2/8 SOILS AND FERTILIZERS 



demands upon the soil water. For example, after a 

 grain crop has been produced, it is best in regions of 

 scant rainfall to plow the land and get it into condi- 

 tion to conserve the water for the next year's crop, 

 rather than to attempt to raise a catch crop the same 

 year. During years of heavy rainfall catch crops may 

 be grown for green manure to increase the humus con- 

 tent of the soil. Crops removing excessive amounts 

 of water should not be grown too frequently. Sun- 

 flowers, for example, remove twenty times more water 

 than grain crops, and cabbage removes more water 

 than many other crops. With a good rotation and 

 systematic cultivation a water balance may be carried 

 in the soil from one year to the next, so that crops 

 will be supplied in times of drought. 



336. Rotation and Farm Labor. The rotation of 

 crops should be so planned that there is an even 

 distribution of farm labor. The importance of this is 

 so plain that its discussion seems unnecessary. It 

 is one of the most important points to consider in 

 economic farming, and should not be lost sight of in 

 planning rotations. 



337. Economic Use of Manures. Farm manure 

 should be applied to those crops which experience has 

 shown to be the most benefited by its use. At least 

 once during a five years' rotation the land should 

 receive a dressing of stable or some other manure. 



