124 



Journal of Agricultural Research 



Vol. X, No. 3 



fallow plots is made clear by the graph. The difference between the 

 moisture in cropped and fallow soils decreased with the larger appli- 

 cations of water. 



Distribution One Week After Irrigation in Beet and Potato Plots 



These data were secured from the unmanured plots 41 F to 45 F and 

 61 F to 65 F on the Greenville Farm during 1912 and 1913. Plots 41 F 



to 44 F and 61 F to 64 





Percentages of mo/sture with 

 different frr'iQafions 



F were irrigated weekly 

 with applications of i, 

 7.y2, 5, and 7X inches, 

 respectively, while 45 

 F and 65 F were unirri- 

 gated. Samples of the 

 soil were taken imme- 

 diately before irrigation 

 and 24 hours after, each 

 plot being sampled in 

 three places to elimi- 

 nate possible inequality 

 in the distribution of 

 the moisture. 



Plots 41 F to 45 F 

 were cropped with po- 

 tatoes, while 61 F to 65 

 F were in sugar beets. 



Figure 7 gives the 2- 

 year average moisture 

 content one week after 

 the irrigation of the 

 beet and potato plots. 

 Increased irrigations 

 are shown to have in- 

 creased the moisture 

 content, but the first 

 2K inches of water 

 produce by far the 

 greatest proportionate 

 gain, especially on the 



Fig. 7.— Diagram showing the effect of different quantities of irriga- l^PPCr SOll layers, 

 tion water on the distribution of moisture one week after irrigation With the exception of 

 ia beet and potato plots to a deoth of 10 feet. Average of two years . . , .„ ^„ 



. the moisture in the po- 

 tato plots receiving no irrigation, there was a marked tendency for 

 the water to accumulate in the second, third, fourth, ninth, and tenth 

 feet, with a depression at medium depths. 



Beets 



^^^^ Potatoes 



