312 DRY LAND FARMING 



with a reasonably porous sandy and clay loam subsoil. 

 Such soils are frequently found in river basins, and 

 when they are, and ground water is within a few feet 

 of the surface, the conditions for alfalfa are all the more 

 favorable. It should be remembered, however, that 

 alfalfa will grow successfully on the average clay loam 

 soil of the semi-arid west, with a moderately clay loam 

 subsoil, though the water table should be hundreds of 

 feet below the surface. Alfalfa will also grow reason- 

 ably well on stiff clay soils, but on these it is more dif- 

 ficult to get a stand than on sandy loam soils. In an 

 average year it will do well even on gumbo soils, but 

 on these it may be greatly lacking in a dry season. 

 Alfalfa will not grow well on soils composed mainly of 

 vegetable matter. It will not succeed in dry areas on 

 light sands or on gravelly soils much lacking in an inter- 

 mixture of clay. It will not succeed in lands which are 

 subject to overflow for any considerable portion of the 

 year, nor will it succeed on land strongly impregnated 

 with alkali. Shallow soils, also, and those underlaid with 

 hard-pan which comes within a foot or two of the sur- 

 face are most unfavorable to the growth. 



Place in the rotation. The normal place for alfalfa 

 in dry areas is always virtually the same. This means 

 that where the average rainfall does not exceed 15 inches 

 the aim should be to sow alfalfa on summer-fallowed 

 land or on land which has grown a cultivated crop the 

 previous year. The reasons for such a rotation are found, 

 first, in the fact that the land is or should be clean, and, 

 second, in the fact that it should contain a relatively 

 hjgh moisture content. When the rainfall is more than 

 15 inches, it is not so necessary that this rotation shall 

 be rigidly adhered to. In new areas it may be grown on 

 land newly broken, a,s a means of obtaining quickly a 

 supply of hay, but with the distinct understanding 'that 

 this is not the best method of growing it. The objec- 



