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Research was conducted to investigate the effects of spraying sewage effluent on hardwood forested land at Sugarloaf Mountain, Maine. Soil, organic matter, tree foliage, groundwater, and effluent samples were collected in 1978 and 1979. Soil samples were taken at two depths, 0-20 cm and 20-40 cm. The entire organic pad was removed as a single sample, with no separation of the 0 1 and 0 2 layers. Sugar maple (Acer saccharum Marsh.) foliage was sampled periodically for nutrient levels. Groundwater sampling was accomplished with a total of 28 suction lysimeters placed at depths of 30 or 64 cm.

Results indicate significant increases, following spraying, in the concentrations of exchangeable cations (calcium, magnesium, potassium, and sodium) in the organic pad and in the upper 20 cm of soil. Sprayed soils and organic matter showed significant increases in pH, in available phosphorus, and in the percentage of base saturation levels. Total calcium, magnesium, sodium, phosphorus, and manganese levels were significantly increased in the organic pad as a result of spraying. Total nitrogen, ammonium-nitrogen, and nitrate-nitrogen levels indicated no differences among treatment groups for both soil and organic pad samples. The C:N ratio in the organic pad was numerically decreased because of spraying, indicating a slight increase in the decomposition rate of organic matter; this loss, however, did not change the percentage of organic matter in the soil. Sprayed sugar maple foliage showed significant increases in the percentage of nitrogen, calcium, magnesium, and phosphorus, but a significant decrease in the percentage of manganese.

The percentage of removal of the elements in the effluent ranged from 48.4 percent for sodium to 98.1 percent for phosphorus. Nitrate-nitrogen removal was 68.1 percent, with the average level measured in the groundwater from sprayed areas being 2.30 mg/ l. Lateral movement of all elements from the spray area was detected. Overall, the disposal system appears to be working quite well, with the plants and soil removing between 48 and 98 percent of the applied nutrients.

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Maine Agricultural and Forest Experiment Station




sprayed effluent, sewage disposal


Forest Biology

B773: Effects of Spraying Sewage Effluent on Forested Land at Sugerloaf Mountain, Maine