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are 6 to 9 inches high, as germination and growing of young 

 seedlings are hindered by the application. It is only in showery 

 weather that it proves highly beneficial. It is therefore 

 applicable to early Bhadai crops or early rabi crops. Grain 

 crops are chiefly benefited, also those which are valued for 

 their leaves, such as pot-.herbs (sags), cabbages, mulberry, &c. 

 Onions, table vegetables and root-crops generally are also 

 benefited by nitrates. Leguminous crops are actually injured 

 by the application. 



829. Each farmer can easily have his own covered 

 and enclosed nitre-bed as a perpetual source of manure for 

 his fields. It is important to secure a uniform tem- 

 perature of about 98 F. Below 40 or 45 F. and above 

 130 F. nitrification ceases. . The earth should be kept 

 loose. There should be enough of moisture, lime and organic 

 matter in it, but not too much of the first two. Warington 

 could not ordinarily discover nitrifying Bacteria below a 

 depth of 1 8" and the looseness of soil in the nitre : bed 

 need not therefore extend beyond 18". Darkness also 

 favours nitrification. This is one reason why manures should 

 be kept in dark cellars and sheds. Compost heaps should be 

 also kept under trees or sheds. Salt, coal-tar, spent lime 

 of gas works, ferrous sulphate and disinfectants or germi- 

 cides generally, retard the process of nitrification. Rapid 

 putrefaction also hinders nitrification, and it is therefore 

 necessary that manure heaps should remain sweet. A wet 

 and puddly pen or cow house is not so suitable for the pro- 

 cess of nitrification as a stall in which the dung is spread 

 about and kept moderately warm and only occasionally 

 moistened with urine. The lime used for nitre-beds should 

 never be in the form of caustic lime which sets free ammonia 

 and hinders nitrification, but in the form of carbonate. 

 Warington has pointed out that if Gypsum is mixed with 

 strong solutions of urine so that the carbonate of ammonia 

 be converted to sulphate and the excessive alkalinity of the 



