138 PRACTICAL FARM CHEMISTRY. 



plant growth as promptly as soil fed with stable 

 manure. It yet needs carbon to loosen it, and to 

 protect it somewhat against the ill effect of a dry 

 season. It needs carbon to assist in providing avail- 

 able nitrogen. This carbon cannot be obtained in a 

 simpler and cheaper way than by growing clover or 

 other green crops, and plowing them under. 



The farmer who has a big supply of barnyard 

 manure might dispense with clover without serious 

 disadvantages. Where concentrated fertilizers have 

 to be depended upon largely or chiefly as sources of 

 plant foods, clover rotation, or still better manuring 

 with green crops, is absolutely necessary to supple- 

 ment and complete the application. 



This I wish to emphasize. Concentrated fertilizers 

 and green manuring go well together, and make a 

 complete substitute for stable manure. With plenty 

 of chemical fertilizers (potash salts or ashes, acid 

 phosphate, bone meal or phosphate meal, etc., and 

 perhaps nitrate of soda or other forms 



Clover and of nitrogen), and the privilege of using 



^Concentrated , ., . -i i j • i. 



Manures, clover, the poorest soil can be made rich 

 in short order, and to produce large 

 yields of any crop — garden or field — for an indefi- 

 nite period, and the soil be rendered mellow, friable 

 and warm; in short brought into a mechanically 

 perfect condition. 



The question now is, what plants are best adapted 

 for the purpose of green manuring ? Those usually 

 named are the clovers, peas, rye and buckwheat. 

 All of these gather organic matter from the atmos- 

 phere, and when plowed under, or left to decay on 

 the surface, add humus to the soil, giving the latter 

 a darker color and increased value. The decaying 

 organic matter is a never-failing source of carbonic 



