Manures in General 



buying various artificial manures for its members, 

 itself controlling the value of the manures. 



In the mean time each farmer could calculate 

 for himself the price per unit that should be asked, 

 and could have the analysis made for his guidance 

 in a deal of any great importance. 



Here is a means of calculating. 



In the Guide to Experiments for 1915 for the 

 County of Northumberland we find that the super- 

 phosphate employed contains soluble phosphoric 

 acid equal to 26 per cent, phosphate of lime, and that 

 it was worth £2 17s. per ton. Phosphoric acid, 

 then, corresponds to 26 units of phosphate of lime. 

 Therefore the unit per ton will come to £2 17 s. -^ 26 

 = 2s. 2d. approx. 



Now, taking this price of 2S. 2d. per unit to the 

 ton as a standard price, and supposing a super con- 

 tent of soluble phosphoric acid equal to 40 per cent, 

 phosphate of lime, one would pay 40 units X 2S. 2d. 

 = £4 6s. 8d. to the ton, and would gain an 

 advantage in using this, as we shall see when we 

 come to consider the cost of transport. Chloride 

 of potash [KCl] costs £9 per ton, and contains about 

 50 per cent, potash (K2O), so that the unit of 

 potash costs here 3s. yd. per ton. If we take 

 kainite, supposing it contains, for example, 13 per 

 cent, of K2O to replace the KCl, we should pay 

 3s. yd. X 13 = £2 ys. per ton, and we should pay 

 even a little too much. 



The same ought to be paid, for the unit of ferti- 

 Hsing matter in compound manures as in simple. 

 For each unit of fertilising matter, the standard price 

 corresponding, should be calculated, and the buyer 



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