CONSERVATION OF SOIL MOISTURE 



formed the capillary channels are broken 

 and the water cannot rise into the loose 

 layer of surface-soil which is separated 

 from the firm soil below by large spaces, 

 across which moisture cannot pass. Ac- 

 cordingly, King writes: "In the conser- 

 vation of soil moisture by tillage there is 

 no way of developing a mulch more ef- 

 fectively than that which is produced by 

 a tool working in the manner of the 

 plow to completely remove a layer of 

 soil and lay it down again, bottom up, in 

 a loose, open condition." 



In the humid regions of America it has 

 been found that a soil-mulch of a depth 

 of three inches is sufficient to conserve the 

 moisture of the soil. But in California, 

 and the semi- arid West, fully twice that 

 depth is necessary for proper protection 

 during the dry, hot season, which some- 

 times lasts for three to six months at a 

 stretch. This is particularly true of 

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