基于无人机遥感的冬小麦追肥推荐模型建立

Design for Winter Wheat Top Dressing Recommendation Model Based on UAV Remote Sensing

为提高小麦氮素精准、高效的管理能力,实现实时、便捷、精准的变量施肥。本文在无人机遥感进行冬小麦氮素营养诊断的基础上,依据光谱诊断施肥模型,建立冬小麦返青期、拔节期和抽穗期等关键生育期追肥推荐模型。研究结果表明:无人机影像获得的DVI与冬小麦关键生育时期氮素参数植株氮浓度相关性最好(R2=0.8698);冬小麦返青期、拔节期和抽穗期氮素诊断临界DVI值分别为0.594、0.784和0.807;冬小麦最高产量为11 364.3 kg/hm^(2),最佳产量为11 230.9 kg/hm^(2),总施氮量为272.9 kg/hm^(2),最佳经济施肥量264.1 kg/hm^(2),基于光谱诊断的追肥推荐模型分别为返青期y=-39.69x+23.58、拔节期y=-129.97x+101.95、抽穗期y=-159.79x+128.93。诊断指标的建立为冬小麦基于光谱诊断的追肥模型奠定了基础,临界DVI值的确定为诊断冬小麦关键生育期是否补充氮肥提供依据,氮肥效应曲线建立和光谱诊断施肥模型选择实现了定量化的追肥推荐。

In order to improve the management ability of wheat nitrogen accurately and efficiently, real-time, convenient and accurate variable rate fertilization was realized. Based on the nitrogen nutrition diagnosis of winter wheat by UAV remote sensing and the fertilization model of spectral diagnosis, the recommended fertilization models for key growth stages of winter wheat, such as green-turning stage, jointing stage and heading stage were established.The results showed that the DVI obtained from UAV images correlated best with plant nitrogen concentration(R2=0.869 8), and the critical DVI values of nitrogen diagnosis at turning green stage, jointing stage and heading stage of winter wheat were 0.594, 0.784 and 0.807, respectively. The highest and best yield of winter wheat was 11 364.3 kg/ha, the best yield was 11 230.9 kg/ha, and the total nitrogen application amount was 272.9 kg/ha, respectively.The optimum economic fertilization amount was 264.1 kg/ha. The recommended fertilizer application models based on spectral diagnosis were y=-39.69 x+23.58 in the green-back stage, y=-129.97 x+101.95 at jointing stage and y=-159.79 x+128.93 at heading stage. The establishment of diagnostic indicators laid a foundation for the model of fertilizer top dressing based on spectral diagnosis. The critical DVI value did provide the basis for the diagnosis of whether nitrogen fertilizer was added in the key growth period of winter wheat. The establishment of the effect curve of nitrogen fertilizer and the selection of the application model of spectral diagnosis realized the quantitative recommendation of top dressing.