title: Municipal composts reduce the transfer of Cd from soil to vegetables.
abstract: Cadmium (Cd) is a non-essential trace element that accumulates in agricultural soils through the application of Cd-rich phosphate fertiliser. Vegetables can accumulate Cd to concentrations that sometimes exceed food safety standards. We investigated the potential of low-cost soil amendments to reduce Cd uptake by spinach (Spinacia oleracea L.), lettuce (Lactuca sativa L.) and onion (Allium cepa L.). Batch sorption experiments revealed the relative sorption of Cd by biosolids, charcoal, lignite, sawdust, two types of compost, bentonite and zeolite. Lignite and compost had the greatest ability to sorb Cd and were subsequently selected for pot trials, which elucidated their effect on Cd uptake by onions, spinach and lettuce in two market garden soils with native Cd concentrations of 1.45 mg/kg and 0.47 mg/kg. The addition of 2.5% (dry w/w) municipal compost reduced the Cd concentration in onions, spinach and lettuce by up to 60% in both soils. The addition of lignite gave variable results, which depended on the soil type and rate of addition. This Cd immobilisation was offset by soil acidification caused by the lignite. The results indicate that municipal compost is a low-cost soil conditioner that is effective in reducing plant Cd uptake.
authors.affiliation: Department of Soil Science, Faculty of Agricultural and Life Sciences, Lincoln University, PO Box 85084, Lincoln 7647, New Zealand.
authors.forename: Shamim
authors.initials: S
authors.lastname: Al Mamun
authors.affiliation: Department of Soil Science, Faculty of Agricultural and Life Sciences, Lincoln University, PO Box 85084, Lincoln 7647, New Zealand.
authors.forename: Guilhem
authors.initials: G
authors.lastname: Chanson
authors.affiliation: Department of Soil Science, Faculty of Agricultural and Life Sciences, Lincoln University, PO Box 85084, Lincoln 7647, New Zealand.
authors.lastname: Muliadi
authors.affiliation: Department of Soil Science, Faculty of Agricultural and Life Sciences, Lincoln University, PO Box 85084, Lincoln 7647, New Zealand.
authors.forename: Ebrahim
authors.initials: E
authors.lastname: Benyas
authors.affiliation: Department of Soil Science, Faculty of Agricultural and Life Sciences, Lincoln University, PO Box 85084, Lincoln 7647, New Zealand.
authors.forename: Munmun
authors.initials: M
authors.lastname: Aktar
authors.affiliation: Department of Soil Science, Faculty of Agricultural and Life Sciences, Lincoln University, PO Box 85084, Lincoln 7647, New Zealand.
authors.forename: Niklas
authors.initials: N
authors.lastname: Lehto
authors.affiliation: AgResearch. Invermay Agricultural Centre, Puddle Alley, Private Bag 50034, Mosgiel 9053, New Zealand.
authors.forename: Richard
authors.initials: R
authors.lastname: McDowell
authors.affiliation: Landcare Research. PO Box 69040, Lincoln, Lincoln 7640, New Zealand.
authors.forename: Jo
authors.initials: J
authors.lastname: Cavanagh
authors.affiliation: Department of Soil Science, Faculty of Agricultural and Life Sciences, Lincoln University, PO Box 85084, Lincoln 7647, New Zealand.
authors.forename: Liv
authors.initials: L
authors.lastname: Kellermann
authors.affiliation: Department of Soil Science, Faculty of Agricultural and Life Sciences, Lincoln University, PO Box 85084, Lincoln 7647, New Zealand.
authors.forename: Lynne
authors.initials: L
authors.lastname: Clucas
authors.affiliation: Department of Soil Science, Faculty of Agricultural and Life Sciences, Lincoln University, PO Box 85084, Lincoln 7647, New Zealand. Electronic address: brett.robinson@lincoln.ac.nz.
authors.forename: Brett
authors.initials: B
authors.lastname: Robinson
mesh_terms: D000327:Adsorption / Q000502:physiology; D000383:Agriculture / Q000379:methods; D002104:Cadmium / Q000032:analysis / Q000737:chemistry*; D003031:Coal; D005308:Fertilizers / Q000032:analysis; D018545:Lactuca / Q000737:chemistry*; D019697:Onions / Q000737:chemistry*; D010710:Phosphates; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis / Q000737:chemistry*; D018724:Spinacia oleracea / Q000737:chemistry*; D014675:Vegetables / Q000737:chemistry*; D014934:Wood / Q000737:chemistry
chemical_list: D003031:Coal; D005308:Fertilizers; D010710:Phosphates; D012987:Soil; D012989:Soil Pollutants; D002104:Cadmium
keywords: Biowastes; Heavy metals; Lignite; Soil amendments; Trace elements