I50 



Journal of Agricultural Research 



Vol. X, No. 3 



and 29. The figures, however, show even more clearly the great part 

 played by soil types in determining the amount of moisture and the dis- 

 tance that it will travel from the source of supply in a relatively short 

 time. For instance, very coarse and very fine soils (sand and clay) 

 show the greatest variations, while in loam the difference is scarcely 



appreciable. 



With thb Action op Gravity 



To show the effect of the distance from the source of water with gravity 

 acting, figure 31 has been prepared from the data of the experiment rep- 

 resented in figure 23. It shows the distribution by 2-inch sections in 

 the tubes which were in contact with moist Greenville loam in the tub. 

 Here it is noticed that distance from the source of supply plays little or 

 no part in the moisture content of the tubes that were vertically and 45° 



Piercent<3se of moisture at various dist ancss from the source of supply 

 in soils of different tupes 





TloTT 





12 



I" 



H 



5Wj57i 





muck 25i 'cLau SOViLcam 5&, 



Tc/pe of different soils 



^__ J \Sand /5% \5and 507ASand 5llfr \Sand i.Uom 



J /i /5 



J I'o /3 



uayi 



CLay 



CL ay 50^ + GreenrilLe 

 Loam 50% Loam 



sinsini 



TTWWli 



Fig. 30.— Diagram showing the horizontal distribution of capillary moisture at various distances from 

 the source of supply in soils of different types. The source of supply in each case was Greenville loam 

 having 30.45 per cent of moisture. 



down. Where the movement was horizontal or up, however, the greatest 

 moisture content was nearest the source of supply. The largest differ- 

 ence between the section nearest and that most remote from the wet 

 soil was found in the column with the movement vertically up. 



Figures 24, 25, 26, 29, 30, and 31 lend excellent support to each other 

 in showing that, except where gravity acts, moisture will distribute 

 itself with the largest amount nearest and the smallest quantity farthest 

 from water held in moist soils, even after several months. 



SUMMARY 



(i) During recent years considerable difference of opinion has grown 

 up regarding the importance of the capillary movements of soil moisture 

 and also regarding the laws governing the final distribution of moisture 

 in the soil. 



