Quantifying heavy metal inputs to agricultural soils in England and Wales

Heavy metal inputs to agricultural soils in England and Wales were estimated from major sources, including atmospheric deposition, biosolids, livestock manures, inorganic fertilisers and lime, industrial by‐product ‘wastes’ and composts (year 2000). Across the whole agricultural land area, atmospheric deposition was the main source of most metals ranging from 25 to 85% of total inputs. Livestock manures and biosolids were also important sources representing 37 and 8% of total zinc (Zn) inputs, 40 and 17% for copper (Cu), and 10 and 4% for cadmium, respectively. The highest heavy metal input rates on a field basis were generally from biosolids, although Zn and Cu inputs from pig manures were equivalent to 46–52% of biosolids inputs (both applied at a rate of 250 kg/ha total N). The study provided baseline information to develop and focus policies limiting heavy metal inputs to and accumulation in topsoils.