Horizon 1 1 17 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES Quimica Nova 342-350 SOL PHOSPHORE METHODE D'ANALYSE SPECTROMETRIE INFRAROUGE EXTRACTION ETUDE COMPARATIVE CALIBRAGE MODELISATION HAUTE ALTITUDE BRESIL GOIAS PLANALTINA 2015 fdi:010063759 ENG Quimica Nova 0100-4042 ISI:000354781600009 3 10.5935/0100-4042.20150009 https://www.documentation.ird.fr/hor/fdi:010063759 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers15-04/010063759.pdf 38 Horizon (IRD) 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. 068ANASOL UR210 Brésil