|OGLE, STEPHEN - Colorado State University|
|BREIDT, JAY - Colorado State University|
|Del Grosso, Stephen - Steve|
|GLEASON, ROBERT - Us Geological Survey (USGS)|
|LINQUIST, BRUCE - University Of California|
|SIX, JOHAN - University Of California|
|VANKESSEL, CHRIS - University Of California|
|Venterea, Rodney - Rod|
|WEST, TRISTRAM - Pacific Northwest National Laboratory|
Submitted to: Government Publication/Report
Publication Type: Government Publication
Publication Acceptance Date: 7/30/2014
Publication Date: 7/31/2014
Citation: Ogle, S., Adler, P.R., Breidt, J., Del Grosso, S.J., Derner, J.D., Franzluebbers, A.J., Gleason, R., Liebig, M.A., Linquist, B., Six, J., Vankessel, C., Venterea, R.T., West, T. 2014. Quantifying greenhouse gas sources and sinks in cropland and grazing land systems. In: Eve, M., D. Pape, M. Flugge, R. Steele, D. Man, M. Riley-Gilbert, and S. Biggar (Eds.) Quantifying Greenhouse Gas Fluxes in Agriculture and Forestry: Methods for Entity-Scale Inventory. Technical Bulletin Number 1939, Office of the Chief Economist, USDA, Washington, DC. pp. 3-1-3-142.
Interpretive Summary: Under provision of Section 2709 of the Food, Conservation, and Energy Act of 2008, USDA has been directed to “establish technical guidelines that outline science-based methods to measure the environmental services benefits from conservation and land management activities in order to facilitate the participation of farmers, ranchers, and forest landowners in emerging environmental services markets.” The legislation further states that the initial emphasis of the methods development should focus on greenhouse gas (GHG) emissions. Agreement on that set of methods is the primary scope and purpose for this Report. The objective is to create a standard set of GHG estimation methods for USDA, and to provide a framework for development of a tool that will help landowners estimate the GHG impacts of their management decisions. The methods presented in the Report address GHG emissions and carbon sequestration for the entire entity or operation, and also provide the opportunity to assess individual practices or management decisions. Therefore, ease of use is critical. A co-objective is to demonstrate the scientific basis for entity-scale estimation of the GHG impacts of landowner management decisions. Therefore, scientific rigor and transparency are also critical. Guidance is provided in this section (Chapter 3) for reporting of GHG emissions associated with entity-level fluxes from farm and/or ranch operations. From the findings in this Report, a web-based tool will be developed that will facilitate estimation of annual emissions and sequestration at the local entity scale. The tool will be accompanied by a user guide that provides the landowner or stakeholder with all of the information required to successfully use the web-based tool to estimate and report emissions and sequestration related to their management activities. Specific potential uses of the methods and tool include aiding: (i) Landowners, NGOs, and other stakeholders in assessing increases and decreases in GHG emissions and carbon sequestration associated with changes in land management, (ii) USDA in assessing GHG and carbon sequestration increases and decreases resulting from current and future conservation programs and practices, and (iii) USDA and others in evaluating and improving national and regional GHG inventory efforts.
Technical Abstract: Crop and grazing land management influences greenhouse gas emissions, which can be reduced by adopting conservation practices. Operators of cropland systems use a variety of practices that have implications for emissions, such as nutrient additions, irrigation, liming applications, tillage practices, residue management, fallowing fields, forage and crop selection, set-asides of lands in reserve programs, erosion control practices, water table management in wetlands, and drainage of wetlands. Operators of grazing systems also have a variety of management options that influence GHG emissions, such as stocking rate, forage selection, use of prescribed fires, nutrient applications, wetland drainage, irrigation, liming applications, and silvopastoral practices. The guidance described here focuses on methods for estimating the influence of land use and management practices on greenhouse gas emissions (and sinks) in crop and grazing land systems. Methods are described for estimating biomass and soil C stocks changes, soil nitrous oxide (N2O) emissions, methane (CH4) emissions from wetland rice, CH4 sinks from methanotrophic activity, carbon dioxide (CO2) emissions or sinks from liming, biomass burning non-CO2 greenhouse gas emissions, and CO2 emissions from urea fertilizer application.