Availability and Distribution of Heavy Metals, Nitrogen, and Phosphorus from Sewage Sludge in the Plant-Soil-Water Continuum

摘要

Research was conducted during 1984 and 1985 to determine Cd, Cu, N, Ni, P, and Zn availabilities to barley (Hordeum vulgare) and corn (Zea mays) grown on four sludge-amended soils. An aerobically digested sewage sludge, which was dewatered for approximately 2 years on sandbeds, was obtained from a sewage treatment plant with major industrial inputs. A 14-day anaerobic N incubation study indicated that mineralization of sludge organic N varied from 9.2% at the 42 Mg ha(-1) sludge rate to 4.2% at the 210 Mg ha(-1) rate. This relatively low percentage of N mineralized from the sludge may reflect the inhibitory effects of the high sludge metal levels on N transformations and the changes in sludge composition during long-term dewatering on sandbeds. Sludge application increased crop yields, except where the amounts of N mineralized from the sludge was inadequate to supply the N requirement of the crop. Crop yields were not decreased by either metal phytotoxity or P deficiency on the four sludge-amended soils.