THE MOISTURE PROBLEM 



87 



able crop management practices followed. The first of 

 these is discussed in the next section and the other two 

 in the chapter that follow^s. 



57. Soil Fertility and Soil Moisture.— One of the chief 

 functions of the water stored in the soil is to dissolve 

 plant food substances and carry them through the root 





-'^j..-,;,..>vM-}>,.-^ 





Fig. 30. — Sugar Beets Growing en Irrigated Land North of Brooks, Alta. 



hairs into the plant. The more of such material a unit 

 of water can carry into the plant the more bushels per 

 acre the limited supply of water may produce. It has 

 been found that when equal amounts of water are sup- 

 plied to rich and poor soils the former produces the 

 larger yield. Widtsoe* states (1) that on a naturally 

 fertile Utah soil 908 pounds of water were required to 

 produce each pound of dry matter in corn, (2) that 



From "Dry Farming" by Widtsoe. 



