The First Book of Farming

o

the earth's crust which is occupied by the roots of

OF SOIL

ture and with it plant food. We learned also that for roots to do these things well, the soil in which they grow mu

composition, its characteristics; also, how it was made and what forces or agencies were active in making it. Are these forces acting on the soil at the present time? Do th

study with an excursio

ine as many kinds of surface soils and subsoils as possible, also decayed leaf mould, the black soil of the woods, etc. If there are in the neighborhood any expo

l should be fresh from the field. Examine the sand, clay and leaf mould, comparing them as to color; are they light or dark, are they moist or not? Test the soils for comparative size of p

e each in an iron spoon or on a small coal shovel and heat in stove to redness. It will be found th

oonful of clay and into the other the same amount of sand; shake both bottles thoroughly and set on t

ee experiments we will f

coarse, not sticky, settles qui

ery fine, quite sticky, settles s

olor, moist, very fine, slightly stic

lled. This sample has perhaps fine particles and coarse particles; part of it will settle quickly in water while part settles very slowly, and it is sticky. Therefore we conclude that there are both clay and sand in it. If we shake a sample of it in a bottle of water and let it settle for several days, we can tell roug

the soil in one side of the pan and stir it with a stick or a spoon, carefully smooth the surface of the soil in the other side of the pan and pour or sprinkle some wat

G.

ith fresh water, and bottle B with water that had be

G.

tle B contains boiled water. Notic

G.

dled clay. Cuttings in B and D died, because there was not s

ICATION

d soils are class

ar or rounded rock frag

es ranging in size from several in

inch down to 1/500 of an inch in diameter.

1/25 to 1/50

1/50 to 1/10

100 to 1/250

d 1/250 to 1/

nearly with the grains of granulate

y when moist. A good illustration of silt is the silicon used for cleaning knives, a small amount of which can be obtained at most any grocery store. B

, too small to imagine. Clay when wet is very soft, slippery and very sticky.

r. This is dark brown or almost black in colo

ed of the ab

rly crops, and are particularly adapted to early truck, fruit and bright tobacco, but are too light for general farm crops. To this class belongs the so-called Norfolk Sand. This is a co

oil is sought out as best adapted to the production of watermelons, canteloupes, sweet potatoes, early Irish potatoes, strawberries, early toma

and, on the Pacific Coast, Fresno Sand. These names are given to these type

eeling when handled, appears to be about one-half sand and the other half silt and clay with more or less organic matter. These are naturally fine in texture and quite sticky when

tilled easily and are the lightest desirable soil for general farming. They are particularl

oils are some of the most difficult to till, but when well drained they are with careful manageme

ils, and some of them are difficult to till. They are generally considered the strongest

oil may be sandy loam, silt or clay loam. They are adapted to various crops according

nder being rock fragments of larger size than the gravel. These fragments are sometimes rough and irregular and sometim

a greater preponderance of the clay characteristics than in the clay loams; they are very heavy, sticky, and difficult to ma

humus. Their peculiar characteristic is that they are very sticky when wet and bake very hard when dry and are, there

f large amounts of humus or decaying organic matter mixed w

gh roots, partially decayed leaves, moss, etc. It is qui

RE SOI

s question collect and examine a numbe

d rub them together. A fine po

ill be finer and will be produced with greater difficulty because the stones are harder.

the size of your fist. Slowly drop water on them till it runs down and partly covers the slate, then set away till the water dries up. F

ut small bubbles are seen to rise from the sample in vinegar. The vinegar which is a weak acid is slowly dissolving the rock. The chemists tell us wate

are ground to powder when rubbed together, some are easil

es which form the gravel, sand and clay of our soils. The organic matter of our soils has been added by the decay of plants and animals. Several agenci

t into a thick glass tumbler or bottle, the inner surface heats and expands faster than the outer parts and the result is tension and cracking. If cold water be poured on a warm bottle or piece of warm glass, it cracks, because there is unequal contraction. In the early part of a bright sunny afternoon feel of the surface of exposed rocks, bricks, boards, or buildings on which the sun has been shining. Examine them in the same way early the next morning. You will find that the rocks are heated by the sun just as the plate was heated when put into the oven, and

OMPARING S

WATER TES

tle B clay and water. The sand settle

made by the sun, may wash out loosened particles; or, during cold weather it may freeze in the cracks and by its expansion chip off smal

throwing them up into sand beds, and carrying off the finer particles to deposit elsewhere. Now visit a quiet cove or inlet and see how the quiet water is laying down the fine particles, making a clay bed. Notice also

eam which carries its small burden of rock dust down the slope, now dropping some particles, now taking up others. Other little streams join this one until they form a brook which increases in size and power as it descends the mountain side. As it grows by the addition of other streams it picks up larger pieces, grinds them together, grinds at its banks and loads itself with rocks, pebbles, sand and clay. As the stream reaches the lower part of the mountain where the slope is less steep, it is checked in its course and the la

d particularly on the hillsides, where often the soil is loosened and carried from higher to lower parts, m

cies in soil formation. Away up in Greenland and on the northern border of this continent the temperature is so low that most if not all of the moisture that falls on the earth falls as snow. This snow has piled up until it has become very deep and very he

ts under surface were frozen sand, pebbles, larger stones and even great rocks. Thus it acted as a great rasp or file and did an immense amount of work grinding rocks and making soils. It ground down mountains and carried great be

s part of the air unites with part of the rock and forms rock rust which crumbles off or is washed away by water. Thus the air helps to break down the rocks. Moving air or wind picks up dust particles and carries them from one field to another. On sandy beaches the

Certain kinds of plants live on the surface of rocks. They feed on the rocks and when they die and decay they keep the surface of the ro

ic matter has undergone a certain amount of decay it is called humus, and these soils are called organic

h their bodies and are partially dissolved. These particles are generally cast out on the surface of the soil. Thus

TEX

By the texture of the soil we mean the size of its particles and their relation to each other. The following terms are used in describing soil textures: Coarse, fine, open, close, loose, hard, stiff, compact, soft, mellow, porous, leachy, retentive, cloddy, lumpy, light, heavy. Which