GOOD TILLAGE. 27 



to the roots of plants both aliment and stimuli. 

 Dews falling upon a hard surface are evaporated by 

 the first rays of the morning sun ; but they penetrate 

 a loose surface, and moisten and fructify it. Hence 

 the high repute of the drill husbandry, which enables 

 the cultivator to keep his crops clean, and the surface 

 of his soil mellow and open. 



Good tillage has reference to depth as well as qual- 

 ity of tilth. " There are many plants, the roots of 

 which are found at fifteen to twenty and even thirty 

 feet under ground sainfoin and lucerne, for instance : 

 even red clover will strike down to nearly three feet 

 if the soil be a fertile loam ; and some of our com- 

 monest vegetables, if it be friable or sandy, push 

 their tap roots to about the same depth. The roots 

 of wheat will penetrate as far as eight inches into 

 the earth ; and when sown on the crown of ridges, 

 they have been found at the depth of twelve. We 

 may therefore assume the depth of twelve inches as 

 the utmost vegetable limit of corn land. Provided 

 the soil be open and fertile, the nearer its depth ap- 

 proaches to twelve inches, the greater number of 

 plants may it therefore be supposed capable of fur- 

 nishing with support." Brit. Husb., vol. ii., p. 49, 

 50. Soils should be ploughed as deep as the sub- 

 stratum will admit, at least once in a course of crops, 

 if this can be reached with the force of an ordinary 

 team ; and when the surface soil is superficial, it 

 should be deepened, as fast as fertility can be im- 

 parted, by turning up, at suitable intervals, some por- 

 tion of the subsoil. The atmosphere imparts to this 

 apparent inert earth more or less of the elements of 

 fertility. Baron Von Vpght increased vastly the 

 value and products of his farm, by increasing the 

 depth of its mould (krume or vegetable pasture), 

 in this way, in the period of sixteen years, from 

 three to fourteen inches. Land that in the outset 

 would not yield him fourteen bushels of rye to the 

 acre, was by this mode of improvement brought to 



