Location: Adaptive Cropping Systems LaboratoryTitle: Review of Phosphate in soils: Interaction with micronutrients, radionuclides, and heavy metals Author
Submitted to: Vadose Zone Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/17/2015
Publication Date: 10/12/2015
Citation: Dao, T.H. 2015. Review of Phosphate in soils: Interaction with micronutrients, radionuclides, and heavy metals. Vadose Zone Journal. 14. doi: 10.2136/VZJ2015.01.0000br.
Interpretive Summary: Inorganic phosphorus present in soil influences the availability and movement of heavy metals to soil-dwelling organisms, aboveground vegetation, and browsing animals that consume that vegetation or directly ingest the contaminated soil. The knowledge of how phosphate interacts with soil components is important to researchers and producers interested in minimizing the entry of these substances into the global food production system. Chemical and biological agents that can be used to tie-up these metals include low-grade rock phosphate ores, and high-P organic sources like animal manures, composts, worm castings, and municipal by-products. However, the same knowledge about phosphate and metals is also useful for developing a good understanding of conditions favorable to enhanced metal availability. Crops can be grown to remove the metals via plant harvest and disposal away from the contaminated sites. It must be noted that using high loads of phosphate to tie-up metals can also present and enhance risks of surface water quality impairments by the added phosphate. Therefore, a thorough risk-benefit assessment was suggested for each field situation, soils, and local climatic conditions before undertaking a remediation program.
Technical Abstract: Phosphate-phosphorus present in the vadose zone of soil as native, added, or residual fertilizer influences the retention, transport, and bioavailability of heavy metals, metalloids, or metallic radionuclides to aboveground vegetation, soil microorganisms, and fauna that browse that vegetation, or directly ingest contaminated soil. This book, "Phosphate in Soils," is a collection of contemporary research on mechanisms of immobilization and the release of metals, metalloids, and metallic radionuclides. The on-going interest in phosphate-containing materials for in situ remediation of contaminated soils is important to researchers in vadose zone sciences because many vadose-zone processes are involved in regulating the availability and transport of metals and metalloids entering the global food production system. It is an informative tool for an audience at the post-graduate level, to researchers in the geosciences, engineers, practicing consultants, resource managers, and planners on the development of mitigation strategies and practices to enhance the remediation of contaminated field sites for years to come. However, a point that was briefly developed was deemed significant for re-emphasis; that is, using high loads of phosphate and repeated applications for reducing bioavailability of metal and metalloids can also present and enhance risks of surface water quality impairments by the added phosphate.