棉花精准生产对于无损、快速的植株氮含量监测技术有迫切需求。研究棉花冠层光谱特征及其与植株氮含量间的定量关系,可以实现棉株氮素的无损监测。通过连续两年不同施氮量试验,采集棉花冠层高光谱数据并同步测定冠层植株氮含量,分析不同氮肥处理下棉花冠层高光谱特征及其与棉株氮含量间的关系。结果表明:不同时期棉株氮含量与光谱反射率在可见光波段(400-700 nm)显著负相关,在近红外700-1 300 nm波段显著正相关,而在短波红外1 300-1 800 nm波段的相关性较为复杂。冠层尺度下,在棉花整个生育阶段,可见光波段均为棉株氮含量的敏感波段,而近红外波段仅在盛铃期是棉株氮含量的敏感波段;短波红外波段仅在盛蕾期是棉株氮含量的敏感波段。利用不同时期棉株氮素敏感波段可以构建棉株氮素监测指标。
Cotton production for accurate non-destructive,rapid monitoring of plant nitrogen content there is an urgent demand.Canopy spectral characteristics of the cotton plant and its quantitative relationship between nitrogen content,can achieve non-destructive monitoring of cotton nitrogen.Two consecutive years by different nitrogen test,cotton canopy hyperspectral data collection and simultaneous determination of canopy nitrogen content,analysis of different fertilizer treatments of cotton canopy spectral characteristics and the relationship between nitrogen content of cotton,the results show that: nitrogen content of cotton plant in different periods and spectral reflectance in the visible band(400~700 nm) was negatively related to the near-infrared 700~1 300 nm band was a significant positive correlation,and in the short-wave infrared 1 300~1 800 nm band correlation is more complicated.Canopy scale,the whole growth stage of cotton,the visible band are sensitive to nitrogen content in cotton band,and near-infrared only is the cotton boll nitrogen content of the sensitive band;short-wave infrared band only in the budding period Cotton nitrogen sensitive band.Using nitrogen-sensitive bands in different periods can be constructed Cotton Cotton Nitrogen monitoring indicators.