TRACE-ELEMENT COMPOSITION OF FERTILIZERS AND SOIL AMENDMENTS

The use of fertilizers and soil amendments has raised concern regardin g the toxic accumulation of their trace components in the environment. The objective of this research was to evaluate the trace element and heavy metal composition of a wide variety of fertilizers and soil amen dments. Thirty-five elements, including priority pollutants, were dete rmined in 24 materials. A microwave HNO3-HF-H2O2-H3BO3, digestion proc edure was used to dissolve the samples. Selected solid samples were di rectly analyzed by neutron activation analysis, while atomic absorptio n and inductively-coupled plasma atomic emission spectrometric determi nations were carried out on the digests. The trace element and heavy m etal concentrations generally decreased in the following sample order: rock phosphate > sewage sludge > phosphorus fertilizer > organic amen dments and liming materials > K fertilizers > N fertilizers. Relativel y high concentrations of toxic elements in the sewage sludge, rock pho sphate, and phosphorus fertilizer samples suggest that these materials should be the primary target materials for environmental evaluations.