132 OF TILLAGE. 



next year, lie will plough eight inches deep, instead of 

 seven, and apply eight loads of manure, instead of seven, 

 he will find his crops increased in that proportion, upon 

 the same land and with no more labor. The next year, or 

 at the beginning of the next rotation, he may, on the same 

 principle, plough to the depth of nine or ten inches. 



It is only in this gradual way that the change can bo 

 safely made. And at each deepening, care must be taken 

 to have a sufficient portion of manure put into that part of 

 the earth which is last brought to the surface, in order 

 that the plants while young may be made to throw out a 

 great number of rootlets. This number will depend 

 upon the amount of manure near the surface, in the 

 immediate neighborhood of the little plant. These root 

 lets, once formed, will penetrate into the deeper earth 

 and feed upon the food there prepared for them. 



When the soil is too rich in carbonaceous matter, burn 

 ing over the surface, and thus reducing bushes and weeds 

 to ashes, is a very useful operation. We commonly get 

 potash, which is so valuable to all vegetables, from the 

 ashes of wood ; but the ashes of shrubs and of herbaceous 

 plants contain more potash than the ashes of the same 

 weight of timber. 



LAND not sufficiently RICH in vegetable remains SHOULD 



NEVER BE BURNT OVER. 



412. USE OF THOROUGH TILLAGE. The more completely 

 the particles of a soil are reduced to powder, the more 

 iv.nlily they act on each other; and the more evenly the 

 immure is diffused through thfc soil, the more readily and 

 immediately do the roots of plants come in contact with 

 them and feed on them. The only difference to be found 

 between some very rich soils in Ohio and some very poor, 

 was the fact that, in the rich soils, the same mineral con- 



