| 磷营养胁迫对冬小麦冠层光谱的影响 |
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| 作者单位： | 南京农业大学资源与环境科学学院，中国科学院资源环境科学数据中心，中国科学院南京土壤研究所 |
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| 摘 要： | 因为磷素重要的营养作用,其胁迫的存在影响冬小麦的正常生长。借助地面遥感仪器获取冬小麦在磷营养胁迫下的多个生育期里的冠层光谱数据并对其影响特征进行了分析。利用因子分析方法提取主因子与含有丰富信息的光谱变量,并结合极显著水平(0.01)的均值比较与检验过程考察了冬小麦冠层光谱,确定了对磷营养胁迫敏感的光谱波段:760nm,810nm和870nm与950nm,并在此基础上结合冬小麦对磷素的吸收利用特征选定了运用冠层光谱敏感波段反射率探测和区分磷营养胁迫的关键生育期:拔节期。结果同时表明,对冬小麦磷营养胁迫而言,近红外区间(760nm~1100nm)光谱反射特征的区分能力要强于可见光区。本文同时指出了研究与发展利用遥感技术进行营养胁迫监测的方法和着重点。
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| 关 键 词： | 磷胁迫 冬小麦 冠层光谱 敏感波段 关键生育期 |
Effect of Phosphorus Stress on Winter Wheat Canopy Spectral Reflectance |
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| Authors: | RENHong-yan ZHUANGDa-fang PANJian-jun QiuDong-sheng ZHANGJia-bao |
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| Institution: | RENHong-yan1,2,ZHUANGDa-fang2,PANJian-jun1,QiuDong-sheng2,ZHANGJia-bao3 |
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| Abstract: | Phosphorus stress holds back normal growth of wheat because of important nutrition of phosphorus. With the help of mobile spectral radiometer, the canopy spectral reflectance of winter wheat stressed by phosphorus at several growth stages were obtained. Canopy reflectance of winter wheat in visible and near infrared region varied differently. As phosphorus deficiency condition improved, spectral reflectance in visible region decreased, but those in near infrared region increased. Spectrums were analyzed by means of factor analysis and means comparison (Compared T-test), and this significance examination attributed to bands selection for detecting phosphorus deficiency. Principal component extracted by factor analysis was used to eliminate collinear variable bands such as 460nm~710nm in this study and PC1 can explain about 95 percent of variance for canopy reflectance difference. With the combination of means comparison between canopy spectrums and PCA, 760nm, 810nm, 870nm and 950nm were selected and validated to be special bands sensitive to phosphorus stress on wheat. When winter wheat plants were growing in the jointing stages (both of pre-jointing and jointing stages in this study), the trend of wheat canopy spectral curves changesd in a different way (like the spectral reflectance at 870 nm). Then the jointing stage was chosen for the key growth stage to detect and estimate phosphorus stress by remote sensing technique. The results showed that phosphorus stress affects canopy spectral reflectance of winter wheat and 760nm-1100nm of near infrared spectral region have better capability of distinguishing phosphorus stress on winter wheat than visible lights. When number of samples was enough, partial least squares (regression), principal components analysis (regression) and some other analytical technology should establish complex models that included many more factors like wheat gene types and so on, which would be much more important in research of monitoring nutrients stress on crops in the future. |
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| Keywords: | Phosphorus stress Winter wheat Canopy spectrum Sensitive bands Key growth stages |
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