Research on Inversion of Nitrogen Content in Apple Tree Canopy Based on Remote Sensing of Unmanned Aerial Vehicles
Rapid and convenient acquisition of real-time nitrogen content in apple tree canopy is the ba-sis for achieving precise fertilization.In this study,using the"Qincrisp"apple trees as research objects,the multi-spectral remote sensing images were obtained by the UAV(unmanned aerial vehicles)remote sensing platform at the flight altitude of 30,50 and 70 m during the periods of new shoot growth,spring shoot stopping growth and fruit expansion,and the canopy nitrogen content was determined synchronously.Forty-three vegeta-tion indices were extracted from the remote sensing images under different experimental conditions,and six sensitive vegetation indices were selected by correlation analysis.The inversion model of canopy nitrogen con-tent was established by GBDT algorithm.The results showed that the GBDT algorithm could achieve better re-sults in the establishment of canopy nitrogen content inversion models for different growth periods of apple trees.The prediction accuracy of the models could be significantly improved by reducing the flight height of the UAV.The optimal model appeared in the new shoot growth period at 30 m of flight height,and its R2 was 0.941 and RMSE was 0.300.The results of this study could provide data support for precise fertilization of"Qincrisp"apple trees and references for related researches.
UAV remote sensingNitrogen content in apple tree canopyMultispectralGradient boos-ting decision tree
万方数据
维普
