418 GREEN VEGETABLES READILY DECAY, AND ENRICH THE SOIL. 



linger in the soil. Thus by burying vegetable substances in his lemd 

 in their green state, the practical man actually saves a portion of the 

 organic food of plants, which would otherwise so far run to waste. 



4°. FinaLy : Green vegetable substances, by exposure to the air, 

 gradually give up a portion of the saline matter they contain to the 

 showers of rain that fall. This more or less escapes and is lost. But if 

 buried beneath the soil this saline matter is restored to the land, and 

 where the green matter thus buried is in the state of a growing crop, 

 both the organic and inorganic substances it contains are more equally 

 diffused through the soil than they could be by any other known process. 



On one or other of these principles depend nearly all the special ad- 

 vantages which are known to follow from green manuring and from the 

 employment of green vegetable matter in the preparation of composts. 



§ 2. Important practical results obtained by green manuring. 



But this explanation of the principles on which thecfficacy of ^een 

 manuring depends, does not fully illustrate the important practical re- 

 sults by which, in many localities, it is uniformly followed. 



Let us glance at these results. 



P. The ploughing in of green vegetables on the spot where they 

 have grown may be followed as a method of manuring and enriching 

 all land, where other manures are less abundant. Growing plants 

 bring up from beneath, as far as their roots extend, those substances 

 which are useful to vegetation — and retain them in their leaves and 

 stems. By ploughing in the whole plant we restore to the surface 

 what had previously sunk to a greater or less depth, and thus make 

 it more fertile than before the green crop was sown. 



2°. This manuring is performed with the least loss by the use of 

 vegetables in the green state. By allowing them to decay in the open 

 air, there is, as above stated, a loss both of organic and of inorganic 

 matter — if they be converted into fermented (farm-yard) manure, there 

 is also a large loss, as we shall hereafter see ; and the same is the 

 case, if they are employed in feeding stock, with a view to their con- 

 version into manure. In no other form can the same crop convey to 

 the soil an equal amount of enriching matter as in that of green 

 Leaves and stems. Where the first object, therefore, in the farmer's 

 practice, is so to use his crops as to enrich his land — he will soonest 

 effect it by ploughing them in in the green state. 



3°. Another important result is, that the beneficial action is almost 

 immediate. Green vegetables decompose rapidly, and thus the first 

 crop which follows a green manuring is benefitted and increased by 

 it. But partly for this reason also the green manuring — of corn crop- 

 ped land — if aided by no other manure, must generally be repeated 

 every second year. 



4°. It is said that grain crops which succeed a green manuring are 

 never laid — and that the produce in grain is greater in proportion to 

 the straw, than when manured with fermented dung. 



5°. But it is deserving of separate consideration, that green manu- 

 ring is especially adapted for improving and enriching soils which are 

 poor in vegetable matter. The principles on which living plants draw 

 a part — sometimes a lari > part — of their sustenance from the air, 



