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 tolerably moist that the natural precipitation 
moves rapidly and freely to the deeper soil layers. 
When the soil is dry, the downward movement 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 investigations at the Utah Station 
that when desert land is broken for dry-farm purposes 
and then properly cultivated, the precipitation 
penetrates farther and farther into the soil with 
every year of cultivation. For example, on a dry- 
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 per cent, and in the spring of 1907, 14.75 per 
cent of 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, 
5.63 per cent of moisture, in the spring of 1906, 11.41 
per cent of moisture, and in the spring of 1907, 15.49 
per cent of moisture. In both of these typical cases 
it is evident that as the topsoil was loosened, the 
full field water capacity of the soil was more nearly 
approached to a greater depth. It would seem that, 
