No. 85.] Ill 



soil. This result is still further increased by most of them being car- 

 ried off entirely from the farm, and consequently they do not return 

 in the form of manure to the soil. They are further detrimental in 

 not admitting of cultivation by hoeing, and hence favor the increase 

 of weeds. These crops, therefore, however important they may be 

 in themselves, should not succeed each other too often in rotation. 

 Indian corn, though naturally allied to this class, differs materially in 

 its broader leaves and more succulent growth, but more especially in 

 admitting a heavy application of manure, and cultivation by the hoe. 



2. Broad leaved seed bearing plants — as the pea, bean, and buck- 

 wheat. These, by ripening their seed, also exhaust the soil. But 

 they differ materially from the last mentioned, in their broader leaves, 

 which by their shade, more effectually prevent the growth of weeds ; 

 or attend their destruction by hoe-culture, as with the bean. They 

 also differ materially in their chemical composition, containing much 

 potash, soda, and lime, while silica enters largely into the composi- 

 tion of wheat and similar grains. Hence they exhaust the soil in a 

 different manner. Clover, when cultivated for seed, may be classqd 

 with the plants of this division, and in common with them, may alter- 

 nate with the cereal grasses in a rotation, in connexion with other crops- 



3. Root crops — as turneps, beets, parsnips, carrots, potatoes. These, 

 from the large quanties of manure which may be applied to them 

 from the modes of culture which thej admit and require, pulverizing 

 and cleansing the soil of weeds ; from their not being seed-bearing 

 crops ; and especially from the abundant supply of manure which 

 they return to the soil, by their consumption as food for cattle ; char- 

 acterize them as decidedly ameliorating crops. Although the alkalies 

 are found to enter largely into their composition, yet most of them 

 are found to be but little exhausting to the soil on which they grow. 

 Indian corn, though naturally allied to the cereal grasses, partakes 

 largely of these beneficial qualities. 



4. Crops for herbage and forage — including plants for meadows 

 and pastures. These are generally regarded as ameliorating crops. 

 Pastures, being fed off green, the manure of the feeding animals being 

 dropped upon their surface, and the enriching vegetable matter fur- 

 nished by the accumulating roots in the soil, render well managed 

 pastures beneficial to the land. The same is true of meadows, if the 

 crop is consumed upon the farm, and returned again in the form of 

 manure ; but where the hay is sold in market, and especially if the 



