Agronomía Colombiana (Jan 2005)
Interpreting redox processes in acid sulphate soils in the upper Chicamocha river basin, Boyaca¹
Abstract
The presence of acid sulphate soils (ASS) in the upper Chicamocha river basin (Boyaca, Colombia) is due to iron and sulphur oxide-reduction processes being located there, influencing the extreme acidification and modification of the area's physicochemical characteristics. This research was aimed at establishing parameters through observing the behaviour of Eh (mV), pH (1:1, soil-water), pHox (1:1, soil- peroxide hydrogen 30%) and Al+3. These parameters indicate severe ASS degradation and its relationship to the presence of organic materials or minerals constituting diagnostic sulphuric horizons. Most sulphuric horizons agree with positive Eh (mV) >400; pH 4.0 and Al+3 >5 cmol. kg-1. These indicators illustrated the heavy oxidation and limitations on agricultural productivity regarding ASS in the upper Chicamocha basin irrigation area