FORAGE CROPS. 343 



plant that is grown has precisely the same peculiarity, and there 

 is, practically, no difference among all of our crops as to the pro- 

 portions in which they take their constituents from the soil and 

 from the atmosphere. The whole reason for the fertilizing effect 

 of clover has never been satisfactorily set forth, and science seems 

 to be thus far at fault in its investigations on this subject. Some 

 things, however, are definitely known which help to account for 

 the manurial value of this crop. 



Clover is a very strongly tap-rooted plant, striking its feeders deep 

 into the earth and finding nutriment where the more delicate roots 

 of cereal plants would be unable to go. The proportion which the 

 roots bear to the top is very large, and on the removal of the crop 

 these are all left to decompose and add their elements to the soil. 

 Not only does the soil in this way receive a large amount of fer- 

 tilizing matter taken from the atmosphere or developed in the sub- 

 soil, but the very mechanical structure of the root causes a fertile- 

 channel to be left, reaching into the lower soil, and easily traversed 

 by the roots of succeeding plants, while the carbonaceous matter 

 that remains after the decomposition of the clover root increases 

 the porosity of the soil and adds very much to its ability to retain 

 moisture. 



Lands that have been exhausted by long-continued cropping, 

 without manure, if they can be made to produce even a small crop 

 of clover, may be, by its persistent growth, rapidly and cheaply 

 restored to the highest fertility. Not only will the growth of 

 clover restore the carbonaceous matter that repeated cultivation 

 has burned out of the ground, but its vigorous and deeply penetrat- 

 ing roots extract valuable constituents from the stubborn sub- 

 soil, and these, disseminated through the entire root, remain, on its 

 death and decay, easily available for the uses of succeeding crops. 



Thus much concerning the effect of this crop is easily compre- 

 hended, but there are other facts with regard to it that are not so 

 readily explained. For instance, it is amply proven that when 

 the second crop is fed off on the land, the manure that it makes 

 being deposited upon it, the effect on the succeeding crop is less 

 favorable than when this second growth is allowed to ripen into 



