217-12 Impacts of Land Use Change On Ecosystem Carbon in Subtropical Grassland Ecosystems.

Poster Number 1218

See more from this Division: ASA Section: Environmental Quality
See more from this Session: Carbon Emissions From Agriculture

Tuesday, November 5, 2013
Tampa Convention Center, East Exhibit Hall

Sutie Xu, Biosystems Engineering and Soil Science, University of Tennessee-Knoxville, Knoxville, TN, Julius B. Adewopo, 125 High Street, International Institute of Tropical Agriculture, Croydon, FL, UNITED KINGDOM, Maria Lucia Silveira, Range Cattle Research and Education Center, University of Florida, Ona, FL and Kanika S. Inglett, Soil and Water Science, Wetland Biogeochemistry Laboratory, University of Florida, Gainesville, FL
Abstract:
Land use intensification often has impacts on plant communities and soil characteristics leading to a change in ecosystem carbon (C) cycling, especially on soil C storage. The objective of this research was to investigate the long-term effects of land use intensification effect on plant biomass, soil organic C stocks, and microbial activities in subtropical grasslands. Experimental sites consisted of native rangelands, pine-bahiagrass silvopasture, and intensively-managed grazed bahiagrass (Paspalum notatum) pastures. Each ecological unit (area of ~ 6 ha) was replicated twice and exhibited the same topography, soil type, and climate conditions. Results indicate that silvopasture system has greater litter C mass relative to native rangelands and improved pastures. Despite the greater root biomass (0 to 90 cm soil depth), smaller soil C stocks (75.6 Mg ha-1, at the 0 to 90 cm depth) were observed in the native rangelands than that in the improved and silvopastures (110 and 101 Mg ha-1, respectively). Grassland intensification promoted soil C accumulation and microbial activity. Our findings suggest that grassland intensification by using proper fertilization and grazing management can promote soil C accumulation in subtropical ecosystems.

See more from this Division: ASA Section: Environmental Quality
See more from this Session: Carbon Emissions From Agriculture