128 Fertilizers 



lime or ashes aid in the rotting, prevent acidity and keep 

 the heap alkaline, and the moisture prevents too hot fer- 

 mentation. By careful management destructive fermenta- 

 tion is prevented, the bulk is very materially reduced and 

 the quality of the constituents greatly improved. The 

 chief difficulty in the making of composts, as well as with 

 other methods used in the improvement of manures, is 

 the expense of labor. 



It pays to take good care of, and to save, manurial 

 products, to reduce wastes and to improve the quality 

 of the constituents by the methods suggested. 



GREEN-MANURES 



A great deal of misconception is prevalent concerning 

 the value of what are termed "green-manures." These 

 do possess a distinct value, and a proper understanding 

 of their place in farm management will undoubtedly re- 

 sult in their large and better use, and in the consequent 

 improvement of agricultural practice. By green-manures 

 is meant any crop that is grown primarily for the purpose 

 of improving the soil, and not for the harvested product. 



"Nitrogen gatherers" and "nitrogen consumers." 



In this sense any crop will serve as a green-manure, 

 yet certain crops possess a greater value than others for 

 this purpose, because they are able to obtain certain of 

 their constituents from sources not accessible to all crops. 

 In other words, the one class of plants can obtain the 

 nitrogen necessary for their growth from the air, as well 

 as from the soil ; the other, as far as we now know, can 

 obtain it only from the soil. These two groups of plants 

 are, therefore, classified as "nitrogen gatherers" and 

 " nitrogen consumers." 



