Location: Pasture Systems & Watershed Management Research
2016 Annual Report
Objectives
1. Quantify and develop practices to reduce the emission of greenhouse gases and pollutants from animal production systems.
1a. Measure greenhouse gas emissions from crop and pasture lands and the reductions obtained through mitigation treatments.
1b. Refine and evaluate emission models for improved prediction of greenhouse gas emissions and mitigation strategies for animal, manure, crop, and pasture components of livestock production.
1c. Evaluate the impact of improvements in animal production facility infrastructure on greenhouse and other gas emissions and water quality.
2. Determine the sensitivity of farm systems and watersheds to climate variability and evaluate strategies for adapting to climate change.
2a. Quantify the effects of projected future climate on dairy and beef production systems and determine the adaptation strategies required to maintain sustainable production systems under future climate variability.
2b. Quantify the effects of projected future climate on nitrogen and phosphorus transformations and losses for watersheds in the Northeast.
2c. Support Northeast Climate Hub activities by developing and providing information on regional climate research and extension capacity, stakeholder vulnerability assessments, and adaptation strategies for the dairy and beef industries including animal, field crop, hay and pasture production, and ecosystem services.
3. Quantify the sustainability of beef and dairy production systems through life cycle assessment and prioritize areas for improvement.
3a. Document production practices and determine farm-gate environmental footprints for beef cattle production throughout the United States.
3b. Evaluate the environmental and economic impacts of alternative practices of milk production in important dairy regions of the United States.
Approach
Long-term monitoring of carbon dioxide and nitrous oxide emissions will be conducted in support of Long Term Agro-ecosystem Research (LTAR). University Park is part of the recently-formed Dairy Agroecosystem Working Group (DAWG) along with ARS units in Idaho, Minnesota, and Wisconsin. DAWG has adopted a framework in concert with the LTAR network to provide data, technologies and decision support tools that enable dairy producers to adapt to current and future production and environmental demands. Air and water quality impacts, environmental footprints, and farm economic viability of dairy production systems will be assessed through detailed case studies of geographically distinct dairy production systems in each of our regions.
Development and evaluation of farm-scale models [Integrated Farm System Model(IFSM) and DairyGEM] will continue. As new process information becomes available, component models used to predict emissions will be revised and evaluated to improve prediction accuracy. Mitigation strategies will be simulated and evaluated to assess interactions within and overall impacts on farm production systems.
Empirically downscaled daily climate files will be developed by collaborators at Texas Tech University for approximately 80 cattle producing locations of the U.S. using 9 climate models and two long term greenhouse gas emission scenarios (current emission levels, RCP=8.5 and reduced emission levels, RCP=4.5). Representative dairy farms will be simulated using IFSM with current and projected future climate, and adaptation strategies will be determined to maintain profitable and environmentally sustainable production.
The downscaled climate files will also be used to model two watersheds (one karst, one non-karst) in the Ridge and Valley physiographic region of the Upper Chesapeake Bay Basin. Current practices will be simulated using historical climate data and a modified version of the Soil and Water Assessment Tool, called TopoSWAT. These same regional watersheds will then be simulated under management practices described in the Bay Watershed Implementation Plan’s (WIPs) for meeting the Chesapeake Bay Loading Reduction goals of 2025.
Collaboration continues with the National Cattlemen’s Beef Association in a national assessment of the sustainability of beef. Producer surveys and visits are being conducted for each of seven geographic regions to determine common production practices. Representative cattle operations are defined and simulated with IFSM to quantify the performance and farm-gate environmental impacts of production systems in each region. This information will be used in regional and national life cycle assessments to benchmark the environmental footprints and overall sustainability of beef production.
Information developed will be used to support the Northeast Climate Hub. In collaboration with Climate Hub university partners, surveys and stakeholder interviews will be conducted to determine perceived challenges relating to climate change and variability and information needs to meet those challenges. A climate adaptation workbook developed by the US Forest Service will be modified for use on agricultural lands.
Progress Report
Under objective 1a, nitrous oxide emissions in response to cover crop residue, fertilizer, and manure inputs were measured regularly throughout the growing season. Eddy covariance flux measurements at this initial Long-Term Agro-Ecosystem Research (LTAR) site were collected, data were monitored for quality control, and repair, calibration or replacement of sensors was performed as needed. Negotiations are underway with Penn State University to procure a second LTAR site. Micromet and chamber measurements of CO2 fluxes were compared during regrowth following the second cutting of alfalfa at the existing LTAR site. Intact soil columns were established on sites of ARS collaborators for measuring nitrogen loss from dairy forage systems in different soils and climates.
Under objective 1b, a process-based model for predicting silage volatile organic compounds (VOC) emissions was refined and evaluated against measured emission data from a dairy farm in Central California. Application of the model for a representative California dairy demonstrated that the primary source of VOC emissions is feed lying in the feed bunk, so future work on mitigating these emissions must focus on feeding methods and feed bunk design. A model was also developed and evaluated for representing compost manure handling in cattle production systems. The model accurately represented nitrogen and carbon emissions measured in a windrowed compost experiment conducted in Canada.
Under objective 1c, a wide range of greenhouse gas mitigation strategies were evaluated with the Integrated Farm System Model (IFSM) for a large dairy farm in New York and a small dairy farm in Wisconsin. The best mitigation options were more efficient feeding of animals and suppressing or capture of methane during manure storage.
Under objective 2a, projected future climate data files were created through collaboration with climate scientists at Texas Tech University for about 80 cattle producing regions of the U.S. using 9 general circulation models and 2 future greenhouse gas emission scenarios. A New York dairy farm was simulated with IFSM using the projected climate data to evaluate impacts of climate change and adaptation strategies needed to maintain sustainable dairy production. Through changes in planting and harvest dates, crop varieties and cropping strategies, profitable production was maintained.
Under objective 2b, watershed-scale simulations were developed and corroborated against measured data for historical climatic data from two northeastern physiographic regions. Active recruiting for a Research Associate to work on the projection analysis has continued throughout FY2016, and the position has been offered to a suitable candidate.
Under objective 2c, a capacity discovery survey of land grant university research and extension personnel from all 13 land grant universities in the northeast was completed by Penn State University and Cornell University collaborators and a summary report was prepared for the Northeast Climate Hub. Collaborators have also conducted multiple focus groups with northeast producers to determine their perceived climate challenges and needs for outreach materials to address those challenges. Work has begun on a white paper summarizing results from the capacity discovery and focus groups for presentation to funding agencies.
Under objective 3a, surveys and visits of beef cattle operations were completed in the Midwest, Southwest and Northwest regions of the U.S. documenting common production practices. Survey and visit information from the Midwest and Northern Plains was used to create representative production systems that were simulated with IFSM to determine the environmental impacts of greenhouse gas emissions, fossil energy use, non-precipitation water use and reactive nitrogen loss for beef cattle production in these regions.
Under objective 3b, IFSM was revised to track and report all forms of nitrogen, phosphorus and carbon loss from simulated production systems. This refinement expands the use of the model for studying the effects of management on nutrient losses and the interaction among the various losses.
Accomplishments
1. Long-term field management database. Great interest exists in the ability to mitigate water quality problems through changes in agricultural management. Long-term watershed and farm management datasets are a unique resource for serving research, management and policy arenas, but they are difficult to develop because they must protect the privacy of farmers and land owners without sacrificing the spatially and temporally specific nature of the data. A novel framework was developed for recording land management, water quality and related data that expands the utility of these datasets across the research community and offers a model for other database management efforts. The initial database populated into the framework contains long-term field management information for about fifteen farms and nearly 300 fields within our long-term experimental watershed located in a non-karst portion of Pennsylvania’s Ridge and Valley Physiographic Province. This database supports research aimed at helping farmers meet long-term production, land stewardship, and water quality goals.
2. Understanding manure-based phosphorus processes. Watershed modeling is critical for guiding strategies to mitigate non-point source pollution. Current watershed models, such as the Soil Water Assessment Tool (SWAT), generally lack explicit representation of surface applied nutrients, a potential problem when forecasting the effects of nutrient management strategies. A new set of soil phosphorus routines was added to SWAT to simulate surface applied manure at field and subwatershed scales. The new routines provided insight into all aspects of nutrient management including method, timing, rate, and form of application. Application of the revised model to the Mahantango Creek watershed in Pennsylvania demonstrated substantial improvements in simulating phosphorus runoff processes, which supports the need to create similar revisions to other agroecosystem watershed models.
3. Subsurface application enhances the benefits of manure redistribution. Moving livestock manure from areas of local nutrient excess to areas of local nutrient deficit is key to the long-term sustainability of our food production systems. Field experiments were conducted in a region that may become a destination for manure redistribution in the Chesapeake Bay watershed to assess trade-offs among available methods of applying poultry litter to soils. While corn yields increased with any method of poultry litter application compared to the use of conventional fertilizer, subsurface application provided many environmental and long-term nutrient conservation benefits that were not seen with surface application methods. Results point to the need to include improved manure application technologies as part of agricultural programs that aim to redistribute manures.
Scientists have participated in activities targeting small farms. Research results related to air emissions, water quality and overall sustainability apply to farms of all sizes. Our research on nutrient management and manure application has focused on smaller farms of the Northeast with gross annual receipts under $250,000.
Review Publications
Rotz, C.A., Asem-Hiablie, S., Dillon, J., Bonifacio, H.F. 2015. Cradle-to-farm gate environmental footprints of beef cattle production in Kansas, Oklahoma, and Texas. Journal of Animal Science. 93:2509-2519.
Jego, G., Rotz, C.A., Belanger, G., Tremblay, G., Charbonneau, E., Pellerin, D. 2015. Simulating forage crop production in a northern climate with the Integrated Farm System Model. Canadian Journal of Plant Science. 95:745-757.
Thivierge, M., Jego, G., Belanger, G., Bertrand, A., Tremblay, G., Rotz, C.A., Qian, B. 2016. Predicted yield and nutritive value of an alfalfa-timothy mixture under climate change and elevated atmospheric carbon dioxide. Agronomy Journal. 108:585-603.
Collick, A.S., Veith, T.L., Fuka, D.R., Kleinman, P.J., Buda, A.R., Weld, J.L., Bryant, R.B., Vadas, P.A., White, M.J., Harmel, R.D., Easton, Z.M. 2016. Improved simulation of edaphic and manure phosphorus loss in SWAT. Journal of Environmental Quality. 45(4):1215-1225. doi:10.2134/jeq2015.03.0135.
Veith, T.L., Richards, J.E., Goslee, S.C., Collick, A.S., Bryant, R.B., Miller, D.A., Bills, B., Buda, A.R., Sebring, R.L., Kleinman, P.J. 2015. Navigating spatial and temporal complexity in developing a long-term land use database for an agricultural watershed. Journal of Soil and Water Conservation. 70(5):288-296. doi:10.2489/jswc.70.5.288.
Liu, J., Kleinman, P.J., Beegle, D., Dell, C.J., Veith, T.L., Saporito, L.S., Han, K., Pote, D.H., Bryant, R.B. 2016. Subsurface application enhances benefits of manure redistribution. Agricultural and Environmental Letters. doi: 10.2134/ael2015.09.0003.
