231-6 Can No-till Sequester Carbon? Overcoming Conjecture with Data.

See more from this Division: ASA Section: Environmental Quality
See more from this Session: Management Practices and Land-Use Impact on Global Warming Potential and Greenhouse Gas Intensity

Tuesday, November 8, 2016: 11:00 AM
Phoenix Convention Center North, Room 127 C

Deb O'Dell1, Neal Samuel Eash2, Bruce B. Hicks3, Dayton Lambert4, Joanne Logan5, Thomas J. Sauer6, James Zahn7, Joel Nathaniel Oetting5 and John Goddard8, (1)University of Tennessee - Knoxville, Knoxville, TN
(2)Biosystems Engineering and Soil Science, University of Tennessee, Knoxville, TN
(3)MetCorps, Norris, TN
(4)University of Tennessee, Knoxville, Knoxville, TN
(5)University of Tennessee, Knoxville, TN
(6)USDA-ARS National Laboratory for Agriculture and the Environment, Ames, IA
(7)Dupont Tate and Lyle, Loudon, TN
(8)Loudon County Extension, Loudon, TN
Abstract:
Soil could become an important sink for atmospheric carbon dioxide (CO2) as global agricultural greenhouse gas emissions continue to grow, but this hypothesis needs supporting data.  Sequestering soil carbon (C) depends upon many factors including soil type, climate, crop, tillage, nitrogen fertilization, cropping history and rotation, as well as the degree of soil degradation.  Reduced tillage, especially no-till, can result in reduced CO2 emissions and sequestering of C if sufficient biomass is produced and near continuous ground cover maintained. In this study we used micrometeorology to estimate the CO2 flux between the surface and the atmosphere by calculating changes in CO2 concentration and energy in and above the crop canopy or soil surface. The study used Bowen ratio energy balance (BREB) micrometeorology to quantify differences in CO2 fluxes between contrasting tillage practices.  Flux calculations showed that no-till was a net sink for CO2 while the tilled plot was a net source during 104 days of the 2015 growing season in north-central Ohio.   In contrast to the conclusions of most recent discussions on this topic, the present study indicates that tillage practices affect C sequestration in a way that is also commensurate with the need for crop productivity.

See more from this Division: ASA Section: Environmental Quality
See more from this Session: Management Practices and Land-Use Impact on Global Warming Potential and Greenhouse Gas Intensity