Use of remediated soil materials for sustainable plant growth

Greenspace is increasingly recognized as a cost-effective end use for brownfield and contaminated sites. These sites are often unsuitable for vegetation establishment, either due to the presence of contaminants, or because the soil is of insufficient quality to support plant growth. The remediation of contaminated sites may also result in a material that is incapable of sustaining vegetation. This paper details the results of a nursery trial to assess the potential of combining a number of soils from contaminated and remediated sites with different amounts of greenwaste compost, in order to establish vegetation. Trials were conducted with grasses, alder (Alnus cordata) and poplar (Populus trichocarpa) over two growing seasons, and the effectiveness of the soil/compost combination was evaluated by soil and plant nutrient analyses and plant growth response. The addition of compost increased the concentrations of P, K, and Mg in soil and leaf tissue, and generally increased the survival, growth and biomass of the grass and trees established in the soils. There was very little improved response from doubling the compost incorporation rate, except for a soil contaminated with hydrocarbons and its thermally remediated counterpart. The study demonstrates that vegetation can be established on remediated materials combined with an appropriate level of compost addition, thus potentially removing a significant portion of contaminated soil from the waste stream. © 2010 EPP Publications Ltd