CHAPTER VIII 
REGULATING THE EVAPORATION 
Tue demonstration in the last chapter that the 
water which falls as rain or snow may be stored in 
the soil for the use of plants is of first importance in 
dry-farming, for it makes the farmer independent, 
in a large measure, of the distribution of the rainfall. 
The dry-farmer who goes into the summer with a 
soil well stored with water cares little whether sum- 
mer rains come or not, for he knows that his crops will 
mature in spite of external drouth. In fact, as will 
be shown later, in many dry-farm sections where 
the summer rains are light they are a positive detri- 
ment to the farmer who by careful farming has 
stored his deep soil with an abundance of water. 
Storing the soil with water is, however, only the first 
step in making the rains of fall, winter, or the preced- 
ing year available for plant growth. As soon as 
warm growing weather comes, water-dissipating 
forces come into play, and water is lost by evapora- 
tion. The farmer must, therefore, use all precau- 
tions to keep the moisture in the soil until such time 
as the roots of the crop may draw it into the plants 
to be used in plant production. That is, as far as 
130 
