204 THE CULTURE OF FARM CROPS. 



accompanied by any waste as would occur were the decom- 

 position to be completed in the open air, and when carbonic 

 acid and ammonia w r ould be produced, and being gases, 

 would escape into the atmosphere. Moreover if this green 

 vegetable matter were to be exposed to the weather during 

 its decomposition, a considerable quantity of its mineral el- 

 ements would be washed out and wasted, the potash for in- 

 stance would be almost wholly lost in this way, but in and 

 under the soil there is no loss. Hence the practice of green 

 manuring, or of the use of any green vegetable matter in 

 the making of composts, is exceedingly advantageous to the 

 farmer, and greatly assists him in the growth of large crops. 



Some of the results from which these advantages accrue, 

 are as follows: 



First. Growing plants, especially the deeper rooted ones 

 as clover, bring up from the deeper soil where the roots of 

 other plants cannot reach them, several substances which 

 are useful to these more shallow rooted crops, and retain 

 them in their leaves, stems and roots; and when these are 

 plowed under the surface, they contribute these acquisitions 

 to the upper soil and greatly enrich it. Thus, although 

 nothing may be gained to the soil but what is taken from 

 it, yet the gain is made from a portion of the soil which 

 could not be reached by the crops to be benefited by it, to 

 the portion where these crops can reach it. Thus it results 

 in practically largely deepening the soil and extending the 

 growth of the roots. 



Second. This manuring is effected with the least loss and 

 the greatest economy, and in no other manner can the same 

 crop carry back to the soil an equal amount of fertilizing 

 matter as in that of its growing leaves and stems. And the 

 farmer will sooner and more cheaply fertilize his land by 

 plowing in green crops than by any other method whatever. 



The selection of plants to be grown for this purpose is to 

 be made from among those which grow most rapidly, and 

 which produce the largest amount of vegetable matter in 

 the shortest time, and at the least cost. There are a large 

 number of plants which may be used in this way. 



