190 Kansas State Board of Agriculture. 



a greater volume of soil from which to draw water than other crops have. 

 Alfalfa makes heavy drafts upon the soil for water. The experiments 

 of Briggs and Shantz, of the United States Department of Agriculture,* 

 to determine the number of pounds of water taken from the soil by crops, 

 for the production of a pound of dry matter, are very instructive. The 

 following data are given for alfalfa: 



TABLE No. 22. Amount of water used by different varieties of alfalfa. 



In comparison with alfalfa, it is interesting to note the amounts of 

 water used by some other common plants in making a pound of dry 

 matter : 



TABLE No. 23. Amount of water used by different kinds of plants. 



Plant. Pounds. 



Sunflower 705 



Potato 636 



Watermelon 600 



Oats 597 



Barley 534 



Wheat 513 



Corn 368 



Sorghums, all kinds (av.) 322 



Millet 310 



These experiments simply record the amounts of water that pass from 

 the ground into the air through the stems and leaves of the plants ex- 

 perimented with, and the ratio, in pounds, of this water to the number 

 of pounds of dry matter produced by the plants. 



In a rough way, these results measure drouth-resistance, in that they 

 show that some plants are more economical crop producers than others, 

 so far as the amount of water drawn from the soil is concerned. Alfalfa, 

 it is seen, takes nearly twice as much water out of the ground as wheat, 

 in proportion to the number of pounds of dry matter made, and there 

 are evidently differences among the alfalfas themselves in this respect. 

 From the tests thus far made, Peruvian seems to be more economical 

 than Grimm, or even Sickle alfalfa. 



For the purpose of the breeder, many more such experiments with 

 a wide range of strains and varieties of alfalfa will be necessary before 

 he can come to definite conclusions as to the most economical strain of 

 alfalfa from the water standpoint. 



Strictly speaking, alfalfa is not a dry-land crop in the sense that 

 Sudan grass is, for example, and present prospects do not afford much 

 hope that it can be made into one. Alfalfa plants do not cease growing 



* "Relative Water Requirement of Plants," by Briggs and Shantz, Journal of Agricul- 

 tural Research, vol. 3, No. 1, Oct. 15, 1914. 



