TILLAGE. - 75 



area in a day in almost any other tillage operation 

 than in plowing. There is a tendency to compact the 

 subsoil unduly by the trampling of the horses and the 

 pressure of the plow. At the best, the plow imperfectly 

 pulverizes the soil. The spading principle seems bet- 

 ter, but this has not been successfully applied in gen- 

 eral practice, although some ingenious machines for 

 the purpose have been introduced. 



Depth of Plowing. — Plow deep has often been 

 given as sound advice for all farmers. Sometimes it 

 is very bad advice. In some soils deep plowing is 

 worse than shallow plowing; in many more it is no 

 better in its results, while it always costs more. 



The statement that the deeper the good soil into 

 which roots may descend for food the better for the 

 crops, is a sound one. Where the soil is of like qual- 

 ity to a considerable depth, and is not naturally suffi- 

 ciently loose, deep plowing will generally be advisable. 

 Sometimes excellent results come from mixing a por- 

 tion of the subsoil with the surface soil, by deep plowing. 

 Plant food which has been carried down several inches 

 in the soil will be brought to the surface. Exposing 

 a portion of the deeper soil to the action of the frost 

 during winter often is a great help to productiveness. 



Deep plowing is rarely advisable on wet, undrained 

 soils. Often this simply increases the depth to 

 which the soil becomes saturated with water, which 

 must escape by evaporation. In shallow soils, with a 

 poor subsoil, any marked increase in depth of plow- 

 ing at one operation will almost certainly do harm. 

 Gradually deepening the soil by increasing the depth 

 of plowing about an inch each year, may be helpful 

 in such soils. 



