114 



DRY-FARMING 



To determine whether or not the natural winter 

 precipitation, upon which the crops of a large por- 

 tion of the dry-farm territory depend, penetrates 

 the soil to any great depth a series of tests were 

 undertaken. At the close of the harvest in August 

 or September the soil was carefully sampled to a 

 depth of 8 feet, and in the following spring sim- 

 ilar samples were taken on the same soils to the same 

 depth. In every case, it was found that the winter 

 precipitation had caused moisture changes to the 

 full depth reached by the soil auger. ]\Ioreover, 

 these changes were so great as to lead the investi- 

 gators to believe that moisture changes had occurred 

 to greater depths. The following table shows some 

 of the results obtained : — 



In districts where the major part of the precipi- 

 tation occurs during the summer the same law is 

 undoubtedly in operation; but, since evaporation 

 is most active in the summer, it is probable that a 



