272 FARM MANURE 



to leaching. The cellulose and other carbohydrates are 

 decomposed and carbon dioxide and water formed. As a 

 result the mass loses weight very markedly. "Humus" is 

 produced, and the litter loses its original form, the whole 

 mass becoming short-fibered, dark-colored, and homogeneous. 



The loss of nitrogen by volatilization as ammonia and 

 free nitrogen is much greater under aerobic than under 

 anaerobic conditions. A good way to prevent loss is to keep 

 the manure pile thoroughly compacted and moist. To 

 prevent loss of potash and phosphoric acid a cover to the 

 pile is advantageous to prevent leaching. Rock phosphate 

 in the stalls absorbs the liquid excrement and thus me- 

 chanically prevents loss of this valuable constituent of 

 manure. 



By the use of gypsum, acid phosphate, kainite, and other 

 potash salts, except potassium carbonate, the ammonia is 

 retained as a non- volatile though soluble compound. 



By spreading manure on the fields as fast as it is formed 

 the greatest benefit can be derived from its use, except on 

 very light, sandy soils where well decomposed manure is 

 preferable. Composted manure is used largely by market 

 gardeners and is a very thoroughly decomposed manure 

 made by mixing manure with soil, and sometimes with 

 lime to hasten decomposition, and with commercial fertilizers 

 to reinforce it. A layer of soil should cover such a compost 

 heap, particularly if it contains lime, to prevent loss of 

 ammonia. 



Although manure is an unbalanced fertilizer, containing 

 too little phosphoric acid, it is nevertheless a very necessarv 

 material for use on the soil. It supplies organic matter, 

 bacteria, and plant food. If used in excessive amounts, 

 however, there results great waste of fertilizing constituents, 

 thus making it a very uneconomical material to employ. 

 Its effect is more lasting on the soil than any other single 

 fertilizer. 



REFERENCES 



Hall. Fertilisers and Manures. 

 Thorne. Farm Manures. 

 Van Slyke. Fertilizers and Crops. 

 Wheeler. Manures and Fertilizers. 



