No. 6. DEPARTMENT OF AGRICULTURE. 487 



apprehended iu allowing it to mature, but if the primary purpose is 

 not to secure the full benefit of the clover crop, but rather to ensure 

 the growth of the succeeding crop, whether it be corn or peaches, 

 pears, plums, etc., then the use of the crop, its time of plowing down, 

 should be made when it will not interfere with the primary pur- 

 pose in its growth. 



Fall Green Manure Crops. 



In the case of crops that are grown during the summer the con- 

 siderations in reference to soil still hold true, and even in a greater 

 degree, since crops i)lowed down during the summer are more liable 

 to rapid fermentation than those plowed down in the spring. Trou- 

 ble from soil acidity may result from plowing down in the late 

 summer or fall crops grown in the summer, still, the results of 

 such practice will depend considerably upon the time that they 

 are turned down and the character of the weather which fol- 

 lows. Cow peas, for example, that have been seeded in July and 

 have grown through August and September may be plowed down 

 in October vrithout any danger to the succeeding crop or soil, uoless 

 the weather conditions are very unfavorable, as, for example, dry and 

 hot, in which case the dangers pointed out in the turning down of 

 the rye in the spring in its mature state would be likely to follow. 

 Otherwise, if the weather should continue moist and hot, the rapid 

 decay of the vegetable matter would be likely to result in a too 

 rapid fermentation, probably inducing acidity of soil; this would 

 not be likely to be a real danger except upon very light, open soils. 

 On heavy clay soils, where the texture is more dense the tendency 

 would be to prevent the too rapid entrance of air, and thus cause a 

 more uniform decay. 



When to Lime. 



Where the crop is very large and where the conditions pointed 

 out here are anticipated, the better practice will be to remove in 

 part at least the burden of crop. It is desirable, also whether in 

 the spring or fall use of the manure crops, to see to it that there is 

 sufficient lime in the soil to assist in the fermentation, as well as to 

 neutralize acids that may be developed. Hence, where green ma- 

 nuring is i)racticed, there is greater need of the occasional appli- 

 cation of lime. It is not necessary that it shall be applied in all 

 cases, since the application of, say 25 bushels of stone-lime per 

 acre, in a rotation once in four years, would be likely to meet all 

 the needed requirements for lime. If these suggestions are ob- 

 served in reference both to soil inoculation and the plowing in of 

 the green crops, there is no question as to the advantages that may 



