Carbon and nitrogen dynamics on a forest site receiving continual papermill sludge applications: a soil column study

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dc.contributor.authorDuncan, Carla S.en
dc.contributor.committeechairBurger, James A.en
dc.contributor.committeememberJohnson, James E.en
dc.contributor.committeememberReneau, Raymond B. Jr.en
dc.contributor.departmentForestryen
dc.date.accessioned2014-03-14T21:47:17Zen
dc.date.adate2009-10-10en
dc.date.available2014-03-14T21:47:17Zen
dc.date.issued1992-12-15en
dc.date.rdate2009-10-10en
dc.date.sdate2009-10-10en
dc.description.abstractSuccessful renovation of wastewater and sludge via land application depends upon sludge-induced soil changes associated with carbon (C) and nitrogen (N) cycles within the soil/plant system. The C, N, and hydrologic cycles within a soil/sludge system receiving a year-round, daily application of paper mill sludge were studied. Soil samples were collected from three locations on a land application site in the Piedmont of Virginia that had received papermill sludge applications for six, two, and no prior years. The average application rate was 4.4 cm/wk, each week of the year, with a N loading of 700 kg N ha⁻¹yr-⁻¹. The column study showed that C and N were still accumulating on the land application site after 6 years, but at a decreasing rate. Based on this study, C accumulation will level out after 13 years of application, but N will continue to accumulate for almost 30 years. As application period increased, soil bulk density increased in the O, A, and B horizons, the percentage of non-capillary porosity fell below 10% in the A horizon and approached zero in the B horizon, and there was a dramatic decrease in the soil's hydraulic conductivity in both the A and B horizons. Nitrogen leaching is expected to increase with time due to high amounts of N in the papermill sludge, a continued narrowing of the C:N ratio, a high percentage of nitrification, and low denitrification rates. Experimental timing and rates of sludge additions were imposed to alter the aerobic/anaerobic properties of the soil system to determine the conditions under which optimum C and N mineralization, nitrification, and denitrification would occur. Application rates were factorially arranged for single or multiple doses on a daily or alternating schedule. The C decomposition and N mineralization processes were both optimized with an increase in the length of cycle; they were maximized with an alternating 9 days on/9 off application schedule. The nitrification potential also increased with the length of cycling, with an average nitrification rate of 96%. Denitrification was minimal in all treatments, with an average denitrification rate of 16%. This was primarily attributed to movement of nitrate-N below the most biologically active zone in the soil column. Sludge renovation will ultimately depend upon the excess N being sequestered in plant biomass or denitrified. Proper management of these processes will ensure that wastes decompose, and that N is stored or evolved as a benign gas rather than leached at unacceptable levels.en
dc.description.degreeMaster of Scienceen
dc.format.extentx, 105 leavesen
dc.format.mediumBTDen
dc.format.mimetypeapplication/pdfen
dc.identifier.otheretd-10102009-020250en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-10102009-020250/en
dc.identifier.urihttp://hdl.handle.net/10919/45131en
dc.language.isoenen
dc.publisherVirginia Techen
dc.relation.haspartLD5655.V855_1992.D863.pdfen
dc.relation.isformatofOCLC# 27691113en
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subject.lccLD5655.V855 1992.D863en
dc.subject.lcshForest site qualityen
dc.subject.lcshPaper industry -- Waste disposalen
dc.subject.lcshSewage disposal in the grounden
dc.subject.lcshSoils -- Carbon contenten
dc.subject.lcshSoils -- Nitrogen contenten
dc.titleCarbon and nitrogen dynamics on a forest site receiving continual papermill sludge applications: a soil column studyen
dc.typeThesisen
dc.type.dcmitypeTexten
thesis.degree.disciplineForestryen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

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