title: A root exudates based approach to assess the long-term phytoavailability of metals in biosolids-amended soils.
abstract: Organic acids present in the rhizosphere of growing plants are widely recognized to be responsible for dissolving the solid phase metals in the soil and making them available for plant absorption. We proposed a root exudates-based model to assess the long-term phytoavailability of metals in biosolids-amended soils. The phytoavailability of biosolids-borne metals was defined in terms of a capacity factor and an intensity factor. The plant available metal pool, C(0) (capacity factor, mgkg(-1)), can be estimated by fitting the successive organic acids extraction data to an exponential decay kinetic equation. The field metal removal rate, k (intensity factor, yr(-1)), can be estimated from the successive extraction-based metal release rate through an effective annual organic acid production in the rhizosphere which was found to be characteristic of plant species. The protocol was successfully used to assess the long-term phytoavailability of metals in biosolids-amended soil from two biosolids land application sites.
authors.affiliation: Department of Natural and Mathematical Sciences, California Baptist University, Riverside, CA 92504, USA.
authors.forename: Bon-Jun
authors.initials: BJ
authors.lastname: Koo
authors.forename: Weiping
authors.initials: W
authors.lastname: Chen
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Chang
authors.forename: Albert L
authors.initials: AL
authors.lastname: Page
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Granato
authors.forename: Robert H
authors.initials: RH
authors.lastname: Dowdy
mesh_terms: D005122:Exudates and Transudates / Q000378:metabolism; D008670:Metals / Q000032:analysis / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism*; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism*; D014865:Waste Disposal, Fluid / Q000379:methods*; D003313:Zea mays / Q000378:metabolism
chemical_list: D008670:Metals; D012989:Soil Pollutants