Quantifying heavy metal inputs from organic and inorganic material additions to agricultural soils in England and Wales

摘要

Heavy metal inputs to agricultural soils in England and Wales were estimated from all major sources, including atmospheric deposition, biosolids, livestock manures and footbaths, composts, anaerobic digestates, industrial 'wastes' (including paper crumble, food 'wastes', water treatment sludges), ash (from poultry manure incineration) and canal/river dredgings. Across the whole agricultural land area, atmospheric deposition was a major source of metals ranging from 8 to 85% of total inputs, with livestock manures and biosolids also important sources as a result of the large quantities of these materials applied. Metal addition rates at the individual field level from pig and poultry manures and composts were similar to (and sometimes greater) than those from biosolids. Moreover, metal inputs from 'new' materials which are increasingly being applied to agricultural land (e.g. food wastes) also sometimes exceeded those from biosolids. The study has provided baseline information upon which to developand focus future policies limiting heavy metal inputs to and accumulation in topsoils.