Farmyard and Green-Manures 133 



its content of fertility elements, an opinion apparently 

 held by many who have observed the good results that 

 often follow their use. (See Fig. 10, Plate VI.) 



Mixtures are advisable. 



It is often advisable to mix legumes with non-legumes 

 on the principle that a variety of seeds often make a 

 better stand. This is particularly true when green- 

 manures are used between cultivated crops. The mixture 

 used must be made up so as to include crops which grow 

 through the same period of time, crops which may be 

 expected to grow when planted at the same time. For 

 example, a mixture composed of sixty pounds of rye, 

 twenty pounds of winter vetch and ten pounds of crim- 

 son clover give most excellent results in southern New 

 Jersey, whereas, conditions in northern New Jersey are 

 not suitable for crimson clover. 



Precautions in the use of green-manures. 



In general, fields covered by green-manure crops should 

 be plowed at the customary time regardless of the growth 

 made by the plants. Legumes accumulate the greater 

 proportion of their nitrogen supply in the early stages of 

 growth, and it is not wise to disturb the farm system of 

 labor. If too great growth is made by the crop, it should 

 be mowed and harrowed before plowing. In case a heavy 

 crop is plowed down, a dry season may cause a lessening 

 of the moisture supply brought about by the formation 

 of an impervious layer of organic matter which, also, may 

 not decompose readily, resulting in serious injury to the 

 physical condition of the soil. 



Non-legume crops contain, as a rule, less nitrogen, and 

 besides, that contained in them is apparently less avail- 



