Residential lawn management practices (mowing, fertilizer, irrigation, reseeding, and aeration) result in aesthetically appealing landscapes, but can result in nutrient losses via overland flow or gaseous losses to the atmosphere (e.g. nitrous oxide - N2O). The overall objective of this study was to determine the effect of lawn management on nutrient losses from residential lawns. The specific objectives were: modify a passive sampling system to determine nutrient loads due to overland flow from lawns; evaluate differences in overland flow frequency, volumes, and nutrient losses during rainfall events (⥠2.54 cm); and compare N2O losses following rainfall events. Three lawn schemes were studied: a high maintenance fescue (Festuca arundinacea) lawn (HMFL), a low maintenance fescue lawn (LMFL), and a mixed forested residential landscape (RFL). The modified passive sampling system allowed 100% recovery of overland flow and demonstrated that differences in maintenance influenced the overland flow frequency, volumes, and nutrient losses. The LMFL had the greatest overland flow volumes and nutrient unit area loads, although N and P concentrations in overland flow exceeded USEPA recommendations from all three lawns. Nutrient losses (g ha-1 yr-1) from all three residential landscapes were 1000 times less than fertilizer (kg ha-1 yr-1) and throughfall (kg ha-1 yr-1) inputs, due in part to the presence of well-structured soils (low bulk densities and high infiltration rates). Irrigation practices between the HMFL and LMFL explained the differences in overland flow volumes and nutrient loads, especially during the first half of the study when drought conditions existed at the study site (Cary, North Carolina). Lack of irrigation in the LMFL resulted in early dormancy, a minimal thatch layer and lower plant density, resulting in higher volumes of overland flow. Trends in the N2O losses from the HMFL and LMFL were associated with timing of fertilizer applications, presence or absence of irrigation, and seasonal growth patterns of the fescue. For the RFL, the presence of a decomposing litter layer limited N2O production. Well-maintained residential lawns, receiving recommended fertilizer N applications and frequent irrigation, reduce nutrient losses via overland flow but may provide optimum conditions for greater N2O fluxes.
| Identifer | oai:union.ndltd.org:NCSU/oai:NCSU:etd-11032009-142926 |
| Date | 03 December 2009 |
| Creators | Spence, Porche' La Phyl |
| Contributors | John T. Walker, Joshua L. Heitman, Hugh A. Devine, Wayne P. Robarge, Deanna L. Osmond |
| Publisher | NCSU |
| Source Sets | North Carolina State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://www.lib.ncsu.edu/theses/available/etd-11032009-142926/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dis sertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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