CANOPY WATER-DEFICIT DETECTION IN PADDY RICE USING A HIGH-RESOLUTION FIELD SPECTRORADIOMETER
CANOPY WATER-DEFICIT DETECTION IN PADDY RICE USING A HIGH-RESOLUTION FIELD SPECTRORADIOMETER
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DOI：
10.1016/0034-4257(93)90036-w
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发表时间：
1993-08-01
影响因子：
13.5
通讯作者：
AKIYAMA, T
中科院分区：
文献类型：
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作者：
SHIBAYAMA, M;TAKAHASHI, W;AKIYAMA, T
在整个作物季节（对照）被淹的水稻种植的冠层的可见光、近红外和中红外范围内的反射因子光谱与在预定日期排水的处理进行了比较，并遮挡了降雨，以诱导水分胁迫。在400 ~ 900 nm和900 ~ 1900 nm范围内，每隔5 nm和10 nm采样一次的光谱及其一阶导数通过方差分析（ANOVA）对两个变异源（品种和水分胁迫）进行统计分析。近红外（1190 ~ 1320 nm）和中红外（1600 nm）波段反射率以及1230 nm波段的一阶导数对水稻地表水的去除响应迅速，即使在植被发育过程中完全地被覆盖（LAI = 5）。在960 nm处的一阶导数对应一个小的吸水带，检测了排水后10天左右冠层的水分状况。在一阶导数的响应前几天，叶片水分亏缺、凋萎和卷叶的视觉症状，以及可见光（red）和近红外（NIR）反射率的下降，用归一化植被指数表示，NDVI = (NIR - red) / (NIR + red)。研究结果表明，高光谱分辨率反射率测量及其在近红外和中红外范围内的一阶导数为早期检测水稻冠层水分胁迫提供了一种有希望的方法。
Reflectance factor spectra in the visible, near, and mid-infrared ranges from canopies of rice plantings that were flooded throughout the crop season (controls) were compared with the treatment drained on a predetermined date, and sheltered from rainfall, to induce water stress. Spectra sampled at 5 nm intervals in the 400-900 nm range and 10 nm intervals in the 900-1900 nm range and their first derivatives were statistically analyzed by ANOVA for two sources of variation, cultivars and water stress, each measurement date. Near infrared (1190-1320 nm) and mid-infrared (1600 nm) band reflectances, and the first derivative at 1230 nm responded promptly to the removal of paddy surface water even for complete ground cover (LAI = 5) during vegetative development. The first derivative at 960 nm, corresponding to a small water absorption band, detected the water status Of canopies about 10 days after drainage. Response in the first derivative preceded by a few days the leaf water content deficit, the visual symptoms of wilting and leaf roll, and the decrease in visible red (RED) and near infrared (NIR) reflectances expressed as the normalized difference vegetation index, NDVI = (NIR - RED) / (NIR + RED). Findings indicate that high spectral resolution reflectance measurements and their first derivatives in near and mid-infrared ranges offer a promising method for early detection Of water stress in rice canopies.