Carbon dynamics and sequestration in urban turfgrass ecosystems

Authors: QIAN, YALING - Colorado State University; Follett, Ronald

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 8/30/2011
Publication Date: 12/9/2011
Citation: Qian, Y., Follett, R.F. 2011. Chapter 8. Carbon dynamics and sequestration in urban turfgrass ecosystems. In: Lal, R. and Augustin, B., editors. Carbon Sequestration in Urban Ecosystems. Springer Science+Business Media B.V. 2012. DOI 10.1007/978-94-007-2366-5_8

Interpretive Summary: Urbanization is a global trend. Turfgrass occupies about 16 million ha. We review existing literature associated with carbon (C) pools, sequestration, and nitrous oxide emission of urban turfgrass ecosystems. Turfgrasses exhibit significant carbon sequestration (0.34–1.4 Mg ha-1 year-1) during the first 25–30 years after turf establishment. Several studies have reported that residential turfgrass soil can store up to twofold higher soil organic carbon (SOC) content than agricultural soils. Published research suggests that the dynamics of nitrogen (N) is controlled by C transformation. Turfgrass areas have high levels of SOC and microbial biomass creating a carbon based “sink” for inorganic N. Therefore, lower than “expected” nitrate leaching and N2O emissions have been measured in the majority of the experiments carried out for turfgrass ecosystems. Increased SOC in turfgrass soil can result from: (1) returning and recycling clippings, (2) appropriate and efficient-fertilizer use, and (3) irrigation based on turfgrass needs. Some turfgrass management practices (such as fertilization, mowing, and irrigation) carry a carbon “cost”. Therefore turfgrass’s contribution to a sink for carbon in soils must be discounted by fuel and energy expenses and fertilizer uses in maintaining turf, and the flux of N2O. More work is needed to evaluate the carbon sequestration, total carbon budget, and fluxes of the other greenhouse gases in turfgrass systems.

Technical Abstract: Urbanization is a global trend. Turfgrass covers 1.9% of land in the continental US. Here we review existing literature associated with carbon (C) pools, sequestration, and nitrous oxide emission of urban turfgrass ecosystems. Turfgrasses exhibit significant carbon sequestration (0.34–1.4 Mg ha-1 year-1) during the first 25–30 years after turf establishment. Several studies have reported that residential turfgrass soil can store up to twofold higher soil organic carbon (SOC) content than agricultural soils. Published research suggests that the dynamics of nitrogen (N) is controlled by C transformation. Turfgrass areas have high levels of SOC and microbial biomass creating a carbon based “sink” for inorganic N. Therefore, lower than “expected” nitrate leaching and N2O emissions have been measured in the majority of the experiments carried out for turfgrass ecosystems. Increased SOC in turfgrass soil can result from: (1) returning and recycling clippings, (2) appropriate and efficient-fertilizer use, and (3) irrigation based on turfgrass needs. Some turfgrass management practices (such as fertilization, mowing, and irrigation) carry a carbon “cost”. Therefore turfgrass’s contribution to a sink for carbon in soils must be discounted by fuel and energy expenses and fertilizer uses in maintaining turf, and the flux of N2O. More work is needed to evaluate the carbon sequestration, total carbon budget, and fluxes of the other greenhouse gases in turfgrass systems.