CONTROL OF SOIL MOISTURE 



The Soil a Reservoir. The rains of the sum- 

 mer rarely are adequate to the needs of growing 

 plants. Some water runs off the surface, some 

 passes down through crevices beyond the effect of 

 capillary attraction, and much quickly evaporates. 

 The part that becomes available is only a supple- 

 ment to the store of water made by the rains of the 

 fall, winter, and early spring. 



If the soil were viewed as a medium for the hold- 

 ing of water to meet the daily needs of plants, and 

 were given rational treatment on this basis, a long 

 step toward higher productiveness would have 

 been taken. As has been stated, rotted organic 

 matter gives a soil more capacity for holding 

 water. It is an absorbent in itself, and it puts 

 clays and sands into better physical condition 

 for the storage of moisture. An unproductive soil 

 may need organic matter for this one reason alone 

 more than it may need actual plant-food. 



Fall-plowing for a spring crop enables land to 

 withstand summer's drouth if it gains in physical 

 condition by full exposure to the winter's frost. 

 It is in condition to take up more water from 

 spring rains than would be the case if it lay com- 

 pact, and it does not lose water by the airing in the 

 spring that plowing gives. 



[231] 



