CHAPTER XIII 



ARTIFICIAL MANURES AND FERTILISERS 



Nature of a Fertiliser. Fertilisers containing Nitrogen — Nitrate 

 of Soda, Sulphate of Ammonia, Soot — their Use and Value. 

 Fertilisers containing Phosphoric Acid. Bones, Superphos- 

 phate or Acid Phosphate, Basic Slag or Phosphate Powder, 

 Ground Rock Phosphate. Potash Fertilisers. Guanos. 

 Industrial Residues. Tankage. Action of Fertilising 

 Ingredients upon Crops. Expenditure on Fertilisers. 

 Character of Fertiliser required for particular Crops. 

 Valuation of Fertilisers. 



It has already been explained that of the elements 

 found in a plant, a certain number are absolutely 

 essential to its development, but that most of these are 

 ordinarily to be found in the soil in sufficient quantities 

 for the plant's requirements. There are, in fact, only 

 three of these substances in which the soil shows any 

 deficiency, and the bodies which we call manures or 

 fertilisers are substances containing one or more of 

 these three elements — nitrogen, phosphorus, or potash. 

 At the present time the terms artificial manure and 

 fertiliser are used indifferently to indicate such com- 

 mercial materials as are of value to the plant, whatever 

 their origin ; from the farmer's point of view an artificial 

 manure is any concentrated plant food which he 

 purchases and receives in bags. In reviewing these 

 substances we must begin by drawing a distinction 

 between the fertilisers which contain only one ingredient 



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