FISH MANURE. 35 



Nitrogenous guano is a highly concentrated manure, 

 and may be employed with excellent effect for corn crops, 

 potatos, and roots. Phosphatic guanos may be employed 

 for turnips, but such guanos are more usually converted 

 into superphosphate before they are applied to the land. 



Pish Manure. This consists of fish refuse dried and 

 powdered. It contains usually 7 8'5 per cent of nitrogen. 

 That made from cod contains 13-14 per cent of phos- 

 phoric acid as phosphate of calcium, and that made from 

 haddock and herring 6 9 per cent. If much oil is present 

 the value is diminished, as the manure decomposes more 

 slowly in the soil. 



Sulphate of Ammonium. This substance is prepared 

 from the ammoniacal products of gas works, coke ovens, 

 bone distilleries, &c. In its crystallised form it is the 

 most highly nitrogenous of all the manures at a farmer's 

 disposal, containing 24 25 per cent, of ammonia, or 19'8 

 20' 6 per cent, of nitrogen. 



It should be ascertained that the manure is free from 

 sulphocyanate of ammonium, as this substance is very 

 injurious to plants. If sulphocyanates are present, a solu- 

 tion of the salt will become blood-red on the addition of 

 ferric chloride. 



Sulphate of ammonium is a " special " manure, valua- 

 ble solely for its nitrogen. It is a powerful manure for 

 corn crops, for which it is best employed in conjunction 

 with superphosphate. Admixture with phosphates and 

 potassium salts is more necessary for obtaining a profit- 

 able result with ammonium salts than it is when nitrate 

 of sodium is employed. 



