摘要
以蓖麻在不同氮、磷施用水平下的大田实验为基础,研究了高光谱遥感在估测蓖麻初级生产力主要参数中的应用。结果表明,随着施肥水平的提高,蓖麻叶面积指数(LAI)和生物量增大,导致冠层光谱特征发生相应变化,近红外波段(700～900nm)的反射率显著增大。350～900nm波段特别是700～900nm波段的蓖麻冠层光谱反射率值在花果盛期最大,种子成熟期次之,苗期最低,与蓖麻LAI变化一致,可以用来监测蓖麻的长势和营养状态。构建的高光谱植被指数NDVI、RVI与LAI和ABM回归模型确定系数均较高,分别达到了0.6115、0.6363、0.7102和0.6148,可以用来估测不同物候期蓖麻的叶面积指数和地上部分生物量。
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 （ R^2 ） as 0.611 5,0.636 3,0.710 2 and 0. 614 8, respectively. This suggests that both NDVI and RVI could be used to estimate castor＇s LAI and ABM during different phenologlcal periods.
出处
《中国农业科技导报》
CAS
CSCD
2009年第5期114-118,共5页
Journal of Agricultural Science and Technology
基金
"十一五"国家科技支撑项目(2006BAD09A04
2006BAD09A08)资助
