CHAPTER IV 



SOIL WATER 



PROBABLY no other phase of modern farming, 

 except the ever pressing problem of how to 

 keep up the fertility of the soil, is now receiving 

 more attention than the problem of how to maintain 

 an adequate supply of soil water. The farmers of 

 our vast arid regions, both in the irrigation and in 

 the dry-farming sections, pay scarcely more atten- 

 tion to it than the farmers in the states east of the 

 Mississippi, where the rainfall is supposed to be 

 sufficient for ordinary crops. 



It is frequently stated that the lack of sufficient 

 water at the right time does more to reduce the 

 yields of farm crops in the United States than the 

 lack of available plant food. This does not refer 

 particularly to the great droughts, which may 

 reduce the corn crop of the whole Mississippi 

 valley 50 per cent. ; nor even to the local droughts, 

 which sere the meadows and shrivel the gardens 

 in scattered localities. The greatest losses from 

 lack of water are not from noticeable droughts, but 

 from the unnoticed dryness which merely lessens 

 the crops year after year, reducing the average and 

 lowering the standard. There are a few restricted 

 sections of the country where the problem of soil 

 water is not pressing; but in most parts of the 

 United States a paramount problem in crop 

 production is how to supply moisture at the right 

 time and in adequate quantity. If a man handles 

 his soil in such a way mat it is in the best condition 



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