This International Standard enables estimation of the environmental bioavailability of trace elements to plants either basically as concentration in shoots and roots or in a more integrative way as the net uptake flux in plants. The biotest procedure includes two successive steps: (i) a pre-growth of plants in hydroponics and (ii) a growth of plants in contact with soil samples. The concentration in shoots and roots as well as the net uptake flux of trace elements in plants are determined at the end of the second step of the biotest procedure.
This International Standard is applicable to the assessment of environmental bioavailability of trace elements to plants, more particularly agricultural plants, in soils or soil materials under oxic conditions, considering that:
— Three plant species (cabbage, Brassica oleracea; tall fescue, Festuca arundinacea; tomato, Lycopersicon esculentum; 7.1) are suggested in the standardised biotest procedure, but additional target-plant species can also be used (7.1, Annex A),
— The standardised biotest procedure is validated for a range of trace elements including arsenic (As), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), lead (Pb), nickel (Ni) and zinc (Zn), but additional trace elements can be also accounted for (Annex A).
This International Standard can be applied to soils and soil materials, including soils amended before or after field sampling with composts, sludges, wastewaters and other (waste) materials.
NOTE 1 This International Standard is not designed to assess the environmental bioavailability of trace elements that are prone to volatilisation or resulting from uptake occurring in plant leaves following e. g. atmospheric fallout.
NOTE 2 This International Standard is not designed to assess the environmental bioavailability to plants of organic contaminants. A similar experimental procedure could be used but the physical separation between plant roots and soil using a polyamide mesh needs to be adapted to avoid organic contaminant sorption on the mesh.