SOIL MOISTURE AND DRY FARMING 83 



into capillary water or until it reaches the water table 

 below. (3) The distance that it goes down as gravita- 

 tional water before it is converted into capillary water 

 will depend mainly on the dryness of the soil and on the 

 copious character or otherwise of the precipitation. (4) 

 The rapidity of the downward movement will be ac- 

 celerated by increase in the degree of the soil saturation. 

 (5) It is being continually drawn upon by the influences 

 of evaporation and to suppy the needs of growing 

 plants. (6) These drafts lead to that upward movement 

 of the water known as capillary movement. (7) When 

 the supply of capillary water is too small to meet the 

 needs of the plants they languish proportionally in 

 their growth. To maintain such supply is one of the 

 most important questions that can engage the attention 

 of the dry land farmer. 



Hygroscopic water is water that is held within the 

 soil grains. The proportion of the hygroscopic water in 

 the soil varies in soils and in localities. In some very dry 

 areas this percentage has been placed at less than 2 per 

 cent. 



Whether such water aids to any extent in promoting 

 plant growth is a disputed question. It may aid in 

 keeping the soil cooler than it would otherwise be in 

 warm areas. It may also exercise some influence in 

 bringing plant food into solution, but there is not enough 

 of it present in the soil to make it a carrying agent. 



The run off waters are those that flow away: (1) in 

 quick melting of the winter snows ; (2) from the down- 

 pour of torrential rains, and (3) from the continuance 

 of prolonged rainfall. Especially in areas where "Chi- 

 nook" winds prevail, the snow melts so rapidly that 

 much of it runs away before it can sink into the soil. 

 In much of the semi-arid country rain frequently falls in 

 showers that are dashing in character. In some locali- 

 ties these assume the character of a downpour. Occa- 



