The researchers studied copper levels in different Louisiana soils. They found that younger soils had more copper near the surface, while older soils had more copper deeper down. The type of soil and parent material influenced copper levels more than soil depth. Most soils had the highest copper levels in the B horizon. Extractable copper was highest in the topsoil and decreased with depth. Soils from Red and Mississippi River areas had more extractable copper. Overall, copper levels ranged from 3.0 to 49.0 ppm for total copper and 0.10 to 5.12 ppm for extractable copper. Copper levels were positively correlated with organic matter but not with soil pH in the topsoil.