Crops and Methods for Soil Improvement

by Alva Agee

Value of Water in the Soil.—The amount of water in the soil each day of the growing season determines in large measure the possibility of securing a profitable crop from land. Observant farmers have noticed oftentimes that the differences in yields on the farms of a region are less in a wholly favorable season than in one of deficient rainfall. The skill of the farmer in conserving the moisture supply in a wet season is less well repaid because it is less needed. The poverty of a worn soil is less marked in a favorable season. The land is accounted poor because the supply of plant-food is inadequate for a drouthy year in which a considerable percentage of the time produces little growth, but most agricultural land has enough plant-food for a fairly good crop when water is present all the time to carry daily supplies into the roots. It is the amount of moisture in the soil that is the limiting factor in the case of most land that is not in a high state of productiveness.

The Soil a Reservoir.—The rains of the summer rarely are adequate to the needs of growing plants. Some water runs off the surface, some passes down through crevices beyond the effect of capillary attraction, and much quickly evaporates. The part that becomes available is only a supplement to the store of water made by the rains of the fall, winter, and early spring.

If the soil were viewed as a medium for the holding of water to meet the daily needs of plants, and were given rational treatment on this basis, a long step toward higher productiveness would have been taken. As has been stated, rotted organic matter gives a soil more capacity for holding water. It is an absorbent in itself, and it puts clays and sands into better physical condition for the storage of moisture. An unproductive soil may need organic matter for this one reason alone more than it may need actual plant-food.

Fall-plowing for a spring crop enables land to withstand summer's drouth if it gains in physical condition by full exposure to the winter's frost. It is in condition to take up more water from spring rains than would be the case if it lay compact, and it does not lose water by the airing in the spring that plowing gives.

Early spring-plowing leaves land less subject to drouth than does later plowing. As the air becomes heated, the open spaces left by the plowing serve to hasten the escape of moisture. If a cover crop is plowed down late in the spring, the material in the bottom of the furrow makes the land less resistant to drouth because the union of the top soil with the subsoil is less perfect, and capillary attraction is retarded. It is usually good practice to sacrifice some of the growth of a cover crop, even when organic matter is badly needed, and to plow fairly early in the spring in order that the moisture supply may be conserved.

The Land-roller.—The breaking-plow is a robber of soil water when used in warm weather. The air carries the water away rapidly. The air-spaces are large. The corrective of this condition is the land-roller. It presses the soil together, driving out the excess of air. Large crumbs are pressed down into the mass, and are kept from drying into hard clods. The roller never should be used on land when fresh-plowed in a moist condition, and it is not needed after fall-plowing, or early spring-plowing in most instances, but land broken when the season is advanced should be rolled before much water evaporates.

Making an earth mulch in a New York orchard.

The Plank-drag.—An excellent implement on a farm is the plank-drag. It is usually made of over-lapping heavy planks, and when floated over the surface, it both pulverizes and packs the soil. The effectiveness is controlled by the weight placed upon it, and oftentimes the drag is to be preferred to the roller.

The Mulch.—In conserving the supply of water in the soil the mulch plays an important work. The dry air is constantly taking up the water from the surface of land, and when the surface is drier than the soil below, the moisture moves upward if there is no break in the structure of the surface soil. The mulch is a covering of material that does not readily permit the escape of water.