OF ROTATION OP CROPS. 317 



to be known by real practitioners : and though the system 

 of alternate green and corn crops, is, beyond question, an 

 excellent one in general, deviations from it may sometimes 

 be admitted ; for instance, when old rich leys are broken 

 up, two crops of oats in succession may be permitted. This, 

 however, is objected to by one of the ablest farmers in the 

 kingdom, who maintains, that on dry lands, the second 

 crop should be either turnips or potatoes, as the situation 

 answers, and on clays, either beans or fallow, which in gene- 

 ral will pay better than a second crop of oats. 



5. To avoid crops likely to encourage weeds ; and found- 

 ed on this principle, Lord Kames objects to the culture of 

 peas, which, if not an extraordinary crop, are apt to foster 

 weeds. If the land has been previously fallowed for wheat, 

 and thus cleared of weeds, peas, after wheat, he thinks, 

 may be hazarded.* This doctrine, however, is in a great 

 measure superseded by modern improvements. 



6. To raise those crops the most likely to be productive 

 of manure ; hence green crops are to be recommended, and 

 barley is to be avoided, producing, when compared toother 

 crops, the smallest quantity of straw. 



7. On strong land, to sow clover with the crop after fal- 

 low, when a great produce may be expected, which in a 

 great measure ensures abundant crops during the remain- 

 der of the rotation. Clover sown upon wheat after beans, 

 is extremely precarious, and often fails. 



8. To arrange the crops so as to keep the land in good 

 condition, and increasing, rather than diminishing in point 

 of fertility.! This is best accomplished by the alternate 



* Gentleman Farmer, p. 143. Mr Robertson of Ladykirk considers 

 peas to be a good crop previous to a fallow, to bring about land that ha* 

 been smartly cropped, and lime has a good effect after peas. 



f Mr Andrew of Tillilumb remarks, that it onght to be a leading max- 



