82 THE PRINCIPLES OP AGRICULTURE 



119. The value of manure depends upon 

 (a) the kind of animal from which it is made, 

 (6) the feed which the animal receives, (c) 

 the amount of bedding or litter which it con- 

 tains, (d) the way in which it is kept or 

 housed. 



120. Some of the most valuable constituents 

 of manure are soluble, and are, therefore, 

 removed by water. Consequently, manures 

 should be housed to protect them from rain. 

 A covered barn -yard is the ideal place in 

 which to keep manures, for they are not only 

 protected from weather, but, if the manure 

 contains enough straw or litter, it makes an 

 agreeable bed upon which stock may tramp, 

 and it absorbs the liquids ; and if it is spread 

 in the yard as it is made and well tramped by 

 stock, its tendency to heat is reduced. In six 

 months' exposure to weather, manures usually 

 lose more than half of their available plant -food. 



121. The more completely rotted the ma- 

 nure, the sooner does it become thoroughly 

 incorporated with the soil ; and the decay of 

 the coarse parts renders their plant- food more 

 available. If the rotting proceeds under cover 

 or in a compost pile (34a, Fig. 5), there should 

 be little loss of plant-food by leaching. 



122. If manure cannot be sheltered, it 

 should be spread on the fields as fast as 



