242 



quiremeuts of a large number of plants. The results of their inves- 

 tigations are given in the following table : 



Water Required to Produce One Pound of Dry Matter at Akron, Col.* 



Millet 310 



Sorghum 322 



Corn 368 



Sunflower 683 



Wheat 513 



Teosinte 383 



Barley 534 



Oats 597 



Flax.. . 905 



Potato .- 636 



Cowpea 571 



Soybean 744 



Sugar beet 397 



Red clover 789 



Sweet clover 770 



Alfalfa 831 



Tumble weed 287 



Russian thistle 336 



It will be seen that the amount of water varies from 287 to 905 

 pounds per pound of dry matter. The average of the above is 550 

 pounds of water for each pound of dry matter. Some crops are 

 better adapted to dry land agriculture than others because of the 

 fact that they require less water, while some have habits of growth 

 that enable them to resist drouth. Many plants must bo acclimated 

 before best results can be obtained. 



The Utah Station found that cultivation lessened the amount of 

 water required. 



Pounds of Water Required to Produce a Pound of Dry Matter of Corn s 



Loss of Water. Kainfall is lost from the soil in four different 

 ways, namely : run-off, percolation, evaporation, and transpiration. 



(a) Run-off. One of the essentials of dry farming is to pre- 

 vent loss of water through surface run-off by putting the soil in con- 

 dition to absorb the rainfall. It is impossible to prevent some loss 

 because of the torrential rains in arid regions. The soil should 

 be kept in a loose condition, so as to absorb water as rapidly as 

 possible. 



(b) Percolation. It is rarely the case that there is so much 

 rainfall on soils well adapted to dry farming that water gets beyond 



