242 THE SYSTEM OF FARM-YARD MANURING. 



In like manner, tlie farmer whose richer ground has 

 enabled him to cany out the three-field system, and 

 whose rich meadows guarantee a supply of manure, who 

 obtains as abundant harvests and as large a weight of 

 corn as the farmer who adopts the system of rotation, 

 and thus surmises that his management has procured 

 what the ground gives of its own free will, will inevitably 

 discover that his fields may be exhausted of the condi- 

 tions of their fertility, and that it is quite erroneous to 

 suppose that all the farmer's art consists in converting 

 manure into Corn and flesh. 



A simple law of nature regulates the permanence of 

 agricultural produce. If the amount of produce is in 

 proportion to the surface presented by the sum total 

 of nutritive substances in the soil, the ijermanence 

 of the crops ^\all depend upon the maintenance of that 

 proportion. 



This law of compensation, the rejDlacement of nutritive 

 substances which the crops have carried away from the 

 soil, is the foundation of rational husbandry, and must, 

 above all things, be kept in \'iew by the practical farmer. 

 He may renounce the hope of making his land more 

 fruitful than it is by nature, but he cannot expect to keep 

 his harvests up to their average if he allows the necessaiy 

 conditions for them to diminish in his land. 



AH those farmers who cherish the notion that the 

 produce of their fields has not dechned, have not hitherto 

 been able to appreciate the force of this law. Assuming 

 that they have an excess of nutritive subsliances to deal 

 with, they think they may continue drawing upon it, 

 until a failure becomes visible, and then they fancy it 

 will be time enough to talk of compensation. 



This view results from want of understanding the 

 nature of their own acts. 



