INTRODUCTION. 



vii 



Composition per cent. 



Composition per cent. 



Cotton soil. Farm soil. 



Cotton soil. I Farm soil. 



Chlorine, 

 Sulphur trioxide. 

 Phosphorus pentoxide, 

 Silica and tungstic oxide (latter 



0-64 

 7-66 

 0-11 



Trace. 

 Trace. 

 0-51 



niaydccom- ( Alumina,... 



posed by ) Oxide of iron, 



SO4. (Silica, ... 

 Insoluble sand, &c., ... 



7-57 

 0-10 

 13-55 

 54-51 



3-37 

 78-56 



94 



in farm soil only), ... 

 Alumina, 



Oxides of iron and manganese,... 



Lime, ... 



Magnesia, 



Potash, 



Soda, ... ... ... 



0-38 

 0-24 

 3-33 

 3-66 

 0-99 

 0-28 

 0-43 



0-13 



4- 20 



5- 59 

 0-90 

 0-91 

 0-32 

 0-08 



Total soluble in hydrochloric 

 acid, 



17-72 



12-64 



Grand total. 



99-81 



10002 



The dark colour of the cotton soil (which almost disappears on drying) is obviously not due to peat, as 

 the proportion of organic matter is so small, but is probably caused by some compound of iron. The most 

 notable point about its composition is the large proportion of gypsum it contains, the sulphuric acid and lime 

 being in such quantities as to be equal to 6 or 7 per cent, of gypsum, even supposing some of the acid to be 

 combined with magnesia, oxide of iron and other bases. 



A notice of the soils of the Proviaces would be imperfect without some account of (1), usar ; (2), 

 kankar ; and (3), the nitrates which are found in the soil and well water of certain localities. 



Usar is the term applied to a yellowish clayey soil which is rendered infertile by containing an 

 excess of soluble salts. These salts chiefly consist of sodic sulphate (Glauber's salts) generally accom- 

 panied by varying proportions of impure sodic carbonate. They often amount to as much as 20 

 per cent, on the weight of the surface soil, which is at least forty times the proportion consistent with 

 fertility. Under conditions favorable to surface evaporation the salts accumulate on the surface, in 

 some places covering square miles of country with a dazzling white efflorescence, which no one who 

 has ridden across will easily forget. The extent of the loss which these salts entail may be judged of 

 from the fact that out of the 64 million acres which form the total area of the N.-W. Provinces* and 

 Oudh 2^ million acres, or 4 per cent., are returned as uncultivable, solely on account of being impreg- 

 nated with them. 



The most extensive tracts of usar are in the Districts of the Ganges- Jumna Doab east of Meerut, 

 where they amount to 11 per cent, on the total area. They occur but sparsely in the damper 

 Districts of Rohilkhand, north Oudh and Benares, and are unknown in Bundelkhand. 



The most striking fact in connection with usar land is the extreme irregularity of its distribu- 

 tion. Not only are usar plains of the most fantastic outline and often interspersed with small oases 

 of fertile land, but frequently single fields may be met with containing narrow strips of usar only one 

 or two feet broad in the midst of a luxuriant crop. It may still be considered a doubtful question 

 whether the salts are peculiar to usar soil, and were originally deposited with it, or whether they 

 have been concentrated in it from the surrounding soil either by a long-continued process of capil- 

 lary attraction and surface evaporation, or by ti'ansfer over the surface in drainage water. But it may 

 be accepted as certain that impermeability to the downward percolation of water is one of the most 

 marked characteristics of usar soil, and this would of course enormously assist surface concentration, 



Excluding the hill tracts of Kumaun and Garhwal. 



