4. TREATMENT OF THE GREEN MANURE CROP 



It is a common practice to turn under crops grown as green manures 

 as soon as their growth is completed, but even in the case of those 

 which are killed by autumn frosts, if protection from wind and washing 

 is especially needed, it may be preferable to leave the crop on the sur- 

 face until the following spring. It is not believed there will be any 

 great loss in manurial value if this practice be followed because the crop 

 on the surface in winter weather will not decay to a sufficient extent to 

 render its constituents soluble. In deciding upon the time for working 

 a green manure crop into the soil it should be remembered that this 

 should be done a few weeks at least before the seed of the following 

 crop is to be sown. The presence of a large amount of undecayed 

 vegetable material a few inches below the surface is unfavorable to the 

 germination and early growth of a following crop. Time should be 

 allowed for the vegetable matter to settle and in part decay and for the 

 capillary connection between the portion of the soil turned over and 

 the undisturbed soil below to have become re-established. In a 

 majority of instances it seems better to turn a green manure crop 

 under rather than to leave it on the surface. A plow turning a large 

 furrow slice is best suited to the work and a disk coulter is desirable. 

 If the crop is tall, a chain fastened to the middle of the evener long 

 enough so that the end will drag in the furrow about opposite the 

 n ould-board may be used with advantage. A chain so used divides 

 the standing crop and bends it forward just ahead of the plow so that 

 it is covered much better than would be possible without it. In some 

 cases the chain is looped in such a way as to accomplish the same 

 result. In the case of a crop killed by winter frosts but allowed to 

 remain upon the surface until spring, it is best to go over the field with 

 a disk harrow, cutting up the stems and working the material some- 

 what into the soil before attempting to plow. 



5. SHOULD GREEN MANURE CROPS BE FERTILIZED 



While a moderate degree of benefit may follow the introduction of 

 green manure crops without the application of any fertilizer, its full 

 benefits will not be realized on soils which are much exhausted without 

 the application of materials that furnish, at least, moderate quantities 

 of the mineral elements of plant food, for which purpose basic slag meal 

 and a potash salt applied broadcast, after plowing, and deeply worked 

 in, will prove among the most useful. 



Further, it will not be possible to greatly enrich the soil in nitrogen 

 from the air through the growth of legumes unless lime be first applied 

 in the case of all soils which are acid, because the nodular bacteria 

 cannot multiply to any great extent, nor actively assimilate nitrogen in 

 soils which are sour. 



