170 Classification of Soils 



Table 111. U.S. Bureau of Soil's Classifitation. 



Coarse sand 

 Mcdiuni sand 

 Fine sand 

 Sandy loam 



Fine sandy loam 



Loam 



iSilt loam 

 Clay loam 

 Sandy clay 



Sill clay 

 Clay 



Fine 



gravel 



2-1 



Coarse " 

 sand 

 1-5 

 mm. 



Medium 

 sand 



More than 25 "„ (1+2) 



More than .W "„ (1+2 + 3) 



Less than 20 "„ (1+2) I 



More than 20% (1+2-t 3) 



Less than 20 "o (1+2 +3) 

 More than 20'?;, (1+2 + 3) 



Less than 20% (1+2 + 3) 



Fine 



sand 



■25-10 



mm. 



Very fine 



sand 



■10-05 



mm. 



Silt 

 •05-005 



mm. 



Clay 

 •005-0 



0-15 \ 0-10 % 



Less than 20 "i, (G + 7) 



0-15% I 0-10% 

 Less than 20 % (6 + 7) 



0-15% I 0-10% 

 Less than 20% (6 +7) 



10%-35%|5%-15", 

 More than 20 "„ ((> H 7 

 l.*'S8 than 50 % (6 + 7) 



More than 20 "„ (6 + 7) 

 Less than 50 "„ (6 + 7) 



Less than 15%-25",, 

 55 % (6) 

 More than 50% (6 + 7) 



More than 

 55 % (6) 



•2.T o' _r,,-, q/ 



I>ess than 

 25 % (7) 



25 %-35 



More than 60 % (6 + 7 1 



Less than 

 25 % (6) 



More than 

 20 % (7) 



Less than 60 % (6 + 7) 



More than 

 55 % (6) 



25%- 

 35 % (7) 



More than 

 35 *^' (7) 

 More than 60% (6 + 7) 



witli a furtlier inoditication. Soils arc clas.'iifipd into fmirtecii uroiips, th« 

 liiiiiting 2)r()porti()ii.s are giveu iu Table 1\', and illustrated grajiliically 

 in Fig. 3. 



Atteiitiou is directed to the following considerations in connection 

 with this method : 



1. Only a comparatively small area of the whole triangle is employed. 



2. The crop types are not so well differentiated as in that of the 

 U.S. Bureau of Soils. 



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