284 HANDY-BOOK OF HUSBANDRY. 



'■'■ fallow more than a hundred years, they will not yield a remuner- 

 *' ative crop of a cereal plant." 



While the case with reference to the regions of America, to 

 which allusion is made, is perhaps too strongly stated, the principle 

 on which those statements are made is entirely correct, and there 

 can be no greater fallacy than to suppose, as many of our farmers 

 do, that a well-selected rotation of crops furnishes a sure means 

 for constantly increasing the fertility of the land. While one crop 

 may prepare the soil for the growth of another, and while 

 during the growth of one crop certain elements which another 

 would require are developed by natural agencies acting within the 

 soil, the effect of all cropping — that is, of the removal of vege- 

 tation from the land on which it grows — is to lessen the supply of 

 mineral ingredients in the soil ; and the longer we may be enabled 

 to carry on such a process the more complete will be the exhaus- 

 tion of the land in the long run. 



Certain excellent writers in America and in other countries are 

 de'voting a great deal of attention to the question of renovating the 

 soil by the growth of clover; and, so far as the present result of 

 the practice is concerned, they have every thing their own way ; 

 that is to say, it is an almost invariable result of the growth of this 

 plant that the increased fertility which its advocates promise is 

 sure to follow. By reference to the subject of " Green Crops " 

 in the preceding chapter, it will he seen that the poWer of certain 

 plants to prepare for the uses of other plants certain elements of the 

 soil not previously fitted for assimilation by them is very great. 

 And it is this action on which the confidence in clover culture is 

 based ; and it may be set down as a fact, that any land on which, 

 by the aid of plaster or any other fertilizer, even a tolerable crop 

 of clover may be grown may be, without the application of any 

 other manure, brought, generally within a short time, to a high 

 state of fertility. 



But there is one feature of the case which these writers over- 

 look, or the existence of which they persistently deny ; that is, 

 that so far as the earthy constituents of vegetation are concerned, 

 the effect of the clover is simply to develop matters already 



