sua OBJECT AM) KFFKCT OF J)r:i:r-PLOUGIIIPSO. 



sink. This is well known to be the case with lime, when laid upon or 

 ploughed into the land. So it is with clay, when mixed with a surface 

 soil of sand or peat. They all descend till they get beyond the reach of 

 the common plough — and more rapidly it is said (in Lincolnshire) 

 when laid down to grass, than when they are constantly brought to 

 the surface again in arable culture. Thus it happens that after the sur- 

 face soil becomes exhausted of one or other of those inorganic compounds 

 which the crops require, an ample supply of it may be still present in 

 the subsoil, though, until turned up, unavailable for the promotion of ve- 

 getable growth. 



There can be little question, I think, that the greater success which 

 attends the introduction of new implements in the hands of better in- 

 structed men, upon farms long held in arable culture, it' to be ascribed in 

 part to this cause. One tenant, during a long lease, has been in the 

 habit of ploughing to a depth of three, or at most, perhaps, of four 

 inches — and from this surface the crops he has planted have derived their 

 chief supplies of inorganic food. He has Hmed his land in the customary 

 manner, and has laid upon it all the manure he could raise, but his crops 

 have been usually indifferent, and he considers th.e land of comparative- 

 ly little value. But another tenant comes, and with better implements 

 turns up the land to a depth of 7 or 8 inches. He thus brings to the sur- 

 face the lime and the accumulated manures which have naturally sunk, 

 and which his predecessor had permitted year after year to bury them- 

 selves in his subsoil. He thus has a new, often a rich, and almost always 

 a virgin soil to work upon — one which, from being long buried, may re- 

 quire a winter's exposure and nriellowing in the air, but which in most 

 cases is sure to repay him for any extra cost. The deep ploughing 

 which descends to 14 inches, or the trenching wliich brings up a new 

 soil from the depth of 20 or 30 inches, is only an extension of the same 

 practice. It is justified and recommended upon precisely the same 

 principle. It not only brings a new soil, containing ample nourishment, 

 to the immediate roots of plants, but it affords them also a deeper and 

 more open subsoil, through which their fibres may proceed in every di- 

 rection in search of food. The full benefits of this deepening of the soil, 

 however, can only be expected where the subsoil has previously been 

 laid dry by drains ; for it matters not how deep the loosened and perme- 

 able soils may be, if the accumulation of water prevent the roots from 

 descending. 



2°. Two practical observations, however, may here be added, which 

 the intelligent farmer will always weigh well before he hastily applies 

 t!iis theoretical principle — sound though it undoubtedly be — in a district 

 with which he has no ])revious acquaintance. It is possible that the 

 deeper soil may contain some substance decidedly noxious to vegetation. 

 In such a case it would be improper at once to mix it with the upper 

 soil. Good drains must be established, they must be allowed some time 

 to act, and the subsoil plough will be used with advantage, before any 

 portion of such an under-soil can be safely brought to the surface. The 

 subsoil plough and the drain, indeed, as I have already mentioned, are 

 the most certain available remedies for such a state of the subsoil. In 

 many localities, however, the exposure Df such an under-soil to a winter's 

 frost, or to a summer fallow, will so faV 'mprove and mellow it, as to ren- 



