MANURES 



31 



TABLE III. COMPOSITION OF COMMERCIAL FERTILIZING MATERIALS 

 Continued. 



*Sometimes as high as 5 per cent. 



fRaw rock phosphate has from 18 to 30 per cent of phosphoric acid. 



jNova Scotia plaster contains 94 per cent pure gypsum and 4 per cent carbonate 

 of lime; Onondaga and Cayuga, 65-75 per cent gypsum and 18-28 per cent carbonate 

 of lime. 



Animal Manures. Manure from animals of the same 

 class may vary greatly in quality according to the kind of 

 food and the condition and age of the animals. Fat 

 animals fed on food rich in nitrogen (grains) produce the 

 best manures. Young, growing animals that are fed on 

 poor food, such as straw, swale hay, etc., produce very 

 inferior manure. The manure from young, growing 

 animals or from milking cows is much inferior to that from 

 fat steers, since, in the case of the young animals, 

 a large amount of nitrogen and phosphoric acid is 

 required to build up the animal body. In the case of the 

 milking cow a large amount of nitrogen is required for the 

 production of the casein of the milk, while very little of 

 the nitrogen in the food is retained in the body of the 

 fattening animal. The fats, oils, and starchy materials 

 that animals use largely are of no value as manures. The 

 nitrogen, potash, and phosphorus are thrown off by the 

 fat animal in the waste products. Manures rich 



