Authors

Abstract

This study provides valuable insights into the interaction between seeds and soil, specifically focusing on quinoa seeds. Accurate discrete element contact models and parameters have been lacking in this area, which has somewhat hindered the optimization and improvement of seeders. By analyzing the collision process between quinoa seeds and soil through contact experiments, the study finds that the adhesive force of the soil on quinoa seeds is much greater than the gravitational force on the seeds and increases with higher soil moisture content. The load-displacement curve obtained from the experiments closely resembles the loading-displacement curve of the JKR (Johnson-Kendall-Roberts) model, leading to the selection of the JKR contact model for simulating the quinoa seed-soil mixture. Using Plackett-Burman experiments, the study identifies the key factors that significantly affect the dynamic angle of repose: soil surface energy, quinoa seed-soil surface energy, and the static friction coefficient between quinoa seeds and soil. Based on the principles of Box-Behnken experimental design, regression analysis and parameter optimization are conducted on these significant factors, resulting in optimal parameter combinations under varying soil moisture content. The verification experiment shows an error of within 1.9%, demonstrating the accuracy of the calibrated parameters. This research provides a solid theoretical foundation for discrete element simulation of seed-soil contact, offering a reference for improving the design and efficiency of seeders.

Abstract in Chinese

种子-土壤相互作用的研究中缺乏准确的离散元接触模型和参数，在一定程度上限制了播种机具的优化改进。本文以藜麦种子与土壤为研究对象，通过接触试验分析藜麦种子与土壤接触碰撞过程，发现土壤对藜麦种子的粘附力远大于种子重力并随土壤含水率的增加而增加。试验所得加载位移曲线与JKR模型加载位移曲线规律相似，因此选用JKR接触模型作为藜麦种子-土壤混料接触模型。通过Plackett-Burman试验筛选出了对动态休止角影响显著的因素。通过Box-Behnken试验得到了不同土壤含水率下的较优参数组合。验证试验误差在1.9%以内，证明了标定参数的准确性。这为种子与土壤接触的离散元仿真提供了理论参考。