CHAPTER IV 



Farm Manures, and Similar Materials 



Animals are among the most essential agents in the maintaining 

 of the fertihty of the land. Farm manures are of great value, not 

 only for the plant-food they contain, but for the humus that they 

 contribute and the organisms that they carry. 



Composition and Characteristics of Manures (Brooks) 



Cattle manure. 



For practical purposes, one will be sufficiently accurate in estimating 

 well-kept barnyard (or cattle) manure to contain one-half of one per 

 cent each of nitrogen and potash, and one-third of one per cent of 

 phosphoric acid. On this basis, a ton of manure would contain 10 lb. 

 each of nitrogen and potash, and 6§ lb. of phosphoric acid. A cord 

 of well-preserved manure kept without loss of urine and without ex- 

 posure to the weather will weigh a little more than three tons. A 

 cord of such manure, therefore, should contain about thirty pounds 

 of nitrogen and potash and twenty pounds of phosphoric acid. 



Stable or horse manure. 



The manure from horses is generally more valuable than that from 

 the other larger domestic animals, excepting sheep, provided it has 

 been well kept. It is richer in nitrogen, and usually also in phosphoric 

 acid and potash, than the manure of either cattle or hogs. It contains 

 relatively little water, and ferments rapidly. 



Experiments at the Cornell Experiment Station showed horse manure 

 to have the following composition : water, 48.69 per cent ; nitrogen, 0.49 

 per cent; phosphoric acid, 0.26 per cent; potash, 0.48 per cent. 

 Plaster was very freely used in this experiment, and this doubtless 

 reduced the percentages, so that the figures are undoubtedly below 

 the average. 



G 81 



