July i6. 1917 Movement and Distribution of Moisture in Soil 



151 



(2) The present paper gives the results of soil-moisture experiments 

 conducted in the laboratory and in the field under irrigation and dry- 

 farming conditions. The experiments represent several thousand mois- 

 ture determinations. 



(3) The field studies include the effect of fallow, kind of crop, manure, 

 irrigation water, surface mulches, cultural methods, and seasonal condi- 

 tions on the movement and distribution of soil moisture. 



(4) The laboratory studies include the efifect of the initial percentage of 

 moisture, gravity, soil type, source of supply, etc., on the movement and 

 distribution of moisture in the soil. 



(5) In field soils the moisture content of the fallow soils averaged 

 greater than that of the cropped soils. 



Percenfage of mo/sfure m^/ZA different d/rechons of mofirm&nf 



VefhcaUu doivn 'ff'do\^n 



Uirectton of rnoi'emenf 



l~fcn£-on/aL 



VerftcaUu cio 



Fig. 31. — Diagram showing the distribution of capillary moisture at various distances from the source 

 of supply as affected by gravity. The source of supply iu each case was Greenville loam with 30-25 per 

 cent of moisture. 



(6) Unmanured irrigated land showed less difference in moisture 

 between cropped and fallow than did the manured. 



(7) Irrigation influenced the top feet of the cropped plots proportion- 

 ately more than the fallow, but water did not appear to penetrate the 

 fallow plots below 7 feet as readily as it did the cropped ones. 



(8) Under dry-farming conditions the difference in moisture between 

 cropped and fallow plots was not noticeable until after June 16. Cropped 

 plots showed more fluctuation than fallow ones. Wheat, corn, potatoes, 

 and peas drew most of their moisture from the first 4 feet in depth. The 

 wheat land contained less moisture in the fall than the other cropped 

 soils, with corn following. 



(9) The increase in moisture due to applications of 5 to 7K inches of 

 irrigation water was felt to depths of 10 feet in 24 hours, although most 

 of the increase was in the first 4 feet. 



