ARS | Publication request: SOIL ORGANIC C STORAGE UNDER PASTURES OF THE SOUTHERN PIEDMONT USA.

Submitted to: Carbon Sequestration In Soil An International Symposium
Publication Type: Abstract Only
Publication Acceptance Date: July 19, 1999
Publication Date: N/A

Technical Abstract: Pastureland comprises approximately 50% of the farmland in the Southern Piedmont ecoregion of the eastern USA. The manner in which pastures are managed may be important for soil organic carbon (SOC) storage in the region. We summarized SOC data collected from several recent studies in Watkinsville GA. Tall fescue grown for 15 years had 2.6 Mg/ha more SOC with hhigh (336 kg N/ha) than with low (134 kg N/ha) annual fertilization. Tall fescue with high endophyte infection had 1.8 Mg/ha more SOC than with low endophyte infection. Cattle grazing hybrid bermudagrass for 15-19 years resulted in 7.5 Mg/ha more SOC than bermudagrass that was hayed. A conventionally cropped field that was divided 24 years previously had 6.7 Mg/ha more SOC under tall fescue-common bermudagrass than under conservation-tillage cropland, which contained 26.5 Mg/ha to a depth of 20 cm. Long-term grazing of cattle on tall fescue resulted in SOC to a depth of 20 cm at the region's estimated steady-state level under climax vegetation (i.e., 40 Mg/ha). Several different pasture management strategies were identified that have the potential to sequester large quantities of SOC in these highly weathered soils.