132 



SOILS AND FERTILIZERS 



affected the composition. In general, animals consu- 

 ming liberal amounts of coarse fodders produce manure 



Fig. 24. Average composition of Fig. 25. Manure after six 



fresh manure? months' exposure, 



i. Nitrogen. 2. Phosphoric acid. 

 3. Potash. 4. Mineral matter. 



with a higher per cent, of potash than of phosphoric 

 acid. This is because the potash in the food exceeds 

 the phosphoric acid. The average composition of 

 mixed stable manure is as follows : 



Average 

 Per cent. 



Nitrogen 0.50 



Phosphoric acid 0.35 



Potash 0.50 



Range 

 Per cent. 



0.4 to 0.8 



0.2 tO 0.5 



0.3 to 0.9 



In calculating the amount of fertility in manures, 

 it is more satisfactory to compute the value from the 

 food consumed and the care which the manure has 

 received, than to use figures expressing average com- 

 position. 



167. Factors which Influence the Composition and 

 Value of Farm Manure. 



I. Kind and amount of absorbents used. 



II. Kind and amount of food consumed. 



