528 THE HOME, FARM AND BUSINESS CYCLOPAEDIA. 



(2) To pulverize the soil and mix thoroughly its constituent parts, 



so as to increase its absorbent and retentive powers, and 

 to effect an equal and economical distribution of manure. 



(3) To destroy weeds and foreign plants, which rob the crop of 



food and check its growth. 



Let us add that, by opening the soil, and rendering it permeable to air 

 and water, the inert materials contained in it, both organic and inorganic, 

 are convertible into soluble plant food. And in regard to many of the 

 insects which prey upon our crops, especially such as work beneath the soil 

 at the roots of plants, frequent tillage is found to disturb them and bring 

 them to the surface, where they get picked up by birds or die. 



Tillage operations include all soil operations which apply directly to the 

 cultivation of farm crops ploughing, cultivating, harrowing, aud rolling, 

 or whatever else is done to bring land to a proper state to receive the 

 seed. They also include the operations of hoeing and weeding the ground 

 after it is sown. 



PLOUGHING. In ploughing we break up the ground into furrow slices, 

 turning them over in such a manner that a new surface is presented to 

 the atmosphere. This or some other mode of loosening and turning up 

 the under parts of soils is necessary to fit them for the reception of the 

 seed and the growth of crops. 



The object of ploughing being to expose the upturned soil to the atmos- 

 phere and to create the greatest quantity of mould the furrow-slices can 

 produce, it follows that the furrow-slice which shows the greatest surface 

 will answer these ends most effectually. In the case of a square-cut fur- 

 row-slice this is found to result when it is laid at an angle of forty-five 

 degrees ; and to this end its width must be to its depth as about ten to 

 seven. If the furrow-slices are ragged, open and broken, and if, being 

 cut of various depths and widths, they are laid at different heights, the 

 work is inferior. A uniform depth of tilth cannot be provided by the 

 harrow, and the seed will be unequally buried. 



The points of merit in ploughing are : (1) a straight furrow of uniform 

 width and depth ; (2) a clean cut slice, both on its land side and floor ; 

 (3) a well laid furrow-slice, having regard to compactness and form ; (4) 

 complete burial of the grass or stubble turned in ; (5) a uniformly ploughed 

 ridge : (G) a finish showing an open furrow with a clean narrow -bottom , 

 the last furrow-slice being equal in width and height with the others, 



CULTIVATING OR STIRRING. The cultivator merely stirs the soil and 

 does not turn it over like the plough ; but it can work to an equal depth . 

 It is especially useful in a spring fallow after autumn ploughing, as the 



