Voluntary Reporting of Greenhouse Gases CarbOn Management Evaluation Tool (COMET-VR) Joint effort between USDA and Colorado State University Natural Resource Ecology Laboratory John Brenner USDA-NRCS WNTSC AQ/AC Change Team Portland, OR Voluntary Reporting of Greenhouse Gases CarbOn Management Evaluation Tool (COMET-VR). USDA agencies contributing to this work include Natural Resources Conservation Service (NRCS) and Agriculture Research Service (ARS). The USDA Global Change Office provides overall coordination in this activity. Colorado State University Natural Resource Ecology Laboratory (CSU-NREL) provides the modeling expertise and the Century model.

Home page for the COMET-VR online tool

COMET-VR BACKGROUND 20 Land Resource Regions with subdivisions Century SOM Model with an uncertainty estimate Ave of 3.6 million records per LRR (90 mil total) Takes ~20 working days to recalculate entire dataset Difficult to manage such a large dataset Overview of how the COMET-VR tool was developed using Land Resource Regions (LRR) and what it can estimate. This version is based on the 20 LRR as defined in Ag Handbook 296. The on line tool utilizes the Century Soil Organic Matter computer model and an associated linear-mixed effects model to estimate uncertainty. The average records per LRR is 3.6 million, or 90 million total which makes it very difficult to manage in a database form.

COMET-VR APPLICATION WEB based Crop production Grazing livestock SOIL CARBON emissions and sequestration Fuel and energy use (estimate or user specified) Grazing livestock COMET-VR is a web based tool designed to estimate: Crop Production soil carbon changes and the associated fuel and nitrogen use. Grazing Livestock Production soil carbon changes.

The LRR assessment was developed using knowledge gained from state assessment in IA, IN and NE which are available upon request. We were able to test model performance in these areas and refined our knowledge on how agro-ecosystems function and how management decisions impact the soil resource and more specifically, soil carbon.

The 20 LRR showing locations and extent of area represented The 20 LRR showing locations and extent of area represented. These land resource regions are groupings of Major Land Resource Regions (MLRA’s) and our initial work was to design a tool that was usable across the US. We are currently working with Colorado State University to address additional crop and grazing management systems at the MLRA scale.

Land cover for LRR F in MT, ND and SD and small part of MN showing cropland, fallow land and grass lands.

Agricultural Experiments Locations of agricultural experiments used to test Century and develop uncertainty analysis. Some areas of the US have many experiments, while some areas have few and we are working with the research groups in ARS and Land Grant Universities to increase the density of experiments in the under represented areas.

Methods Use Century to model the management impacts on SOC storage based on field experiments - 60 experiments with over 800 treatments Statistically evaluate differences between the model results and field measurements for SOC storage linear-mixed effect model reflecting uncertainties in model and measurements prediction error for the LRR carbon estimates The Century SOM model is used to estimate management impacts on soil C storage and is based on long term field experiments in North America. An uncertainty estimate is derived for each system modeled.

Management/Environmental Variables of Interest land management systems tillage practices residue management organic amendments fertilizer management climate soil texture potential vegetation length of practice Variables of interest for the uncertainty analysis are shown. For additional information on this analysis, contact Steve Ogle at Colorado State University.

Required Responses to Utilize COMET-VR Location State and County Parcel Information Soils Information Soil Texture/Hydric Condition Management History (crop rotations, tillage systems or grazing systems) Pre 1970’s 1970’s-1990’s Base: 1990’s-Current Reporting Period: Current + 10 years Required Responses to use COMET-VR: The tool requires 7 inputs by the user based on information that we feel land managers only know. The location is needed to determine climate data for the model run. Parcel information is for the user to identify which lands they are working on. Soils information is based on soil texture and hydric class which allows the model to capture artificially drained areas. We are only dealing with mineral soils in the version of COMET-VR. The management history is selected by the user and is limited at this time, but is currently being expanded to capture the systems as reported in the National Resources Inventory. Once all the data is entered, the user selects Get Carbon and the tool delivers a response in 5 seconds or less.

Response returned in < 5 seconds Modeling Procedure CO2 Century SOM Model Active SOM Slow Passive Residues Plant Growth Spatial Data: Soils and Climate Survey Data: Land Use and Mgmt Data (CSRA) WEB INTERFACE Experiments Uncertainty Estimator Results 1605b Framework for the modeling procedure. Response returned in < 5 seconds

Home page for the COMET-VR online tool

Starting the COMET-VR tool and this is the first screen that the user needs to enter data. Here we are selecting the state to work in which is Indiania.

Final input screen for Example 1 in Tippecanoe County, IN Final input screen for Example 1 in Tippecanoe County, IN. The data on the right side of the web page screen shows what was entered and the user can change any value using the navigation bar located above Step 6. When the user is satisfied that the data is correct, then they proceed by clicking on the Next button.

Summary page for Tippecanoe County, IN based on corn-soybean crop rotation. This shows that we are storing 13t of C per year due to a management decision to use no till on these 160 acres or 48 tons of CO2 per year. COMET-VR also estimates an uncertainty value of 7.81% based on existing research data. It should be noted that if there is no sufficient data to calculate an uncertainty, a value of -9999.00 will be returned along with a small text message stating that the model is unable to calculate an uncertainty for the management system selected.

The final page of information returned by COMET-VR deals with Fuel and Fertilizer. For Tippecanoe County, IN growing a corn-soybean crop rotation using no till, COMET-VR estimates a fuel use decreased of 792 gallons of No. 2 diesel (1064 gallons to 272 gallons) per year and N fertilizer use is the same. The user has the option to enter the specific fuel and N fertilizer use for this parcel of land. The user then can write the file to their computer, or they can e-mail the report to any address they input. No user input data or private information is stored in COMET-VR.

Example 2 is the summary page for Yuma County, CO based on winter wheat-fallow crop rotation. This shows that we are storing only 1t of C (4 t CO2) per year on 160 acres due to a management decision to use no till. The uncertainty value for this area and rotation is 5.99%.

Example 2 Fuel and Fertilizer page for Yuma County, CO based on winter wheat-fallow crop rotation using no till. This shows that fuel use decreased of 950 gallons of No 2 diesel (1086 gallons to 136 gallons) per year and N fertilizer use is the same. Again, there is an option to enter the specific fuel and N fertilizer use for this parcel of land.

Example 3 summary page for Edwards County, TX based on livestock grazing. This shows that we are storing 4t of C (15 t CO2) per year due to a management decision to use rotational grazing.

SUMMARY Flexible Tool Uses Web based Update and expand easily Expandable to address other GHG’s in agriculture Uses 1605b reporting system Conservation programs In Summary: This tool is flexible and can be expanded to cover other crop and livestock grazing systems. It is capable to being expanded to cover nitrous oxide and methane gases. It uses include 1605b reporting system and conservation program within NRCS.

PARTICIPANTS Colorado State University - Natural Resource Ecology Laboratory Keith Paustian, Kendrick Killian, Steve Ogle, Mark Easter, Steve Williams USDA NRCS - Jill Schuler, Joel Brown and Maury Mausbach (retired) ARS - Ron Follett, Steve Shafer and Mike Jawson GCPO - Bill Hohenstein and Kathryn Bickel Participant list of people involved. This work is only possible with the cooperation and dedication of many individuals and the support of the their organizations.