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Soil Carbon Sequestration Methods and Tools for Measurement, Monitoring and Verification. Charles W. Rice University Distinguished Professor Department of Agronomy. K-State Research and Extension. Global economic mitigation potential for different sectors at different carbon prices.
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Soil Carbon Sequestration Methods and Tools for Measurement, Monitoring and Verification Charles W. Rice University Distinguished Professor Department of Agronomy K-State Research and Extension
Global economic mitigation potential for different sectors at different carbon prices Energy Supply Transport Buildings Industry Agriculture Forestry Waste 6 Non-OECD ET OECD World Total Gt CO2-eq 5 4 US$/CO2-eq 3 2 1 0 IPCC, 2007
Agriculture • A large proportion of the mitigation potential of agriculture (excluding bioenergy) arises from soil C sequestration, which has strong synergies with sustainable agriculture and generally reduces vulnerability to climate change. • Agricultural practices collectively can make a significant contribution at low cost • By increasing soil carbon sinks, • By reducing GHG emissions, • By contributing biomass feedstocks for energy use IPCC Fourth Assessment Report, Working Group III, 2007
Cropland Reduced tillage Rotations Reduced bare fallow Increased intensity Cover crops Fertility management Water management Agricultural management plays a major role in greenhouse gas emissions and offers many opportunities for mitigation • Grasslands • Grazing management • Fire management • Fertilization
Measurement, Monitoring and Verification • Detecting soil C changes • Difficult on short time scales • Amount of change small compared to total C • Methods for detecting and projecting soil C changes • Direct methods • Field measurements
Estimating Changes in Soil Organic Carbon • Issues • Choice of baseline • Comparison to current practice • Start and end time points • Measure C sequestration or avoided C loss • Uncertainty and cost in estimating soil C • Measure and report mean and variation • Seasonality • Soil sampling • Depths • Roots • Carbonates • Rocks
Spatial variability influences estimates of soil organic C • 100 samples to detect 2-3% change in SOC • 16 samples to detect 10-15 % change in SOC Garten and Wullschleger (1999)
Geo-reference microsites • Microsites reduces spatial variability • Simple and inexpensive • Used to improve models • Used to adopt new technology • Soil C changes detected in 3 yr • 0.71 Mg C ha-1 – semiarid • 1.25 Mg C ha-1 – subhumid Ellert et al. (2001)
Soil C sequestration No-till continuous corn, started in 1990
Measurement, Monitoring and Verification • Methods for detecting and projecting soil C changes • Direct methods • Field measurements • Indirect methods • Accounting • Stratified accounting • Remote sensing • Models Post et al. (2001)
Methods to Extrapolate Measurements and Model Predictions from Sites to Regional Scales • Models • CENTURY • Comet VR • EPIC • RothC • Other models are also being developed • Spatial aggregation of soil carbon distribution • Remote sensing and climatic data • Indices: • Productivity • Practice monitoring
Resources Available for National-level Assessments • NRCS/STATSGO soil data • Daily Climate data from NOAA • 1997 NRI area weights • NRCS/ERS Cropping Practices Survey • NRCS/National Soils Laboratory Pedon Database
Remote Sensing and Carbon Sequestration • Remote sensing cannot be used to measure soil C directly unless soil is bare • Remote sensing useful for assessing • Vegetation • Type • Cover • Productivity • Water, soil temperature • Tillage intensity? Crop identification for spatial modeling. Courtesy: P Doraiswamy, USDA-ARS, Beltsville, MD
In Situ Measurements of Soil Carbon with Advanced Technologies R.C. Izaurralde, M.H. Ebinger, J.B. Reeves, C.W. Rice, L. Wielopolski, B.A. Francis, R.D. Harris, S. Mitra, A.M. Thomson
Mid-Infrared Reflectance Spectroscopy: MIRS Laser Induced Breakdown Spectroscopy: LIBS In Situ Measurements of Soil Carbon with Advanced Technologies • Portable • Non-destructive method measurement of C in soils McCarty et al. (2002) Soil Sci. Soc. Am. J. 66:640-646 Cremers et al. (2001) J. Environ. Qual. 30:2202-2206
New Technologies Laser Induced Breakdown Spectroscopy: LIBS Mid-Infrared Reflectance Spectroscopy: MIRS
Conclusions • By using principles of soil science • Minimize spatial variability • Reduce number of samples • Decrease costs • Increase efficiency • Increase sensitivity for detecting change • Allow adoption of new technology • Extrapolation • Modeling • Remote sensing
Chuck Rice Phone: 785-532-7217 Cell: 785-587-7215 cwrice@ksu.edu • Websites www.soilcarboncenter.k-state.edu/ K-State Research and Extension