146 BOARD OF AGRICULTURE. 



to support animal life. So far as the planWood accumulations 

 of the soil are concerned, the circumstances are now all 

 changed. True, nature is not dead or idle. All her forces 

 work perpetually, and are doing their appropriate work ; but 

 the power of the plant to consume is greater than the power of 

 production, and it not only consumes in a single year all the 

 food produced in the year, but a portion of that which the soil 

 had accumulated, and, when removed, depletes it thus much of 

 its store. In a new soil, where this store is large, the process 

 may go on year after year ; in rare cases, may continue a quarter 

 of a century, with no diminution of the crop. But sooner or 

 later the end will surely come ; the store will be exhausted, the 

 crops cease to pay the cost of cultivation, and the land to such 

 a cultivator is worthless. Leave this destroyed soil to the care 

 of nature, and it will in due time be again made fertile by the 

 original process. This is the method pointed out by the great 

 Hebrew law-giver : " Ye shall not deprive your land of its Sab- 

 bath's " — rest, that it may recuperate. The English fallow, in 

 all its forms, is but an imitation of this great divine law ; but, 

 in the changed circumstances of the world and its population, 

 will not meet our wants. The unceasing calls for food of a 

 dense population require a process quicker and more efficient. 

 We therefore resort to expedients to accelerate and make na- 

 ture's methods more powerful, by cultivating and stirring the 

 soil, changing its mechanical texture, and opening it to the per- 

 fect action and influence of natural law. But while the crop- 

 ping process goes on, this is inefficient, for the plant carries 

 away faster than the powers of production can develop. 



We now resort to an interchange or rotation of crops to 

 secure or aid us in securing the desired result. There are sev- 

 eral natural laws which seem to indicate that this process may 

 be effectual whatever may be the teachings of experience in the 

 matter. And first, nature seems to adopt a system of rotation 

 in her forest growth, where the elements of plant-food taken 

 away are not all returned again until after scores of years, or 

 perhaps for centuries. The pines or fir trees on immense tracts 

 in Northern Europe, in Switzerland, and along the Rhine, have 

 died out, and a hardwood forest, luxuriant and strong-growing, 

 has taken their place. In our own country large sections can 

 be found where the hardwood trees seem to have become pre- 



