玉米叶片的光谱响应及其氮素含量预测研究

以不同施肥水平下两年玉米田间试验为基础，利用高光谱技术探讨大喇叭口期不同层次玉米叶片光谱响应的敏感区域，并依据叶片氮素含量与原始光谱反射率及其一阶导数的相关性，最终构建了叶片氮素含量的预测模型。结果表明：不同施肥水平下叶片光谱反射率差别明显区域集中在550 nm附近波段、761～1 300 nm波段，不同层次间叶片光谱反射率差别明显区域集中在550 nm附近波段，叶片氮素含量与470～760 nm波段光谱反射率及其一阶导数呈极显著相关。经过对比筛选，以光谱指数DSI(564，681)和DSI(681，707)构建的指数预测模型效果最好，预测精度达93.43%和93.39%，能有效估测叶片氮素含量。

Spectral Response of Maize Leaves and Prediction of Their Nitrogen Content

In the present study, a 2-year maize field experiment with different fertilizer dose was conducted. The spectral response sensitive area of maize leaves in different levels was discussed using hyperspectral technology at booting stage. Based on the correlation analysis of original reflectivity and its first derivation with maize leaf nitrogen contents, prediction models were constructed. The results indicated that under different fertilizer dose spectral response sensitive areas of maize leaves were in visible band around 550 and 761~1 300 nm; under different levels which was in visible band around 550 nm; maize leaf nitrogen contents were significantly correlated with spectral reflectance and its first derivative in 470~760 nm band. Through further comparison and selection, the index prediction models built with spectral indices DSI(564, 681) and DSI(681, 707) were the best prediction models, the prediction accuracy were 93.43% and 93.39%, therefore nitrogen content of maize leaves could be effectively estimated.