ON ROTATION OF CROPS. 171 



the vegetables ; even the cows avoid the strong coarse 

 grass which grows on spots they have manured too abun- 

 dantly. But the stock of manure is generally so limited, 

 that it has been the study of agriculturists to discover some 

 means of compensation for a deficiency, rather than to 

 apprehend danger from excess. This compensation has 

 been found in a judicious system of crops ; but it is too 

 late to enter upon a new subject to-day, and one of so 

 extensive a nature well deserves to have a morning ded- 

 icated to its consideration. 



CONVERSATION XIV. 



THE ACTION OF SOIL ON PLANTS CONTINUED. ROTATION 



OF CROPS. 



Mrs. B. It has long been observed, that two succes- 

 sive harvests of the same species of plants, or even of 

 plants of the same family, do not succeed : the second ap- 

 pears to degenerate, as if the first had been injurious to it. 



Caroline. The first crop had no doubt exhausted the 

 soil of nutriment. 



Mrs. B. In the infancy of agriculture, when land was 

 plentiful, because inhabitants were scarce, this was easily 

 remedied by cultivating only a certain portion of land, and, 

 after having exhausted it, transferring the cultivation to 

 another part, and thus successively bringing new land into 

 tillage, till, after a series of years, they return to the spot 

 which had been previously cultivated. This mode, called 

 ecobauge, was first introduced by the Celts, and may still 

 be traced among some of their descendants in Brittany. 

 They usually commenced their operations by burning the 

 natural produce of the soil before they ploughed it. If 

 the soil was stiff and argillaceous, the ashes resulting from 

 this combustion seemed to ameliorate it, by increasing the 

 stock of carbon, of sand, and of salts ; but if light, such a 

 proceeding was not judicious. 



The system of fallows, which we derive from the Ro- 

 mans, is an improvement on that of the Celts ; the soil is 



941 .What has long been observed! 942. In the infancy of agri- 

 culture how was this remedied 1 943. What was this mode called, 

 and by whom was it introduced into Britain 1 ? 944. How did they 

 commence operations, and what was the result! 94, What is the 

 system of fallows, and from whom was it derived? 



