( 66 ) 



The debris of plants, the stubble of the dif- 

 ferent cereals, and the leaves of forest trees are 

 also considered as green manures. The latter, 

 however, should be subjected to fermentation 

 previous to their application to the soil. 



Of all green manures, those furnished by 

 the meadows are the most abundant and least 

 costly. The use of other plants is subordinate 

 to their success, especially as regards their 

 equivalent of Nitrogen. In the majority of 

 cases, it is preferable to cultivate those plants 

 proper for the nutrition of animals; so that the 

 soil may again receive a greater part of the 

 elements, while the other portion gives rise to 

 an animal product of greater value. 



CHAPTER X. 



VEGETABLE DEBRIS. 



Spit-dung. The muck formed at the bot- 

 tom of ponds and marshes In calcareous lo- 

 calities, though poor in Nitrogen, is used as a 

 manure. Its large amount of Carbon renders 

 it appropriate to land deficient in that material. 

 The richest mucks, and the most advantageous 

 to agriculture, are those which have not been 

 formed under water. 



