VEGETATION INDICES AND THEIR CORRELATION WITH SECOND-CROP CORN GRAIN YIELD IN MATO GROSSO DO SUL, BRAZIL

Jorge Wilson Cortez,Hermano José Ribeiro Henriques,Dário Alexandre Schwambach,Vanessa Jordão Marcato Fernandes

doi:10.18512/rbms2021v20e1195

Jorge Wilson Cortez, Hermano José Ribeiro Henriques + Show 2 more

Open Access

https://doi.org/10.18512/rbms2021v20e1195

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Abstract

The emergence of satellites covering new electromagnetic wavelengthsallowed developing different vegetation indices, enabling the study of theircorrelation with grain yield. In this sense, this study aimed to evaluate the accuracy between the mean values of seven vegetation indices and the mean corn grain yield in the field by applying linear regression equations. The indices NDVI, NDRE, GNDVI, GRNDVI, and PNDVI were used, with changes proposed in the equations of the indices GRNDVI and PNDVI, in which the red wavelength was replaced by the red edge. The multispectral bands provided by the Sentinel-2A and Sentinel-2B imaging instruments were used as a source of data to calculate the vegetation indices, while the values recorded by the grain harvester were used for the survey of grain yield data. A high correlation was observed between indices and grain yield. The replacement of the red wavelength with the red edge improves the correlation between vegetation indices and grain yield. Moreover, the indices GNDVI and NDVI easily saturate, reaching maximum values and not allowing the distinction between sample classes. Therefore, the vegetation indices PRENDVI and GRENDVI are recommended for estimating grain yield.

Highlights

Resumo - O surgimento de satélites abrangendo novos comprimentos eletromagnéticos de onda permitiu o desenvolvimento de diferentes índices de vegetação, possibilitando o estudo da correlação destes com a produtividade de grãos
Verificou-se que a substituição do comprimento de onda vermelho pelo vermelho da borda melhora a correlação entre índices de vegetação e a produtividade de grãos, e que os índices green normalized difference vegetation index (GNDVI) e normalized difference vegetation index (NDVI) saturam facilmente, atingindo valores máximos, não permitindo a distinção entre classes amostrais
This process is influenced by the spatial variability in the field, requiring the adjustment of tools that assist in the decision-making

Summary

Introduction

Resumo - O surgimento de satélites abrangendo novos comprimentos eletromagnéticos de onda permitiu o desenvolvimento de diferentes índices de vegetação, possibilitando o estudo da correlação destes com a produtividade de grãos. Mean (M) VI in nanometer and yield in kg ha−1; amplitude (A); variance (V); standard deviation (SD); standard error of the mean (SEM); coefficient of variation (CV, %); pan normalized difference vegetation index with green, red edge, and blue (PRENDVI); pan normalized difference vegetation index with green, red, and blue (PNDVI); green-red edge normalized difference vegetation index (GRENDVI); green-red normalized difference vegetation index (GRNDVI); normalized difference red edge index (NDRE); normalized difference vegetation index (NDVI); green normalized difference vegetation index (GNDVI).

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