De Oliveira J.F. auteur aut IRD Brossard Michel auteur aut IRD Corazza E.J. auteur aut IRD Marchão R.L. auteur aut IRD Siqueira Vendrame P.R. auteur aut IRD Rodrigues Brito O. auteur aut IRD Guimarães M. de F. auteur aut IRD text journalArticle eng text/pdf reformatted digital access 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 Pm and Prem 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 Pm and Prem 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 2200-2300nm. However, the regression models generated were not suitable for quantitative phosphate analysis. Solubilization of organic matter and reactions during the PM extraction process hindered correlations between the spectra and these P soil fractions. For Prem,, the presence of Ca in the extractant and preferential adsorption by gibbsite and iron oxides, particularly goethite, obscured correlations with the spectra. specialized SOL PHOSPHORE METHODE D'ANALYSE SPECTROMETRIE INFRAROUGE EXTRACTION ETUDE COMPARATIVE CALIBRAGE MODELISATION HAUTE ALTITUDE BRESIL GOIAS 068ANASOL 38 3 342-350 2015 0100-4042 https://www.documentation.ird.fr/hor/fdi:010063759 10.5935/0100-4042.20150009 0100-4042 [F B010063759] https://www.documentation.ird.fr/hor/fdi:010063759 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers15-04/010063759.pdf IRD - Base Horizon / Pleins textes 2015-04-20 2016-04-01 fdi:010063759 fre