GREEN-MANURES 



549 



Table CXXV 



INFLUENCE OF THE TIME OF TURNING-UNDER OF GREEN-MANURES 

 ON THE NITRATE ACCUMULATION IN THE SOIL. 1 



It is apparent that the decay of the green-manuring crop 

 is hastened by fall plowing, as the nitrates in every case are 

 higher in April on land so handled. In June, however, the 

 nitrate accumulation has passed its highest point in the fall- 

 plowed soil, leaving the spring-plowed plats, where the decay 

 was initiated later, in the ascendancy. The table also shows 

 the advantage that a legume has over a non-legume in causing 

 nitrate accumulation. Oats fall-plowed appear about on an 

 equality with rye. Spring plowing, since the oats are then 

 dry and dead, gives the rye a marked advantage. All of the 

 points above noted have a very practical field application. 



In turning under green-manures, the furrow slice should 

 not be thrown over flat, since the green-crop is then deposited 

 as a continuous layer between the surface soil and the sub- 

 soil. Capillary movement is thus impeded until a more or 



1 Unpublished data. Dept. Soils, Cornell University. 



