LEGUMINOUS FORAGE CROPS 183 



"Alfalfa occupies one-sixth the cultivated area of Argentina. 

 It has caused the development without irrigation of vast areas 

 of semi-arid land in the northern and western portions of 

 Argentina. It is estimated that about eight acres of natural 

 pasture are required to supply one steer, but that one acre of 

 alfalfa will support the same animal. Besides being pastured, 

 it is used extensively for hay, and is exported in no incon- 

 siderable quantities." 1 



Over three- fourths the area in alfalfa in the United States 

 in 1899 was in the western states, while over 98 per cent, was 

 grown west of the Missouri River. Since that time alfalfa 

 growing has increased somewhat in the eastern states. Al- 

 though the distribution is in large measure influenced by its 

 adaptability, it is also to some extent influenced by the fact 

 that east of the Missouri River timothy, red clover, and other 

 grasses and clovers thrive relatively better than they do west 

 of the Missouri River. 



206. Adaptation. Alfalfa is naturally adapted to a warm 

 climate. Kansas raises much more than Nebraska, South 

 Dakota much less, while North Dakota raised scarcely none at 

 all in 1899. About two-thirds the area in hay in New Mexico 

 was in alfalfa; in Colorado one-half; in Wyoming one-fifth; 

 while in Montana only one-fourhundredth part of the area in 

 hay was in alfalfa. Owing to its deep-root system alfalfa is 

 highly drought-resisting and is also well adapted to irrigation. 

 An excess of rainfall as well as an excess of water in the soil 

 is injurious. It thrives better in an alkaline than an acid soil, 

 being fairly alkaline resistant. The sub-soil is more important 

 than the soil, probably because of the effect of the former upon 

 the water table rather than because of its permeability to the 

 roots or the plant food contained therein, although both of the 

 latter are important. 



1 The Author: How to Choose a Farm, p. 358. 



