PAEM MANURE 517 



10 and 50 per cent., respectively, for these constituents. While 

 such losses are necessary and are usually compensated by the 

 animal products, their magnitude must be considered in esti- 

 mating" the value of manure in the ordinary rotation. 



294. Losses due to handling and storage. — ^As about one- 

 half of the ammonia and three-fifths of the potash of average 

 farm manure are in a soluble condition, the possibility of loss 

 by leaching is usually great, even though the manure is not 

 exposed to especially heavy rainfall. The loss of phosphorus 

 is also of some consequence. In addition, decomposition, espe- 

 cially that of an aerobic nature, will cause a rapid waste of 

 ammonia, one-half of that present being especially susceptible. 

 Packing and moistening the manure will change the decay 

 from aerobic to anaerobic, thus reducing the waste of am- 

 monia while encouraging the simplification of the manurial 

 constituents. Tight floors in the stables and impervious bot- 

 toms in the manure pit or under the manure pile will con- 

 siderably diminish leaching losses. 



It is impossible, in quoting figures for waste of manure, 

 to separate the losses due to fermentation and putrefaction 

 from those due to leaching. The two processes go on simul- 

 taneously, the loss from one source being dependent, to a cer- 

 tain extent, on the other. It is only the nitrogen, however, 

 that may be lost by both decomposition and leaching, the min- 

 erals being wasted only through the latter avenue. 



While the figures are variable (Table CXIII), it is easily 

 seen that one-half of the ammonia and potash and one-third of 

 the phosphoric acid are readily lost under fairly careful meth- 

 ods of storage. On the average farm where manure very often 

 remains outside for several months, the losses will run much 

 higher, easily amounting to 50 per cent, of the organic mat- 

 ter, 60 per cent, of the ammonia, 40 per cent, of the phos- 



Matter in the Soil; Jour. Amer. Soc. Agron., Yol. 9, No. 3, pp. 97-105, 

 Mar. 1917. 



Also Armsby, H. P., and Fries, J. A., Net Energy Values of Feeding 

 Stufs for Cattle; Jour, Agr. Res., Vol. Ill, pp. 435-491, 1915. 



