SAVING WATER BY CULTIVATION 



WATER LOST (IN INCHES) BY EVAPORATION FROM A FREE-WATER 

 SURFACE FROM APRIL TO SEPTEMBER, INCLUSIVE 



State 



Highest 



Lowest 



Arizona 56.2 



California i_. 71.8 



Colorado .1 61.6 



Nevada 51.0 



New Mexico 54.6 



Utah 42.0 



Washington 27.6 



Wyoming 39.4 



Kansas 59.9 



Michigan 32.1 



Montana 32.6 



Nebraska 41.3 



North Dakota 31.4 



South Dakota 38.0 



Texas 54.6 



Wisconsin 28.8 



Massachusetts 28.6 



New Jersey 29.5 



New York 26.7 



Ohio . 24.6 



54.2 

 21.2 

 29.3 

 39.9 

 40.1 

 30.7 



45.2 

 30.2 



34.8 

 29.8 

 33.7 

 45.7 

 26.9 



25.8 



This table is not complete, but it shows unmistak- 

 ably, first, that evaporation is much greater in the arid 

 than in the humid region, and, second, that in both 

 humid and arid regions the evaporation from a free-water 

 surface, during the six summer months, is considerably 

 more than the total quantity of irrigation water that 

 should properly be applied in any one year. In the arid 

 states, as, for instance, California, with its high evapora- 

 tion record of nearly 72 inches, several times the quantity 

 of water that should be applied in irrigation may easily 

 be evaporated into the air during the growing season. 



From soils kept wet at the surface, evaporation goes 

 on even faster than from a water surface. For instance, 



