Kriterien für die Akzeptanz von recyceltem Phosphatdünger aus Abwasser und Klärschlamm im ökologischen Landbau

Summary

Plant available phosphorus is a limiting factor in organic farming. In the wake of an increasing awareness of the planetary boundaries of phosphate rock deposits, various research efforts to develop fertilizers based on recycled phosphorus from wastewater, sewage sludge and sewage sludge ashes have been initiated. The study aimed at the future potential of these fertilizers for organic farming and tried to identify and evaluate criteria that need to be fulfilled so that fertilizers of recycled phosphorus would be accepted by organic farmers. The survey revealed that the most important criterion for the acceptance is the non-existence of hazardous substances in the fertilizer. Plant availability, low energy input and high transparency of the production process of the fertilizers were also regarded as relatively important. Spreadability, price, public acceptance and superficial distinction compared to mineral fertilizers play a minor role for the acceptance.