CHAPTER IV 

 SAVING WATER BY CULTIVATION 



WATER added to the soil by the natural precipitation 

 or by irrigation is disposed of in two chief ways : One part 

 runs off the land; another part soaks into the ground. 



The water which soaks into the soil may be disposed 

 of in three ways: (1) Immediately after water has entered 

 the soil, evaporation begins at the surface and, in time, 

 if not checked, the water in the greater depths will be 

 brought to the surface, to be returned to the air in the 

 form of water vapor. (2) If an excess of water has been 

 applied, another part sinks below the reach of the plant 

 roots and may connect with the country drainage, and 

 thus be lost to the farmer. (3) A part remains in the 

 soil and supplies the plant with the water needed in its 

 growth. 



The vital thing in irrigation practice is to bring the 

 water into the soil properly and to keep it stored there, 

 within reach of the roots, until it is needed by the plant. 



32. The run-off. The run-off collects in hollows or 

 cuts channels to connect it with the larger streams of 

 surface water. The quantity of water thus lost often 

 forms a very large part of the total water added by the 

 natural precipitation or by irrigation. To prevent this, 

 it is necessary to keep the top soil in a loose, open con- 

 dition, so that the water that falls upon it may be 

 absorbed quickly. Where the major part of the precipi- 

 tation comes during the winter or spring, the best way of 



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