THE DRY FARMING CONGRESS. 157 



RAIN FALL AT NORTH PLATTE NEB. 



§ 



■06 



1 10 INCHCSl 



APRIL 



MAY 



JUNE 



JULY 



AUGUST 



SEPTEMBER 



sasoN 



2.9 



2.8 



0.7 



ai 



6.6 



4.3 



19.4 

 8.6 

 28.0 

















1 



1 lu. 



1 .. L.. 





h 



il Jl 









1 



0.2 



2.« 



2.5 



4.8 



1.S 



2.4 



14.3 

 6.8 

 19.6 





















.1. 



L . . 





1 .ll. 



.1 



. .. 1, 



ll 



•08 



t 



0.5 



4.6 



6,0 



3.4 



1.9 



0.2 



16.6 

 3.4 

 20.0 



















.1 . 



t ., 



J.. 



...L 





,ll 1. 



1 I 1 M . 



1 



Fig. 4. 



Nebraska (Fig. 4). The total annual rainfall was practically the same 

 at this station for the years 1907 and 1908, being about 20 inches. In 

 1907, in spite of a dry August, the heavy rain on the first of September 

 was sufficient to germinate the fall grain. In 1908, no rains occurred after 

 July 21 that were sufficient to wet through the dry surface soil. The 1.9 

 inches of rain which fell in numerous showers during August was con- 

 sequently entirely lost before seeding. Septemiber was almost completely 

 without rain. As a result, the only fall sown grains that germinated were 

 those sown on summer fallowed land. 



Summer Fallow. 



"The efficiency of a summer fallow in storing moisture is greatly 

 influenced by the amount of rain falling during the day, and the rapidity 

 with which it comes. Referring again to the North Platte rainfall chart 

 for August, 1908, it will be seen that nine rains occurred during that 

 month, none of which exceeded .4 inches. The total rainfall for the 

 month was 1.9 inches, yet none of the rains were sufficient to wet through 

 the mulch on the summer fallow. It has been the general experience of 

 the men in charge of our dry land stations that rains of less that .3 or .4 

 of an inch are of no value in storing water in a summer fallow. These 

 light rains serve simply to pack the mulch, and necessitate extra culti- 

 vation without increasing the amount of soil moisture. 



"The other extreme is met with in the case of torrential rains, where 

 the water falls so rapidly that it has little opportunity to enter the 

 ground, so that a large percentage of it is lost. Even summer fallowed 

 land is not capable of absorbing the rainfall in the case of torrential 

 rains. Observations by Mr. Farrell made last season at the Nephi sta- 

 tion in Utah, showed that during a torrential rain of 2.6 inches which 

 fell in about four hours, the summer fallowed plots were able to absorb 

 only an amount of moisture equal to about a quarter of an inch of rainr 



