GEAIN-SOEGHUM EXPERIMENTS IN THE PANHANDLE OF TEXAS. 



15 



Temperature. 



The daily range in temperature is large, but not excessive. In 

 general, the days in summer are warm to liot and the nights nearly 

 always cool. Owing to the altitude (3,600 feet) the summer tem- 

 peratures are not as high as might be expected from the southern 

 Location. On the other hand, winter temperatures are not as low 

 as might be expected from the elevation. 



The data on maximum, mean, and minimum temperatures and 

 ^eatest daily range, by months, in the 10 years from 1907 to 1916, 

 nclusive, are given in Table IV, which also contains data on precip- 

 tation, the aspect of the sky, and the movement of the wind. 

 Ihe lowest recorded temperature in the period covered by these rec- 

 ords was —11° F. on January 6, 1912, and the highest 105° F. on 

 lune 25, 1911. The average date of the last spring frost is April 

 L9 and that of the first fall frost October 30, leaving an average frost- 



"ree period of 194 days. 



Evaporation. 



The loss of moisture by evaporation in the Panhandle district is 

 T-ery great. The chief factors concerned are precipitation, wind, 

 md temperature. The maximum evaporation naturally occurs, 

 therefore, in periods of high temperatures and strong winds. 



Table V contains a comparison of monthly precipitation and 

 evaporation records made at the Amarillo Cereal Field Station^ during 

 :he six months from March to September in the 10-year period from 

 L907 to 1916, inclusive. The evaporation measured is from the free 

 ivater surface of a tank 8 feet in diameter. During this period, the 

 evaporation was nearly four times as great as the precipitation 

 luring the same period. In 1909 a maximum of 0.69 of an inch was 

 evaporated from this tank in 24 hours. These data show contrib- 

 iting causes for certain crop results in various years. 



Cable V. — Monthly, seasonal, and 10-year monthly average precipitation and evapora- 

 tion, in inches, at the Amarillo Cereal Field Station, during the six months from April 

 to September, inclusive, for the 10-year pe^riodfrom 1907 to 1916, inclusive. 





April. 



May. 



June. 



July. 



August. 



September. 



Seasonal 

 total. 



Year. 

































Prec. 



Evap. 



Prec. 



Evap. 



Prec. 



Evap. 



Prec. 



Evap. 



Prec. 



Evap. 



Free. 



Evap. 



Prec. 



Evap. 



907... 



1.3 



6.4 



1.1 



8.1 



2.2 



9.6 



1.5 



10.7 



6.2 



9.4 



1.0 



7.9 



13.3 



52.1 



908... 



1.9 



7.3 



3.4 



9.3 



1.7 



10.4 



4.6 



8.1 



3.4 



8.6 



1.5 



6.8 



16.5 



50.5 



909... 



.3 



8.1 



1.1 



10.0 



5.9 



10.3 



2.2 



10.0 



1.4 



9.7 



1.9 



8.4 



12.8 



56.5 



aio... 



.5 



8.5 



2.6 



8.0 



1.5 



12.0 



2.6 



12.2 



2.5 



8.8 



.1 



9.1 



9.8 



58.6 



911... 



3.9 



7.4 



6.7 



10.1 



.4 



11.5 



5.9 



7.5 



2.5 



8.9 



1.3 



7.3 



20.7 



52.7 



912. . . 



.8 



7.1 



1.6 



9.9 



2.3 



9.0 



2.5 



10.9 



1.5 



9.5 



2.3 



6.5 



11.0 



52.9 



913... 



1.7 



7.7 



1.7 



9.8 



2.3 



7.0 



1.4 



12.7 



• .5 



10.3 



5.6 



5.9 



13.2 



53.4 



914... 



1.3 



6.7 



3.8 



6.7 



.7 



10.1 



1.9 



8.7 



2.5 



8.9 



1.1 



8.0 



11.3 



49.1 



915... 



4.8 



4.6 



2.0 



6.9 



1.2 



8.8 



3.7 



9.3 



4.6 



7.3 



4.9 



6.0 



21.2 



42.9 



916... 



1.8 



6.0 



.9 



10.3 



2.7 



10.7 



1.2 



11.7 



3.4 



10.2 



2.2 



7.7 



12.2 



56.6 



Av 



1.8 



7.0 



2.5 



8.9 



2.1 



9.9 



2.8 



10.2 



2.9 



9.2 



2.2 



7.4 



14.2 



52.5 



^ 1 The precipitation and evaporation data given in Table V were obtained at the Amarillo Cereal Field 

 Station in cooperation with the OflQce of Biophysical Investigations and the OfQce of Dry-Land Agriculture 

 )f the Bureau of Plant Industry, U. S. Department of Agriculture. 



