AMMONIUM SULPHATE 



MANURES 



Mineral 



Mustard (p. 184), Safflower (p. 283), Til (p. 986), Cotton (p. 613), Earth-nut (p. 82) 



HI ..I Cocoanut (p. 300) tiro much favoured as cattle food*, while the other* that 



!> classed aa non-edible are largely used tut manure, the most important of 



M.-I- class being Castor-oil (see p. i2'2) ; but Poppy (p. 860) and Mahua 



(p. li'ii) may be added. U iili highly profitable crops, such a* sugar-cane, many 



<>t tl <iible cakes ore occasionally employed as manure*. Mollison point* 



out that tin- cultivators in this respect often act against their own interest*, 

 tin- IM-I..I- c.iUn very often fetches a higher price than some of the edible 

 uln.-li thoy refuse to use as manure. The advantage to India of the 

 oil-seeds being expressed in the country, instead of being exported, has been 

 repeatedly urged (Voelcker, I.e. 104). Profitable labour would be secured for 

 m. 1 1 iy persons and a larger percentage of cake retained and to a greater extent 

 than at present, very possibly, returned to the soil. The Annual Report* of 

 tin- various Agricultural Departments and Experimental Farms of India have 

 for many years past abundantly demonstrated the value of the cakes a* special 

 immures. '{('/. Leather, i.e. 157-62; Mollison, I.e. 122-33; Lehmann, Comm. 

 Firtil., in .\</ri. Journ. Ind., 1906, i., pt. ii., 123-6; also see article Oils and Oil- 

 seeds, p. sis.] 



Special Plant* as Manures. Adhatoda (see p. 26); helpful vegetation (see 

 pp. 54, 113-4). Plants with milky sap, such as Calotropls (pp. 53, 206) and 

 Euphorbia (p. 530), are specially preferred ; the refuse of Indigo (aeet, see p. 679) ; 

 aii'l many other such substances are valued as manures and often resorted 

 to by the cultivators. The reputation of .4/ii //, both as a manure and a 

 poison to destructive organisms that appear in the flooded rice-fields, is specially 

 worthy of attention. 



///. Mineral Manures. Though several very valuable manures of 

 this kind exist plentifully in many parts of India, their value and uses 

 are hardly anywhere appreciated. Some of these have already l>f'n 

 so fully dealt with in other positions in this work that all that need !><> 

 necessary is to furnish cross references : 



Lime. (See p. 712). As a rule lime is present in such abundance in the 

 agricultural tracts as scarcely to require its addition as a manure. 



Qypsum. (See p. 717). 



Ammoniacal Liquors and Ammonium Sulphate as Manures. (See pp. 48, 346.) 

 Sir John Lawes has pointed out that the objection to sulphate of am- 

 monia and all other " highly nitrogenous " manures, is that " they use up certain 

 natural ingredients in the soil, which when exhausted cause the plant to fail." 

 Jn iv further communication he condemned sulphate of ammonia, because it 

 removes lime from the soils. Where the percentage of lime is naturally low, 

 as for example in the tea lands as a whole, it should not be used, or only in ex- 

 ceptional cases. All artificial manures have the further objection that in countries 

 subject to heavy rains, soluble manures are very readily washed out of the soil, 

 so that their action is often only temporary ; a fall of rain of only a very few 

 inches may suffice to remove them entirely. For crops that occupy the soil 

 for brief periods only, such as wheat and barley, if given in combination with 

 potash either present in the soil or added as an ingredient of the special manures, 

 these chemical nitrogenous fertilisers may be of special value. [Journ. Soc. 

 Chem. Indust., 1899, xviii., 486; Mollison, I.e. 117-8; Watt and Mann, I.e. 

 154-5.] 



Nitrates. The nitrates of potash and soda are both largely employed as 

 manures. In a crude sort of fashion the Native cultivators of India here and 

 there show that they are aware of the value of crude saltpetre as a manure by 

 the value they place on surface soil collected near the homestead. Certain 

 localities, as for example Bihar, have been noted from time immemorial for 

 the large stores of saltpetre found naturally in the soil, and such localities have 

 accordingly been famed centres for the production of the salt. Saltpetre is 

 specially valued as a manure with tobacco, sugar-cane, and garden crops gener- 

 ally (see Saltpetre, p. 974). [(?/. Mollison, I.e. 119-21; Leather, Calcium 

 Nitrate and Nitric Acid, in Agri. Journ. 2nd., 1907, ii., pt. ii., 209-10.] 



Potash Manures: Pearl Ash, Kalnlt, etc. Saltpetre is valued not only as 

 a source of nitrogen, but on account of its potash. Continuous cultivation and 

 removal of crops must, therefore, gradually lower the stores of this all-important 

 material. With the return to the soil of decomposed vegetable matter or of 

 plant ashos, the potash is to some extent restored. But sooner or later it must 



771 



AdrtnUffM of 



oil 



I'roducUoo of 



Mineral. 



Lime. 



.-'..ij :. L!.-. 



D.E.P., 

 v., 175-6. 



Potuh. 



