Taking into account the global phosphorus (P) depletion, the use of alternative nutrient-rich materials is important in order to save natural resources. The Swedish Government's goal is that by 2015, at least 60% of P originating from treated sewage sludge (biosolids) should be recycled to soil (Swedish EPA, 2010). However, conflicting information exists on e.g. migration of heavy metals in soil amended with biosolids.