INFLUENCE OF CULTIVATION 3 1 



The three ways in which crops are deprived of 

 water are by (i) percolation, (2) evaporation, and (3) 

 transpiration. With proper methods of cultivation, 

 losses by percolation and evaporation may be controlled, 

 and losses by transpiration may be reduced. 



INFLUENCE OF CULTIVATION UPON THE WATER SUPPLY 



OF CROPS 



25. Capillarity Influenced by Cultivation. — The 



capillarity of the soil is subject to change with different 

 methods of cultivation, as rolling and subsoiling, deep 

 plowing and shallow surface cultivation. The method of 

 cultivation which a soil should receive in order to secure 

 the best water supply for crops must vary with the 

 rainfall, the nature of the soil, and the crop to be pro- 

 duced. It frequently happens that the annual rainfall 

 is sufficient to produce good crops, but is too unevenly 

 distributed. It is possible, to a great extent, to vary 

 the cultivation to meet the water requirements of 

 crops. 



26. Shallow Surface Cultivation. — When shallow 

 surface cultivation is practiced, the capillary spaces 

 near the surface are destroyed and the direct connec- 

 tion of the subsoil water with the surface is broken. 

 When the soil particles have been disturbed and a layer 

 of finely pulverized earth covers the surface, there is not 

 that close contact which enables the water to pass 

 from particle to particle. When evaporation takes 

 place there is a movement of the subsoil water to the 



