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CHAPTER IX. 



VEGETABLE SUBSTANCES. 



Green Manures. Under this title, are 

 comprised all the green sprouts of roots and 

 tubercles ; such are the fallen leaves of carrots 

 and potatoes, the leaves of beets and turnips. 

 As these materials are serviceable both as ma- 

 nure and forage, the farmer must determine 

 which of the two uses is most profitable. Ac- 

 cording to Boussingault, these substances are 

 only middling food, but excellent manures. 

 He found that the potato tops from two and a 

 half acres represent 1800 pounds barn yard 

 dung, supposed to be dry ; and that beet 

 leaves from the same extent of surface are 

 equal to more than 5800 pounds of same ma- 

 nure in the same state of dryness. 



Marine plants are a species of green manure 

 which serve for the amelioration of the soil 

 neighbouring to the sea coasts. These strongly 

 nitrogenous plants are applicable directly as 

 they come from the water, or in a semi-dried 

 state, macerated or even partially incinerated. 

 They act as well by their saline constituents 

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