Location: Pasture Systems & Watershed Management Research
2017 Annual Report
Objectives
Objective 1: Describe and quantify processes controlling agriculturally related environmental contaminants (C, N, and P) to reduce inputs to receiving waters (C2, PS 2.1).
Subobjective 1.1: Characterize chemical, physical and biological controls of contaminant mobility and transport in water at pedon, field, landscape and watershed scales.
Subobjective 1.2: Characterize the spatial nature and temporal dynamics of transport pathways connecting sources of key agricultural contaminants with surface and ground waters.
Objective 2: Adapt and develop management practices that farmers can use to reduce the environmental impacts of agriculturally derived contaminants on receiving waters (C1: PS 1.5; C2: PS 2.4; C3: PS 3.1 and 3.2; C4: PS 4.2).
Subobjective 2.1: Identify, evaluate, and develop fertilizer, manure, tillage, irrigation and drainage management practices that improve production use efficiency and minimize off site transfers to surface and ground waters.
Subobjective 2.2: Develop new technologies, management practices and decision support tools that recognize the spatial variability of the landscape and focus mitigating efforts on critical source areas or critical pathways.
Objective 3: Conduct plot, field and watershed studies to understand processes that link cranberry production to water resources and develop appropriate conservation practices to protect water quality (C1: PS 1.5; C2: PS 2.4; C3: PS 3.1 and 3.2; C4: PS 4.2; NP305 C1: PS 1B).
Subobjective 3.1: Characterize temporal and spatial patterns of N and P discharge from cranberry farms.
Subobjective 3.2: Develop new technologies and management practices that improve water quality and enhance water use efficiency on cranberry farms.
Objective 4: As part of the LTAR network, and in concert with similar long-term, land-based research infrastructure in the mid-Atlantic Region, use the Upper Chesapeake Bay Experimental Watersheds LTAR site to improve the observational capabilities and data accessibility of the LTAR network and support research to sustain or enhance agricultural production and environmental quality in agroecosystems characteristic of the region. Research and data collection are planned and implemented based on the LTAR site application and in accordance with the responsibilities outlined in the LTAR Shared Research Strategy, a living document that serves as a roadmap for LTAR implementation. Participation in the LTAR network includes research and data management in support of the ARS GRACEnet and/or Livestock GRACEnet projects. (C4: PS 4.1; NP 212 C1: PS 1B; NP 216 C5: PS 5A)
Subobjective 4.1: Support the LTAR common observatory by monitoring and modeling long term changes affecting water resources and contributing to LTAR’s common database.
Subobjective 4.2: Support LTAR’s common experiment and Dairy Agro-ecological Working Group (DAWG) water research objectives by comparing water resource impacts of a long term conventional dairy forage rotation (corn, soybean, and alfalfa) with a diversified dairy forage rotation that, in addition, includes winter cover crops, perennial grasses for bioenergy feedstock, and grazed pasture.
Approach
Research will span the Chesapeake Bay and Buzzards Bay watersheds, relying upon core sites in the Atlantic Coastal Plain (Manokin watershed, MD; Buzzards Bay watershed, MA), Appalachian Piedmont (Conewago watershed, PA), Appalachian Valley and Ridge (Mahantango Creek watershed, PA and Spring Creek watershed, PA), and Allegheny Plateau (Anderson Creek watershed, PA). Research emphases will vary across these locations, reflecting issues that are of current management or scientific relevance as well as constraints imposed by available resources. Our primary distinction is between the Atlantic Coastal Plain (in the Chesapeake and Buzzards Bay watersheds) and the upland physiographic areas of the Chesapeake Bay watershed, as hydrologic flow paths are dramatically different in these landscapes (subsurface flow is the dominant hydrologic pathway in the Atlantic Coastal Plain, whereas overland and shallow lateral flows are the major pathways in the upland provinces). We have landowner contacts and research collaborators at all major (core) sites and have a research infrastructure that enables routine measurement and chemical sampling of surface runoff, subsurface flow, and stream flow. When necessary, we move infrastructure from one location to another to provide a greater intensity of observations. We combine field observations with laboratory experiments in which greater control may be obtained over indirect variables. Our process-oriented research (Objective 1) involves observational and experimental studies, using parametric and nonparametric statistics to quantify temporal and spatial trends or to determine differences between management/land use, landscape units, and watershed components. Our applied research (Objectives 2-4) includes experimental studies, remote sensing and modeling. Experimentation involves a high degree of replication due to the inherent variability in processes impacting water quality. We have strong in-house statistical capability and, when necessary, consult with outside statisticians to ensure confidence in our findings.
Progress Report
Nine wetlands in the Delmarva area are divided into four equal-area topographic class subdivisions. Four soils in each topographic class division were sampled by auger to a 50-cm depth, divided into four depth categories and submitted for laboratory characterization. Intact soil monoliths encompassing manure injection bands were obtained from a no-till corn field at Rock Springs Research Farm immediately after shallow disk injection and tillage incorporation of broadcast dairy manure. Perforated tubes were inserted and gas emissions are being monitored. Fourteen sites representing agricultural ditches, forested ditches, and wetlands were identified on a private farm in the Manokin River watershed. Water quality parameters are being monitored with ISCO samplers and a YSI® EXO multiparameter water quality meter; illumina sequencing using the MiSeq platform with the 16S rRNA gene marker shows taxonomic differences in microbial communities at the class level across sites. Experimental stream reaches were established in the Mahantango Creek watershed and flumes were installed for stream gauging. Detailed monitoring of streams, seeps, and hyporheic groundwater was initiated and will continue through the summer of 2017. A Pennsylvania State University (PSU) graduate student began analyzing archived water samples for stable isotopes using our in-house Picarro Isotope Analyzer; projected completion date is FY 2018. A MODFLOW model of WE-38 also was developed and refined for the proposed travel time research. The shallow lateral subsurface flow study was initiated on the University of Maryland Eastern Shore (UMES) Research and Teaching Farm by installing an array of ERI (electrical resistivity imaging) electrodes and hydrometric monitoring equipment. In addition, EMI (electro-magnetic interference) surveys of the surrounding 1.5 ha cropped field were conducted to assess the variability of soil properties. Manure injection plots on perennial grasslands were established and are being monitored at the Rock Springs Research Farm and in the Mahantango Creek watershed. Corn was planted on the field scale lysimeter plots at Rock Springs; cover crops, manure treatments and sampling will be implemented later in the growing season. Gypsum was applied at the rate of 1 ton per acre on the corn and sorghum plots on the UMES Research Farm; soil samples were collected and analyzed, and runoff and leachate are being collected after storm events. Diatomaceous earth contaminated with manure solids were collected during testing of the full-scale MAPHEX system. Ashing the solids at 550 degrees C for four hours resulted in clean diatomaceous earth that thus far has been successfully reused twice. One additional diversion bioreactor was established on a drainage ditch on the Delmarva; all sites have been instrumented for monitoring nitrate reduction. A literature review of riparian ecosystem services was completed as part of the PSU Master’s thesis, and 150 Conservation Reserve Enhancement Program sites in Chesapeake Bay Watershed were surveyed. Qualitative comparisons of four runoff forecasting tools were completed, and the results were published in the Journal of Environmental Quality. Scenarios to guide SWAT (Soil and Water Assessment Tool) simulations of decision support tool implementation in the Upper Chesapeake LTAR (Long-Term Agroecosystem Research) basins were completed. Twenty-five cranberry bogs from among 40 farms in Buzzards Bay watershed were selected for in-depth soil characterization. Previously collected flow monitoring data were organized and are in the process of being analyzed. Instrumentation for monitoring evapotranspiration has been installed and measurements are being taken. Laboratory experiments using five calcium, iron or aluminum salts identified alum as best suited for reducing phosphorus concentrations in pond water that is used to flood irrigate cranberry bogs. A cooperator has granted permission for conducting a field scale trial later this season. A water sampling scheme for characterizing base flow (one-hour sampling frequency) and storm flow (15-minute sampling frequency) was found to provide excellent characterization of water quality parameters in the Mahantango Creek watershed. Downscaled climate projections from nine climate models were assembled. The data have been analyzed for long-term trends and extreme climate events, and the results of these analyses will be featured in several conference presentations in the latter part of FY 2017. The Upper Chesapeake Watershed LTAR common experiment is the continuation of a Northeast SARE project that was initiated in collaboration with PSU in 2010, but modified with the addition of a dairy forage crop as part of the business-as-usual rotation. Due to temporary personnel shortages, we were not able to establish alfalfa this season, but all other crops in the rotation were established and monitored as planned. The dairy forage crop will be established in 2018. Lysimeters were installed at Kimberly, Idaho and are being tested under irrigation. A flood irrigation event resulted in water being preferentially collected in the trenches where the lysimeters were installed; a situation that may preclude the use of lysimeters installed in this manner. Observed and modeled water budgets were completed for research sites in the Mahantango Creek watershed and at Rock Springs, and the development of nutrient budgets for both sites are in progress.
Accomplishments
