Soil organic carbon changes following the revegetation and episodic rewetting of acid sulfate soils

Abstract

Revegetation trials of exposed, but formerly sub-aqueous sandy soils containing hyper and hyposulfidic materials on the shoreline of Lake Albert resulted in a 6 to 13 fold increase in soil organic carbon at one of the two trial sites. The average baseline C:N ratio was < 10 and consistent with an aquatic origin for the carbon. Following revegetation, the C:N ratio remained < 10 indicating the additional organic was not from the terrestrial plants used in the revegetation, with soil microbial biomass appearing to be the likely source. Following reflooding, this labile carbon will be an important energy source in re-establishing reducing conditions and decreasing accumulated acidity.