STORING WATER BY FALL PLOWING 127 



at the right time. In the very great majority of 

 cases over the whole dry-farm territory, plowing 

 should be done in the fall. There are three reasons 

 for this: First, after the crop is harvested, the soil 

 should be stirred immediately, so that it can be 

 exposed to the full action of the weathering agencies, 

 whether the winters be open or closed. If for any 

 reason plowing cannot be done early it is often advan- 

 tageous to follow the harvester with a disk and to 

 plow later when convenient. The chemical effect on 

 the soil resulting from the weathering, made possible 

 by fall plowing, as will be shown in Chapter IX, 

 is of itself so great as to warrant the teaching of 

 the general practice of fall plowing. Secondly, the 

 early stirring of the soil prevents evaporation of the 

 moisture in the soil during late summer and the fall. 

 Thirdly, in the parts of the dry-farm territory where 

 much precipitation occurs in the fall, winter, or early 

 spring, fall plowing permits much of this precipita- 

 tion to enter the soil and be stored there until 

 needed by plants. 



A number of experiment stations have compared 

 plowing done in the early fall with plowing done 

 late in the fall or in the spring, and with almost 

 no exception it has been found that early fall plowing 

 is water-conserving and in other ways advantageous. 

 It was observed on a Utah dry-farm that the fall- 

 plowed land contained, to a depth of 10 feet, 7.47 

 acre-inches more water than the adjoining spring- 



