An effective method to monitor heavy metal stress in crops is of critical importance to assure agricultural production and food security. Phenology, as a sensitive indicator of environmental change, can respond to heavy metal stress in crops and remote sensing is an effective method to detect plant phenological changes. This study focused on identifying the rice phenological differences under varied heavy metal stress using EVI (enhanced vegetation index) time-series, which was obtained from HJ-1A/B CCD images and fitted with asymmetric Gaussian model functions. We extracted three phenological periods using first derivative analysis: the tillering period, heading period, and maturation period; and constructed two kinds of metrics with phenological characteristics: date-intervals and time-integrated EVI, to explore the rice phenological differences under mild and severe stress levels. Results indicated that under severe stress the values of the metrics for presenting rice phenological differences in the experimental areas of heavy metal stress were smaller than the ones under mild stress. This finding represents a new method for monitoring heavy metal contamination through rice phenology.
展开▼
机译:监测农作物重金属胁迫的有效方法对于确保农业生产和粮食安全至关重要。物候学作为环境变化的敏感指标,可以响应农作物中的重金属胁迫,遥感技术是检测植物物候变化的有效方法。这项研究的重点是使用从HJ-1A / B CCD图像获得的EVI(增强植被指数)时间序列,并使用不对称的高斯模型函数,确定在不同重金属胁迫下的水稻物候差异。我们使用一阶导数分析提取了三个物候期:分er期,抽穗期和成熟期;分别建立了日期间隔和时间积分EVI这两种具有物候特性的指标,探讨了轻度和重度胁迫下水稻的物候差异。结果表明,在重度胁迫下,重金属胁迫试验区表现水稻物候差异的指标值小于轻度胁迫。这一发现代表了一种通过水稻物候监测重金属污染的新方法。
展开▼