不同氮素水平下甜菜的光谱响应

Spectral Response of Beet under Different Nitrogen Levels

为研究甜菜叶片冠层光谱反射率与甜菜植株生理参数之间的关系,测定不同施氮条件下甜菜冠层光谱反射率及对应植株各部位干重、含氮量,对数据进行相关分析,以期揭示甜菜光谱与植株生物量之间相关关系,为甜菜氮肥精确施用奠定基础。研究表明,生产中可以利用高光谱遥感技术对甜菜植株的氮含量及其他生理参数进行监测。1000nm、1020nm、1040nm三个波段的光谱反射率分别与甜菜叶丛干物质积累量、块根干物质积累量、植株干物质积累量的拟合程度最高,这3个波段可用于建立光谱反射率与甜菜吸氮量的拟合方程。采用分时期分析方法建立拟合方程拟合程度较高。

In order to study the relationships between canopy＇s spectral reflectance and physiological parameters of sugar beet, we measured the canopy＇s spectral reflectance, the dry weight and nitrogen content of sugar beet（leaves, root and petiole, separately） under different N-application conditions, and made an integrated analysis of these data. The results showed that the nitrogen content and other physiological parameters of sugar beet plant could be monitored by using hyperspectral remote sensing technology in field condition. Three wave bands＇ spectral reflectance 1000 nm, 1020 nm and 1040 nm related to dry matter accumulation of leaf, root and plant,respectively, in which relationship of them reach to the highest fitting degree. Hence, these three bands could be used to establish the fitting equation between spectral reflectance and beet nitrogen uptake, furthermore, in each growth period of sugar beet using above mentioned methods, we can establish a higher regression fitting equation of canopy＇s spectral reflectance of sugar beet.