88 FARM DEVELOPMENT 



slice in the preparation for planting, and keeps it loose 

 and open during the cultivation of crops planted in rows 

 for intertillage. Both plowing and tillage have other 

 functions than so controlling the water as to provide 

 the optimum amount of film water best for the plants. 

 Crops thrive with an amount of water somewhat less 

 than that required to entirely satisfy the force of capil- 

 larity, and can adjust themselves to some range of 

 moisture content between saturation of capillarity and 

 such a low amount of water that they cannot get all 

 they need, and wither, and are stunted in their growth. 

 In drouthy regions, the application of water and the con- 

 servation of soil water are often the controlling factors 

 in crop production. 



