Authors

Abstract

Traditional uniform fertilization in rice paddy fields is associated with low fertilizer-use efficiency and severe agricultural non-point source pollution. Existing variable-rate fertilization equipment commonly presents limitations such as reliance on single-source prescription information and insufficient control precision. To address these issues, this study uses an impeller-type fertilizer applicator as the working platform and, considering the characteristics of cold-region rice cultivation in Heilongjiang Province, constructs an integrated ternary nitrogen-phosphorus-potassium fertilization prescription map. A mapping model between fertilizer application rate and motor speed is established, and a fuzzy PID controller optimized using an improved whale optimization algorithm (IWOA) is designed. Fertilizer-discharge calibration tests and field trials were conducted. The results showed that the coefficient of determination (R²) between fertilizer discharge rate and motor speed reached 0.9912. The IWOA-fuzzy PID algorithm achieved a step-response overshoot of only 3.3% and a settling time of 1.55 s, while the relative error of field fertilization was controlled within ±5%.

Abstract in Chinese

水稻格田传统均匀施肥模式存在肥料利用率低、农业面源污染突出等问题，现有变量施肥装备普遍存在处方信息单一和控制精度不足等缺陷。针对上述问题，本文以叶轮式施肥装置为作业载体，结合黑龙江寒地水稻种植特点，构建氮磷钾三元融合施肥处方图。建立施肥量 - 电机转速映射模型，设计基于改进鲸鱼算法（IWOA）优化的模糊 PID 控制器。开展排肥标定试验，以及田间试验。试验结果表明：排肥量与电机转速拟合决定系数R2=0.9912，IWOA - 模糊 PID 算法阶跃响应超调量仅 3.3%，调节时间 1.55 s，田间施肥相对误差控制在 ±5% 以内。