Estimation of biomass and C and N accumulation at the maturity stage of corn using synchronous SPOT-5 spectral parameters

In order to quickly estimate above-ground biomass, carbon and nitrogen accumulation at the maturity stages of corn, remote sensing estimation models were constructed using synchronous SPOT-5 spectral parameters. The correlations between the synchronous SPOT-5 in 14 kinds of selected spectral parameters and the aboveground biomass, carbon and nitrogen accumulation amount of maize at mature stage were calculated using Pearson correlation analysis, and the suitable spectral parameters were screened out. The regression analysis was used to fit suitable spectral parameters, and to compare and obtain the optimal estimation models of above-ground biomass weight, C and N accumulation. Among the 14 spectral parameters, there are significant positive correlations between soil-adjusted vegetation index (SAVI) and the above-ground biomass weight and carbon accumulation, and the correlation coefficients are 0.831 and 0.846, respectively. So the fitting effect to SAVI as regression equation, the power function models are the best of the estimations of biomass and carbon accumulation, and decision coefficients (R2) are 0.698 and 0.722 and the F test shows a significant under the 0.01 level. The significant correlation with N accumulation amount is determined by the ratio index of near infrared band and green band (R3/R1), the correlation coefficient is 0.844, thus nitrogen accumulation fitting appears the best effect by R3/R1 for the linear model variable, the coefficient of determination (R2) is 0.713 (significant at the 0.01 level). It is feasible that the remote sensing models constructed using soil-adjusted vegetation index (SAVI), ratio index (R3/R1) can best estimate corn mature biomass, C and N accumulation amount in this study.