Use of organic wastes in agriculture

As the number of biogas plants and wastewater treatment plants continues to grow, there is an urgent need to find sustainable usage of the organic wastes produced in these facilities Recycling of organic wastes within agriculture can reduce the need for mineral fertilizer and restore organic carbon deficiency in the soil. The results from a 16-year long field experiment, where agricultural lands have been amended using sewage sludge and biogas residue is presented in this paper. Plant nutrients, organic contaminants and metals have been analyzed in order to evaluate the impact of the wastes on soil and crop quality. The results show that only small differences in plant uptake of metals and organic pollutants appear after 16 years. In addition, biogas residues performed well as a fertilizers, although not as well as mineral fertilizers. (C) 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license.