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United States Department of Agriculture

Agricultural Research Service

2007 Annual Report

1a.Objectives (from AD-416)
1. Determine how crop, biomass and soil management practices alter the rate at which carbon and nitrogen are stored in soil or released as greenhouse gas emissions to develop economically viable practices that enhance storage and minimize emissions particularly in the cool, wet, glacial-till soils in the north Central United States. 2. Evaluate impacts of global environmental changes on traditional, biofuel and alternative crops.

1b.Approach (from AD-416)
Carbon cycling will be conducted as part of a national monitoring effort (GRACEnet). Soil physical, chemical and biological factors, and crop inputs will be monitored over time. Established long-term field experiments will be continued to assess impact of tillage method on carbon storage, trace gas emission and economic yield. The active, transitional and passive pools will be assessed in the tillage treatments to determine the rate and direction of change in the various pools. On-farm research is comparing the impact of high manure application on gas exchange monitored by eddy covariance and monitoring the nutrient content of tile water samples. Economic analysis will be conducted to evaluate the economic returns for the different residue removal/tillage combinations. Field experiments will be conducted to obtain plant parameters from a range of species and management systems. The plant data will be integrated with the soil carbon data to statistically model dynamics of C inputs and subsequent changes in carbon pools. Plant information will be collected from growth chamber and/or greenhouse experiments utilizing controlled conditions to mimic desired environmental stresses.

3.Progress Report
California Landfill Emission project:

This report serves to document research conducted under a reimbursable agreement between ARS and Landfills+, 3645-11000-003-01R, Improved GHG Inventory Methods for California. The objective of this three-year cooperative research project is to develop and validate a new method designed to estimate methane emissions from landfills taking into account the oxidation of methane in cover soil by soil bacteria (methanotrophic bacteria). As much as possible, the model will be driven by data currently collected and compiled by regulatory agencies. To accomplish these tasks, research was initiated in February 2007. The project is currently on-schedule or slightly ahead of schedule. Current year accomplishments were: 1. Contact was established with the state regulator agencies and initial site data was collected. 2. Feedback is being gathered on the current data template with regulators including members of the California’s Integrated Waste Management Board, Public Interest Energy Research, and California’s Air Resource Board as well as the technical advisory committee for the project. 3. Initial field gas emission monitoring was completed, including methane fluxes and soil gas profiles. 4. Installed weather station and soil microclimate monitoring equipment at the two field validation sites. 5. Collected soil samples of the three cover types (daily, intermediate, and final cover) for laboratory incubation and testing. Laboratory batch incubations for methane oxidation were initiated at various moisture contents and temperatures. The results from the field and laboratory testing will be utilized in the development of a new methane oxidation model to predict seasonal variability in the oxidation capacity of soil methanotrophic bacteria. Methods of monitoring this project have included discussing project plans at conferences as well as teleconferences to reduce travel costs. In addition, a technical advisory committee and the California project team is consulted via email and conference calls. There are monthly reports that are distributed via email. It is planned in the next two years to hold the technical advisory committee meetings at the two field sites to illustrate further the methodology and field measurements occurring as part of this project. Personal communication and email communication occurred regularly on the progress of the grant and invoices were reviewed regularly.

Title: Low tillage means low CO2 emissions. Problem: Information is needed on the mechanism and magnitude of gas generation and emission from agricultural soils with specific emphasis on tillage mechanisms. Accomplishment: Recent concepts on conservation agriculture as related to tillage-induced carbon losses by different tillage methods and the environmental benefits (increase infiltration, increase fertility, decrease wind and water erosion, minimize compaction, enhance water quality, decrease C emissions, impede pesticide movement and enhance environmental quality) of C sequestration were presented. Impact: The sum of each individual benefit adds to a total package with a major positive role for conservation agriculture that will impact US agriculture, global sustainability and our future quality of life. This has received international recognition, with several invited presentations. NP 204 Component I: Carbon cycle and carbon storage. Problem statement: Cropping System and Tillage.

Title: GRACEnet - Greenhouse gas assessment. At the plot scale, greenhouse gas emission differed among contrasting management systems and differed over time, such that the greatest nitrous oxide flux was observed during spring thaw in cool, wet soils. Problem: Large amounts of nitrogen fertilizer are applied to many cool wet soils for grain production, which can increase nitrous oxide efflux and decrease methane uptake, thus offsetting the global warming benefits of sequestered carbon in soil. Accomplishment: Greenhouse gas emissions were monitored in plots representing three management scenarios during both the growing season and the off-season for the final year of a three-year trial. Impact: This research contributed to the GRACEnet project that represents a coordinated national effort by the Agricultural Research Service to provide information on the soil C status and greenhouse gas emission of current agricultural practices, and to develop new management practices to reduce net greenhouse gas emission and increase soil C sequestration primarily from soil management. This accomplishment contributes to the NP 204 Component I: Carbon Cycle and Carbon Storage Component, Problem statements: Cropping System and Tillage, organic carbon transformations, interactions of carbon and nitrogen cycles and to Component II Trace Gases Component Problem Areas: Cropping systems.

Title: Plow depth and soil carbon dioxide loss. Agricultural ecosystems can play a significant role in the production and consumption of greenhouse gases, specifically, carbon dioxide. Problem: Intensification of agricultural production is an important factor influencing greenhouse gas emission, particularly the relationship between intensive tillage and soil carbon loss. Accomplishment: Significant progress was made in understanding the effect of tillage intensity on soil carbon management. Cumulative carbon dioxide release measured immediately following moldboard plow (MP) tillage at four depths relative to no till (NT) were 3.8, 6.7, 8.2, and 10.3 times larger than NT for the MP 0.102m, MP 0.152 m, MP 0.203 m and MP 0.280 m, respectively. Impact: Any effort to decrease tillage depth and maximize crop residue return to the soil surface should result in lower fuel consumption and increased soil C sequestration, thereby having a positive influence on environmental quality. NP 204 Component I: Carbon cycle and carbon storage. Problem statement: Cropping System and Tillage.

Title: Plant quality and decomposition. Problem: Information was lacking on how chemical composition of plants impacts crop residue decay products. Understanding decay is needed to predict how crop residue may contribute to carbon sequestration in soils. Accomplishment: Demonstrated that short-term decomposition kinetics correlate well with plant composition (e.g., C:N ratio, carbohydrates and lignin), but after 120 days decomposition kinetics correlates poorly with initial plant composition. Results from a laboratory study were published on how plant composition impacts the rate of decomposition. Impact: This information will allow improvement of mechanistic models. Understanding biological aspects of carbon and nitrogen cycles lead to improved best management practices for broad agronomic and environmental benefits. NP 204 Component I: Carbon cycle and carbon storage Problem statement: Organic Carbon Transformations and Interactions of Carbon and Nitrogen Cycles.

5.Significant Activities that Support Special Target Populations

6.Technology Transfer

Number of non-peer reviewed presentations and proceedings7
Number of newspaper articles and other presentations for non-science audiences12

Review Publications
Gesch, R.W., Reicosky, D.C., Gilbert, R.A., Morris, D.R. 2007. Influence of tillage and plant residue management on respiration of a Florida Everglades Histosol. Soil & Tillage Research. 92:156-166.

Johnson, J.M., Barbour, N.W., Lachnicht Weyers, S.L. 2007. Chemical Composition of Crop Biomass Impacts Its Decomposition. Soil Science Society of America Journal. 71(1):155-162.

Reicosky, D.C., Archer, D.W. 2007. Moldboard plow tillage depth and short-term carbon dioxide release. Soil & Tillage Research. 94:109-121.

Reicosky, D.C. 2006. Tillage and gas exchange. In: Lal, R., editor. Encyclopedia of Soil Science. 2nd edition. New York, NY: Marcel Dekker. p. 1773-1775.

Reicosky, D.C., Saxton, K.E. 2007. The benefits of no-tillage. In: Baker, C.J., Saxton, K.E., editors. No-tillage seeding in conservation agriculture. 2nd edition. Rome, Italy: FAO. p. 11-20.

Reicosky, D.C. 2006. Revegetation and carbon cycling in China's Loess Plateau. In: Fischer, A., Rui, L., Saxena, K.G., Jayakumar, R. editors. The Loess Plateau in Central China: Ecological Restoration and Management. ERSEC Ecological Book Series -3. Beijing, China: Tsinghua University Press/Springer. p. 135-148.

Johnson, J.M., Sharratt, B.S., Reicosky, D.C., Lindstrom, M.J. 2007. Impact of high-lignin fermentation byproduct on soils with contrasting soil organic carbon content. Soil Science Society of America Journal. 71(4):1151-1159.

Reicosky, D.C., Saxton, K.E. 2007. Reduced environmental emissions and carbon sequestration. In: Baker, C.J., Saxton, K.E., editors. No-tillage Seeding in Conservation Agriculture. 2nd edition. Rome, Italy: FAO and CAB International. p. 257-267.

Spokas, K.A. 2007. Methane: Signs of progress along the road [Editorial]. Waste Management. 27(4):459-460.

Last Modified: 4/22/2015
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