4. TREATMENT OF THE GREEN MANURE CROP 



It is a common practice to turn under crops <^ro\vn 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 surface until the following spring. It is not believed 

 there will be any great loss in manurial value if this ])ractice 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 mould-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 somewhat 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 multiph^ to any great extent, nor actively assimilate 

 nitrogen in soils which are sour. 



