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Annual ryegrass (Lolium perenne L.) is an important cool-season forage grass in the southeastern US. Since large portions of soils in this region are too acidic for optimum ryegrass production, there exists an opportunity to use lime mud waste from numerous regional pulp and paper mills as an agricultural liming material. In this study, four lime mud application rates, 2.25 (L1). 4.51 (L2), 9.01 (L3), and 22.50 (l4) ton ha-1 dry weight basis, and a control (L0) were evaluated for response to ryegrass growth during the first 6 weeks to estimate an optimum application range over the testing soil for future field test. Results indicated that applied lime mud slowed ryegrass germination and seedling emergence, with differences of whole plant length among treatments L0-L4 significant only during the first three weeks. Differences of whole plant dry weight among treatments L0-L4 reduced thereafter. The initial soil pH increase due to the lime mud application dropped in treatments L1-L4 by the end of the 6-week experiment. The optimum lime mud application range was estimated between L2 and L3, which provided higher ryegrass yields (kg ha-1) of 84 and 80 over 77 of the control and complied with the Code of Federal Regulation, CFR 40 Part 503 for land application. [ABSTRACT FROM AUTHOR]

Two oil-contaminated sites were bioremediated by stimulating indigenous microbes by tilling, liming, and fertilizing; the hydrocarbon contents were reduced by 84% in 7 weeks at one site and by 83% in 56 weeks at the other site. The process was monitored by measuring the most probable number (MPN) of oil-degrading microbes and the total petroleum hydrocarbon (TPH) concentration in soils. Bioremediation occurred at MPNs of 10 5 to 106 cells g-1 soil, mean water-holding capacities of 54–82% and mean soil pH values of 4.75–5.97. The initial control TPH concentrations remained unchanged at the end of the study at both sites. Bioremediation was not required at depths greater than 6 in except at one location; tilling at 18 in was necessary and remediation took 19 weeks longer than the surface remediation of 56 weeks. As revealed by gas chromatographic analyses of soil extracts before and after bioremediation, the diversity and amounts of hydrocarbons were substantially reduced during bioremediation. There were 10 oil-degrading bacteria isolated from the sites, representing the following genera: Alcaligenes, Actinomyces, Bacillus, Citrobacter, Corynebacterium, Enterobacter, and Pseudomonas. [ABSTRACT FROM AUTHOR]