46 EARTHS AND SOILS. 



Quarterly Journal of Agriculture, who had practised it 

 two years. The plough operated to the depth of twelve 

 or fifteen inches, and was worked by a three or four- 

 horse team. " The field in which the operations were 

 commenced," says Mr. Laing, [in 1S36,] " consisting of 

 ten Scottish acres, was at the time, and during the whole 

 operation, so saturated with rain, that the horses' feet 

 sunk in the unploughed ground from four to six inches. 

 Notwithstanding the disadvantages consequent upon the 

 w^et state of the field, the results have been of the most 

 flattering description. Since the work has been finished, 

 [the communication being written two years afterwards,] 

 little or no water has stood upon the surface, and in the 

 spring of 1837, this field, which was usually last worka- 

 ble upon the farm, from its wetness, was the first ; and 

 it had the advantage of land working like loam, when 

 compared with the solid soured furrow that was wont to 

 be turned up." The land thus managed produced in 

 1837, the season after it was subsoil ploughed, 48 bush- 

 els of beans to the Scottish acre, at least one quarter more 

 than it would have yielded had the field not been subsoil 

 ploughed, and in 1838, it produced 48 bushels to the Scot- 

 tish acre. The opinions of Mr. Laing, of the great ad- 

 vantages of subsoil ploughing, are amply sustained by the 

 experience of many farmers, whose communications have 

 appeared in the foreign agricultural periodicals. The 

 subsoil plough should, however, be preceded by furrow- 

 draining. 



4. Chalk soils, or those containing an excess of calca- 

 reous earth, do not much abound with us. Lime is deemed 

 essential in a wheat soil ; and if it amounts to two per 

 cent, of the tillable surface, it is considered adequate to 

 the wants of this crop. Soils derived from primitive roi-- 

 mations seldom contain much if any of this earth, and 

 hence the difficulty of raising wheat upon them. If com- 

 bined with clay and other earthy and vegetable matters, 

 these soils are very productive ; if with sand or gravel, 

 they are light and often unfertile. Calcareous earth has 

 a strong affinity for putrescent vegetable and animal mat- 

 ters, and increases the absorbent powder of soils to which 



