CHAPTER VIII 



REGULATING THE E^'APORATION 



The 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, onh^ 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 



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