Technical ArticleEffectiveness of Bauxite Residues in Immobilizing Contaminants in Manure-Amended SoilsUdeigwe, Theophilus K.1; Wang, Jim J.1; Zhang, Hailin2Author Information 1School of Plant, Environmental and Soil Sciences, Louisiana State Univ. Agricultural Center, Baton Rouge, LA. Dr. Jim J. Wang is corresponding author. E-mail: [email protected] 2Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK. Received July 31, 2009. Accepted for publication October 9, 2009. Soil Science: December 2009 - Volume 174 - Issue 12 - p 676-686 doi: 10.1097/SS.0b013e3181c5e4e3 Buy Metrics Abstract The release of contaminants from manure-amended soils is a major source of water quality impairment. This study examined the potential of using bauxite residues in reducing the release of phosphorus (P), organic carbon (OC), and heavy metals such as copper (Cu) and zinc (Zn) from manure-impacted soils to the environment. Five bauxite residues including one brown mud, two fresh red muds, and two seawater-neutralized red muds were evaluated with three manure-impacted soils at 2 and 4% application rates. The various bauxite residue amendments reduced water-extractable P by 58 to 95%, OC by 10 to 40%, Cu by 2 to 98%, and Zn by 10 to 90% in these manure-impacted soils. Neutralization of red muds with synthetic seawater lowered the pH, increased the soluble calcium and magnesium, and enhanced their ability to immobilize these contaminants. Amending soil with 4% of the two seawater-neutralized red muds and brown mud showed no improvement over the 2% application rate on reducing water-extractable P and C. Overall, the results suggest that the application of neutralized red mud at 2% (40 ton ha−1) to manure-amended soils could significantly immobilize soluble P, OC, Cu, and Zn, reducing their release to the environment. © 2009 Lippincott Williams & Wilkins, Inc.