EDAFOLOGÍA, Vol 12. (2), pp 115-126, 2005
MECANISMOS DE AMORTIGUACIÓN DE IMPACTOS ACIDIFICANTES. INFLUENCIA DE LA LITOLOGÍA, PROPIEDADES SUPERFICIALES Y GRADO DE DESARROLLO EDÁFICO
F. MACÍAS, L. RODRÍGUEZ LADO, M. CAMPS ARBESTAIN, E. BARREAL.
Dpto. de Edafología y Química Agrícola. Fac. Biología. Universidad de Santiago.15782 Santiago de Compostela. felipe.macias.vazquez@usc.es
A revision of the main buffering mechanisms against acidifying impacts on soils of the Ibe- rian Peninsula and Brazil (states of Sao Paulo and Minas Gerais) allows the establishment of a soil sensiti- vity model against acidification which is more adequate than those based on cation exchange properties or on factors of soil formation (mainly lithology). The most important reactions for protections of soils against acidity are those that display a fast kinetics, such as cationic exchange and anionic adsorption reactions. In contrast, mineral weathering reactions are only efficient (as buffering mechanisms against acidification) when they occur (i) on rocks of basic reaction and intense reactivity and/or (ii) under conditions of intense weathering. Sulfate adsorption in acid soils is, together with the solubilization of Al reactive forms present in soils with either andic, aluminic, or ferralic character, one of the main buffering mechanisms against acidifying impacts.
Keywords: soil acidification, neutralization, sulphate adsorption.