Increasing the width of disturbance of plough pan with bionic inspired subsoilers

Subsoiling technology is an important method in conservation tillage. The effect that the plough pan was broken by bionic subsoiler was successfully simulated by EDEM in this paper. The force of mole's paw in soil excavation was first analyzed by mathematical model, and then bionic subsoiler meeting the excavation requirements was designed by combining the structure of mole's claw with standard subsoiler. The breaking situation of plough pan and the stress state of the subsoiler were analyzed in EDEM and verified in both soil bin test and field test. The results showed that the bionic subsoilers could effectively improve the breakage effect of the plough pan, and the greater the width of disturbance of plough pan was and the better the subsoiling effect was. Compared with standard subsoiler, the soil looseness of the plough pan formed by bionic subsoiler-C increased by 18.2% at the tillage depth of 300 mm, 20.0% at the tillage depth of 380 mm and 20.6% at the tillage depth of 460 mm, respectively. The Critical depth of subsoiling was 380 mm, where the best breakage effect of plough pan and soil looseness of the soil layer were obtained at low energy consumption. Soil bin and field tests could prove that the bionic design of the subsoiler decreased the draft force, and increased the width of disturbance of plough pan, which was consistent with the analysis results of EDEM. The bionic subsoilers could better break the plough pan and improve the farming quality of the soil.