CHAPTER VII 



PULVERIZING. 



Reduce the soil to a powder, or bring it as nearly to that con- 

 dition as you can. The roots of plants absorb only such matters 

 as are presented to them on the outsides of the particles of the 

 soil, and the air, water, and manure which prepare the plant 

 food to be taken up, can only act on such surfaces, A soil may 

 contain enough mineral food for twenty crops, and yet be prac- 

 tically barren, if its food is locked up within impenetrable clods. 



As the draining away of the water in which the particles of the 

 soil are immersed, allows roots to travel over wider pasturage, 

 and allows the changing air to do its work of chemical prepara- 

 tion, so the finer pulverization of the particles is conducive to the 

 increasing richness of the land, to the better supply of food, and 

 to the easier seeking of food by the plant. 



The great pulverizer in our northern latitudes is frost, to the 

 action of which sufficient reference has been made in the preced- 

 ing chapter. The tools which we use for the work of pulver- 

 ization, after the plow and the subsoiler, are the roller, the harrow, 

 the cultivator, the horse-hoe, etc, 



THE ROLLER. 



The best roller (and the most costly) is made of cast-iron 

 wheels, from twenty to thirty-six inches in diameter, and twelve 

 wide, set close together on an iron axle, on which they revolve 

 independently. From four to six of these wheels (or sections) are 

 used together, and they are provided with a pole and double-trees, 

 and with a box in which stones may be placed if extra weight 



