390 



Average composition of Fertilizers. 



The following table gives the average percentage composition of 

 the various artificial fertilizers in common use. From this table it will 

 be easy to see what quantity of any particular fertilizer can replace 

 any other in order to supply equivalent quantities of the same consti- 

 tuent. 



Nitrogen Fotash O. Phosphoric acid. Lime Ca O 

 N. per cent. per cent. per cent. per cent. 



Ammonium Sulphate 20% 



Potassium Nitrate 13% 46% 



Sodium Nitrate 15.5% 



Ordinary Super- 

 phosphate ... ... 20% 35% 



Double or concentrat- 

 ed Superphosphate ... ... 44% 



Basic Slag ... ... 17% 



Mineral Phosphate ... ... 36.5% 



Bone meal ... ... 21% 



Bone dust ... ... 20% 



Potassium Chloride ... 6o% 



Potassium Sulphate ... 52% 



Kainit ... 12.4% 



Perils Guano (Phos- 



phatic) ... ... 15.5% 



Ground Nut Cake 8% 1.2% 1.2% 



Rape Cake 6% 1.2% 2.3% 



Para Seed Cake 5% 1.2% 1.2% 



Castor Seed Cake 6% 1.2% 1.2% 



Calcium Nitrate 13% 



Calcium Cyanamide 20% 



REMARKS ON THE PURCHASE AND USE OF FER- 

 TILIZERS: — No fertilizers should be purchased without a guarantee 

 from the vendor of the percentage of the essential constituent in each 

 case. In most countries the buyer is protected by a Fertilizers Act. 



The purchase of mixed manures is not recommended as these are 

 much more expensive, since the buyer has to pay for the cost of 

 mixing and the experience of the vendor. 



The following manures should not be mixed together, otherwise 

 loss results due to volatilization or to chemical action between the 

 constituents : — 



1. Lime and Ammonium Sulphate. 



2. Basic Slag and Ammonium Sulphate 



3. Lime and Superphosphate 



4. Superphosphate with Sodium, Potassium or Calcium Nitrate 



5. Lime and Nitrogenous Guanos 



6. Basic Slag and Nitrogenous Guanos 



B. J. EATON, F.i.c, F.C.S., 



Agricultural Chemist, F.M.S, 



