基于主动光谱仪的水稻叶面积指数监测

Study on LAI monitoring model of rice with GreenSeeker

叶面积指数(LAI)是描述作物长势的重要参数,LAI的实时动态监测对水稻生长诊断和管理调控具有重要意义。为分析水稻LAI与光谱参数的定量关系,设置了不同年份、不同氮肥水平的田间试验,于移栽后定期测试水稻冠层光谱参数,并同步定株测量LAI。结果表明,LAI可以基于主动光谱仪构建的植被指数(NDVI和RVI)进行模拟,NDVI(770,660)、RVI(770,660)均能较好地模拟LAI,预测精度分别为0.97、0.92,RMSE分别为0.41、1.32,RE分别为0.16、0.28,利用主动光谱仪可以实现水稻LAI的快速无损监测,为指导水稻精确管理提供了技术支持。

In order to make clear the quantitative relationship between leaf area index （LAI） and canopy reflectance spectra of active sensor in rice, and coach the rice management, three field experiments with different rice varieties and nitrogen levels were conducted in different years. The time-course measurements were taken on canopy reflectance and LAI during the experimental period. The result showed that LAI could be estimated with the vegetation indice of the active sensor, and the R2 （prediction precision） were 0.97 and 0.92, the RMSE were 0.41 and 1.32, RE were 0.16 and 0.28. So LAI in rice could be monitored directly by vegetation indices of active sensor, and it could give a technical suovort for rice manaement.