title: Long-term effects of clipping and nitrogen management in turfgrass on soil organic carbon and nitrogen dynamics: the CENTURY model simulation.
abstract: Experiments to document the long-term effects of clipping management on N requirements, soil organic carbon (SOC), and soil organic nitrogen (SON) are difficult and costly and therefore few. The CENTURY ecosystem model offers an opportunity to study long-term effects of turfgrass clipping management on biomass production, N requirements, SOC and SON, and N leaching through computer simulation. In this study, the model was verified by comparing CENTURY-predicted Kentucky bluegrass (Poa pratensis L.) clipping yields with field-measured clipping yields. Long-term simulations were run for Kentucky bluegrass grown under home lawn conditions on a clay loam soil in Colorado. The model predicted that compared with clipping-removed management, returning clippings for 10 to 50 yr would increase soil C sequestration by 11 to 25% and nitrogen sequestration by 12 to 28% under a high (150 kg N ha(-1) yr(-1) nitrogen (N) fertilization regime, and increase soil carbon sequestration by 11 to 59% and N sequestration by 14 to 78% under a low (75 kg N ha(-1) yr(-1)) N fertilization regime. The CENTURY model was further used as a management supporting system to generate optimal N fertilization rates as a function of turfgrass age. Returning grass clippings to the turf-soil ecosystem can reduce N requirements by 25% from 1 to 10 yr after turf establishment, by 33% 11 to 25 yr after establishment, by 50% 25 to 50 yr after establishment, and by 60% thereafter. The CENTURY model shows potential for use as a decision-supporting tool for maintaining turf quality and minimizing negative environmental impacts.
authors.affiliation: Department of Horticulture and Landscape Architecture, Colorado State University, Fort Collins, CO 80523-1173, USA. yaqian@lamar.colostate.edu
authors.forename: Y L
authors.initials: YL
authors.lastname: Qian
authors.forename: W
authors.initials: W
authors.lastname: Bandaranayake
authors.forename: W J
authors.initials: WJ
authors.lastname: Parton
authors.forename: B
authors.initials: B
authors.lastname: Mecham
authors.forename: M A
authors.initials: MA
authors.lastname: Harivandi
authors.forename: A R
authors.initials: AR
authors.lastname: Mosier
mesh_terms: D001673:Biodegradation, Environmental; D002244:Carbon / Q000378:metabolism*; D003247:Conservation of Natural Resources; D003657:Decision Making; D004787:Environmental Pollution / Q000517:prevention & control*; D005308:Fertilizers; D008962:Models, Theoretical; D009584:Nitrogen / Q000378:metabolism*; D018515:Plant Leaves / Q000378:metabolism; D031785:Poa / Q000737:chemistry* / Q000378:metabolism; D012989:Soil Pollutants
chemical_list: D005308:Fertilizers; D012989:Soil Pollutants; D002244:Carbon; D009584:Nitrogen