ENRICHING THE SOIL— FA KM RESOURCES 79 



(r) cover- crops, which are sowii late in the 

 <oasoii for the purpose of protecting tlie soil 

 dniiiiir winter as well as for firreen-iiianurin«^. 



lli>. ( irt'cn-mannrinir <'rops may lie afrain 

 ilivjtlt'd into those which leather nitrogen and 

 those which do not, — or those which have the 

 power of using the nitrogen (see Chapter vi.) 

 of the air, antl those which olitain all their 

 nitrogen <lirectly from the soil. The nitnvgen- 

 gatlierers leave th«'ir nitrogen in the soil, when 

 they decay, for the use of other plants. The 

 nitiv^gen-gatherers are the legiuninous jilants, 

 or those which heloiig to the pea family, as 

 all kinds of peas and heans, clovers, alfalfa, 

 vetch. The otln'r class, or nitrogen-consumers, 

 comprises all other plants used t'or green-ina- 

 nuriiiL'", as rye, o.it^. rape, mustard, hiick wheat, 

 maize. 



111. In general, the best gjeen-mamu-e crops 

 are liie leginnes, — re*! clover for the North, 

 alfalfa for dry region<, <'ow-peas and Japan 

 clover for th«' Snuth. With tii.* excejition of 

 tlie »'oNv-peas, these crops recjuire one or more 

 seasons for full <level(»pment, and, then't'oii'. 

 cannot he used in intensive farming. 



2''. Iht mnntiijimtnt of <jrn tt • nuiiiurt s 



ll'J. The iileal green -manuring is that which 

 IS a part of a regular rotation, — the greeu- 



