1764 



The Cornell Reading-Courses 



All soil- working implements may be divided into four groups: (1) 

 plows that invert the soil in addition to effecting pulverization; (2) culti- 

 vators that stir the soil; (3) pulverizers designed to reduce lumps and level 

 the surface; (4) compactors that bring the soil particles closer together 

 and smooth the surface. 



^"OS/O. 







SHARE ■ 



Fig. 94. — The plow. (/) Modern walking plow, with parts named; (2) types of 

 moldboard for (c) fallow ground, light soil, (6) fallow ground, clay soil, (c) 

 sod ground, (d) general purpose, fairly well suited to a wide range of soil con- 

 ditions; {3) deep-tilling disk plow; (4) subsoiler; (5) plow attachments: (a) jointer, 

 (b) knife or beam colter, (c) fin colter, (d) rolling colter 



The plow 



The plow is the most efficient implement used on the soil in proportion 



to the power required. It operates as a double, twisted wedge, which 



lifts and inverts a ribbon of soil. (Fig 87.) By this operation the furrow 



slice is sheared or split into many thin layers both vertically and horizon- 



