Metal Contents in Soils of Alabama

Abstract

Metal contamination of soils and water resources continues to be a serious public concern. Accumulations in the ecosystems and subsequent uptake by humans via the food chain pose a major health risk. The total copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), zinc (Zn), cadmium (Cd), chromium (Cr), and lead (Pb) contents of eight benchmark soils of north Alabama were determined. The overall goal was to provide information for future pedological studies. The specific objectives were to determine baseline values of total Cu, Fe, Mn, Ni, and Zn, which are plant nutrients, and Cd, Cr, and Pb, which are relatively serious pollutants. Expressed in mg kg⁻¹ soil, the ranges, median, geometric mean, and arithmetic mean values, respectively in parentheses, were Cu (3.2–81.9, 24, 18.2, 24.8); Cd (< 0.2–2.85, 0.15, < 0.1, 0.40); Cr (13.4–132, 51.7, 54.6, 61); Fe (1535–70,840, 34,035, 26,783, 31,720); Mn (30.2–4643, 540, 426, 1012); Ni (7.6–61, 27.5, 25.3, 27.7); Pb (< 2.0–22.8, < 2.0, < 0.1, 3.63); and Zn (22.6–339, 116, 108, 125). The order of abundance in the soils was Fe > Mn > Zn > Cr > Ni > Cu > Pb > Cd. Total Pb, Cd, Zn, Cu, and Ni contents determined were comparable to the reported average values for most United States soils. The presence of Cd, Cr, and Pb in measurable amounts in some of the samples is of environmental concern.

Keywords:

• Alabama
• Metal contents
• Soil contamination
• Benchmark

Acknowledgments

The authors are grateful to Mr. D. Clendenon (NRCS) for assisting in site selections and soil sampling. This work is a contribution of the Agricultural Experiment Station, Alabama A&M University. Journal no. 544.