ROTATION OF CROPS. 



is carried away from the farm, they 

 are to be rej,'ar(le(l as exhausting 

 rather than restorative crops. 



"In speaking of these different 

 classes of plants, the following terms 

 may be employed : 



"1. The cereal grasses may be 

 termed corn crops. 



'• 2. The leguminous plants culti- 

 vated for their seeds, pulse crops. 



"3. The turnip, and other plants 

 of the same kind, cultivated for their 

 roots and leaves, may, with reference 

 to their mode of consuming them, be 

 termed green crops ; or, with refer- 

 ence to the manner of preparing the 

 ground for tliem, fallow crops. 



"4. The potato! and plants of oth- 

 er families cultivated for their roots 

 and tubers, may. in like manner, be 

 termed green or fallow crops. i 



" 5. The leguminous plants culti- 

 vated for green food, as the lucern 

 and tare, may be termed green for- , 

 age crops. | 



" And, lastly, the mixture of gra- 

 mineous and leguminous plants culti- 

 vated for herbage or green feed may, 

 in compliance with common lan- 

 guage, be still termed the sowed or 

 artificial grasses. 



"Farther, distinguishing these dif- 

 ferent classes of crops according to 

 their effects upon the fertility of the 

 farm, they might be divided thus : I 



"I. Corn crops — exhausting crops, 

 and favourers (jf weeds. 



"2. Pulse crops — exhausting or 

 cleaning crops, or capable of being 

 rendered so. 



" 3. Green or fallow crops — resto- 

 rative and cleaning crops. 



"4. Green forage crops — restora- 

 tive, and sometimes cleaning crops. 



"5. The sowed grasses — restora- 

 tive. crops. 



" Knowing these the general char- 

 acters of the cultivated plants, we 

 have, in devising a rotation, to cause 

 the restorative and cleaning crops so 

 to alternate with the exhausting crops 

 as that the land may be preserved 

 fertile and clean. Farther, when we 

 find that land cannot be sufficient- 

 ly cleaned by means of cleaning crops, 

 we must make use of the summer 

 fallow ; and again, when we find that 

 land requires rest, we may lay it 

 down to grass for a longer or shorter 

 time, taking care, when this is done, 

 that the land shall be in as fertile a 

 state as circumstances will allow, 

 and free from weeds." — {Low.) 



There are not many established 

 rotations in the United Slates. The 

 following is one which is found suc- 

 cessful in Pennsylvania. It is, how- 

 ever, adapted only to strong, new 

 soils. The manure should be added 

 to the Indian corn : 



It is very defective, as there are 

 neither roots nor pulse crops ; pota- 

 toes or roots might be introduced in 

 part, after the leys, which may be of 

 grass ; and beans or pease can come 

 after wheat, with the manure, or 

 succeed the Indian corn. 



Where a particular staple is culti- 

 vated, as tobacco, hemp, sugar, or 

 cotton, it is to be introduced in its 

 place according as it is a grain or 

 green crop. Thus, in the above ta- 

 ble, cotton or hemp, cultivated for 

 672 



seeds, may come in the place of 

 wheat, and tobacco after manure. 



Near cities, where there is a de- 

 mand for everything raised, the rota- 

 tion becomes much more managea- 

 ble, and may be made to approach the 

 very complicated formulas given in 

 Europe, of which the one on the next 

 page is a good specimen. 



The chemical principles of rota- 

 tions are under discussion, and can- 

 not, therefore, be entered upon in a 

 practical work. It may, however, be 



