Estimation of Biomass and CN Accumulation in Corn at Maturation Stage Based on SPOT-5

Abstract

The monitoring models to estimate the above-ground biomass weight and carbon and nitrogen (CN ) accumulation of corn at maturation stage were established based on SPOT-5 images to provide reference for prediction of land production, effective nutrient balance of cultivated soil and carbon and nitrogen cycles. The appropriate spectral parameters were filtered out and the optimal monitoring equations were established between spectral parameter and above-ground biomass weight and CN accumulation by using Pearson correlation analysis and linear and nonlinear simulations. The adjust brightness vegetation index (SAVI) showed a significant positive correlation with the above-ground biomass weight and carbon accumulation and the correlation coefficients were 0.831 and 0.846.The strongest correlation with nitrogen accumulation was ratio index (R3/R1) and the correlation coefficient was 0.844.The power function model based on SAVI inversed above-ground biomass weight and carbon accumulation was the best, R2 were 0.6982 and 0.7216.The linear function model based on R3 / R1 inversed nitrogen accumulation was the best and R2 was 0.7129.Based on the optimal monitoring models, the thematic maps were produced to monitor above-ground biomass and CN accumulation in corn at maturation stage. The estimating model based on the SPOT-5 images can achieve high precision in estimating the above-ground biomass weight and CN accumulation in corn and it has a wide application prospect.