TILLAGE. 71 



you deepen your ploughings,you increase the necessity 

 for manures."* 



"From six to eight inches may be taken as the 

 ordinary depth of sufficient ploughing."! And, 



4th- Of the different modes of ploughing (level o? 

 ridge ploughing), which is to be preferred ? 



This question admits no absolute answer. We 

 have already suggested the use of the latter mode 

 in stiff, heavy, wet clays ; and, in our opinion, all 

 ground in which clay predominates, whatever be 

 the culture, should be made to take this/orm: be- 

 cause it powerfully tends to drain the soil, and car- 

 ry off from the roots of the growing plants that su- 

 perfluous water, which, left to itself, would seri- 

 ously affect both the quality and the quantity of 

 their products.J In sandy, porous, and dry soils, 

 on the other hand, level ploughing is to be prefer- 

 red ; because ridging such soils would but increase 

 that want of cohesion which is their natural defect. 



A loamy soil, which is a medium between these 

 two extremes, ought, in a dry climate, to be culti- 

 vated in the^Zfitf way, that it may the better retain 

 moisture ; and in a wet climate, in ridges, that it 

 may the sooner become dry. 



* Young. t Idem. 



t It has been objected to ridge ploughing that it accumulates 

 the good soil on the crowns of ridges, and impoverishes the 

 sides and furrows. These objections are obviated by narrow 

 and low ridges, which alternate every crop with the furrows. 



