FARM MANURES 



179 



ing it more concentrated. Pound for pound, composted 

 manure is richer in plant food than fresh manure, be- 

 cause, if properly cared for, nearly all of the nitrogen, 

 phosphoric acid, and potash of the original manure are 

 present in smaller bulk. A ton of composted manure is 

 obtained from about 2800 pounds of stable manure. 

 Composting is sometimes resorted to in order to destroy 

 obnoxious weed seeds. 



In composting manure it should be the aim to induce 

 anaerobic fermentation by excluding the air and retain- 

 ing the water. This can be accomplished best by using 

 mixed manure and making a compact pile, capable of 

 shedding water. The compost pile should be shaded to 

 secure better conditions for fermentation. If the pile 

 becomes offensive, a little earth on the surface will 

 absorb the odors. 



202. Use of Preservatives. - - The use of preservatives, 

 as gypsum and kainit, has been recommended to prevent 

 fermentation losses. Opinions differ as to the value of 

 this practice,. Moist gypsum, when it comes in contact 



