香蕉假茎自动对靶精准施肥装置的设计与试验

目的 针对华南地区蕉园施肥模式不能满足农艺要求、施肥效率低以及施肥机械自动化程度低等问题，设计一种香蕉假茎自动对靶精准施肥装置。方法 根据蕉园实际沟施过程和农艺要求，确定装置的控制原理和关键部件的安装位置，并基于此建立施肥时间滞后模型；对外槽轮排肥器结构进行创新设计，建立排肥机构单圈排肥量和周期排肥量的数学模型，并通过EDEM仿真对肥料运动特性进行验证。采用响应曲面优化方法对排肥机构的工作参数进行优化，满足香蕉在不同生长时期的需肥要求，并以施肥量变异系数、施肥长度变异系数和假茎中心偏移距离为评价指标，进行最优参数组合下的田间试验，进一步验证精准施肥装置的工作性能。结果 确定排肥机构最优工作参数为：排肥轴转速85 r/min，槽轮内芯初始有效工作长度6 mm。田间试验结果表明，施肥量变异系数和施肥长度变异系数均小于4%，假茎中心偏移距离平均值最高为7.4 cm，满足农艺要求。结论 该施肥装置工作性能可满足香蕉施肥要求，本研究可为蕉园精准施肥装置的设计提供参考。

Design and experiment of precision fertilization device with automatic target for banana stalk

Objective In order to solve the problems that the fertilization mode of banana orchard in South China does not meet the agronomic requirements, the fertilization efficiency and the automation level of fertilization machinery are low, a precision fertilization device with automatic target for banana stalk was designed.Method According to the fertilization process and agronomic requirement of banana orchard, the control principle of the device and the installation location of key components were determined, and the time lag model related to fertilization was established. Through the innovative design of the fluted fertilizer distributer, the mathematical models of single cycle and periodic fertilization amount were established, and the motion characteristics of fertilizer were verified by EDEM simulation. In order to meet the fertilizer requirements of banana at different growth stages, the response surface methodology was used to optimize the parameters of fertilizer discharging mechanism. The variation coefficient of fertilization amount, variation coefficient of fertilization length and offset distance from the center of banana stalk were used as the evaluation indexes. Field test was performed using the combination of optimization parameters to further verify the performance of the precision fertilization device.Result The optimal parameters were determined as follows: The rotational speed of fertilizer-distributer shaft was 85 r/min, and the initial length of inner core of fluted roller was 6 mm. The field test showed that the variation coefficients of fertilization amount and fertilization length were both below 4%, and the highest average offset distance from the center of banana stalk was 7.4 cm, meeting the agronomic requirements.Conclusion The working performance of the device can meet the requirements of banana fertilization. This study can provide references for the design of the precision fertilization device for banana orchard.