EDXRF ANALYSIS to estimate the maximum temperature reached in burned soils from an amazonian region.

Maximum temperature reached in soil during burning is important to evaluate fire intensity. Forest conversion is an ongoing process in Amazon ecosystem. It is of utmost importance to predict fire effects on soil properties and avoid damaging environmental systems. Spectroscopic methods combined with multivariate statistics may provide chemical and mineralogical information from soil. This study aims at predicting the maximum temperature reached in Oxisols from an Amazonian region in Brazil. Slash-and-burn and pasture samples collected after fire events, and unburned forest soil samples submitted to heating (250 to 800°C) were investigated. Energy dispersive X-ray fluorescence (EDXRF) was employed to acquire chemical data. The experimental procedure is rapid, requires minimal sample preparation and no hazardous chemical reagents. EDXRF data combined with partial least squares regression was applied in controlled-heated samples from five different sites of forest, pasture and slash-and-burn area. Estimated temperatures for burned samples ranged from 317 to 609°C. Considering the instrumental advantages and the achieved results, the EDXRF employment combined with multivariate analysis has proved to be a feasible alternative technology to evaluate fire effects in soil. This article is protected by copyright. All rights reserved.