关键词: 蓖麻；高光谱遥感；叶面积指数；生物量

Abstract:

This paper studied on the estimation of main parameters of castors primary productivity by hyperspectral remote sensing data, using field experiment with different nitrogen and phosphorus levels. The result showed that with increasing application of nitrogen and phosphorus, LAI and ABM all increased, and castor canopy spectral reflectance was correspondently changed, especially the reflectivity of near-infrared ray (700~900 nm) was notably increased. Canopy spectral reflectance in 350~900 nm (especially 700~900 nm) was the highest in flowering and fruiting  period, higher in seed maturing period, and the lowest in seedling stage. These changes were positively correlated with LAI. This suggests that the canopy spectral reflectance could be used to monitor castors growth vigor and nutritional status. The relationships between hyperspectral vegetation index NDVI, RVI and LAI, ABM were all highly significant with determination of coefficients (R2) as 0.6115、0.6363 、0.7102 and 0.6148, respectively. This suggests that both NDVI and RVI could be used to estimate castors LAI and ABM during different phenological periods.

Key words: castor, hyperspectral remote sensing, LAI, ABM