1a. Objectives (from AD-416):
1: Identify, through experimentation and plant growth and habitat modeling, pasture-based dairy and livestock production systems and management practices that improve food security by enhancing productivity, improving long-term environmental sustainability, and increasing flexibility to adapt to changing environmental and climatic conditions. We will initially delineate current land-use practices for grazing lands in the eastern US and investigate how land use might change in the future (sub-objective 1.A). Primary land use practices to be considered are pasture-based animal agriculture and bioenergy feedstock production systems. Sub-objective 1B will characterize potential changes in forage species distribution and dairy cow grazing behavior in response to climate change (adaptation), and evaluate plant and animal management strategies to mitigate climate change. Sub-objective 1.C will identify conservation practices and animal management strategies that improve nutrient utilization efficiency and reduce sediment and nutrients movement off-farm. 2: Develop best management practices and identify management systems that improve productivity and environmental sustainability of bioenergy production as part of multifunctional agricultural systems. Objective 2 focuses on bioenergy cropping systems and will identify management systems that increase soil C sequestration and reduce N loss and net GHG emissions (sub-objective 2.A) and evaluate the effects of miscanthus production at the commercial scale on C sequestration and GHG intensity (sub-objective 2.B). Sub-objective 2B will also include a life-cycle inventory assessment to profile the energy and GHG emissions associated with miscanthus production. Objective 3. Improve dairy industry production capacity and environmental sustainability to meet the demands of existing and emerging markets, and improve dairy industry resilience to abiotic and biotic stressors while maintaining producer economic viability. Using a comprehensive, systems approach along with existing/new databases and models to identify opportunities and support Livestock GRACEnet, LTAR and Climate Hub efforts to improve the environmental performance of dairy systems across the Northeast, Midwest, and West. The following research focus areas will be prioritized: a) Improve nutrient use efficiency across dairy production, emphasizing the conservation of nitrogen and phosphorus in local and regional crop production and reduction of off-farm nitrogen and phosphorus losses, especially through novel/greater use of forage crops and innovative practices. b) Improve carbon sequestration and reduce greenhouse gas emissions from dairy cattle, production facilities and land application of manure. c) Improve the understanding of pathogen transport and control through water and/or bioaerosol pathways.
1b. Approach (from AD-416):
This research will provide the necessary information for developing decision-support tools that bring together diverse forage production systems, innovative animal management strategies and novel biofuel production practices to build multifunctional farms and landscapes. The purpose is to provide guidance on optimizing the placement and management of pasture and bioenergy crops in ways that are appropriate to the landscape context and that will increase productivity and enhance ecosystem services of farming enterprises. We will initially delineate current land-use practices for grazing lands in the eastern US and investigate the production and environmental consequences of potential future management changes. Primary land-use practices to be considered are pasture-based animal agriculture and bioenergy feedstock production systems. We will provide information on plant and animal adaptation to climate change and on the effectiveness of greenhouse gas (GHG) mitigation strategies for grazing animals, pasturelands, and biofuel feedstock production systems. We will provide farm scale life cycle inventory (LCI) data on miscanthus and identify water quality and GHG impacts of switchgrass and miscanthus production on marginal lands We will also assess the effects of grazing management and manure application strategies on nutrient movement and water quality as part of the pasture component of the national Grazing Lands Conservation Effects Assessment Project (CEAP). Results will fill gaps in our knowledge of management practices that increase resilience to climate change, improve conservation of soil and water resources, and reduce GHG emissions. Successful completion of this project will 1) increase farm productivity, 2) improve adaptation to climate change and 3) provide targeted conservation practices to enhance ecosystem services.
3. Progress Report:
For sub-objective 1.A.1, a multi-year effort to identify plant-relevant climate statistics, such as growing degree days, temperature extremes, and drought lengths, and to calculate them for the output of sixteen climate models and four scenarios for the period 1960-2099 has been completed. Prior work identified the unsuitability of existing soils data for regional and national modeling efforts, necessitating the identification of new datasets. These have been incorporated into site type development efforts, and the climate change predictions developed with the revised classification. For sub-objective 1.A.2, a post-doctoral research associate developed a model of dairy nutrition and production related to land use choices among annual and perennial crops, and published the results for representative sites in the northeastern United States. Simulation modeling using APEX provides additional environmental context to land use decision-making. For sub-objective 1.B.1, the forage species distribution models previously developed under this objective have been applied to the predicted future climate data (1.A.1) to map potential future distributions in the northeastern US. One peer-reviewed paper with distribution maps for nine species has been published, and a manuscript on potential future distributions is in preparation. In addition to the species distribution models, a controlled environment study was used to characterize the freeze tolerance of perennial ryegrass, and a paper published on the physiological limits to its current and potential future distribution. Additional technology transfer outlets for species distribution maps are being developed. Sub-objectives 1.B.2 has been completed. Sub-objectives 1.B.3 has been completed. For sub-objective 1.B.4, a continuous culture fermenter study that evaluated the effects of forages containing tannins ruminal fermentation and methane output of a pasture-based diet was completed. The results of this study showed that increasing the tannin concentration of legumes in the diet of grazing ruminants decreased methane output; however, ruminal fermentation was adversely impacted and must be considered in animal studies. For sub-objective 1.C.1, a continuous culture fermenter study that evaluated the effects of brassica forages on ruminal fermentation and methane output of a pasture-based diet was completed. Addition of brassicas provided similar nutrient digestibility to annual ryegrass while reducing daily methane production, potentially making brassicas a more environmentally friendly alternative for annual ryegrass in pasture-based ruminant diets. For sub-objective 1.C.2, manure applications have continued in 2017, with monitoring of yield and nutrient runoff at both sites. Ammonia and nitrous oxide emissions have continued at Rock Springs. Sub-objective 1.C.3 has been completed. For sub-objective 2.A.1, water quality and soil N2O emissions data were collected regularly at the Mattern watershed. Biomass yield was determined at the end of the growing season. Data on N2O emissions and biomass production were summarized and published. For sub-objective 2.A.2, soil N2O emissions and C sequestration, and biomass yield and other data on biochar impacts were summarized, life cycle assessment was completed, and using GIS analysis of marginal soils in Pennsylvania, results were scaled up to identify areas with greatest potential benefit of biochar. For sub-objective 2.B.2, fuel use during land preparation, and management and harvest of miscanthus were summarized, C and N2O emissions of miscanthus production were modeled, and a LCA of miscanthus production was conducted.
1. Improved rising plate meter to estimate forage yield in multi-species pastures. The rising plate meter was developed in New Zealand to estimate forage yield of pastures with one or two forage species. ARS scientists at University Park, Pennsylvania found that default calibration equations provided by the manufacturer are not reliable for complex pasture mixtures. However, the complex pasture mixtures commonly found in the U.S. where forage structure is much different may yield over- or under-estimation. ARS scientists at University Park, Pennsylvania have developed a more reliable forage yield rising plate meter. This new meter is being used by the Natural Resources Conservation Service and Pennsylvania State Extension to provide better results to farm consultants and other researchers.
Adler, P.R., Spatari, S., D'Ottone, F., Vazquez, D., Peterson, L., Del Grosso, S.J., Baethgen, W., Parton, W. 2017. Legacy effects of individual crops affect N2O emissions accounting within crop rotations. Global Change Biology Bioenergy.10:123-136.doi: 10.1111/gcbb.12462.
Pourhashem, G., Adler, P.R., Spatari, S. 2015. Time effects of climate change mitigation strategies for second generation biofuels and co-products with temporary carbon storage. Journal of Cleaner Production. 112:2642-2653. doi:10.1016/j.jclepro.2015.09.135.
Saha, D., Kemanian, A., Rau, B.M., Adler, P.R., Montes, F. 2017. Designing efficient nitrous oxide sampling strategies in agroecosystems using simulation models. Atmospheric Environment. 155:189-198.
Debasish, S., Rau, B., Kaye, J., Montes, F., Adler, P.R., Armen, K. 2016. Landscape control of nitrous oxide emissions during the transition from conservation reserve program to perennial grasses for bioenergy. Global Change Biology Bioenergy. doi:10.1111/gcbb.12395.
Egan Jr, J.F., Barlow, K.M., Mortensen, D.A. 2014. A meta-analysis on the effects of 2,4-D and dicamba drift on soybean and cotton. Weed Science. 62(1):193–206. doi:10.1614/WS-D-13-00025.1.
Hafla, A.N., Soder, K.J., Brito, A., Kersbergen, R., Benson, F., Darby, H., Rubano, M.D. 2016. Feeding strategy and pasture quality relative to nutrient requirements of dairy cows in the northeastern U.S. Professional Animal Scientist. 32:523-530.
Hill, J., Egan Jr, J.F., Stauffer, G., Diefenbach, D. 2014. Habitat availability is a more plausible explanation than insecticide acute toxicity for U.S. grassland bird species declines. PLoS One. 9(5):e98064. doi:10.1371/journal.pone.0098064.
Egan Jr, J.F. 2014. Herbicide-resistant crop biotechnology: potential and pitfalls. In A. Richrock, S. Chopra, & S. Fleischer (Eds.), Plant Biotechnology: Experience and Future Prospects. p.143-154.
Egan Jr, J.F., Graham, I.M., Mortensen, D.A. 2014. A comparison of the herbicide tolerances of rare and common plants in an agricultural landscape. Environmental Toxicology and Chemistry. 33(3):696–702. doi:10.1002/etc.2491.
Hafla, A.N., Macadam, J.W., Soder, K.J. 2013. Sustainability of US organic beef and dairy production systems: soil, plant and cattle interactions. Sustainability. 5:3009-3034.
Dillard, S.L., Hafla, A., Roca-Fernandez, A., Brito, A., Rubano, M.D., Soder, K.J. 2017. Effect of feeding warm-season annuals with orchardgrass on ruminal fermentation and methane output in continuous culture. Journal of Dairy Science. 100(2):1179-1188.
Dillard, S.L., Hafla, A.N., Rubano, M.D., Stout, R.C., Brito, A.F., Soder, K.J. 2016. Evaluation of a rising plate meter for use in multi-species swards. Agricultural and Environmental Letters. 1:160032.