Effect of liquid wastewater sludge application on crop yield and water quality

• Published in: Journal - Water Pollution Control Federation 1982-01, Vol.54 (8), p.1185-1193
• Main Authors: Duncomb, D. R., Larson, W. E., Clapp, C. E., Dowdy, R. H., Linden, D. R., Johnson, W. K.
• Format: Article
• Language: English
• Subjects: Corn; Grasses; Liquids; Process Design; Sewage sludge; Sludge; Sludge treatment; Soil water; Wastewater; Wastewater treatment; Watersheds
• ISSN: 0043-1303; 2327-7467

For 6 years (1974 to 1979, inclusive) liquid digested wastewater sludge was applied to a 16-ha terraced watershed. During that period, 73.9 metric tons/ha (4 160, 2 060, and 320 kg of N, P, and K, respectively) was applied to an area cropped to corn, and 85.2 metric tons/ha (4 810, 2 050, and 410 kg of N, P, and K, respectively) was applied to an area cropped to reed canarygrass. Mean corn grain yields during the 1976 to 1979 period were 10.4 metric tons/ha, and mean yields of grass were 10.9 metric tons/ha. Corn and reed canarygrass removed 26 and 34% of the sludge-applied nitrogen (N), respectively, during the 1976 to 1979 period. Up to 200 mg/l of sludge-derived N, in the form of nitrate $({\rm NO}_{3})$, was detected in soil water sampled at the 150-cm soil depth from sludge-treated areas in corn. Lower amounts of ${\rm NO}_{3}$ were found in soil water taken from areas in reed canarygrass because of N volatilization from surface-applied sludge and the higher N demands of reed canarygrass. No significant increases in P or trace metal concentrations were detected in plant tissue or soil water sampled.