Authors

Abstract

Fluid seeding is a new technology for drought resistance, water saving and yield increase in modern agriculture. To improve the uniformity of fluid seed metering of millet, the mechanical stirring device was added to the metering device, and the single-factor tests were carried out on the size parameters of the pump tube, the installation position and the parameters of mechanical stirring. The stirring speed, the ratio between the length of stirring paddle and the diameter of seed box and distance between the pump tube and the stirring paddle were selected as independent variables, and the right rate of hill distance, right rate of seeds per hill and rate of no seed hill were selected as response values. According to the test design principle of Central Composite Design, a response surface analysis method was used to establish mathematical models between each experimental factor and performance index, and the influencing factors of fluid seed metering were analyzed. The single-factor test results showed that when the pump tube was installed on the side of the seed box, and its inner diameter and wall thickness were 4.8 mm and 1.6 mm, respectively, the seeding performance was better. The response surface test results showed that the selected factors all have an influence on the performance of millet fluid seed metering, and the optimal stirring parameters were the stirring speed of 30 r/s, the ratio between the length of stirring paddle and the diameter of seed box of 0.69, and distance between the pump tube and the stirring paddle of 0.11 cm. The verification test was conducted under these parameters, and the right rate of hill distance, right rate of seeds per hill and rate of no seed hill were 94.14%, 84.24%, and 2.21%, respectively, and the error from the predicted values was less than 4%. The performance indexes of fluid seed metering were improved compared with the fluid seed metering device without stirring device, indicating that the optimized stirring parameters can improve the performance indexes of millet fluid seed metering. This study can provide a reference for the research and development of key technologies and equipment for precision fluid seed metering of millet.

Abstract in Chinese

流体播种是现代农业抗旱、节水和增产的一种新技术。为提高谷子流体排种均匀性，在现有输送泵式谷子流体排种器的基础上增设了机械搅拌装置，对泵管尺寸参数、安装位置及搅拌技术参数进行了单因素试验。选取搅拌速率、搅拌桨-种箱直径比和泵管-搅拌桨垂直距离为自变量，以穴距合格率、穴粒数合格率和空穴率为响应值，按照Central Composite Design试验设计原理，采用三因素五水平响应面分析方法建立了各试验因素与性能指标之间的数学模型，并对各因素进行分析。单因素试验结果表明：当泵管安装于种箱侧面，其内径和壁厚分别为4.8 mm、1.6 mm时，排种性能较优。响应面试验结果表明：搅拌速率、搅拌桨-种箱直径比和泵管-搅拌桨垂直距离均对谷子流体排种性能有一定影响，且流体排种器最佳搅拌参数为搅拌速率30 r/s、搅拌桨-种箱直径比0.69、泵管-搅拌桨垂直距离0.11cm。该参数下进行验证试验得到谷子流体排种穴距合格率、穴粒数合格率和空穴率分别为94.14%、84.24%、2.21%，与预测值误差小于4%。通过与未加搅拌装置的流体排种器进行对比试验，流体排种性能指标均有明显改善，说明增设的搅拌装置及其最优技术参数可提高谷子流体排种性能指标。该研究可为谷子精量流体排种关键技术与装备的研发提供参考。