242 Bureau of Farmers' Institutes. 



therefore, more valuable than the insoluble fertilizing materials 

 contained in the solid excrement. It therefore follows that the 

 more digestible a food is, the larger is the proportion of its fertiliz- 

 ing constituents that will appear in the urine, and the greater will 

 be the value of the plant food in the manure produced. 



The Use of Littee. — Litter is used in stables primarily to 

 furnish a clean and comfortable bed for animals. In connection 

 with the manure, it is used to absorb the liquid portion of the ma- 

 nure, thus preventing loss by drainage. The presence of litter 

 mixed with manure makes the manure easier to handle, tends to 

 check and control its decomposition, and in some cases influences 

 both the physical and chemical action of the manure. The ma- 

 terials commonly used for litter are usually not rich in fertilizing 

 materials. The use of too much litter diminishes the relative 

 value of the manure and adds to the cost of handling. Enough 

 should be used not only to absorb and retain the urine, but also 

 to absorb any ammonia formed in the process of decomposition. 



Fermentation of Manure. — Causes. — It is a familiar ex- 

 perience of every farmer that fresh stable manure, when left in a 

 heap, commences very soon to ferment or undergo decomposition. 

 In this process the vegetable matter used as litter and the excre- 

 ments pass through several changes. The fermentation is caused 

 by minute living organisms, and varies according to the kind of 

 organisms at work. Some will flourish only in the presence of 

 an abundant supply of air, others will thrive only away from air; 

 some require much moisture, others little, etc. According to cir- 

 cumstances, then, one kind or another will flourish, and the fer- 

 mentation taking place will vary according as it is caused by the 

 action of one kind of organism or another. 



Conditions. — The more important conditions influencing the 

 character of fermentation in manure are the following: (1) Tem- 

 perature, (2) moisture, (3) the amount of air supplied as regulated 

 by looseness or compactness of manure heap, (4) the composition 

 of the manure, and (5) the kind of preservatives added. 



Manure ferments more quickly at higher temperatures. "Where 

 air is supplied freely, as on the outside of the heap, the tempera- 

 ture may rise as high as 150 degrees Fahrenheit or even higher. 

 The most favorable temperature seems to be about 130 degrees 

 Fahrenheit. On the inside of the heap, Avhore the supply of air 

 is very limited, a sloAver form of fermentation occurs and the tem- 

 perature rarely goes above 05 degrees Fahrenheit. 



If a manure heap is too loose, the fermentation is too rapid. 

 The result is that the humus-forming material is destroved and 



