46 On the Great or Jersey Trench- Plough. 



sumes the greatest part of the siUcate of potash in a soil, whilst 

 the plants which succeed it are of such a Idnd as require only 

 small quantities of potash, as is the case with the Leguminosae, 

 turnips, potatoes. Sec, the wheat may be again sowed with advan- 

 tage after the fourth year ; for, during the interval of three years, 

 the soil will, by the action of the atmosphere, be rendered capable 

 of again yielding silicate of potash in sufficient quantity for the 

 young plants." This is precisely the Jersey practice. 



It will be perceived that my anxiety is to prove that these 

 scientific discoveries are in accordance with the soundest practice ; 

 that I imagine it to be dangerous to grow the grass family in suc- 

 cession, as, wheat on an old grass ley, to destroy the noxious 

 excrementitious matter of which requires from five to seven 

 ploughings, and a whole season of labour and waste of land ; 

 whereas, bv the use of the Jersey trench-plough, those crops may 

 be grown, which prepare the land well, and themselves furnish 

 nutritive matter for wheat or barley. By the mode of culture 

 described, from 13 to 14 tons per acre of potatoes are grown on 

 all good soils in this island, though 16 is a frequent crop, and the 

 same soils usually produce 30 bushels of wheat per acre in ordi- 

 nary seasons; while in the best, they regularly produce 48 impe- 

 rial bushels. I should recommend this system for all lands that 

 can be ploughed from 9 inches to any greater depth — as a trench 

 9 inches deep, and of proportionate width, say 18 inches, would 

 receive the turf and manure skimmed 3 inches, then be perfectly 

 covered by 6 inches of clean soil, with the trench-plough and a 

 pair of, or three, horses. Wherever the till or subsoil is new and 

 uncultivated, only an inch or two of it should be brought up in a 

 season and well top-dressed, by which means 2 or 4 inches of 

 working soil might be gained in every four- course shift. When a 

 failure in a crop takes place by the increase of depth of ploughing, 

 it is usually from too suddenly bringing a large quantity of maiden 

 soil to the surface, so that its acrid nature injures the young 

 rootlets of the crop ; whereas, if only a small portion be brought 

 up and well intermixed with the old soil, which it would be most 

 completely so by using the paddle-plough, it may merely act as a 

 stimulant, and be beneficial. This is a condition to which the 

 attention of experienced as well as young farmers is specially 

 invited. 



A very competent farmer in East Lothian* thus writes of the 

 Jersey trench-plough, used by him last year for the first time : — 

 '' It is hard work for four horses ploughing 14 inches. I used 

 six; they can work it without straining themselves 16 inches 

 deep. Nothing can do its work better; it makes the best sole to 

 a furrow I have ever seen. No person could know the land had 



* I have permission to name that distinguished friend to agriculture the 

 Marquis of Tweeddale. 



