juiyi6, I9I7 Movement and Distribution of Moisture in Soil 



121 



irrigation conditions. The quantities of manure applied were none, 

 5 tons, and 15 tons. 



Figure 4 gives the effect of these quantities of manure on the moisture 

 in the fall to a depth of 10 feet. This figure brings out a remarkable 

 difference between the manured and unmanured plots. For the un- 

 manured plots, both cropped and fallow, the moisture approached a 

 maximum in the second, third, sixth, and seventh feet, with a rapid 

 decrease to the tenth foot. In the manured fallow soil the maximum 



Percenfa-ge of moulufe 4Vith different amounts of manure 



\FoLL^*y 



JS^Cropped 



Fig. 4. — Diagram showing the effect of different applications of manure to irrigated soils on the distribution 

 of moisture in the fall to a depth of 6 feet. Average of three years. 



moisture occurred at the same depths as in the unmanured soil, but the 

 eighth instead of the tenth foot had least. 



The cropped manured plots showed the moisture to decrease rapidly 

 from the surface to the sixth foot, after which it increased until at the 

 tenth foot in the 5-ton plot there was more moisture than at any other 

 depth. The unmanured plot showed a much higher average moisture 

 content than the 5-ton plot and about the same as the one that received 

 the 15 tons. The variation between the moisture in cropped and fallow 

 soils was greatest in the 5 -ton plot and least in the unmanured, the 

 greatest differences occurring in the fifth, sixth, and seventh feet in 

 the manured, and in the top few feet of the unmanured plots. 

 98974°— 17 2 



