Abstract

                                It is well-known that the plant-food to which crops react generally readily is nitrogen. The soil surveys of the various districts have pointed to a general deficiency of this ingredient. The natural supplies are mainly Farm Yard Manure and green leaves. These sources are far too poor to supply the demands and the need for chemical manures is great. Of these, the most aportant ones are Nitrate of Soda, Sulphate of Ammonia, and Jalcium Cyanamide. The first is as much a natural manure as farm Yard Manure since it is dug out of the natural deposits in Chili. Its supply is certainly not inexhaustible and Scientists are entertaining serious fears of its extinction. Till very recent times, Ammonium sulphate was a by-product of the coal-gas industry and its price was rather very high and its future was not much brighter than that of Sodium Nitrate.

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