FARM MANURE 133 



III. Age and kind of animals. 



IV. Methods employed in collecting, preserving 

 and utilizing the manure. 



Any one of the above, as well as many minor 

 factors, may influence the composition and value of 

 farm manure. 



168. Absorbents. The most universal absorbent 

 is straw. Wheat straw and barley straw have about 

 the same manurial value. Oat straw is more valu- 

 able. The average composition of straw and other 

 absorbents is as follows : 



Straw. I^eaves. Peat. Sawdust. 

 Per cent. Per cent. Per cent. Per cent. 



Nitrogen 0.40 0.6 i.o o.i 



Phosphoric acid 0.36 0.3 .. 0.2 



Potash 080 0.3 .. 0.4 



When a large amount of straw is used the per cent, 

 of nitrogen and phosphoric acid is decreased, while the 

 per cent, of potash is slightly increased. Sawdust 

 and leaves both make the manure more dilute. Dry 

 peat makes the manure richer in nitrogen. The ab- 

 sorbent powers of these different materials are about 

 as follows : I4 



Per cent, of 

 water absorbed. 



Fine cut straw 30.0 



Coarse uncut straw 18.0 



Peat 60.0 



Sawdust 45.0 



The proportion of absorbents in manure ranges from 

 a fifth to a third of the total weight of the manure. 



169. Use of Peat and Muck as Absorbents. On 

 account of the high per cent, of nitrogen in peat and 



