On Grass Land. 405 



not take place, the land may be trenched or double-ploughed. 

 This is effected, by means of two ploughs following each 

 other, the first plough taking off a thin surface of about 

 three inches, and the second going deeper in the same place, 

 covering the surface sod with fine mould ; both furrows not 

 exceeding the thickness of the vegetable mould or other 

 good soil ( a9 $. 



If the land is ploughed with one furrow, the operation 

 ought to be performed before winter, that it may receive the 

 benefit of the succeeding frosts, by which the success of the 

 future operations will not only be promoted, but many of 

 the insects lodged in the soil will be destroyed. 



When one furrow alone is taken, the best size is, four in- 

 ches and a half deep, by eight or nine broad. The strain 

 on horses, in ploughing ley land, is mostly from the depth. 



3. The rotation of crops to be adopted, when grass lands 

 are broken up, must partly depend upon the soil, the local 

 demand for peculiar kinds of crop or produce, and partly 

 on the manner in which it is prepared for cultivation. As ' 

 a general principle however, it may be laid down, that un- 

 less, by the course of cropping to be pursued, the bad 

 grasses, and other plants indigenous in the soil, are extir- 

 pated, and the defects, if any, in the soil, for the growth of 

 the more essential pasture grasses be corrected, and genuine 

 seeds of them be sown, they will, when the land is again 

 laid down to grass, increase and prevail, with more rapidity 

 and effect, than the seeds chosen by the farmer ; and the 

 consequence must be, a heavy disappointment in the future 

 crops of grass, perhaps solely, or at least principally attri- 

 butable, to a previous defective management ( z98 ). It is ne- 

 cessary therefore, to enter into details upon this subject, as 

 applicable to clay ; chalk ; peat ; loam ; and sand. 



Clay There are two kinds of clay, chiefly distinguished 

 by the excess of alumine or pure matter of clay, and of silex 

 or impalpable matter of flint, which enter into the composi- 

 tion of each. The former is observed to be more benefited by 

 burning than the latter under ordinary circumstances. The 

 process of conversion, in clayey soils, should in general com- 

 mence with paring and burning, more especially where cal- 

 careous matter abounds in the soil, and the existence of 

 the grub is suspected. The following course may then be 

 adopted : 1. Rape, fed with sheep ; 2. Beans ; 3. Wheat ; 

 4. Beans ; 5. W T heat ; 6. Fallow ; 7. Wheat, sown with 

 grass-seeds. This may seem- severe cropping, but is justi- 

 fied by experience. When old grass clay land is broken up, 



