it touches, unless they are cemented together by excesses
of lime or similar substances. The clay in a path will be found

VERTICAL FARMING 13

to have its particles arranged in much the same way as the sand,
with the important exception that each is pressed close to its
neighbor and bound there by cohesion, by adhesion, by some
other substance present, by interlocking corners of the parti-
cles, or by other means. When such a soil is disturbed it does
not fall apart like sand, but remains in close, hard lumps or
clods. In these soils we have the extremes of structure — the
open structure, or the individual grain and the dense structure
or arrangement of the pubbled soil. A well-
tilled plat of clay or loam will be found to
have an entirely different structure. Here
the fine particles of clay, silt and sand are
bound together in little groups or crumbs.
These crumbs or granules can be easily de-
tected by picking up a handful of the soil and
gently breaking it apart. These crumbs diagram of soil
lie close against other crumbs, but unless granules
poorly handled in cultivating they do not be-
come sealed together. This is the ideal structure of a soil, and it
is toward the formation of such graimles that we should direct
our attention, especially in the heavier soils. When such a soil
is cultivated wet, the pressing action of the plow or harrow
tends to force the particles closer together and to form the
undesired puddled structure; but if the moisture content is just
right, the same plowing will tend to make the granulation still
better. Additions of humus material, and, on some soils, of
lime, help also.

Such a crumb structure in a soil brings about most of the
benefits and advantages of both a sand and a clay. It drains
well, and because of its open structure warms up well in the
spring. The openness permits easy and good plowing. The
fine particles absorb and hold the large amount of water needed
for the crop, and if properly cultivated to preserve this moist-
ure, will tide heavy crops over longer periods of rainless times.
Another great advantage of the crumb or open structure of
clay and loam soils is that they allow the roots to grow quickly
to great depths. This affords the plant a much larger amount

14

VERTICAL FARMING

of soil from which to draw moisture and food, and consequently
yields heavier crops. In another paper the good effects of this
open structure on beneficial bacteria will be pointed out.

Hardpan and Plow Soil. — Another soil structure that needs
attention is hardpan. Sometimes this is simply the tight pud-
dled clay that has already been described; and sometimes it is
clay, silt or sand that has been cemented together by some
chemical or mineral substance in the soil, or by the soil particles
themselves being so tightly pressed together that they prevent
the movement of water and air, and retard the growth of roots.
One kind of hardpan is called plow sole, and is found just at
the bottom of the plowed furrow where the slide of the plow
has been for years packing down the soil just where it needs to

; OP£N SOIL -no \
MEDIUM depth'-

COMMON TYPES OF HARI3PAN

be opened. The relief from such conditions is found in deep
cultivation that will crack the material to pieces and permit
good drainage where it is bad. This breaking must, of course,
be deep enough to reach the seat of the trouble. Any adverse
conditions, such as an excess of alkali or a lack of lime, should
be immediately corrected.

Soils and Subsoils. — By soil we mean the surface as con-
trasted with the lower stratum of subsoil. Ordinarily they have
come from the same source, and at times are so much alike that
it is hard to distinguish between them. This is particularly
true in the semi-arid regions, and in the deep aluvial belts.
Usually there is a difference in texture, structure, and color.
The soil has been well weathered and has undergone changes

VERTICAL FARMING 15

that will permit the giving up of its mineral plant foods to the
roots of plants. These changes have gone on more slowly in
the stiffer subsoils, and much of the mineral substances have
not been acted upon sufficiently by the air and by bacteria to
give up the needed foods. Deep cultivation and the use of
explosives open up these soils to the action of the air and other
agencies so that these foods may be prepared for the roots, and
increased fertility and greater returns in crops are the result.

Soil Areas, Series, and Names. — The soils of the United
States are classified into thirteen subdivisions called " Soil
Provinces," or regions, according to the essential geographic
features, such as the Atlantic and Gulf Coastal Plains Province,
the Appalachian Mountain and Plateau Province, the Great
Plains Region, the Arid Southwest Region, and the Pacific
Coast Region. The soils of a province are classified in soil
series. The soils in a series have the same range of color, same
general character of subsoil, a common or similar origin, about
the same structure, and broadly, the same type of relief and
drainage. The soil series are divided into individual soils, which
generally receive local names, as : Portsmouth Sandy Loam,
which is found in several states from Delaware to Mississippi ;
Vermont Silt Loam, of Kansas and Texas ; and the San Joaquin
Fine Sandy Loam, of the Pacific Region. A soil class includes
all the soils having the same texture, and are called: sands,
loams, clays, fine sandy loams, clay loams, clay loam adobe, or
such other combination of descriptive words as best fits the
peculiarity of the soil.

Maps of the soil surveys of the various provinces, and
descriptions of the series and individual soils of the surveyed
areas will be found in the annual reports of the U. S. Bureau
of Soils, and may be consulted at the larger public libraries ; or
if a particular county has been mapped, the report on it can be
gotten from the U. S. Department of Agriculture.

Chemistry of the Soil. — While it is true that the productive-
ness of a soil depends more on its physical character and con-
dition than upon its chemical composition, yet the chemical ele-

16 VERTICAL FARMING

ments are of great importance and must be taken into consider-
ation. Many chemical elements are needed for the production
of a plant, but it is seldom, with tlie exception of potash, lime,
phosphorus, or nitrogen, that any of these is not present in
sufficient amounts. All of these except the last named occur in
many rocks, and are therefore found in the soils in varying
amounts. When, on a particular soil, one or more of these is
absent or deficient, it is necessary to add it in some form of
fertilizer or manure.

The soil particles may not be weathered enough to make these
minerals available, or there may be little in the surface soil and
more in the subsoil. In either case the soil is improved and
the plant food brought within the reach of the crop by breaking
and stirring up the land with explosives.

Fertilization and Chemical Correction. — In addition to the
proper physical condition, it is necessary to have the chemical
condition of a soil well regulated in order that we may get the
proper returns from our labor. Some foods may need to be
added to the soil, or it may be essential that a harmful sub-
stance be removed or neutralized. This work will be considered
in a following chapter.

VERTICAL FARMING 17

QUESTIONS

1. Describe the formation of one type of soil not made from

rock particles.

2. Does the action of the air always soften freshly exposed

rocks ?

3. Name the forces that have been most effective in forming

the soils in your vicinity.

4. By what agencies have your soils been moved?

5. Is the typical soil of your farm finer or coarser than the

underlying subsoil ?

6. Can a mixture of coarse sand and clay become as tightly

compacted as a dense clay?

7. What, in detail, are the processes in the formation of plow

sole on your typical soils ?

8. Why are arid soils less troubled with shortages of plant food

than humid soils ?

9. What physical characteristic of your soils lends itself most

readily to improvement ?

THE RESULT OF GOOD DRAINAGE, GOOD AERATION AND
PLENTY OF PLANT FOOD

VERTICAL FARMING

PART II

Fertilizers and the Chemical Properties
of the Soil

HOW PLANTS FEED

The fertility of a soil is its ability to produce crops. It is
not one condition, or two or three conditions, but the sum of all
conditions. It does not consist simply in hauling manures or
buying chemicals. It means that the water, air, temperature,
soil bacteria, tilth, and plant food or soil solution exist in the
right conditions and proper balance as well as in proper amount.
It is possible for seed to sprout, the crop to grow and ripen, and
the yield to be the best only when all these conditions are ful-
filled. Mere richness in mineral foods avails nothing if water
is lacking to maintain a large amount of soil solution for the
roots to absorb. The plant food may be there but may not be
soluble and cannot be absorbed. It may be soluble, but in a
form distasteful to and therefore rejected by the roots.

All soils, even those considered poor, contain vast amounts
of plant food that is not naturally available, but which can be
converted into an available form. In such a case the problem
is one of condition and not one of total content. A worn out
soil is often only an unsanitary one and can be rebuilt to a high
state of productivity by proper cultural methods.

Chemical Properties of the Soil. — While hundreds of min-
erals are known to science, only a few are used in nature in
forming the common rock from which most soils are derived.
The more important of these to the farmer are potash, phos-

20

VERTICAL FARMING

phorus, and lime, as these are at times deficient or else appear
to be deficient. Such elements as iron, aluminum, and silica
may be ignored, as they are nearly always present in sufficient
quantity to more than supply any demand made on them.

For most agricultural conditions it is almost imperative that
the soil be not acid. The chief corrective for a sour condition
is lime, which is usually present in sufficient amounts for a
food, but in many soils is needed to overcome the sour condi-
tions produced by vegetable decay or bad drainage. It may be
added in several dififerent forms. At present, carbonate of
lime or finely ground limestone or marble dust is largely used
for this purpose. This form is preferred by many on account
of there being no danger of trouble from an over-application.
Hydrated lime is also largely used, as is rock or quick lime. In

Courtesy Charles ll'cniier Co.

MAMMOTH LIME KILN

VERTICAL FARMING

21

using the last named form, care must be exercised to prevent a
heavy appHcation from burning the organic matter or humus
out of the soil. Ground or burned sea shells are also extensively
used and make an excellent form of agricultural lime. Gypsum
is used under certain conditions. Lime also has a material
effect on the structure of the soil, especially when it has a
tendency to be sour, by causing it to granulate better, thereby
increasing its power to absorb and hold water. Especially in
the east and southeast the use of lime is imperative for the best
success .in growing alfalfa and certain other legumes. The
cow pea seems to resist a sour condition in the soil remarkably
well. Lime also helps somewhat to liberate potash from resist-
ant minerals. Salt is sometimes used for the same purpose.
The growth of nitrogen fixing bacteria is greatly stimulated
when lime is added to make up any deficiency that may exist in
the natural soil.

Potash is a highly essential plant food. It exists naturally in
most soils and in some of them is found in large amounts. In
some soils, notably coastal plains sands, it is present in but

SHIP DISCHARGING CARGO OF EXPENSIVE FERTILIZERS

22 VERTICAL FARMING

small amounts and must be added artificially. Considerable
amounts are found in natural manures, but the great supply is
imported into this country from Germany.

Phosphorus is also present in most normal soils, but the per-
centage is small in some of the most valuable soil provinces of
the country so that it must be added artificially. Large amounts
of phosphate rock are mined in this country. The rock may be
ground and added to the soil in the form of a fine powder, pro-
vided the soil has a good supply of organic matter. If this
organic matter is deficient and the soils are thin, the best results
are reported from the use of acid phosphate which is the phos-
phate rock after it has been treated with sulphuric acid. Large
amounts of phosphorus are used in the form of slag and bone
products. The United States is more than self-sustaining in
the supply of phosphates and export large amounts annually.

Another of the important elements is nitrogen, which is found
in the form of nitrates in some of the desert regions. In this
form it is very soluble and is washed out of the soil by rains. It
is found in normal agricultural soils in varying amounts, but is
often in too small quantities. Commercially it is obtained from
fish and packing house scrap, from cotton seed, from nitrate of
soda imported from Chili, and from the air. Nitrogen is a gas
and makes up the larger part of the air, from which it may be
taken in large amounts by certain bacteria growing on the roots
of legumes and by other microscopic plants working alone.
Further mention will be made of this later.

How Plants Feed. — Plants feed by absorption through the
roots and by inhaling the air. When a plant is burned, most
of its weight is lost in the form of gases and but a small part
is left as ash. The ash contains the mineral matter which came
originally from the breaking up of the soil minerals, or was
added as a fertilizer. The rest, or the part that was lost in the
gas is made up of carbon, hydrogen, oxygen, and nitrogen. The
carbon is taken in through the leaves from the carbonic acid gas
of the air. The hydrogen and the rest of the oxygen are taken
in through the roots in the form of water, and the nitrogen is

VERTICAL FARMING

23

derived from the soil where it may have accumulated from arti-
ficial supplies, from the action of bacteria, or from the decay
of organic matter. The relative amounts of these elements
demanded by different plants varies considerably, as some re-
quire a large supply of one food element while others can grow
well with much less of it.

Only the root hairs, the most delicate
part of the root system, can absorb foods.
These are tiny threads growing out from
the roots just back of the tiny feelers or
root tips that thrust themselves through the
soil. The walls of these root hairs are
very thin and absorb the soil solution direct
as they lie in close touch with the soil par-
ticles covered with their thin coat of '' Min-
eral Soup." These dissolved mineral foods
then pass on into the circulating system of
the plants as sap, and are carried up to the
leaves. The sap in conjunction with the
carbonic acid taken in by the leaves then
forms the starch, sugar and similar com-
pounds of the plant and the excess of water
is lost through the leaves. The amount of
water evaporated in this way is enormous.
It has been found on experimentation that
it requires from 200 to more than 600 pounds
of water, passing through a plant in this
way, to make one pound of dry crop.
These large amounts of evaporated water
show how necessary it is to keep the soil in
such a condition that it will absorb the maximum amount of
rainfall and hold it to supply the growing crop. It is also
necessary that these tiny root hairs, that are so small that it
would take 300 or more laid side by side to cover an inch in
width, be able to creep and grow always deeper and further
into the soil, unhindered by impacted soil, hardpan, or other
obstructions.

ROOT HAIRS

24 VERTICAL FARMING

The roots do not reach down to all of the water they use.
Some of it is pumped up to them as oil rises in a lamp wick, by
capillary action. This rise is much faster in well granulated
soils than in hardpan or tight clay. It is evident, therefore,
that no method of cultivation can reach down deep enough to
overcome the difficulties of feeding roots except blasting the
subsoil with explosives.

Unavailable Plant Foods. — Attention has already been
called to the large amounts of mineral plant food bound up in
insoluble minerals, and to the enormous amount of the highest
priced plant food (nitrogen) that is present in the air but not
directly available to the field crops as food. The changes that
some of these must undergo in order that they can nourish the
roots are chemically very complex, but, in the practice of the
art of farming, can be well controlled. The nitrogen must be
combined with oxygen. This change is most effectively brought
about by a certain group of bacteria which grows in knots on
the roots of peas, beans, clovers, alfalfa, and kindred plants.
They breathe in the free nitrogen gas and combine it with other
elements in such a way that large amounts are fixed and held
in the soil in a combined form that is very nourishing to suc-
ceeding crops and also to the crop with which they grow. Other
forms of organisms accomplish the same purpose, working
without the assistance of the leguminous associates. Both forms
require certain well defined conditions in which to work. Each
of these is so essential that it would be hard to name the more
important one. The soil must be well drained so that there is
no clogging up of the soil pores with water, but at the same time
the soil must be moist. The soils must also be warm, for the
activities of these wonderful little farmers' aids are retarded if
stopped by frost. Large supplies of air are equally essential.
As most of these conditions attend a deep tilled soil, it might be
said that the beneficial bacteria of the soil are all deep tillage
enthusiasts. They are found at considerable depths in the
porous types of soil, but cannot live much below the surface in
tight clays and hardpan. They also keep busy on insoluble

VERTICAL FARMING

25

THE DEEPER PLANT FOOD MIGHT JUST AS WELL BE IN EUROPE FOR
ALL THE ATTENTION THAT IS USUALLY GIVEN IT

26 VERTICAL FARMING

forms of combined nitrogen that may be added to the soil, and
convert it into usable forms.

Soil changes also materially affect the availability of phos-
phate material. In nature it is always combined in slowly
soluble compounds. In commercial fertilizers it is usually com-
bined with lime. Different relations in the amount of lime to
the phosphorus effect the solubility of the phosphorus. In
badly drained land the phosphorus is often found combined
with iron in little balls of " bog ore " that are very insoluble.
Many other examples of combinations of plant foods could be
brought out going further to show how the air, water and
bacteria assist the changes. In every case the benefits brought
about demand deep stirring of the soil, such as is produced by
exploding small charges of slow powders in the subsoil and
opening a way for the liberators of plant food. No other
practical method can bring about the desired results.

Deficient Plant Food. — If the rocks from which a soil is
derived are deficient in any needed food, it becomes imperative
sooner or later to add some material that will make up the
deficiency. The original and best general fertilizing material
is manure, as it adds not only certain amounts of plant food,
but also large amounts of humus. Forest mould, litter, straw,
and other materials of like nature add some of the fertilizing
elements and also humus. The number of materials that may
be used to add plant food is great. Some materials carry but
one needed element, while others carry two or three. There can
be no general rule promulgated to guide in choosing fertilizers,
as different soils and different crops demand certain chemicals
in different forms.

Soil Amendment or Correction. — Some soils well supplied
with mineral and organic plant foods have some trouble, such
as sourness or an excess of alkali. Materials not classed as
foods are used in the correction of such conditions. These
materials are generally known as ** Soil Amendments." In the
correction of black alkali, gypsum is added to change the sodium
carbonate to a less harmful compound which can more readily
be leached out.

VERTICAL FARMING 27

The other great amendment is lime, the chief use of which
has been described in the correction of sour or acid soils.

Use What You Already Have. — From the foregoing we see
that there are supplies of practically afl the plant foods in
normal soils, and that additions of fertilizing materials, while
absolutely essential in some cases, are expensive. Some of the
foods already in the soil are not in the form needed by the plant,
but can be changed into usable forms by properly controlled
natural agencies. The agencies needed for these changes are
always at their best under certain soil conditions. For the
different changes the conditions are identical — a moist but
well drained soil, an abundant supply of air in the soil, the pres-
ence of more or less humus, and a suitable temperature. To
obtain most of these is easy, when we consider only the soil, as
it can be done with a plow, but the surface is not half of the
farm — we want to use several feet of depth
for a good reservoir for moisture, a factory
to rework and prepare the foods, and a good
home for the roots. This naturally de-
mands that the clay or hardpan be broken
up. The plow cannot sret down to the ^^^ ^^ , ^._,.

^ ^ ^ SECTION BREATH-

trouble and there is but one other agent that ,^,^ ^„^ _„ , ^

^ . ING PORE OF A LEAF

can do the work— a reliable low-freezmg (greatly enlarged)
explosive.

Making Fertilizers More Effective. —

Heavy applications of fertilizers to force
bumper crops are attended with certain
dangers. If everything goes along all right,

,^u • , 1^ r ' , ' SURFACE VIEW OF

and there is always plenty of moisture to
dissolve the fertilizers and prevent the
soil solution from becoming too rich, the desired results will in
all probability follow. In most regions where such fertilization
is practised, such constant supplies of soil moisture are not
always to be relied upon. The result is that when the young
plants get vigorously started on their nourishing ration and
then meet a season of drouth they are " scorched " or " burned "

28 VERTICAL FARMING

by the too concentrated food, and are left in worse shape than if
there had been no f ertiHzation and they had been forced to draw
all their food from the soil minerals.

Even where the conditions are normal rather than extreme,
the increased growth caused by the fertilizer calls for a greater
supply of moisture to support the enormous loss through evapo-
ration from the leaves, and the fertilizer has in no way met
the increased demand for the water. The correction for either
condition is simply the prevention of excessive amounts of the
water being lost by drainage and holding it stored in a deep
tilled, open subsoil. A tight subsoil will not absorb and hold
the moisture in this way and needs the welcome relief of a
small amount of well placed explosive to shatter and open the
soil, so that it can meet the demands for more water.

QUESTIONS

1. Name in full the conditions necessary for heavy yields of

your money crop.

2. What fertilizing material is lacking in your soil, and in what

form would you supply the deficiency ?

3. Do the large brace and tap roots of plants absorb plant food

from the soil ? What is their duty ?

4. Will a large tree draw most of its food from the ground

immediately around the stump or from the soil further
away ?

5. What is the source of the most used chemical fertilizer in

your community, and how is it prepared before being
offered for sale?

6. What eflfect has lime on clover on your farm? On wheat?

How can you prove your statement ?

7. Which shows wilt first during a season of slight rainfall, a

heavy or light crop ? Why ?

VERTICAL FARMING

PART III

Soil Moisture
ITS CONTROL AND CONSERVATION

Crops must have sufficient amounts of water at the right
time. The greatest demand for water is often during the
season of least supply. The water must come from the feeding
zone of the roots within the soil. No phase of agriculture is of
more importance or worthy of more study than how to main-
tain an adequate supply of soil moisture. A soil may be rich
In plant food and not have water enough to dissolve it and carry
it to the plant roots. Nothing reduces the fertility of the soil
and the yields of farm crops in the United States annually more
than the lack of a proper supply of water at the season when
the crops demand it. The rainfall may be deficient or too
unevenly distributed so that the farmer is forced to store water
somewhere and in some way. There are few sections of the
country where this is not necessary ; where there is rain enough
during the growing season to water the crops. They must draw
their supplies from reservoirs that are above or below ground,
and the best of all is utilizing the soil itself as a reservoir.

Soil Water as a Plant Food. — All vegetable matter consists
largely of hydrogen and oxygen, which elements are obtained
from the soil water and combined with other elements in the
plant itself. These combinations of the water forming elements,
together with a small amount of carbon from the air, form by
far the greater weight of domestic plants even when they are
thoroughly dried. Tt is the water used as food that makes up

30

VERTICAL FARMING

GOOD TOP AND ROOTS POSSIBLE ONLY ON
A WELL DRAINED SOIL

VERTICAL FARMING 31

the greater part of all the starch, sugar and other similar com-
pounds so valuable, in that they form one of the essential parts
of the foods for men and lower animals.

Water as a Carrier of Plant Food. — ^AU of the plant foods
in the soil have first to be dissolved in water and then carried
by it to and through the roots and up to the above ground parts
of the plant. The tiny feeding roots must be immersed in the
thin film of water that clings to the soil particles. The soil
solution is absorbed into the rootlets through their walls and
forced upward with a considerable pressure. This can easily
be noticed by cutting off a rank growing weed and watching
how quickly the sap is thrown up over the newly cut stump.
This pressure is often several pounds per square inch. All the
water that is not combined in the plant as a part of it is thrown
out through the leaves, this process being called " transpira-
tion."

If the moisture conditions of the soil are good and water is
abundant, transpiration is encour.iged and there is an attending
satisfactory growth of crop ; but if the conditions are reversed,
the plant growth is immediately stunted by the deficiency in the
amount of the essential water.

Amounts Necessary for Crops. — Taking crops altogether,
from rice to date palms, the amount of water required varies
from complete submergence to almost perpetual drouth, and
within this range crops vary widely as to the amount necessary
for living. As a rule the amount is large, as it is only the desert
plants that thrive on a scant supply. Take a small potted plant
and place it under a glass jar and notice how soon the jar is
clouded by the water vapor taken up from the soil and given
off through the leaves. From 200 to 600 pounds of water are
transpired by ordinary crops for every pound of dry matter
produced, but this varies with each crop according to the
climate and other factors affecting it.

A good yield of pea vine hay will draw 1200 to 1500 tons of
water through its roots and stems and liberate it in the air. Corn
and cane drew equally heavily upon the soil supply of moisture.

32 V ERTICAL FARM I N G

The water required by a field of any of the ordinary field cro])S,
if spread over the surface, would cover it to a depth of sever^il
inches, sometimes as much as a foot or more. This is only the
water used by the plant itself, and does not include the amount
that is lost by being evaporated or that passing too deep into the
soil to be drawn back to the roots. In addition, a plant cannot
take all of the moisture out of the soil in the range of its roots.
In irrigated districts the amount of water applied to and
absorbed by the soil* often reaches an amount equal to three
feet, and in some localities more.

This water used by the plant or lost by evaporation from the
soil during rainless days must all come from the soil, and shows
what care must be exercised in storing and holding all that is
possible.

Water and Soil Temperature. — A uniform soil temperature
is essential to the best growth of crops, and a soil properly sup-
plied with moisture will change its temperature very slowly,
while a dry, parched soil will quickly heat up during the day and
cool off again as rapidly at night, and the crops will suffer
accordingly. Coarse soils retain only a relatively small amount
of moisture and are warm and early. Fine soils, like the clays,
retain much more water and are cooler and later in the spring.

Storing Water. — Where irrigation is practised, reservoirs
are used to store and hold water, but in most of the states this
method is inadvisable. The best place to store the water for
use in time of drouth is in the soil itself, by converting the sub-
soil of every acre into its own reservoir. This large storage
may be assisted and encouraged in several ways. The first thing
to do is to be sure to get the rain water down into the soil
instead of allowing it to be wasted by running off on the sur-
face, because it cannot enter a hard or impacted soil readily, if
at all. Such soils may be found to be dry even after a heavy
rain. In '' dry farming," and also in farming where the rainfall
is heavier, some practise rough plowing before the seasons of
heavy rain to increase the absorption of rain water, and later
harrow or drag the surface to form a mulch and prevent loss

VERTICAL FARMING

33

U. S. Rec. Service
IRRIGATION DAM-

-THE EXPENSIVE METHOD OF STORING WATER
FOR PLANTS

through evaporation. Where this practice has been carefully
followed, good has resulted, but ordinarily the depth to which
plowing is possible is insufficient to reach the zone of the great-
est trouble. Others have gone further and plowed deeper, using
heavy tractors with subsoil plows. The results obtained have
been variable, and it is quite evident that the efforts along this
line, while well conceived and of benefit, have fallen short of
their mark by not disturbing the soil to a sufficient depth.

In most cases of resistant soils, the trouble is at a considerable
depth, in fact, below the depth that could possibly be reached
by any form of plow. For relief then, there is nothing prac-
ticable but a rational use of a subsoiling explosive. This, like
the subsoil plow, is used when the subsoil is dry, so that the
force of the explosion will shatter and pulverize the subsoil
rather than pack it into a more impervious mass. Usually this
is in the late summer and early fall, when the plants have

34

VERTICAL FARMING

pumped all of the available water out of the soil. This season
is followed by the fall and the winter rains which can then
find their way deep into the cracks and fissures where they are
absorbed and held indefinitely if proper care is given to the sur-
face. The heavy rains following such a shattering of the sub-
soil have the additional advantage of resettling any parts of
the soil where the explosion may have opened it up too much.
In the spring and summer following such a soil treatment, the
young roots find an easy path into the deeper soil, where they
can continue to draw their full ration of water from the stored
supply and thus nourish the crop during long seasons of drouth.

SUBSOIL SHATTERED BY A BLAST THE CHEAP WAY OF STORING

WATER FOR PLANTS.

Excesses of Water Must be Drained Away. — Field plants
will not grow in a soil saturated with water. An ample supply
is necessary and must be maintained, but a great deal depends
on how the supply is kept up, or in other words, on the moisture
condition. Land animals require water to drink, but perish if
immersed in it, for the air necessary for their existence is then
shut off. Plant roots die if the soil is saturated with water
because their air is cut off. Fortunately, soil will hold only a
certain amount of moisture if the water is free to move, the
excess gravitating downward and draining away. This is
called gravity of free water. The gravity water sinks until met
and checked by impervious material or reaches standing water ;
that is the water table. Unless such free water sinks too deep,
it is not entirely lost to the plant, as it not only sinks through
gravity, but is also brought back to higher levels, when the top
soil begins to dry, by capillary attraction, just as water climbs

VERTICAL FARMING

35

up a piece of cloth, one end of which is allowed to hang in water.
This capillary water is the water that supplies the immediate
demands of the plant. Some of the water collects on the surface
of each soil particle and sticks to it with a peculiar force, form-
ing a film over the soil grain. This *' Film Water " is very
important, for the force that holds it so closely to the grains
enables it to dissolve the mineral plant foods in the particle and
prepare them for absorption by the roots.

Air Must Circulate in the Soil. — The air in the soil is as
essential to plant growth as the air above the soil. This soil
atmosphere below the surface is heavier than the air above, and
contains more carbon dioxide and similar compounds than our
atmosphere. These gases are absorbed into the soil water and
become a part of the attacking force that liberates the mineral
foods from the dense minerals. The nitrogen supply of the

CYPRESS ROOTS THROW UP KNEES THROUGH WHICH TO

BREATHE. FIELD CROPS CANNOT DO THIS SO THE

EXCESS OF MOISTURE MUST BE DRAINED AWAY

36 . VERTICAL FARMING

legumes is also' drawn from the soil air. This air circulates
through voids or pores which are stopped up by excesses of
free water that cannot drain away. Such a condition stops
the actions just described, and must be guarded against by
keeping free water drained away from the active feeding zone
of the roots. When the water table is within the reach of the
deeper roots, small feeders are sent down to or near the water
surface and drawn from the moister soil there.

Cultivation and Yields. — The easiest soil to plow or cultivate
is one that has all excesses of free water drained away, and has
dried a little so that it will crumble rather than break in lumps.
A wet, soggy soil is not only hard to cultivate, but the very act
of working it injures instead of being a benefit. The air is
worked out, and the air spaces themselves are closed by the
process, and the granulation is destroyed. A very dry soil
breaks up cloddy, and the condition produced by plowing it
when it is in this condition is sometimes nearly as bad as if it
had been plowed wet. The proper storage of capillary moisture
by good cultivation is the only safeguard to maintaining the
proper tilth of the soil and to prevent ptiddling or the forma-
tion of clods.

The aim of the farmer is to produce crops at a profit. Water
is the cheapest article he has to handle, and is at the same time
one that allows itself to be handled almost at will, but becomes
a serious drawback if allowed to take its own way. It must be
there as a food and a carrier of other foods, as a control of
the temperature of the soil, and to insure the proper granu-
lation of the soil. Everything that can be done to the soil in the
way of getting rid of excesses of free water and holding the
maximum of capillary water will make itself known in the
increased yields it aflfords.

Erosion. — Erosion or washing steals plant food. If bad, it
takes the whole of the surface soil away. An excess of water
often causes damage by erosion. In addition to taking away
valuable plant food and the cultivated top soil, erosion leaves
the fields cut up and rough and exposes material that requires

VERTICAL FARMING

37

U. S. D. A.

A BADLY ERODED HILL

much effort and long exposure to weathering before the plant
food reaches a satisfactory state of availability. Gentle, slow
rains are always preferable, because they have more time to
soak into the soil, but as the intensity of rainfall is beyond the
control of the farmer, he must fortify his soil against attacks
of erosion due to heavy precipitation or large amounts of rain-
fall in a short time. The answer is to get the water down into
the soil before it can run off. It is a difficult matter to do this in
a big wash, where thousands of barrels of watier are coming
down, but these large washes are started by little trickles of
only a few spoonfuls further up the hill. These little trickles
start because the soil is too tight for the water to enter. The
surface ma}^ be sealed over by a little crust or there may be
plow sole, tight clay, or hardpan deeper down which limits the
soils absorption to the immediate surface. The correction of
such conditions prevents the wasting of the valuable soil into the
drainage courses. The surface crust can be destroyed with
even the lightest tools, and a deep shattering by blasting will
open up the subsoil so that it will be able to absorb hundred of
gallons of water, where before it took but sparingly.

38

VERTICAL FARMING

CU'mson College S. C. Bulletin

EXPENSIVE TERRACING TO PREVENT EROSION

Drainage. — Attention has already been called to the neces-
sity of removing all excesses of free v^^ater. Where such
excesses are caused, as they so frequently are, by the water
being held on or near the surface by hardpan or other imper-
vious material below^, the trouble may be overcome by breaking
through the holding material into more open material belov^.
The full extent of the possibilities of this method of drainage
have not yet been developed, and it is quite likely that many of
the upland sw^amps will later be entirely controlled by this
method.

A more rapid development of the larger swamp areas has
been retarded on account of the great expense of ditch digging
by hand or by the machines suitable for digging under such
conditions. Again, a rational use of dynamite has answered
the question, for it has been absolutely proven by experimenta-
tion and practical application on large and small drainage areas
that ditches can be quickly, economically and satisfactorily
excavated by blasting. The wet soils of the swamps and over-
flowed regions have made digging by hand expensive on account
of the difficulties encountered by the labor, but swamp water has
no terror for the swift cutting action of a high power dynamite
that will rip open a long stretch of large or small ditch at one
efifort. Such a blast not only opens the ditch, but levels down

VERTICAL FARMING

39

the harmful spoil pile. or bank, scattering the dirt over the
adjoining land for a distance of over a hundred feet.

A BEAL ilFLL liLASitU DliCH

Ditch blasting is by no means limited to wet lands, for it is
being successfully used in excavating even in dry hill soil, pro-
vided it is not sandy. Changes in the soil or the soil condition
require changes in the selection of the explosive and the method
of loading, which are details that can best be learned from the
books of practical instruction of the manufacturer or from one
of their representatives.

The use of blasting in connection with drainage is not limited
to the shattering of deep drainage courses to permit of down-
ward drainage, but is being used largely in connection with
open and blind ditches where the subsoil is so hard that it pre-
vents the passage of the water into ihe drainage channels.

40 VERTICAL FARMING

Thorough subsoil blasting opens up these subsoils and permits
the drains to collect and carry away the water that has rendered
the fields worthless.

Dynamite and farm powders are also being used to control
old-established gullies or washes. The banks are shot down
into the bottom of the gully so that teams can be driven across
to plow the banks down to the desired level. This shattering
also loosens deeply and increases the immediate absorption of
water and benefits further by holding out of the surface drain-
age much of the water that before increased the run off and
attending erosion.

QUESTIONS

1. What is the amount of the annual rainfall in your part of the

state ?

2. How is this distributed during the year?

3. Which of your crops suffer most from lack of water ? Why?

4. Describe your ideal method of storing water on your farm

for the use of crops?

5. What have been your experiences with deep plowing?

6. What is your method of controlling erosion, and what results

have you obtained?

7. What modifications in your practice of controlling erosion

do you think necessary?

8. Describe an ideal plan for the general drainage of your

farm, that will include the control of the hill water as well
as that of the bottoms.

9. What is the best method of correcting a small stream that

has a crooked, shallow bed?

VERTICAL FARMING

PART IV

Soil Bacteria

The most constantly active part of the soil is its bacterial life.
These are tiny little plants that are very close to the border line
of being animals, and are known by a number of popular and
slang names. They are the smallest known living organisms.
Some are so small that 50,000 of them lying side by side would
not measure over an inch, and a single drop of blood or milk
would form a desirable tenement for thousands to live in and
multiply. They reproduce very rapidly, usually in from 15 to
45 minutes. If unchecked, a single bacterium could multiply
to 17,000,000 in 24 hours. This reproduction is seriously
checked by lack of room, insufficient food and unfavorable sur-
roundings, such as. lack of air or too much water for some
and the reverse for others. They are also checked in their
development by the presence of their own excreta. They form
spores for their reproduction and for preservation and distribu-
tion. In the spore stage they can live over long periods of con-
ditions unfavorable for their growth and reproduction, and
then begin their work again when conditions are favorable.
The total number of bacteria is inconceivable, for they are in
the air, water, soil, and everywhere.

Some of them are harmful, and their development should be
checked, while others are so helpful to mankind that every effort
should be made to encourage their growth. The different
forms require widely different conditions for their best growth.
One class thrives in an abundant supply of air, and are called
" aerobic." Another form, " anaerobic," get their oxygen from

42

VERTICAL FARMING

different forms of bacteria
(greatly enlarged)

breaking down compounds containing this element and thriv.e
best in places that are not well ventilated. The first named

form includes the beneficial
forms of soil organisms, while
those of the second class are
usually harmful. The very
cultivation and aeration of the
soil, therefore, promotes the
growth of the beneficial forms
and checks the activities of the
harmful ones. The deeper the
soil is loose and well a-erated,
the deeper the helpful forms
are found.

Harmful Bacteria. — Some
forms of bacteria produce de-
structive diseases in the plants,
both in the tops and branches and in the roots. The greatest
trouble from bacteria in the soil, however, comes from the
forms that attack the nitrogen carrying foods and cause the
nitrogen to be unlocked from its combined form and to escape
as gas. These forms thrive best in wet and packed soil,
where they cause the organic substances to undergo a waste-
ful putrefaction rather than a beneficial decay. Their ac-
tivities are at once checked by the presence of free air. Some
crops grown continuously on the same soil for a long time
cause it to become filled with forms that cause diseases in the
roots. Generally these can be destroyed by a rotation of
crops attended with deep tillage.

" In short the control of harmful soil organism is accom-
plished by thorough drainage and good, deep cultivation. Many
of them seem to thrive best in sour soils which can be made
sweet and desirable for the beneficial forms by additions of lime.

Beneficial Organisms. — Bacterial action is beneficial to
agriculture in many ways. As soon as a plant or animal dies,
the influences that have restrained the action of the organisms
of decay are removed and the bacteria at once begin breaking

VERTICAL FARMING

43

down the complex organic substances into forms that are
again suitable for plant food. In this way they are the health
patrol, the scavengers of the soil. Some forms have the power
of liberating food from the insoluble mineral soil grains and
are the fairy chemists whose laboratory is the surface of the
soil particles. These soil builders have already been described
elsewhere is these articles.

In fact there are millions of these tiny forms that are eager
and willing to assist the farmer and gardener if given proper
soil atmosphere, proper soil moisture, and proper soil temper-
ature.

Nitrogen Fixing Bacteria. — Attention has been called to the
likelihood of a deficiency of nitrogen in the soil and the high
cost of replenishing the supply through the use of expensive
fertilizing materials. Certain of the air-loving bacteria form
little colonies, called nodules, on the roots of leguminous plants
and take the free gaseous nitrogen of the soil air and tie it up
in compounds that furnish the nitrogen fertilizer to the higher
forms of plants. These
bacteria do not thrive in
either a wet or a sour soil,
and are not found naturally
in the soils of many parts
of the country. They can
be planted or started in
such soils by the use of
certain commercial cul-
tures, or by additions of
soil in which they are
known to be present. Abun-
dant supplies of these bac-
teria are necessary in the
soil before it is possible to
get a good growth of the
most beneficial legumes

without robbing the soil of nodules on roots of a

the supply of nitrogen al- legume

44

VERTICAL FARMING

ready present in a properly combined form. Even in soils rich in
nitrogen the growth of these crops is materially benefited by the
presence of the bacteria.

Other forms of bacteria and kindred plants of microscopic
size have the power of gathering bacteria from the soil air and
their development should also be encouraged. These forms are
not so well known as those that produce the nodules on the
roots, but their benefits are marked. They demand a well
drained and well aerated soil.

Helping a Friend Along. — Aside from the nodule forming
bacteria, most of the other beneficial forms are found in all
normal soils. It is not necessary to add them in artificial cult-
ures, but their activities can be materially increased by keeping
them in suitable surroundings and supplying their constant but
simple desires. These forms get their oxygen from the air,
and must therefore not be closed, up in a tightly sealed soil.
They do not thrive in the deep subsoil unless it is well aerated.
Large excesses of water that clog up the pores of the soil also

SWAMP CONDITIONS OR EXCESSIVE AMOUNTS OF WATER SEAL
THE SURFACE AND STOP BENEFICIAL BACTERIAL ACTION

VERTICAL FARMING

45

exclude the air and smother out the good forms, but permit the
harmful bacteria to grow at will. While too much water is
bad for them, too little water also retards their work. A good
moist soil, just about what the plants want, is their favorite
— in short, a well drained soil. Most of them need a supply of
organic matter, such as partly decayed plants or animals. This
is also just what the plants want. Another one of their desires
is for even tempered soil, where the changes are not too sudden
from hot to cold. Here again they agree absolutely with the
plants. In fact the beneficial bacteria and plants seem to be
such good friends and neighbors that anything that benefits one
equally benefits the other, and if one feels sick, the other wants
the doctor also.

In keeping up the bacterial activities care in turning under
green manures or additions of litter or manure is always repaid
many fold. These additions of humus forming material also
assist greatly in maintaining the needed moisture supply as
humus has a wonderful power of absorbing and holding water
and also assists in granulating the soil.

More About Nitrogen. — Free nitrogen is everywhere. The
air over a single acre contains about 75,000,000 pounds of this
peculiar element. To buy a pound will cost from 15 to 20 cents.

TWO SOURCES OF NITROGEN
HOME TRAPPED BY LEGUMES BOUGHT AT GREAT COST

46 VERTICAL FARMING

The farmer, through his good Httle friends, the " bugs," traps
and stores this in his soil, provided he goes about it in a business-
Hke way.

This way is simple. Prepare the soil for the best content of
moisture and air, and see that it is not sour. Be sure that the
right bacteria are present, and then grow deep rooted legumes
that suit the locality best. Selections of legumes can be made
for practically any purpose. Some of them yield the most
nutritious hay, while others furnish grain that is good for food
for both man and all kinds of farm animals. Others furnish
excellent pasture. Some are best suited for soil building in the
shape of green manure.

The deeper the preparation of the soil the better the results
that are obtained. A few inches of loose soil will give just so
much room for these activities. A few inches more will be of
benefit, but the desired production cannot be reached until the
air-loving bacteria and the deep-rooted plants have several feet
of good mellow soil in which to operate. The only satisfactory
method of effecting such deep tillage is by blasting.

48 VERTICAL FARMING

QUESTIONS

1. Are the changes due to the rotting of a plant or animal under

water the same as rotting in the air ?

2. What are the most noticeable differences you have detected

in the two kinds of rotting?

3. What are five beneficial effects of bacteria on the farm?

4. What are five harmful effects of bacteria on the farm?

5. How would you prepare a bottom having a cold, wet subsoil,

and drained by a deep open ditch, for growing ordinary
field crops?

6. How would you prepare a tight hillside subsoil, low in lime,

for growing alfalfa?

VERTICAL FARMING

PART V

The Movement of Moisture and the
Feeding Zone of Roots

The movement of moisture in the soil is of the utmost impor-
tance to plants. It is first necessary that the water received
from rain or irrigation should move downward through the
soil, leaving behind only such as is held by capillary attraction.
The excess should move out of the soil and into the drainage.
This movement of moisture is entirely one of gravity. Water
moving in this way is called " free water."

Movement of Water by Gravity. — In order to get the water
down into the subsoil and prevent its running away as surface
drainage, or standing on the surface and stopping all possi-
bilities of air circulation through the soil pores, it is essential
that it move downward very soon after it is deposited on the
surface. This movement depends on the openness of the soil.
Sometimes in a sandy soil the water soaks into the soil too
rapidly and too much drains away, but such is not the case with
clay and other dense soils. In such soils the pores are naturally
small and the water is held back. The movement can be
hastened by tilling or stirring the soil to the depth to which it
is desirable to carry the water. The deeper this can be made
effective the better, and so it is very apparent that soils where
the water is likely to stand on the surface are in need of the
deepest practical tillage. As the free water clogs the pores and
stops many of the soil processes, the plants do not draw their
moisture from it, but get it instead from the smaller capillary
supply left behind.

50

VERTICAL FARMING

Movement of Capillary Water. — The capillary or film move-
ment of moisture takes place in all directions, but its most
important direction is upward. When tight soils prevent the
downward percolation of free water, some is carried downward
by this pull which has been described elsewhere as the same
movement as the oil moving in a wick. As the amount of moist-

FALUNG or

TWO EXAMPLES OF CAPILLARITY

ure that is held by capillarity is limited and if not replenished,
the supply within reach of the roots may soon be exhausted.
This available supply is partially maintained by the upward
movement of capillary water. As one point becomes dry, the
water is drawn from below by a constant pull on the thin film.
When capillary water moves from the more abundant supply
below, it brings with it soluble plant foods to assist in nourish-
ing the plant.

The movement of capillary water is efifected by several con-
ditions.. It is governed very largely by the texture of the soil.
The finer the soil and the more surface the soil particles expose,
and the more points of contact between the particles, the greater
is the pull. For example, a heavy clay soil containing 20 per
cent, of moisture may draw water from a coarse sand contain-
ing only 10 per cent. Sandy or coarse soils move water very
rapidly and in large amounts, but the movement in such soils
cannot take place over long distances. With clay, which has a

VERTICAL FARMING

51

much stronger capillary pull, the movement is much slower,
but may take place over greater distances against gravity. The
amount of moisture moved in this way decreases as the limit
of distance is reached.

In addition to the texture, the structure of a soil has an im-
portant part in governing the capillary movement. The better
granulated a heavy soil, the greater the pore space and conse-
quently the greater the pull. Additions of humus materially
increase the capillary pull as well as the reservoir capacity of a
soil. In a puddled soil the movement is very slow and the
amount of water moved very small. The denser the soil be-
comes, the slower the movement.

Dry layers of soil break off the capillary pull on account of
the coating of the soil particles being of ^_______^.^_„^_

such a nature that they resist wetting. It
is this fact that makes the effectiveness of a
dry dust mulch, in holding the water below
the surface and not allowing it to rise to the
surface and be lost by evaporation. Capil-
lary movement is much faster in wet or
moist soils than in dry ones, so it is advis-
able at all times to preserve some moisture
in the soil if only for its benefits in a rapid the capillary
equalization of the moisture content when rise of moisture
water is applied. The ratio of the move- checked by a
ment in wet and dry soils has been shown dust mulch
to be as high as i to 4.

This upward movement continues to the surface and when
allowed to go unchecked will result in all the movable moisture
being pulled up and lost by evaporation. The rate of evapora-
tion of moisture from the surface is governed largely by tem-
perature and wind velocity. When water is stored at great
depths in the soil it is harder for it to be pulled to the surface
and lost. This surface loss at times approximates an amount
equal to a sheet of water 5 inches deep, over the whole surface
in a month. A handy example of the upward movement of
water and a check to its loss can be observed by turning over an

52

VERTICAL FARMING

old log or plank that is lying on the ground and noticing the
large amount of water in the soil immediately underneath.

The Feeding Zone of Roots. — The root systems of plants
require as ample room in which to develop as does the stalk and
leaf system above. Roots must both anchor the plant in place
and reach down for food and water. The feeding zone of a
plant determines the amount and value of the top. The soil
must be cultivated in order to provide a proper feeding zone,
for the earth in its natural condition will not yield as abundantly
as well cultivated soil. Just below a good surface mulch in a

well cultivated field we find
moist soil full of roots revel-
ling in an ideal feeding zone.
On an adjoining uncultivated
field one must dig down to find
moist soil, and discovers only
a few roots feeding in a mea-
ger compact feeding zone.
Rootlets are ever pushing into
fresh soil zones where more
water and food are to be
found, yet the feeding zone
in ordinary farming is con-
fined largely to the shallow
depths of the plowed furrow,
simply because it is the only
warm, mellow, well ventilated
soil within the reach of the
roots. When given a chance,
feeding roots advance rapidly
to meet the capillary rise of soil moisture, and the energetic
way in which they go down and search in every direction for
food and water proves them to be highly organized parts of
the plant and possessed of instinct or something akin to intelli-
gence. Plants having large or active root systems, making
a rapid growth, remove more water and more plant food from
the soil in a given time than those with a small system or

PECAN ROOTS FROM BLASTED
AND TIGHT SOIL

ROOTS GOING DOWN FOR FOOD AND WATER.

BETTER.

THE DEEPER THE

54 V ERT I C AL F ARM I N G

sluggish action. A corn crop when in the season of most
vigorous growth will remove more water from the soil in
a day than will a crop of wheat. Some crops are slow, weak
feeders, while others feed ravenously, and, while taking up
more substance, may be able to overcome more unfavorable
conditions. Roots should be thrown down into the soil as far as
possible in order to get away from danger of drouth, and
excesses of temperature, as well as from injury by cultivating
machinery.

The desirable conditions for a root system can be improved
by thorough cultivation of the subsoil, much deeper than any
plow can go, by means of explosives. They loosen up the soils
so that the roots are not checked in going downward, the rise of
capillary water is aided, aeration is improved, and deep reser-
voirs of water made accessible. This method more than doubles
the depth of the feeding zone.

Depths to Which Roots Go. — The natural tendency of most
roots is to go deep into the soil. Many who have not investi-
gated this subject believe that roots do not go deeper than one
or two feet and cutivate accordingly. On the contrary, they go
to much greater depths if the soil conditions permit. Corn
roots that have been confined and have occupied all the soil to a
depth of 2 feet, will go to a depth of 8 feet if the restriction is
removed. Wheat, oats and barley will penetrate from 8 to lo
feet, grass roots will go down 6 and 8 feet, while alfalfa has
been known to go down over 30 feet. Grapevine roots have
been found 22 feet below the surface, while the root systems
of trees correspond in extent and branching to the parts above
ground. The roots of clover weigh as much as the total weight
of the year's crops, while the roots of an oat crop are nearly
50 per cent, of the weight of the seed and straw. The total
length of all the roots of a wheat plant was found to be about
268 feet, of one rye plant 385 feet, and of one corn plant
1452 feet. Such facts show that the size and depth of the root
systems are generally not appreciated, and are generally under-
estimated. It is evident that the roots need a far deeper feeding

VERTICAL FARMING

55

Courtesy Prof. Ten Eyck, Kas. Rxpt. Sta.

DEEP ROOTING OF CORN AND ALFALFA

zone than is^ ordinarily given them. The feeding zone has been
shallow and meager, largely because the farmer could formerly
find no suitable means for the deep cultivation. No practical
machinery can till the soil as deep as 2 feet, and even that limit
is not sufficient for the needs of crops. Such deep cultivation
is possible only with high explosives.

The benefits of deep rooting of a crop do not pass away when
the crop is harvested, for the roots are left down where they
grew, and on decaying form humus at a depth where it would
be impossible to place it by artificial means, down where it
will help to perpetuate the granulated condition of the subsoil,
and keep alive the deep feeding and working bacteria, helping
the farmer to gain thereby the full return from all of his field
rather than from the top only.

56

VERTICAL FARMING

Weeds and Their Effects. — Weeds injure crops by robbing
them of their water and food. The escape of water is intangi-
ble, Hke the setting free of plant food, because we cannot see
either with the eye and must put our wits to work to detect its
departure. Weeds may have a mission in life; anyway they are

WEEDS THE STAR HOARDERS

stimulating rascals. When the farmer gets mad enough to go
after them, their mission is ended, for by destroying them he
conserves the moisture by unconsciously cultivating the ground
and increases the fertility of the soil.

Conserving the Moisture. — Where the moisture supply is
deficient, weeds should not be allowed at any time before,
during, or after the crops, for they remove water from the
soil as rapidly as the useful plants. When the water is ample,
but the soil too fine to permit rapid enough capillary movement,

VERTICAL FARMING 57

green manure should be grown and plowed under deeply. The
chief feature in conserving moisture is, of course, to get the
moisture in hand. This can only be done by leading it down
into the soil to great depths. If the soil is of such a nature that
this takes place of its own accord, all well and good, but many
soils are not that way. They are stubborn, and need a real first-
class shooting with an explosive to subdue them. Then the
maintenance of the organic matter and surface mulch can reach
their desired effects.

QUESTIONS

1. What soil conditions cause water to be held on the surface of

fields?

2. Will oil rise faster in a moist or dry lamp wick? Will the
^ same principle always hold true of soils?

3. Why does a dry layer of soil stop the capillary rise of

moisture ?

4. When should a dust mulch be renewed ?

5. What effect would a few inches of loose straw on the surface

have on the soil moisture during a rain ? During hot, dry
weather ?

6. Why is it beneficial to fall plow and deep till thin, hard

lands and cover the surface with trash?

7. Which will you find at greater depths, wheat or clover

roots ?

THE PLOW GIVES THE IDEAL SURFACE BREAKING BUT ONLY
EXPLOSIVES CAN ATTACK THE DEEP TROUBLES '

VERTICAL FARMING

PART VI

Cultivation — Use of Explosives

The present means and methods of cultivation are behind
the times. They are not up to date with the progress made all
along other lines. They all work too shallow, cultivating the
land a few inches where they should loosen and stir to a depth
of several feet. A world of wealth in thought, money, inven-
tion and machinery has been bestowed upon the first few inches
of the soil at the surface, but up-to-date agriculture demands
ihat the depths of the soil be considered also. It is nbt enough
to just scratch the surface and leave untouched the storehouse
of wealth below.

A World of Tools. — The farmer has at his command for
working this thin skin of the surface inches a wonderful array
of tools. He has plows of all kinds and qualities to select from
to fit every surface condition imaginable — hillside, landside,
hinge, and swivel plows — equipped with every shape of mold-
board, and coulters that may be fin, knife or rocking.' He may
use hand, sulky, or motor plows, and work them single, double,
or in gangs. He has harrows without number, home-made and
latest patent, coulter, spring, chain, slicing, spading and cuta-
way, all of them equipped with teeth set vertical or set slanting,
with plain, twisted, shovel, coulter, spike, and spring teeth in a
bewildering dental display. He has cultivators of all sorts and
breeds — hand, walking, and riding. He has drags, rollers,
plankers, floats, boats, clod crushers, pulverizers, and smooth-
ers, and he has so-called subsoilers in good variety that work
only a few inches deeper than the tools already mentioned.

60

VERTICAL FARMING

Yet with all this to select from he can do but little better than
the Romans did — prepare the seed beds and scratch the surface,
while at greater depth the roots still have to scratch for them-
selves, as they did centuries ago. It is too much on the prin-
ciple of the man who only greased the front wheels of his
wagon, saying that if they went the hind ones would *' just
naturally have to follow."

Progress Demanded. — With lands becoming scarce and
prices higher, there is a demand for methods that are more
efficient, that will cultivate the ground to greater depths, that
will meet the demands of the feeding roots, that will double the
feeding zone, that will furnish deep moisture reservoirs, that
will extend bacterial activity downward, that will double and
treble the farmer's acreage of productive soil by depth, and not
by area. So far as these demands are concerned, farm machin-
ery is so far a failure and but little advance has been made on
the primitive plow, the sharp stick with a V-branch. It is not

MARVELOUS IMPROVEMENTS HAVE BEEN MADE IN SURFACE
CULTIVATION

VERTICAL FARMING 61

enough to secure ease of draft, or raise heavier and faster
walking horses. It is not enough that the ox, horse and mule
are giving way to steam, gasoline, and electricity, to cable
traction and automobile luxury. It is not enough to point with
pride from the one-negro-one-mule-one-plow combination to the
monster steam gang plows. Something more is demanded.
The present machinery is good so far as it goes, and is the best
that the world has ever seen until recently, but it does not go far
enough. It does not go down. Many remedies have been sug-
gested only to meet with a cold reception. It is always difficult
to change old conditions, old customs, for there is ever prejudice
against such changes. The kind of prejudice that the first cast
iron plows (Newbolds, 1797) " poisoned the land " and " caused
weeds to grow " is still in existence, and can only be overcome
by enlightenment.

PLOW USED BY EARLY AMERICAN

THE ANCIENTS TYPE

Shallow Methods Prevail. — All methods and machinery in
common use are good for preparing the seed bed, but are of
little or no use in helping the roots to go down to their natural
length ; of no use in improving the soil atmosphere more than a
foot or two, or in meeting the many and varied demands of the
plant system below the surface. The function of the plow is
essentially to turn a thin ribbon of the soil on edge or upside
down, and to shatter and break the surface of the earth as much
as possible, and to destroy weeds, and bury refuse. Harrows
and cultivators have primarily a stirring action that forms
mulches and prevents surface evaporation, but they work at
even shallower depths than the plow. Some of the instruments
used tend to form plow sole, or hardpan and impacted con-
ditions of the soil close to the surface, defeating the very object
of cultivation.

62

VERTICAL FARMING

The most effective of all farm tools in breaking up the sur-
face soil is the plow, and its use in working up a tight surface
soil into a satisfactory condition of tilth must never be over-
looked. The effectiveness of the plow has been improved by
using modifications that will disturb the soil to greater depths
than is possible with an ordinary moldboard plow. The best

known tool of this type is the
narrow subsoil plow that fol-
lows along in the freshly
turned furrow of the regular
plow, deepening the cultiva-
tion several inches. Such a
plow does not bring the sub-
soil to the surface but simply
stirs the subsoil. The depth reached is seldom as much as i8
inches and is usually not more than 12 to 14 inches. A more
improved implement is the new double disc Spaulding Deep
Tilling Machine, which combines in one tool both the surface

COMMON SUBSOILER

SPAULDING DEEP TILLING MACHINE

VERTICAL FARMING

63

and the sub-surface plow. One heavy disc follows behind
and below another, and by their cutting, twisting action
break and mix Lhe surface soil with a layer of the material
lying underneath. Excellent results have been obtained with
both forms of deep plows, and their use is strongly recom-
mended, as their immediate action is to break up the plow sole
or shallowest hardpan material. They also leave the surface
and immediate sub-surface in a most desirable condition to
receive the rain water and allow it to be conducted to the deeper
subsoil that has been shattered with an explosive, where it may
be held by capillary absorption.

Benefit of Using Explosives. — It is admitted that present
methods of cultivation do not go deep enough, and it must also
be admitted that the use of specially prepared agricultural
explosives offers the desired remedy. It is admitted by all

k^

li-

PLOWl/^O-

PBEP TILLA&C

BLA3TBO 3UeSO/L.

NEARLY lh]PER\IIOU3 CL/KY 5UB50IL

GF{/\yEL OH 5ANO

COMPARATIVE DEPTHS REACHED BY DIFFERENT FORMS OF TILLAGE

authorities in agriculture that the plow and harrows do not
go deep enough and they advise the use of subsoilers. Scores
of books explain how and why each piece of machinery turns
over the soil, reduces it to fineness, forms mulches, saves water,
breaks clods, aerates, stimulates bacteria, etc. If all this wealth
of invention and labor is worth while bestowing upon the first
feiv inches of the soil why it is not w^orth following the roots

64 VERTICAL FARMING

down to their second foot of growth, their third, and even their
eighth and tenth foot when they flourish at those depths. The
only reply is, " Yes it would pay, but how can it be done ? ". It
can be done economically, quickly, and thoroughly by the use of
explosives. Deep plowing is recommended by all authorities
" wherever the resisting soil will permit." Machinery made
especially for deep work may be stopped, but nothing can
resist the explosives. The farmer plows, harrows, and spends
time, labor and money in cultivating the surface foot and re-
joices in the wonderful alchemy that follows his endeavors — the
mysterious activities he has set in motion. He works cheerfully
and with confidence, largely because he can see what he is doing.
In the new agriculture he must work by faith and reason in
depths where he cannot see with his eyes what is taking place.
The result will place before his eyes in the form of bumper crops
proofs of the benefits of his work. The new agriculture simply
points out the benefits acquired by the thorough cultivation of
the foot, or two feet, and by explaining how and why this is
accomplished, points out the value of extending the cultivation
further down by the simple means of explosives. The harrow
warms and aerates the soil and promotes activity by loosening
and separating the soil particles at the surface. Explosives do
the same, breaking, loosening, pulverizing at depths machinery
cannot reach. Drainage is recommended by all because it
removes excess of water, admits air, and gives proper moisture
conditions. Explosives have drained many a field and secured
all these benefits at far less cost in time, labor and money than
the usual methods of ditching and tilling.

The importance of nitrification is proven, but why confine it
to the thin furrow slice when the action of bacteria has been
proven at depths of 6 feet in the humid soils of the East, and
still deeper in the porous soils of the arid and semi-arid regions
of the West ? Why not loosen the soil and secure proper condi-
tions by the use of some charges of explosives? It is admitted
that there is much of plant food below the shallow plowed and
cultivated ground, aiid that the roots will go down if they can.
Why not open the way and make it easy for them by cracking

VERTICAL FARMING

65

and pulverizing the soil with explosives as far down as the roots
care to go ? It is admitted that water may be stored, as in dry
farming, by converting the soil itself into a reservoir by making
it porous so that it absorbs water and holds it like a sponge.
Why not use explosives and make the reservoirs two and three
times as great and secure absolute instead of partial insurance
against drouth?

It is admitted that much of the rainfall is lost by running off,
and consequent damage done by erosion. Why not check this
by the use of explosives before the rainy season, storing the
rainfall in porous soil instead of letting it run to waste? It

is admitted that some of the

soils called " wornout," or
" poisoned " and " worthless "
may be reclaimed if the soil is
thoroughly stirred up from the
depths. What can do this so
efficiently as explosives ? It is
admitted that much of the
plant food in the soil is una-
vailable because it is un-
weathered. Why not make it
available by opening the
ground to weathering agencies
by explosives?

The benefits of clean sum-
mer following every other
crop, under low rainfall, and
occasionally under abundant
rainfall are admitted. Why
not secure these benefits by
means of explosives? It is
admitted that granulation of
a soil is a benefit, that any

treatment that increases the lines of weakness in the soil
structure facilitates the movement of capillary water, and the
action of moisture films. The more numerous the lines of
weakness the quicker granulation is secured.

FROM DEEP SHATTERED
SUBSOIL

66

VERTICAL FARMING

The fewer the lines of weakness the more close and cloddy
the structure. What will granulate soil to the depths quicker
than explosives? It is admitted that present machinery can
only increase the feeding zone of the roots an inch or two.
What can explosives do in this line? A cubic yard of hard soil
has 6 faces and 9 square feet in each face, or a total of 54 square
feet. Divide it into i foot cubes and there are 162 feet of
surface. Break it into inch cubes and it presents 1944 square
feet, or nearly 1/20 of an acre of feeding surface for the roots.

TOY BLOCKS TO REPRESENT THE INCREASE IN SURFACE AREA

THE REPRESENTED CUBIC YARD HAS A SURFACE AREA OF 54

SQUARE FEET. THE 2/ CUBIC FEET A SURFACE OF 162

SQUARE FEET. IF BROKEN TO INCH CUBES THE

AREA IS 1944 SQUARE FEET

VERTICAL FARMING

67

SHATTERING SUBSOILS WITH FARM POWDER

A single cartridge of explosive can easily convert several yards
of compact and useless hardpan into half an acre of new feed-
ing ground. Costly, massive, improved machinery enables the
farmer to spread out his operation, to move horizontally, and
handle more acreage in the same time, and he is ever eager to
double and treble his holdings of fertile soil. \\'hat is wanted
that enables him to move vertically down and

IS

something

double his acreage, and double his yield by doubling the fer-
tility of the soil, by doubling the depth of the feeding zone, by

68 VERTICAL FARMING

doubling the water supply, by cultivating the ground to double
and treble the former depths. '' Vertical Farming/' to coin a
name, is the keynote of a new agriculture that has come to stay,
for inexpensive explosives enable the farmer to farm deeper, to
go down to increase his acreage, and to secure larger crops.
Instead of spreading out over more land he concentrates on less
land and becomes an intensive rather than an extensive agri-
culturist, and soon learns that it is more profitable to double the
depth of his fertile land than to double the area of his holdings,
and he learns that his best aid and servant in this work is a good
explosive. Peace congresses demand that swords be turned into
pruning hooks. The farmer is busy turning explosives from
war to agriculture, from death dealing to life giving work.

There is a demand to-day for farmers who think, and who
think long and closely as well as observe; for men who reject
nothing because it is an innovation, because it is new. Men
are wanted everywhere who have thought for themselves how
soil first came into being and what its form and character are
and what they mean ; men who are not satisfied until they know
how plants feed, where they feed, and the nature of their food ;
men who look below the surface of the ground and realize that
as much of their future crop is there as will be above the sur-
face, that plant roots must have air and water at the right
times and in the right abundance as much as the animals in their
barns.

This kind of men have been and are using explosives freely
as the best and simplest means of securing success and accom-
plishing their object. Their success may be duplicated by all
who care to do so. The use of explosives for deep cultivating
and other farm purposes has come to stay.

Vertical farming with explosives is another step forward
as truly as irrigation and dry farming, and is greater, for unlike
them it is not limited to any area or region but may be practised
everywhere and anywhere. It has the world for its field.

VERTICAL FARMi'nG 69

QUESTIONS

1. What is your investment in tools per acre of land tilled?

2. What is your total cost of preparing, seeding, cultivating,

and harvesting one acre of money crop?

3. What improvements over the practices of your father have

you made in the use of field machinery and supplies?

4. How deep do you actually plow? (^Measure the depth at

the unbroken side of the furrow.)

5. Did you ever follow up the full development of the roots of

a tree or a field plant ? What did you find ?

6. Have you any actual knowledge of the character of your

subsoil ?

The Ideal Explosives for

VERTICAL FARMING

RED CROSS FARM POWDER
RED CROSS STUMPING POWDER

Q Both are low-freezing, hence require no thawing
in any weather fit for work out-of-doors. They can
be used successfully in the winter-time when farm
duties are lightest. Both are as safe as anything
explosive can possibly be.

^ Both are easy to use by following the plain
illustrated instructions in our booklet.

^ Red Cross Farm Powder is made especially for
blasting subsoils, either for tree-planting or general
crops, for electric ditch blasting, and for light
stump-blasting.

^ Red Cross Stumping Powder is made especially
for heavier stump and ditch blasting.

Q DuPont Dynamite 50% is best for boulder blast-
ing and ditch blasting without a blasting machine
in mucky or saturated soil.

9 Make every acre productive. Get the most pos-
sible per acre. High prices of farm products will
continue for many years to come.

Q Write for our free Farmer's Handbook of
Explosives and learn the how of vertical farming.

AGRICULTURAL DIVISION

E. L du Pont de Nemours Powder Co.

Wilmington, Delaware

~-^^:

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YG 4057C

U.C.BERKELEY LIBRARIES

CDMS^mb73

UNIVERSITY OF CALIFORNIA IvIBRARY