CONTROLS ON THE DYNAMICS OF DISSOLVED ORGANIC MATTER IN SOILS: A REVIEW

作者：Karsten Kalbitz, Stephan Solinger, Ji‐Hyung Park, Beate Michalzik, Egbert Matzner · 发表于：Soil Science · 年份：2000 · DOI：10.1097/00010694-200004000-00001 · 被引用次数：2430 · 研究领域：Soil and Water Nutrient Dynamics、Peatlands and Wetlands Ecology、Soil Carbon and Nitrogen Dynamics

Dissolved organic matter (DOM) in soils plays an important role in the biogeochemistry of carbon, nitrogen, and phosphorus, in pedogenesis, and in the transport of pollutants in soils. The aim of this review is to summarize the recent literature about controls on DOM concentrations and fluxes in soils. We focus on comparing results between laboratory and field investigations and on the differences between the dynamics of dissolved organic carbon (DOC), nitrogen (DON), and phosphorus (DOP). Both laboratory and field studies show that litter and humus are the most important DOM sources in soils. However, it is impossible to quantify the individual contributions of each of these sources to DOM release. In addition, it is not clear how changes in the pool sizes of litter or humus may affect DOM release. High microbial activity, high fungal abundance, and any conditions that enhance mineralization all promote high DOM concentrations. However, under field conditions, hydrologic variability in soil horizons with high carbon contents may be more important than biotic controls. In subsoil horizons with low carbon contents, DOM may be adsorbed strongly to mineral surfaces, resulting in low DOM concentrations in the soil solution. There are strong indications that microbial degradation of DOM also controls the fate of DOM in the soil. Laboratory experiments on controls of DOM dynamics have often contradicted field observations, primarily because hydrology has not been taken into account...