[ 6? ] 



The above three analyses give some idea of the variableness of 



composition of the soil of Sibpur Farm, which is chiefly in lime and 

 the alkalis. 



V. Calcareous soil from Pratapgarh (Oudti) : 



Insoluble Silicates and Sand ... ... ... 57*52 / o 



Fe 2 O 3 ... ... 3' 2 3 



A1 2O 3 3'39 .1 



MnO Nil 



CaO ... ... 14-54 



MgO ... ... ... r86 



K 2 ... ... ... ... - 44 



Na 2 O ... ... ... ... -02 



P 2 5 ... ... ... 'i8 



SO 3 ... ... -08 



CO 2 ... 11-42 ,,, 



Organic matter and combined water ... *j 32 



lOO'OO 



* N = 'i8o/o 



72. Though calcareous soils are rare in India, beds of 

 kankar commonly underlie the Indo-Gangetic alluvium, the 

 black cotton soil and other soils. The surface soil of the 

 alluvium is usually free from kankar, except where there is an 

 outcrop of the bed of kankar. In the black cotton soil, the 

 kankar occurs in beds as well as mixed up with the soil. Some 

 of \\\t.regur soils contain as much as 10 % of calcium car- 

 bonate. iThe soil of the Sibpur farm is rich in calcium 

 carbonate (about 3. per cent.). The amount of P 2 O 5 aUo in 

 Indo Gangetic alluvial soils is usually more than in other 

 Indian soils. The amount of potash in the samples examined 

 is sufficient. The amount of N and organic matter in Indo- 

 Gangttic alluvium is usually low. The amount of iron and 

 allumina in the Indo Gangetic alluvium is usually higher than 

 in European loams and clays. The sandy soils contain 

 about 2^7 of these. The proportion is higher in loams, while 

 in. clays ft is 6 to- 8/.. The proportion of magnesia which, 



