基于光谱信息的作物氮素营养无损监测技术

氮素是作物生长发育和产量品质形成所必需的营养元素。快速、无损、准确地监测作物氮素状况,对于诊断作物生长特征、提高氮肥运筹水平和利用效率、降低过量施氮带来的农田环境污染,深入开展精确农业和数字农业的研究与应用具有重要意义。本文围绕作物氮素特征光谱产生的机制、反射光谱对氮素营养的响应及光谱指数的生理意义等解析了作物氮素营养光谱无损监测的技术机理,阐明了作物氮素监测的光谱学和生理生态学基础,进而概述了国内外有关作物反射光谱获取及叶片、冠层和空间水平上氮素营养光谱监测的研究进展。针对作物氮素营养监测亟待解决的问题和作物生产需求,提出今后进一步研究的领域应重点围绕氮素生化组分的监测方法、氮素监测模型的普适性、氮素监测仪的开发、地空遥感信息的融合、遥感与其他技术的集成等方面。

Non-destructive monitoring of crop nitrogen nutrition based on spectral information

Nitrogen is one of the necessary nutrient elements for crop growth and yield formation,and the non-destructive,rapid and accurate monitoring of crop nitrogen nutrition is of significance in estimating crop growth parameters,enhancing nitrogen management and use efficiency,reducing farmland contamination from excessive use of fertilizer nitrogen,and promoting the research and application of precision farming and digital agriculture.In this paper,the mechanisms of non-destructive monitoring of crop nitrogen nutrition were interpreted with spectral and eco-physiological bases through clarifying the theoretical basis of the generation of crop nitrogen-specific spectra,responses of reflectance spectra to nitrogen nutrition,and physiological signification of spectral index.The research progress on the acquisition of reflectance spectra and the spectral-based monitoring of nitrogen nutrition in leaf,canopy and spatial levels were reviewed comprehensively,with the possible research directions recommended to address the urgent issues facing crop nitrogen monitoring and management in modern crop production,which included monitoring methods of nitrogen components,wide applicability of nitrogen estimation model,development of nitrogen monitoring apparatus,coupling of air-borne and ground-based spectral information,and integration of remote sensing and other key techniques.