Some experiments in wheat-growing have shown how readily water might be saved if plowing were done at the right time. Wheat sowed on land that was plowed as soon as the summer crops were taken off yielded a very much larger return than wheat sowed on land that remained untilled for some time after the summer crops were gathered. This difference in yield on lands of the same fertility was due to the fact that the early plowing enabled the land to take up a sufficient quantity of moisture.
Fig. 285. Red Kafir Corn in Shock
In addition to a vigilant catching and saving of water, the farmer in these dry climates must give his land the same careful attention that lands in other regions need. The seed-bed should be most carefully prepared. It should be deep, porous, and excellent in tilth. During the growing season all crops should be frequently cultivated. The harrow, the cultivator, and the plow should be kept busy. The soil should be kept abundantly supplied with humus.
Some crops need a little different management in dry-farming. Corn, for example, does best when it is listed; that is, planted so that it will come up three or four inches beneath the surface. If planted in this way, it roots better, stands up better, and requires less work.
Just as breeders study what animals are best for their climates, so farmers in the dry belt should study what crops are best suited to their lands. Some crops, like the sorghums and Kafir corn, are peculiarly at home in scantily watered lands. Others do not thrive. Experience is the only sure guide to the proper selection.
To sum up, then, farmers can grow good crops in these lands only when four things are done: first, the land must be thoroughly tilled so that water can freely enter the soil; second, the land must be frequently cultivated so that the water will be kept in the soil; third, the crops must be properly rotated so as to use to best advantage the food and water supply; fourth, humus must be freely supplied so as to keep the soil in the best possible condition.
SECTION LXIX. IRRIGATION
Irrigation is the name given to the plan of supplying water in large quantities to growing crops. Since the dawn of history this practice has been more or less followed in Asia, in Africa, and in Europe. The Spanish settlers in the southwestern part of America were probably the first to introduce this custom into our country. In New Mexico there is an irrigating trench that has been in constant use for three hundred years.