710 SOILS: PROPERTIES AND MANAGEMENT 



have shown that moisture may be effectively stored in the 

 soil to a depth of more than eight feet and be readily used 

 by crops the next season. The total amount of water to 

 be applied depends on many things. The following factors 

 affect the duty of water: (1) character of the crop; 

 (2) climate ; (3) texture and structure of the soil ; (4) depth 

 of the soil; (5) fertility of the soil, including the total 

 amount of soluble material ; (6) kind of tillage practiced ; 

 (7) thickness of planting ; (8) season when the crop grows ; 

 (9) frequency and method of applying water ; (10) amount 

 and time of applying water. A fertile soil and a large 

 and rapid growth of the crop go with economy of water. 

 Many of the above factors, such as thickness of planting, 

 tillage practice, and manner of using water, determine the 

 loss from the soil that has no direct relation to the crop. 



The total amount of water to be applied 1 in irrigation 

 should range from five to twenty inches, with the tendency 

 toward the lower figure. This means a duty of 280 to 

 75 acres a second-foot for a season of sixty days. From 

 one to four applications of water are usually made. The 

 larger the plant and the deeper the root system, the larger 

 the individual application of water may be, and the fewer 

 the number of applications. 



668. Conservation of moisture after irrigation. The 

 conservation of moisture applied by irrigation should be 

 provided for whenever practicable. Crops planted in 

 rows should be cultivated as soon as the soil is dry enough 

 not to puddle. As suggested above, when the furrow 

 method is employed the furrows should be deep, so that 

 only a small part of the surface soil will be wet. Coupled 



1 Widtsoe, J. A. Principles of Irrigation Practice, Chapter 

 XVII. New York. 1914. 



