Inversion of Nitrogen Accumulation in Sugar Beet Leaves Based on UAV Multispectral
[Objective]To investigate the correlation between nitrogen accumulation(LNA)and vegetation index of sugar beet at different sowing dates,and to provide theoretical basis for precise fertilization and scientific management in the later stage,[Methods]In this experiment,eight sowing dates(March 27,April 6,April 16,April 26,May 6,May 16,May 26,June 5)were set up,and multispectral remote sensing images of sugar beet and field measurements of canopy nitrogen accumulation(LNA)data were obtained using DJI Elf 4 multispectral UAV.Green Normalized Vegetation Index(GNDVI),Normalized Difference Red Edge Index(NDRE),Leaf Chlorophyll Index(LCI)and Optimized Soil Adjusted Vegetation Index(OSAVI)were obtained by data calculation.The inverse model of nitrogen accumulation(LNA)was established by monitoring the growth status of sugar beet at different sowing stages using unmanned aerial photography.[Results]The results showed that the leaf nitrogen accumulation increased significantly with the increase of the growth period,and gradually decreased with the delay of the sowing dates,with the highest leaf nitrogen accumulation on April 6.The field measured LNA was fitted with five vegetation indices respectively,and the coefficient of determination(R2)was above 0.7,among which NDRE had the best fitting effect,with the coefficient of determination(R2)of 0.885,root mean square error(RMSE)of 4.54 and standard root mean square error(NRMSE)of 8.22%,demonstrating a good prediction effect.[Conclusion]It demonstrates that UAV remote sensing technology has high feasibility in the prediction of LNA in sugar beet,which provides an important theoretical basis for exploring reasonable sowing date,precise fertilizer application and increasing yield and income.
sugar beetUAV remote sensingmultispectralnitrogenvegetation index
国家科技期刊平台
