i 9 4 



THE FIRST BOOK OF FARMING 



nitrogen fertilizers. It is used for quick results and 

 should be applied only to land that has a crop or is 

 to be immediately planted, otherwise it is liable to 

 be lost by leaching. 



Sulphate of Ammonia contains 20 per cent, 

 of nitrogen. It is a white salt, finer and cleaner 

 looking than the nitrate. It is a by-product of the 

 gas works and coke ovens. The nitrogen in it is 

 quite readily available. 



Dried Blood contains 8 to 12 per cent, of nitro- 

 gen. This is blood collected in slaughter-houses 

 and dried by steam or hot air. It decays rapidly 

 in the soil and is a quick acting nitrogen fertilizer. 



Tankage contains 4 to 8 per cent, of nitro- 

 gen and 7 to 20 per cent, of phosphoric acid. 

 Slaughter-house waste, such as meat and bone 

 scrap, are boiled or steamed to extract the fat. The 

 settlings are dried and ground and sold as tankage. 

 It is much slower in its action than dried blood and 

 supplies the crop with both nitrogen and phosphoric 

 acid. 



Dried Fish Scrap is a by-product of the fish oil 

 factories and the fish canning factories. It contains 

 7 to 9 per cent, of nitrogen and 6 to 8 per cent, of 

 phosphoric acid. It undergoes nitrification readily 

 and is a quick acting organic source of nitrogen 

 and phosphoric acid. 



Cotton-seed Meal contains 7 per cent, of nitro- 

 gen, about 2.5 phosphoric acid, and 1.5 per cent, of 

 potash. It is a product of the cotton oil factories 

 and is obtained by grinding the cotton seed cake 



