150 



THE PRINCIPLES OF SOIL MANAGEMENT 



When two soils of different texture are placed in 

 contact with moisture free to move from one to the 

 other, they come into moisture equilibrium after a time, 

 and each holds a certain proportion of the water. The 

 curvature of the water surfaces between the particles 

 80r 



NO. 2 FINE SAND 



VERY FINE SAND 



NO. 3 SILT 



NO. 4 CLAY 



NO.1 FINE GRAVEL 

 COARSE SAND 



MEDIUM SAND 



SOIL SEPARATES 

 Fig. 47. Curves showing the mechanical composition of the soils whose 

 capillary moisture capacity is shown in Table XX and Fig. 46. 



of the two soils is the same. But since in a given volume 

 of soil the fine texture has so many more of these indi- 

 vidual drops of water, its total content is greater than 

 that of the coarse-textured soil. This matter of the 

 curvature of the water surfaces in the soil will conie up 



