Submitted to: Critical Reviews in Plant Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/15/2009
Publication Date: 12/31/2009
Citation: Robinson,B.H., G.S.Banuelos,H.M. Conesa,W.H. Evangelou, R. Schulin. 2009. Phytomanagement of Trace Elements in Soil. Critical Reviews in Plant Science. pp.28:1-27 Interpretive Summary: Trace elements (TEs) occur at low concentrations in organisms, yet they have a large biological effect, both as essential nutrients and environmental contaminants. Phytomanagement describes the manipulation of soil-based systems to affect the fluxes of TEs in the environment with the goal of remediating contaminated soils, recovering valuable metals, or increasing micronutrient concentrations in crops. Phytomanagement includes all biological, chemical, and physical technologies employed on a vegetated site. Successful phytomanagement should either cost less than other remediation or fortification technologies, or be profitable operation, by producing valuable plant biomass products. This may include bioenergy or timber production on contaminated land, a practice that does not reduce food production. We review the components of phytomanagement and the underlying biogechemical processes, with a view to elucidating situations where this technology may be successfully applied.
Technical Abstract: Biological trace elements (TEs) occur at minor concentrations (< 1000 mg/kg) in organisms, yet they may have a major effect on life, both as essential nutrients and environmental contaminants. Excess consumption of and exposure to TEs has a detrimental effect on humans. Human activities such as mining, industrial production, transport and agricultural release ever-increasing amounts of bioavailable TEs into the environment. TEs are immutable and mostly have a low mobility in soil. Therefore, they accumulate over time under specific environmental conditions. At high concentrations, all TEs are toxic to organisms, even those essential for life. Worldwide, some 22 million hectares of land are contaminated with trace elements. Phytomangement describes the engineering or manipulation of soil-plant systems to control the fluxes of TEs in the environment. Thus, the goal of phytomanagement may be to alleviate deficiencies of essential TEs or to reduce the environmental risk posed by contaminating TEs. A key component of phytomangement is that it should either cost less than other remediation or fortification technologies, or be a profitable operation, by producing valuable plant biomass products. Phytomanagement exploits plants as bio-pumps that use the sun's energy to remove water and perhaps TES from the soil to the aboveground portions, while returning some of the products of phtosynthesis back into the root zone. Phytomanagement describes an assemblage of related technologies that include phytomining, phytoremediation, which is divided into phytoextraction and phytostabilization, as well as biofortication. We have reviewed the components of phytomanagement and the underlying biogeochemical processes, with a view of elucidating situations where this technology may be successfully applied and for identifying future research needs.