THE KOTATIOK OF CHOPS. 57 



The weight of the grain of the first crop was fifty- 

 eight and five-tenths pounds per bushel, and that of the 

 twentieth, or last, was sixty-two and seven-tenths pounds 

 per bushel, so that after continuous cropping, without 

 manure, the land produced in the twentieth year two 

 and one-fourth bushels more per acre, and the wheat 

 weighed four and one-fifth pounds more per bushel than 

 the first season. 



Can there be a doubt that on any other than a heavy 

 clay soil the results of these experiments would have 

 been different ? Is there a soil on the southern sea coast, 

 void of clay, which, after continuous cropping for twenty 

 years without manure, would produce more oats or rye 

 (wheat requires clay) or any other crop, to the acre, than 

 it would the first season ? If so, to what is the exhaus- 

 tion of our cotton plantations to be attributed? Better 

 farming, or cotton seed, cow peas and rotation might 

 have preserved their fertility. 



Neither the areas, nor the varieties of crops of the truck- 

 farmer are sufficient to enable him always to practice 

 regular courses of rotation; nor should a lack of manure 

 ever compel their strict observance, but he should aim : 



First. To have a crop which succeeds another as dis- 

 similar in composition and the demands it makes upon 

 the soil as possible. 



Second. Never to have plants of the same family suc- 

 ceed each other. For instance, melons should not follow 

 cucumbers; tomatoes should not follow egg-plants, or 

 Irish potatoes; beans should not succeed peas, or vice 

 versa. 



Third. Tuberous plants should not be allowed to fol- 

 low plants of the same character. 



Fourth. Roots should not succeed to root crops, as 

 turnips, beets, etc. 



Fifth. Deep or tap-rooted plants should succeed 

 others of dissimilar growth. 



