79-2 Soil Carbon Source and Accumulation Over 12,000 Years in a Semi-Natural Miscanthus Sinensis Grassland in Southern Japan.

See more from this Division: ASA Section: Environmental Quality
See more from this Session: Carbon Sequestration and GHG Emissions From Agricultural & Grassland Systems: Part I
Monday, October 22, 2012: 2:45 PM
Duke Energy Convention Center, Room 237-238, Level 2
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David S. Howlett, Energy Biosciences Institute, University of Illinois, Henderson, NV, Yo Toma, Faculty of Agriculture, Ehime University, Ehime, Japan, Hong Wang, Prairie Research Institute, University of Illinois at Urbana-Champaign, Champaign, IL, Shinji Sugiyama, Paleoenvironment Research Co., Ltd., Miyazaki, Japan, Toshihiko Yamada, Hokkaido University, Sapporo, JAPAN, Aya Nishiwaki, University of Miyazaki, Miyazaki, Japan, Fabian G. Fernandez, 1102 South Goodwin Avenue, University of Illinois, Urbana, IL and J. Ryan Stewart, Plant and Wildlife Sciences, Brigham Young University, Provo, UT
Miscanthus, a promising feedstock for the production of lignocellulosic ethanol, will likely see a considerable increase in cultivation and production in the U.S. and Europe in the coming decades. To better predict the effect of this change on land use, we examined a Miscanthus sinensis-dominated grassland in its native range in southern Japan. Soil organic carbon age, accumulated carbon stock, and carbon source were determined on pyrolysis volatile (Py-V) and pyrolysis residue (Py-R) fractions of soil organic matter. Stable carbon isotopic composition of soil organic matter was also determined. Values of total sequestered C summed from two soil profiles (0 – 1.5 m) were 515 and 559 Mg C ha-1. Stable isotope analysis showed that about 66.8% of soil C, ranging from 52.0 to 84.8%, was derived from C4 plants. Variation of soil age indicated by 14C dates of Py-V and Py-R fractions was correlated linearly with soil depths with a R2 value ranging from 0.98 – 0.99. Phytolith data showed an increase in abundance of Miscanthus sinensis and Pleioblastus sect. Nezasa following a pyroclastic eruption 7 kyr ago, and a decrease in Sasa sect. Crassinodi from 12 to 7 kyr ago. Organic carbon flux ranged from 0.85 to 1.63 Mg C ha-1 yr-1 through 1.5-m soil profiles, and Miscanthus-derived carbon flux was distributed in a similar pattern to the total C throughout the soil profiles. Over a 12,000 year history of land use at the Aso caldera, Japan, Miscanthus sinensis was found to be a major contributor to soil carbon and a sink for atmospheric CO2, which has implications for the potential sequestration of soil carbon under Miscanthus in cultivated conditions.
See more from this Division: ASA Section: Environmental Quality
See more from this Session: Carbon Sequestration and GHG Emissions From Agricultural & Grassland Systems: Part I