152 



THE PRINCIPLES OF SOIL MANAGEMENT 



moisture-holding capacity while a reasonable granulation 

 of a clay soil increases its moisture-retaining capacity. 



This effect of structure on the moisture capacity 

 of two soils is illustrated by the following curves, based 

 upon the results of Buckingham. The mechanical 

 analysis of these soils may be found in curves already 

 given. (See page 150.) The sandy loam is No. 3, and the 

 clay is No. 5. 



50 



10 



--30 



5 



>. 20 



< 

 olO 



10 20 30 40 50 



Fig. 48. Curves showing the distribution of water in columns of sand and 

 clay when loose and compact and capillarily saturated. Figures given in 

 Table XXI. 



Table XXI. Per Cent of Water in Sand and Clay, Loose 



and Compact 



