PRINCIPLES OF TILLAGE. 113 



As we have before observed, the atmosphere and the 

 rams are not only charged with the elements of fertility, 

 but they are indispensable agents, together with heat, in 

 preparing the vegetable food deposited in the soil. Com- 

 plete pulverization, therefore, is essential to the full de- 

 velopement of their enriching properties. They should 

 not only be permitted to enter^ but to circulate in the soil. 

 Stagnant air and stagnant water soon become hurtful to 

 plants as well as to animals. 



The old practice of carrying the main furrows to the 

 extremity of the field, and of dispensing with head-lands, 

 is a bad and slovenly one, and ought to be every where 

 exploded, because, under this practice, the head-lands can 

 only be imperfectly worked. The cut-and-cover prac- 

 tice is still worse, as it leaves one half, and sometimes 

 two thirds ©f the soil, undisturbed by the plough. We 

 remember well, when we followed the plough in our boy- 

 hood, and knew nothing of the philosophy of ploughing, 

 our aim was, to go over much ground, and show a plough- 

 ed surface, regarding the complete breaking up of the soil 

 as of minor importance. There will always be a great 

 many boys at the plough, until the importance of good 

 ploughing is well understood. Good ploughing consists 

 in turning and breaking every inch of the soil to the re- 

 quired depth ; and good tillage requires that the harrow 

 and roller should finish, if the plough has failed to effect, 

 a complete pulverization. A green sward becomes pul- 

 verulent as the roots of the grasses decay, and is best 

 without a second furrow, because this turns again to the 

 surface, to the wasting influence of the sun and winds, 

 the vegetable matters buried by the first ploughing, and 

 which, if left buried, would contribute largely to the sus- 

 tenance of the crop. As the roots of the grasses decay, 

 the soil becomes loose and porous, and is permeable to 

 moisture, air, and heat. Hence the advantage of fallow 

 crops over naked fallows, and of depositing seeds upon 

 the top of a clover ley ; the sod then imparts fertility to 

 the soil, while it enables it to derive important advantages 

 from the co-operation of external agents. 



Good tillage requires that, when practicable, as in the 

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