CLIMATIC CONDITIONS ON THE TRUCKEE-CARSON PROJECT. 29 



Table V. — Average monthly wind velocity, in miles per hour, at the experiment 



farm, Fallon, Nev., 1909 to 1912, inclusive. 



RAINFALL. 



The rainfall in the region of the Truckee-Carson Project is so light 

 that it is of little benefit to growing crops. Table VI gives the 

 monthly precipitation for the seven years 1906 to 1912, inclusive. 



Table VI.— Monthly and annual rainfall at Fallon, Nev., 1906 to 1912, inclusive. 



EVAPORATION. 



The amount of evaporation from a free water surface depends 

 chiefly upon three factors, namely, air temperature, humidity of 

 air, and wind velocity. Table VII shows that the evaporation is 

 greatest during the hottest months. During these months the sur- 

 face of the soil dries out quickly, and farmers often find difficulty in 

 getting seeds planted at this time to germinate before the surface soil 

 dries out. In the spring while there is low evaporation it is not 

 usually difficult to get seeds to come up without irrigation, but dur- 

 ing the period of high evaporation it is often necessary to irrigate 

 fields after seeding in order to get a good stand. 



[Cir. 114 j 



