SOIL WATER 



155 



does not receive a sufficient supply of rain water for 

 the production of profitable yearly crops. These 

 soils are rendered unfertile by the lack of this one 

 all important factor of fertility. They can be made 

 fertile and productive by supplying them with suffi- 

 cient water through irrigation. 



The crop-producing power of some lands is low- 

 ered even in regions where the rainfall is sufficient, 

 because these lands are not properly prepared by 

 tillage and the addition of organic matter to ab- 

 sorb and hold the water that comes to them, or 

 part of the water may be lost or wasted by lack of 

 proper after-tillage or after-cultivation. This state 

 of affairs is of course improved by better prepara- 

 tion to receive water before planting the crop and 

 better methods of after-cultivation to save the water 

 for the use of the crop. 



LOSS OF SOIL WATER 



Aside from what is used by the crops the soil may 

 lose its water in the following ways : 



Rain water which comes to the soil may be lost 

 by running off over the surface of the land. This 

 occurs especially on hilly farms and in the case of 

 close, compact soils. 



Water may be lost from the soil by leaching 

 through the lower soil. 



Water may be lost from the soil by evaporation 

 from the surface. 



The soil may lose water by the growth of weeds 



