116 DRY-FARMING 



Importance of a moist subsoil 



In the consideration of the downward movement 

 of soil-water it is to be noted that it is only when the 

 soil is toleralily moist that the natural j^recipitation 

 moves rapidly and freely to the deeper soil layers. 

 When the soil is dr}', the downward mo^Tment of 

 the water is much slower and the bulk of the water 

 is then stored near the surface where the loss of mois- 

 ture goes on most rapidly. It has been observed 

 repeatedly in the invi^stigations at the Utah Station 

 that when desert land is bniken for dry-farm purposes 

 and then proi)erly cultivated, the precipitation 

 penetrates farther and farther into the soil with 

 every }'ear of cultivation. For example, on a drv- 

 farm, the soil of which is clay loam, and which was 

 plowed in the fall of 1904 and farmed annually there- 

 after, the eighth foot contained in the spring of 1905, 

 6.59 per cent of moisture; in the spring of 1906, 

 13.11 ]jer cent, and in the s]>ring of 1907, 14.75 per 

 cent (jf moisture. On another farm, with a very 

 sandy soil and also plowed in the fall of 1904, there 

 was found in the eighth foot in the spring of 1905, 

 5.03 per cent of moisture, in the spring of 1906, 11.41 

 ]X'r cent of moisture, and in the sjjring of 1907, 15.49 

 ])er cent of moisture. In Ijoth of these tyjMcal cases 

 it is evident that as the t(jpsoil was loosened, the 

 full field water ca])acity of the soil was more nearly 

 ap])roached to a greater depth. It would seem that, 



