Vertical stratified simulation of chlorophyll content of summer maize based on PROSAIL model
WANG Shengfeng1, XU Yaze1,2, PENG Zhigong2*, WEI Zheng2, ZHANG Baozhong2,CAI Jiabing2, WANG Feiyu2, MOU Yanwen2
1. College of Water Resources, North China University of Water Resources and Hydropower, Zhengzhou, Henan 450046, China; 2. State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropo-wer Research, Beijing 100038, China
Abstract:Simulation research on crop vertical layered chlorophyll monitoring was made to provide ba-sic data support for precision fertilization, irrigation and pest control. Summer maize chlorophyll and spectral reflection monitoring tests were carried out at different nitrogen application levels from 2019 to 2020, and the vertical stratified law of summer maize chlorophyll content was simulated. The results show that the chlorophyll content of summer maize shows a lateral bell shape as the canopy depth increases;the reflectance that the most sensitive band of chlorophyll is 699-722 nm was used to construct the summer maize chlorophyll simulation cost function, realizing the vertical stratification simulation of chlorophyll content in summer maize based on PROSAIL. Based on the comprehensive analysis of the estimation accuracy of chlorophyll in each layer at different growth stages, the simulation effect of vertical stratification of chlorophyll in summer maize was further clarified on the basis of controlling the re-lative error RE of average chlorophyll simulation within 45%, that is, the determinant coefficient R2 of the first layer of leaves during the tasseling and filling stage and the other layers in the whole fertility simulation is in the range of 0.114 5-0.799 3, the root mean square error RMSE is in the range of 2.41-12.13 μg/cm2 and the relative error RE is in the range of 9.67%-98.22%. The relevant research results can provide theoretical and technical support for the vertical stratified simulation application of crop chlorophyll.