Autoria: OLIVEIRA, J. F. de; BROSSARD, M.; CORAZZA, E. J.; MARCHAO, R. L.; VENDRAME, P. R. S.; BRITO, O. R.; GUIMARAES, M. de F.

Resumo: Abstract: The objective of this study was to evaluate the relationships between the spectra in the Vis-NIR range and the soil P concentrations obtained from the P-M and P-rem extraction methods as well as the effects of these relationships on the construction of models predicting P concentration in Oxisols. Soil samples' spectra and their P-M and P-rem extraction solutions were determined for the Vis-NIR region between 400 and 2500 nm. Mineralogy and/ or organic matter content act as primary attributes allowing correlation of these soil phosphorus fractions with the spectra, mainly at wavelengths between 450-550, 900-1100 nm, near 1400 nm and between 2200-2300 nm. However, the regression models generated were not suitable for quantitative phosphate analysis. Solubilization of organic matter and reactions during the P-M extraction process hindered correlations between the spectra and these P soil fractions. For P-rem,, the presence of Ca in the extractant and preferential adsorption by gibbsite and iron oxides, particularly goethite, obscured correlations with the spectra.

Ano de publicação: 2015

Tipo de publicação: Artigo de periódico

Unidade: Embrapa Cerrados

Palavras-chave: Análise do solo, Espectrometria, Espectroscopia VIS/NIR, Espectroscopia do infravermelho próximo (NIR), Espectroscopia na região do visível (VIS), Extração, Fosfato, Latossolo