Results of the between-subjects effects test.

At present, potato seeders in China generally have poor uniformity of seed rows and high coefficients of variation in plant spacing during seed rows, causing difficulties for subsequent mechanized plant protection and harvesting. Based on the effect of seed discharge to analyze the sowing process, a potato seed discharger with a double-layer seed picking spoon structure was designed. By analyzing the seed discharging mechanism and its operation process, the shape and size structural parameters of the seed picking spoon were determined. Finite element simulation of the seed pickup process and seed carrying process of the seed discharging mechanism was carried out by EDEM software to determine the double-layer seed scoop scheme and the range of factors for subsequent tests. A two-factor test was conducted with seeding line speed and seed drop height as test factors, and plant spacing coefficient of variation and seed potato lateral offset dispersion as test indexes. The test results showed that the double-layer seeding spoon chain seeder reduced the coefficient of variation in plant spacing by 5.8%, and the dispersion in lateral offset by 5.5 mm, compared with the single seeding spoon seeder, when the seeding speed was 0.184 m/s and the height of falling seed was 9 cm.目前，国内马铃薯播种机普遍存在种行均匀性欠佳、种行内株距变异系数偏高的问题，给后续机械化植保与收获作业带来了较大困难。本研究以排种效果为依据开展播种过程分析，设计了一款采用双层取种勺结构的马铃薯排种器。通过对排种器及其作业流程进行解析，确定了取种勺的外形与尺寸结构参数。采用EDEM软件对排种器的取种过程与携种过程开展有限元仿真，以此确定双层种勺方案及后续试验的因素取值范围。以播种线速度、投种高度为试验因素，以株距变异系数、种薯横向偏移离散度为试验指标，开展两因素试验。试验结果表明：当播种速度为0.184 m/s、投种高度为9 cm时，相较于单种勺播种机，双层种勺链式播种机可将株距变异系数降低5.8%，种薯横向偏移离散度缩小5.5 mm。