130 



THE ESSENTIALS OF AGRICULTURE 



fallowing consists of allowing the ground to go uncropped for one 

 season for the purpose of storing moisture. Summer-fallowed 

 ground is usually plowed deep soon after the rainy season be- 

 gins. At that time the ground is moist and plows well, and the 

 deep plowing provides a rough, open surface that absorbs water 

 readily. The fallow is cultivated frequently enough to prevent 

 weed growth and to keep the surface from crusting. It has been 

 shown that land alternately cropped to winter wheat and 

 summer-fallowed contained on an average of 5.7 inches more 



FIG. 56. Listed soil catches and holds winter moisture 



water in the upper six feet of soil at seeding time than did land 

 that was cropped each year. The summer-fallowed ground pro- 

 duced, as an average of four years, 26.3 bushels of wheat per 

 acre, while the continuously cropped ground produced but 1 1 .6 

 bushels. Another experiment showed that, as an average of 

 three years, land summer- fallowed for wheat has produced 12.3 

 bushels per acre, while early-fall-plowed, continuously cropped 

 land has produced 13.9 bushels, and late-plowed, continuously 

 cropped land has produced 7.5 bushels per acre. Alternate 

 cropping and fallowing is necessary only where the rainfall is 

 very light. Over much of the dry-land area it is necessary to 



