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为研究基于高光谱优化NDVI值在反演喇叭口期玉米叶片氮含量的可行性,使用Fiedspec3.0光谱仪和Greenseeker分别对不同施氮量下玉米叶片的光谱反射率和NDVI进行了测定,并对NDVI值进行了提取和优化,建立玉米叶片氮含量优化NDVI反演模型,对其反演精度进行验证。结果显示:优化NDVI值与NDVI测定值、玉米叶片氮含量均呈显著正相关(r=0.913 2,0.949 8),优化NDVI值对玉米叶片氮含量反演精度达到显著水平(r=0.908 1),反演精度高于NDVI测定值。优化NDVI值能通过群体的速测来决策玉米叶片的氮含量,为玉米进行氮营养诊断提供新的技术支持,具有重要的现实意义。
In order to study the feasibility of retrieving nitrogen content in the flare stage of maize leaves based on hyperspectral NDVI values, the spectral reflectance and NDVI of maize leaves under different nitrogen rates were determined by Fiedspec 3.0 spectrometer and Greenseeker respectively. NDVI values were extracted and optimized to establish a nitrogen content optimized maize leaf NDVI inversion model to verify the accuracy of its inversion. The results showed that there was a significant positive correlation between optimized NDVI value and NDVI value and nitrogen content of maize leaves (r = 0.913 2, 0.949 8), and the optimized NDVI value of maize leaf nitrogen content reached a significant level (r = 0.908 1) , The inversion accuracy is higher than that of NDVI. Optimizing the NDVI value can determine the nitrogen content of maize leaves through rapid population test and provide new technical support for the diagnosis of nitrogen nutrition in maize, which has important practical significance.