Chapter VI

MAKING THE SOIL PRODUCE CROPS

There are many treatises available that deal with the soil, its composition and its treatment. No attempt will be made here to go exhaustively into that subject. There are a few fundamental factors, however, which the potential owner should know regarding soil treatment, for that is the base upon which he will build his income-producing operations.

The particles of soil have had their genesis in rock. The rock has become disintegrated and decomposed through natural processes. The action of the weather is the most important factor in creating soil. Water falling on rock not only wears it away mechanically, but through certain mild acid elements which it acquires, disintegrates the binding materials that hold rock segments together. In addition, there is the action of frost and freezing, too, making the moisture in rock expand and contract and thereby causing the breaking down of the segments. With this action is coupled that of hot suns which cause expansion and breaking up of the rock as it becomes heated and cooled under atmospheric influence.

A great deal of the soil surface in many sections of the country is the result of glacial action. These glaciers not only eroded the surface, thereby creating millions of rock particles, but they also carried large deposits of the rock particles to more distant areas and deposited them over a subsoil that may be totally different in character from the surface soil thus deposited.

How Tillable Soil Is Made.—The action of plants themselves has a great effect in adding to our supply of tillable soil. Seeds of plants or seeds of trees become established in some slightly weathered rock areas and begin to grow. The roots penetrate wherever there is any loose soil, and partly by their pressure and partly through the acidity accompanying decomposing plant tissue, complete a further breaking down of the rock. There is a continuous process of destruction of rocks and leveling off of mountains and hills to fill the valleys below.

Many groups of deep-rooted plants tend to increase the depth of the surface soil by growth of the roots in the subsoil and by creating therein a condition approaching that which already exists on the surface. The action of earth worms and similar forms of life in bringing subsoil to the top and in opening channels through which water and surface air can penetrate constitutes another continually operating force in the creation of a productive soil. A deeper layer of productive soil can also be created through a plan of consistently deeper plowing, bringing up with each annual plowing operation a small portion of subsoil which, when mixed with the surface soil, tends to become like it.

[Larger Image]

(Courtesy New Jersey Department of Conservation and Development)
Soil is created from rock by nature’s weathering processes and by plant growth.
At the bottom may be seen solid rock; just above are disintegrating rock fragments, and at the top, the soil.