COMPOSITION OF ANIMAL MANURES 367 



The liquid excreta of the sheep contains in a given 

 quantity more fertilizing material than that of any of the 

 other animals. 



Comparing the solid and liquid excreta of these 

 animals as a whole, it will be seen that, in general, the 

 urine is richest in nitrogen and alkalies, while the solid 

 excrement is richest in phosphoric acid. 



The amount and composition of the urine is more 

 constant than that of the solid excrement. Both are 

 influenced by the character and amount of feed, but the 

 urine much less so than the solid excrement. Experi- 

 ments conducted at the Rothamsted Experiment Sta- 

 tion have shown that from 57 to 79 per cent of the total 

 nitrogen of the food is excreted in the urine, and from 

 16 to 22 per cent in the solid excrement. 



236. Litter. The use of a bulky absorbent, like 

 straw, sawdust or leaves, is almost universal where live 

 stock are kept in a stable. This is useful in providing 

 a soft bed for the animal, in absorbing the liquid excre- 

 ment, in lightening the manure, making it easier to 

 handle, less likely to undergo undesirable fermentation, 

 and more effective in improving the physical condition 

 of heavy soils. 



Straw is the absorbent usually used, and is, all 

 things considered, the most satisfactory. It decomposes 

 readily in most soils and, in decomposing, adds to the 

 soil considerable fertilizing material. Of the different 

 kinds of straw, oat straw has the greatest fertilizing 

 value. A ton of oat straw contains about 16 pounds 

 nitrogen, 4 pounds phosphoric acid, 26 pounds of potash, 

 and 9 pounds of lime. As this is more nitrogen and 



