The spread of sewage sludge on farmland - long term effects on soils and crops and effects on antibiotic resistance

Field trials with sewage sludge application on arable land in southwestern Sweden are ongoing since 1981, and these trials are thereby unique in the world. The goal is to evaluate and quantify the effects of applied nutrients, metals, trace elements and humus forming substances. The results from the trials have contributed significantly to the current knowledge about long term effects of sludge application on soil as well as crops. Within the context of the long term field trials, a dedicated study will now be performed on the possible presence of antibiotics, antibiotic resistant bacteria and antibiotic resistance genes in sludge and sludge-fertilized soil.