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varies from J / Q (in sandy soils) to ii/ i n clays, is also a little 

 higher than in similar English soils. Sulphates are practically 

 absent from the regur, the red-soils of Madras and the laterite 

 soils, but alluvial soils sometimes contain a small amount. 



73. We next come to the black cotton soils or regurs. 

 Their composition is not very variable in soluble silicates and 

 sand (65 to 75%.) Few samples contain less than 65% or 

 more than 75%. Fe 2 O 3 , 5^ to 8J% , rarely more than 8J and 

 less than 54%. /4/ 2 P 3 , 85 to 11 percent, rarely more or less. 

 Mridras regur soils contain more alumina than iron (by I to 

 2%) and C. P. regur soils more iron than alumina. Manga- 

 nese, '12 to '25%, sometimes, but very rarely, n"ore or less. 

 CaO, as carbonate and also partly as silicate. In those 

 samples in which there is 2% or more of lime, the greater 

 part is carbonate, where it is less than 2% it occurs chiefly 

 as silicate. Regurs usually contain 2 up to 4 or 5%. MgO, 

 1 '3 to 3' ! %- usually 2 to ?i%, which is rather a high propor- 

 tion. Alkalis, '15 to 2'44y/. The potash is unusually high 

 in regur soils. P 2 O 5t usually small. Below -I /, is the 

 rule; occasionally goes up to '2 / CO 2 , combined with 

 CaCo 3 , chiefly in small nodules of kankar^ is very variable in 

 proportion. SOs, hardly appreciable. Nitrogen, '012 to 

 050%. Regurs are poor in N. like most other Indian soils. 

 Organic matter and combined water occur in very high pro- 

 portion, but it is chiefly combined water and not organic 

 matter. In heating the regur changes colour from black 

 to dark brown and contracts very much in volume. 

 This is due to the loss of the water of hydration from 

 hydrated ferric oxide or alumina in which substances 

 the regur is specially rich. The regur is rather poor 

 in organic matter and nitrogen and its richness is chiefly 

 due to its friability and its power for retaining mois- 

 ture. Indeed the outturn of crops from unmanured land at 

 the Nagpur Farm is lower than from similar loamy soil in the 

 Gahgetic alluvium. At any rate, it is Dr. Leather's opinion, 



