SUMMER FALLOW 123 
years, to be used for one crop? It is unquestionably 
true, as will be shown later, that clean fallowing or 
“summer tillage” is one of the oldest and safest 
practices of -dry-farming as practiced in the West, 
but it is not generally understood why fallowing is 
desirable. . 
Considerable doubt has recently been cast upon 
the doctrine that one of the beneficial effects of fallow- 
ing in dry-farming is to store the rainfall of succes- 
sive seasons in the soil for the use of one crop. Since 
it has been shown that a large proportion of the 
winter precipitation can be stored in the soil during 
the wet season, it merely becomes a question of the 
possibility of preventing the evaporation of this 
water during the drier season. As will be shown 
in the next chapter, this can well be effected by 
proper cultivation. 
There is no good reason, therefore, for believing 
that the precipitation of successive seasons may not 
be added to water already stored in the soil. King 
‘has shown that fallowing the soil one year carried 
over per square foot, in the upper four feet, 9.38 
pounds of water more than was found in a cropped 
soil in a parallel experiment; and, moreover, the 
beneficial effect of this water advantage was felt 
for a whole succeeding season. King concludes, 
therefore, that one of the advantages of fallowing 
is to increase the moisture content of the soil. The 
Utah experiments show that the tendency of fallow- 
