Effect of seeder blade size on tillage quality

Abstract

There were found the patterns of changing soil fraction structure as well as width of track and furrow profile left by blades of seeder units depending on their width, operating speed of a unit and soil moisture. A mathematical model is given to determine the width of track left by the hoe blade on soil. The mathematical model was verified by experiments with blades of 260, 370 and 410 mm wide carried out at the Siberian Research Institute of Mechanization and Electrification of Agriculture. There were determined confidence intervals at 5% significance level for the average value of track width. Calculated values of track widths are different from actual ones by no more than 4.4%. The model adequately describes the operation of the blade within operating speeds of the unit from 4 to 8 km/h (1.11-2.22 m/c). The width of track is influenced by soil adhered to the blade. With that, a soil wedge, which shapes the inclination of the blade working surface, is formed. When it reaches the critical values of 30 - 35o, the blade begins pushing soil, and the track from it is getting deeper. With soil density of 0.98-1.1 g/cm3 and average moisture of 13.7%, the 260 mm blade leaves a deeper furrow than the 370 and 410 mm blades do. Soil moisture significantly influences the fraction structure of soil in the track. With increasing moisture, the amount of soil aggregates larger than 50 mm decreases, and the amount of soil aggregates lesser than 10 mm does not increase.