Soils on a sewage farm in the Buch Forest area - origins and properties

摘要

The wastewater irrigation of the Hobrechtsfelde sewage farm near Berlin led to high heavy metal concentrations in the soil and to rising ground water levels. After its closure, the ground water levels dropped, nutrients leached, and soil acidification and heavy metal mobilisation began. More than 80 percent of the sewage farm was originally oligotrophic with sandy layers uninfluenced by groundwater, and these are often covered with Regosole and rusty brown soil, characterised by low pH values, highheavy metal concentrations and dehydration. Sewage sludge resulted in a thick colluvial soil layer in places. The mobilization of the heavy metals is prevented by the sorption efficiency. The soil quality can be improved by the application of lime fertilizer, the improvement of the water storage capacity, and the improvement of the sorption efficiency.