DRY-LAND AGRICULTURE 



253 



are used both for forage and grain. In the southern part of the 

 Great Plains in Kansas, Oklahoma, Texas and New Mexico these 

 form a very important crop. Jardine states that the average yield 

 of shelled grain from milo maize was -10 bushels per acre in the 

 Panhandle of Texas. 



Where a severe drouth occurs these crops stop growing but re- 

 main alive. They start quickly again when rains come. 



(i) Alfalfa. No crop has been of greater value on the irri- 

 gated land of the West than alfalfa, and it is proving to be a very 

 valuable crop on the dry-land farm as well. It is, however, very 

 difficult to start under arid conditions. The fact that the roots 

 penetrate to such a great depth in these dry-land areas makes it 



FIG. 112. Dry-farm potatoes. Utah. 



adapted to using the moisture stored to a great depth in the sub- 

 soil, and no single season's drouth will affect it seriously after it 

 becomes thoroughly established in the soil. Thick seeding must 

 be avoided. It is better adapted to light and medium soils than 

 to heavy clays. Cultivation is as essential in growing alfalfa as for 

 any other crop. The seed crop is one of the most profitable of the 

 alfalfa field. For producing seed it is best to plant the alfalfa in 

 hills or rows so that it may be cultivated. Tt may be necessary 

 to thin it to one plant every six to twelve inches. The second crop 

 is usually left for seed, the amount of seed produced varying from 

 150 to 300 pounds per acre. 



(j) Potatoes (Fig. 11 '2} are coming to he looked upon as one 

 of the staple crops of dry-land agriculture. With a rainfall of 1? 

 inches or more potatoes produce excellent crops, both in yield and 



