MOLDBOARD PLOW PERFORMANCE IN A CLAY SOIL: SIMULATIONS AND EXPERIMENT

Abstract

The effects of moldboard plow components and adjustments on its performance when used on a clay soil wereanalyzed using both modeling (Finite element method, FEM) and experimental results. With the FEM simulations, theaverage longitudinal force (Fx) was 1.4 and 2.7 times the average vertical (Fz) and lateral (Fy) forces, respectively. Thespecific vertical force (Fzs) was found to decline with width because of both the share edge effect and the greater soil-toolsurface in contact which increased friction. The effects of the sharepoint seemed only predominant at very shallow depthsto initiate penetration. A decrease in friction reduced specific longitudinal force (Fxs) but increased Fzs to promote plowpenetration. From simulations with the same plow bottom Fy, a longer landside is required to prevent lateral movement ofthe plow bottom. During the field experiment, only the specific draft force (Ds) and fuel consumption showed a statisticaldifference between plowing depths with reductions of 16% and 8%, respectively, with the shallowest setting. Knife coulterand short landside had a lower Ds of 8% and 3%, respectively. Depth SD and distance to obtain average depth wereconsidered as a measure of plow stability throughout the plot. The long landside and the knife coulter had both anincreased in distance of 74 and 293 mm, respectively over the short landside and disc coulter.