1a. Objectives (from AD-416):
Objectives: 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. a. Investigate historic, current and potential future land use patterns to determine the suitability of grazing lands for pasture and biofuel production, and to assess potential responses of grazing agriculture to changing climate. b. Characterize potential changes in forage species distribution and dairy cow grazing behavior in response to climate change, and evaluate plant and animal management strategies to mitigate climate change. c. 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. a. Identify management systems that increase soil Carbon (C) sequestration and reduce Nitrogen (N) loss and net Greenhouse Gas (GHG) emissions in bioenergy crop systems across the landscape in the Northeast. b. Evaluate GHG emissions of miscanthus production when grown at the farm scale in Northeast across soils typical of the region and previous land use history. 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. a. Using a comprehensive, systems approach along with existing/new databases and models to identify opportunities and support Livestock GRACEnet, Long Term Agroecosystem Research Network (LTAR) and Climate Hub efforts to improve the environmental performance of dairy systems across the Northeast, Midwest, and West.
1b. Approach (from AD-416):
Calibration and testing of the Agricultural Policy/Environmental Extender (APEX) model for use in northeastern temperate pastures will continue, in support of Grazing Lands Conservation Effects Assessment Project (CEAP) goals. University Park is leading this CEAP effort to configure the farm-scale model for use with National Resource Inventory pasture data for the continental United States. A consistent and well-documented dataset containing topography and derived variables, historical and projected climate data and derived indices such as CLIMDEX and BIOCLIM, and digital soil mapping products that reduce the positional error in standard Soil Survey Geographic Database (SSURGO) soils maps is being used to map and model forage, biofuels, and crop species distributions under current and potential future climates. These models incorporate field, greenhouse, and survey data (National Resource Inventory, Census of Agriculture and other sources) to better understand shifting patterns of agricultural diversity and productivity for both Long-Term Agroecosystem Network sites and the nation as a whole. To evaluate the environmental effects of growing biomass crops on marginal lands, we will continue to monitor N2O emissions and continuously record soil moisture, temperature, and oxygen concentration across a moisture gradient of perennial grasses switchgrass and miscanthus. The location is an 11 ha watershed in the Mahantango Creek watershed and was formerly Conservation Reserve Enhancement Program (CREP) marginal lands. To better characterize spatial biomass yields across the watershed, we will use structure from motion with a unmanned aerial vehicle (UAV). The moisture gradient will allow us to characterize biomass yield potential across a range of marginal lands from droughty to poorly drained. A life cycle inventory of energy use at the farm scale with over 4,000 acres of miscanthus production will continue. Different establishment strategies are being evaluated to increase production. Spatial yield variation is occurring at both the whole and sub field scales and will be quantified and evaluated. Eddy covariance systems are being used to estimate changes in soil carbon across a soil carbon gradient. Determine if overseeding of annual warm-season grasses into perennial cool-season pastures can help to extend the grazing season during the traditional summer slump found in cool-season perennial, as well as determine the best method of establishment and yield differences of pastures either overseeded or not overseeded. Develop, refine and field test an improved grazing behavior monitor that combines animal grazing patterns, jaw movement, and telemetry into one unit.
3. Progress Report:
This is a bridge project for 8070-21000-008-00D which terminated in November 2017. Objective 1: Research into agricultural uses and land use choices is being extended from the Northeast across the continental U.S., focusing especially on Long Term Agroecosystem Research Network (LTAR) inference regions. The newly released 2017 Cropland Data Layer has brought the spatially-referenced continental agricultural land use record to ten years. This dataset was to develop a broader understanding of major themes in agricultural land use and corresponding potential for sustainable intensification. The results of field, greenhouse, and modeling research were synthesized to better understand the current and potential future constraints on the distribution of the important forage species perennial ryegrass. Developed tools to facilitate parameterization and testing of the Agricultural Policy/Environmental Extender (APEX) model for use in northeastern temperate pastures, compiled the necessary data to parameterize the model, and began the process of sensitivity analysis of temperate forage species parameters. Budget and hiring issues have delayed the hiring of the postdoctoral research associate who was to be responsible for the modeling component of this work. A novel behavior recorder halter has been developed to measure the frequency and amplitude of jaw movements of grazing ruminants to quantify bite rate, number and length of meals, ruminating time and resting time. In addition, this unit has a Global Positioning System (GPS) that will pinpoint location of a cow on pasture to monitor movements throughout a pasture or rangeland which can be important for factors such as grazing fragile environments (e.g., riparian areas) or estimating diet selection by combining location and grazing behavior with patches of various forages in a biodiverse pasture. This unit also contains a graphical user interface, which allows the user to remotely download the data onto a computer or smartphone without disturbing the animals. In addition, the unit can send a distress signal if there is a malfunction with the recorder so corrections can be made without losing large amounts of data. A patent application has been filed and the unit is currently being beta tested. Objective 2: Plant height of miscanthus was measured using structure from motion with an unmanned aerial vehicle (UAV). Eddy covariance systems were used to estimate changes in soil and biomass carbon of miscanthus fields. Field plots of miscanthus and switchgrass at Mattern watershed were monitored for changes in soil carbon and soil moisture, and water quality, soil N2O emissions, and biomass yield data were collected Fuel use was measured during field preparation, and miscanthus planting and harvest. Objective 3: A ten-year study comparing soil carbon sequestration was completed and documented as part of ARS-GraceNet (see accomplishment and publications listed in this report).
1. Soil carbon sequestration with alternative land uses. Land management practices that increase soil organic matter (measured as soil organic carbon) has multiple benefits including partially offsetting carbon dioxide emissions and improving soil health and productivity. A ten year study comparing soil carbon sequestration with a corn (3 yr)/soybean (1yr)/alfalfa (4 yr) rotation, switchgrass and reed canarygrass managed as bioenergy feedstocks, and grazed pasture led to positive soil Carbon (C) sequestration over the duration of the experiment, with reed canarygrass and five-species pasture mix providing the greatest accumulation of organic matter.
Dell, C.J., Gollany, H.T., Adler, P.R., Skinner, H., Polumsky, R.W. 2018. Implications of observed and simulated soil carbon sequestration for management options in corn-based rotations. Journal of Environmental Quality. 47:617-624. https://doi.org/10.2134/jeq2017.07.0298.
Veith, T.L., Goslee, S.C., Beegle, D.B., Weld, J.L., Kleinman, P.J. 2017. Analyzing the distribution of hydrogeomorphic characteristics across Pennsylvania as a precursor to phosphorus index modifications. Journal of Environmental Quality. 46:1365-1371. doi: 10.2134/jeq2016.10.0416.
Gall, H.E., Schultz, D., Veith, T.L., Goslee, S.C., Mejia, A., Harman, C., Raj, C., Patterson, P.H. 2018. The effects of disproportional load contributions on quantifying vegetated filter strip sediment trapping efficiencies. Stochastic Environmental Research and Risk Assessment (SERRA). 1-12. https://doi.org/10.1007/s00477-017-1505-x.