310 Manures, Composts, Green Manures 



Table 67. Losses from Exposure of Manure in the Open Yard 

 (from Salter and Schollenberger) 



* Thorne, C. E., Farm Mannres, p. 146, Orange Judd Publishing Co., New York, 

 1914. 



fShutt, M. A., Barnyard manure. Can. Dept. Agr. Cent. Expt. Farm Bull. 31, 1898. 



X Thorne, C. E., ei al.. The maintenance of soil fertility, Ohio Agr. Expt. Sta. Bull. 

 183, 1907. 



§ Roberts, I. P., and H. H. Wing, On the deterioration of farmyard manure by leach- 

 ing and fermentation, Cornell Unir. Agr. Expt. Sta. Bull. 13, 1889. 



is then compressed to produce anaerobic conditions, a compost is 

 formed which behaves differently from the commonly composted 

 manure. Hot fermented manure has also the advantage that many 

 of the disease-producing organisms carried in the manure are de- 

 stroyed. 



In the decomposition of stable manures, both in composts and in 

 soils, considerable quantities of humus are formed. The processes 

 involved are similar to the general processes of decomposition of 

 plant and animal residues discussed previously. Because of the spe- 

 cific nature of the manure and because of the particular conditions 

 under which the decomposition may take place in composts, a num- 

 ber of special problems are involved. Most important among these 

 are the conservation of the nitrogen in the manure, as pointed out 

 above, hygienic treatment of the solid human excreta to prevent 

 epidemics and infectious diseases, and maximum production of 

 humus. It is believed by many that, when equal amounts of nutri- 

 ent elements are added to the soil in the form of mineral fertilizers, 

 on the one hand, and of stable manures, on the other, the resulting 

 equal increases in plant growth tend to prove that the manure is not 

 superior to the fertilizer. The fact is frequently overlooked that 

 manure may not give immediate superior effects because it does not 

 contain sufficient concentrations of available nitrogen. Further, 

 insufficient consideration is usually given to the importance of the 



