On the Draft Resistances of Tractor Plows and Diok Harrows for Soil-improvement Use

Abstract

Surveying the draft resistances of the current tractor plows and disk harrows for soil-improvement use, in the different types of soils-heavy clay soil, clay-loam and volcanic light sandy loam or gravelly soil, we obtained the following results. i. e.
1. The specific resistance of subsoil-plow is influenced by the type of soil, it appears 0.304kg/cm², in dry heavy clay soil 1.640kg/cm², and in clay-loam or wet heavy clay soil a little above 0.7kg/cm².
2. The specific resist. of layer-mixing plow, a variety of deep plow, appears 0.414kg/cm² in volcanic gravelly soil.
3. If the sizes of disk harrows are similar, their draft resistances are nearly equal regardless of the types of soils described above. It map be required about 550kg. with the standard disk harrow -18″ diameter, 32 disks -and about 700kg. with the large disk harrows for soil-improvement use -20″ -26″ diameter, 10-20 disks.
4. In general, the specific resist. of the current disk harrows are in the range of 0.1-0.2kg/cm², however 0.14-0.2kg/cm² in heavy caly soils and 0.1-0.14kg/cm² in volcanic soils.
5. In order to select the current implements appropriate to the tractor, we have surveyed the slip increasing rates of tractors caused by the draft at the even fields, before and after plowing, in the different types of soils. (vid. Fig. 1, 3).