AGRICULTURAL ECONOMICS 



pie rainfall." And yet, with respect to the pro- 

 portion of these arid regions which may be made 

 productive, the same authority gives the follow- 

 ing rather discouraging estimate : "If every drop 

 of water which falls on the mountain summits 

 could be utilized, it is not likely that more -than 

 ten per cent, of the total area of the arid West 

 could be irrigated, and it is certain that, because 

 of physical obstacles, it will never be possible to 

 get water to even this small percentage/' 1 



The introduction of new varieties of grains 

 and forage crops which are suited to semi-arid 

 regions makes possible the extension of agricul- 

 ture where the rainfall is too light for the crops 

 which are commonly grown in the humid regions. 

 For example, the drought-resisting macaroni 

 wheats have recently been introduced with great 

 profit. "In many places west of the looth mer- 

 idian, where wheat growing with other varieties 

 is practically impossible on account of drought, 

 the eastern Russian varieties by virtue of their 

 extreme drought-resisting qualities will produce, 

 ordinarily, a crop of from twelve to twenty 

 bushels per acre. By the use of these wheats, 

 therefore, these localities may become important 

 additions to the wheat area." 2 



The growth of our population is sure to make 

 increasing demands upon the agricultural re- 



1 Irrigation Institutions, pp. 2, 3, and 5. 



2 United States Department of Agriculture, Bureau of Plant 

 Industry, Bulletin, No. 3, p. 28. 



16 



