326 SOILS AND FERTILIZERS 



Scheme of Soil Classification 



(Adapted from Bureau of Soils Report, U. S. Dept. Agr.) 



Coarse sand contains more than 20 per cent of coarse sand and 

 more than 50 per cent of fine gravel, coarse sand, and medium sand, 

 less than 10 per cent of very fine sand, less than 15 per cent of silt, 

 less than 10 per cent of clay, and less than 20 per cent of silt and 

 clay. 



Medium sand contains less than 10 per cent of fine gravel, more 

 than 50 per cent of coarse, medium, and fine sand, less than 10 per 

 cent of very fine sand, less than 15 per cent of silt, less than 10 per 

 cent of clay, and less than 20 per cent of silt and clay. 



Fine sand contains less than 10 per cent of fine gravel and 

 coarse sand, more than 50 per cent of fine and very fine sand, less 

 than 15 per cent of silt, less than 10 per cent of clay, and less than 

 20 per cent of silt and clay. 



Sandy loam contains more than 20 per cent of fine gravel, coarse 

 sand and medium sand, more than 20 per cent and less than 35 

 per cent of silt, less than 15 per cent of clay, and less than 50 per 

 cent of silt and clay. 



Fine sandy loam contains more than 40 per cent of fine and 

 very fine sand and more than 20 per cent and less than 50 per cent 

 of silt and clay, usually 10 to 35 per cent of silt and from 5 to 15 

 per cent of clay. 



Silt loam contains more than 55 per cent of silt and less than 25 

 per cent of clay. 



Loam contains less than 55 per cent of silt and more than 50 

 per cent of silt and clay, usually from 15 to 25 per cent of clay. 



Clay loam contains from 25 to 55 per cent of silt, 25 to 35 per 

 cent of clay, and more than 60 per cent of silt and clay. 



Clay contains more than 35 per cent of clay. 



Sandy clay contains more than 30 per cent of coarse, medium, 

 and fine sand, less than 25 per cent of silt, more than 20 per cent of 

 clay, and less than 60 per cent of silt and clay. 



Silt clay contains more than 55 per cent of silt and from 25 to 35 

 per cent of clay. 



