THE BENEFITS OF FREE WATER 



83 



cannot make use of it. Its presence excludes the air so that most 

 farm crops cannot thrive, until the surplus water is removed. An 

 abundance of free water may wash out valuable plant food in 

 solution. 



If the free water stands at a level in the soil of say two feet 

 below the surface, such level is called the free water table in the 

 soil. In practically all field conditions the free water table is 

 constantly moving. After a period of heavy rains it may be near 

 the surface and during dry weather may recede to a great depth. 

 In regions where wells are shallow the depth of the water table is 

 practically that of the surface of the water in the wells. In the 







FIQ. 64. Moisture conservation methods. Spring and fall plowing in Colorado for corn 



Note the heavier growth on left due to fall plowing. (U. S. D. A,) 



spring after the heaviest rains have ceased it is a good plan to 

 determine the depth of the free water table. This may be done 

 by digging holes a few feet deep as if for the setting of fence posts. 

 The Benefits of Free Water. Probably the greatest benefit 

 of free water to the growing crop comes from the replenishing of 

 other forms of water in the soil from it. As the capillary water is 

 used up by plants, more is supplied from the soil below the water 

 table, if the distance is not too great. A secondary advantage 

 sometimes exists by the free water washing away injurious sub- 

 stances in the soil. This is apparent where the soil contains 

 alkali, as in some of the arid regions. 



