44 



ARID AGRICULTURE. 



INCREASES 



STORAGE 



CAPACITY 



PULVERIZES 

 THE 



will absorb over 40 per cent, of their weight of 

 water. If they contain from. 8 per cent, to 20 

 per cent, of moisture they are in condition to 

 support growing crops. A crop of oats at Lara- 

 mie did not wilt for some days when the soil con- 

 tained as little as 3 per cent, of moisture. 



How the storage capacity of a soil may be in- 

 creased by deep plowing; may be illustrated by a 



n A "1 I- ' t' 



few figures. A soil weighing one ton per cubic 

 yard, weighs approximately 1613 tons per acre 

 taken one foot deep. If such a soil will absorb 

 and hold 20 per cent, moisture and is plowed six 

 inches deep, it will take up 161.3 tons of moist- 

 ure per acre. A rainfall of 1.4 inches will sup- 

 ply this amount of moisture and fill up our six 

 inch reservoir. If the ground is plowed only 

 three inches deep, and the sub-soil is hard, it 

 would not be able to store a rainfall of more than 

 seven-tenths of an inch and should more water 

 fall at one time it will be lost and may wash the 

 soil away with it. If plowed nine inches deep 

 and put in good condition, such a soil reservoir 

 would absorb and hold over two inches of rain- 

 fall at one time. A soil already containing a 

 considerable water would be filled up with less 

 rain, and deep plowing would be still more im- 

 portant. 



Deep plowing is usually good plowing in 

 grinds up and pulverizes the soil. Soils 



