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Research Project: Integrated Strategies for Improved Water Quality and Ecosystem Integrity within Agricultural Watersheds

Location: Water Quality and Ecology Research

2017 Annual Report


1a. Objectives (from AD-416):
Objective 1. Develop and evaluate farm and land management practices that reduce erosion, conserve soil, improve water quality, and protect ecological resources. Sub-objective 1a. Quantify the effects of conservation practices on runoff water quality and soil resources in Beasley Lake Conservation Effects Assessment Project (CEAP) watershed. Sub-objective 1b. Assess the influence of conservation practices on ecology and agricultural contaminant fate and transport in alluvial plain landscapes. Objective 2. Characterize and/or quantify the structure, function, and key processes of ecosystems in agricultural settings. Sub-objective 2a. Evaluate how nutrients, pesticides, and sediments interact with watershed hydrology to influence mechanisms regulating water quality and aquatic ecosystem structure and function in agricultural watersheds. Sub-objective 2b. Examine effects of water flow, climate-change-induced drought, and agricultural nutrient contaminants on stream microbial productivity and nutrient processing. Sub-objective 2c. Examine associations between fish species composition, hydrologic connectivity, and hypoxia in agricultural watersheds. Objective 3. Integrated assessment of the effects of agriculture on ecosystem services for watershed-scale endpoints. Sub-objective 3a. Develop integrated remote sensing tools to better evaluate wetlands and riparian buffers. Sub-objective 3b. Develop agricultural conservation strategies to adapt to climate change. Sub-objective 3c. Develop integrated modeling tools to assess the effectiveness of conservation practices that enhance ecosystem services at multiple scales. Objective 4. As part of the Long-Term Agro-ecosystem Research (LTAR) network, and in concert with similar long-term, land-based research infrastructure in Lower Mississippi River Basin (LMRB), use the Beasley Lake Experimental Watershed to improve the observational capabilities and data accessibility of the LTAR network, to support research to sustain or enhance agricultural production and environmental quality in humid environments characteristic of the LMRB, as per the LTAR site responsibilities and other information outlined in the 2012 USDA Long- LTAR Network Request for Information (RFI) to which the location successfully responded, and 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.


1b. Approach (from AD-416):
Long-term viability of U.S. agriculture depends upon implementation of management strategies that address goals of environmental sustainability and economic viability. Despite significant financial investment in conservation practices and water quality protection over recent decades, water quality issues remain unsolved in many agricultural landscapes. Off-site and downstream impacts of agricultural water pollution continue to raise concerns, most notably marine dead zones linked to excess nitrogen (N) and phosphorus (P). Biodiversity continues to decline due to water quality and habitat degradation. Future influences on environmental quality include synergistic effects of climate change, biofuel production, increased human population and exotic species. To address issues of water quality and watershed ecosystem function, investigations will pursue complementary approaches that consider the entire landscape, from upland fields to receiving water bodies. First, farm and land management technologies that reduce erosion, pesticide, and nutrient losses, conserve and improve soil, and protect ecological resources will be assessed. Second, studies will be conducted to improve understanding of structure, function, and key processes of aquatic systems, guiding better management of these systems and providing a scientific basis for regulatory agencies to establish water quality criteria. Third, investigations will develop and assess technology for improving water quality and ecosystem function in agriculturally impacted aquatic systems. Fourth, investigations will assemble and use long-term databases to develop and further enhance computer models for quantifying effects of conservation measures on agricultural watershed ecosystem services. This plan calls for experiments to be conducted across a range of spatial scales from the laboratory bench to the watershed.


3. Progress Report:
This is the final report for this project which has been replaced by project 6060-13660-008-00D, "Strategic Investigations to Improve Water Quality and Ecosystem Sustainability in Agricultural Landscapes." Long-term (1996-present) assessments in the Conservation Effects Assessment Program (CEAP) Beasley Lake watershed demonstrated effectiveness of integrated agricultural management practices including Conservation Reserve Program (CRP) acreage, sediment retention basins, and vegetated buffers and ditches, all aimed at reducing concentrations of sediment, nutrients, and pesticides being transported from production acreage into the oxbow lake. As a result of these implemented management practices, water quality of Beasley Lake has improved, resulting in lake conditions shifting to becoming more sustainable, benefitting fisheries and other ecosystem services provided by Beasley Lake. USDA Annualized AGricultural Non-Point Source (AnnAGNPS) pollutant loading model enhanced prairie pothole wetland features. The modeling research demonstrated an integrated watershed systems approach to quantitatively evaluate the impact of prairie pothole wetlands on water loads and quality. This technology provides conservationists in prairie pothole regions the capability for improved management of watershed systems. A new version (AnnAGNPS v5.46) that includes integrated tillage, gully, wetland, prairie potholes and riparian buffer components has been released. Several research projects examined edge-of-field conservation practices centered around vegetation, including drainage ditches and constructed and natural wetland management. Significant findings of these projects include the superior denitrification rate of the common plant, cutgrass, as well as the plant’s ability to serve as a significant sink for nitrogen assimilation, even in winter months. Other studies found that while common aquatic plants may have similar efficiency at removing pesticides, mixtures of plants, as well as monospecific stands of plants have different removal efficiencies of nutrients. Since 2010, ecological assessments in the Mississippi-Delta Bayou watersheds continually identified factors influencing ecosystem health in bayous influenced by agricultural activities. Seasonal patterns of excess sediment and nutrients are influenced by changes in cropping patterns and conservation practices in the shallow, low-gradient, low-flow bayous. Organic matter processing studies demonstrated rapid breakdown of both agriculturally derived and natural riparian organic matter combined with excessive nutrients influenced dissolved oxygen dynamics in bayou waters. A study on depth manipulation through a weir was conducted during a drawdown experiment to help understand how water depth, flow, and quality varies seasonally, as farmers utilize bayous as a source of surface water irrigation. A tailwater recovery system including a reservoir was assessed for its ability to improve water quality leaving production acreage, as well as reducing the dependence on groundwater sources for crop irrigation. Continuous monitoring and flow-triggered sampling runoff events have two years of storm sampling. Additionally, three years of bi-monthly water quality sampling helped establish baseline water quality for the tailwater recovery system. Results indicate mitigation of nutrients within the tailwater recovery ditch, resulting in lower nutrient concentrations being transported to rivers, lakes, and streams within the watershed drainage. Leadership in the Agricultural Research Service’s Long-Term Agroecosystem Research (LTAR) project was established. Unit scientists engaged and coordinated alongside the national LTAR network in the development of the common experiment, measurement approaches, infrastructure needs, and data management. Significant progress was made to secure both business-as-usual and aspirational long-term agricultural research sites in rice-soybean production systems in the Mississippi Delta.


4. Accomplishments
1. Enhanced technology improves placement of conservation practices. Placement of constructed wetlands in agricultural watersheds for pollutant mitigation is often subjective, lacking quantitative understanding of their impact on reducing pollution. ARS researchers in Oxford, Mississippi, found that newly developed Geographic Information System (GIS) wetland management tools linked with current watershed management models improved the effectiveness of constructed wetlands through their strategic placement within the watershed. Utilization of this technology will allow conservation managers and action agencies to provide more accurate prospective management planning as part of their decision-making process.

2. Common herbicide runoff affected by land use and conservation practices. ARS researchers in Oxford, Mississippi, performed lake water quality assessments as part of the Conservation Effects Assessment Program (CEAP) in the Beasley Lake watershed in Mississippi for sixteen years. Atrazine concentrations in lake water were influenced by the presence of conservation practices, as well as rainfall amounts and cropping patterns within the watershed. Concentrations of metolachlor in lake water were influenced by on-field application as well as conservation practices. With this knowledge, conservation planners can improve and sustain lake and floodplain water quality with proper placement of management practices targeted for herbicide mitigation.

3. Potential soil amendment increases grain yield. Polyacrylamides (PAMs) are being evaluated as soil amendments to improve soil filtration, decrease erosion, and reduce agrochemical transport in runoff. These amendments have not been fully assessed on soils typical of the Lower Mississippi Delta Alluvial Plain. ARS researchers in Oxford, Mississippi, collaborated with the Mississippi State Delta Research and Extension Center in Stoneville, Mississippi on a field study evaluating the soil amendment in corn and found polyacrylamide application increased infiltration and corn grain yield by 6%, but effects on sediment, nitrogen, and phosphorus loss were inconsistent. Research shows promise for polyacrylamides for improving crop production; however, further studies are needed to confirm their ability to mitigate environmental impacts of agrochemical transport and sediment loss.


Review Publications
Lizotte Jr, R.E., Yasarer, L.M., Locke, M.A., Bingner, R.L., Knight, S.S. 2017. Lake nutrient responses to integrated conservation practices in an agricultural watershed. Journal of Environmental Quality. 46:330-338. doi:10.2134/jeq2016.08.0324.

Lizotte Jr, R.E., Moore, M.T. 2017. Do varying aquatic plant species affect phytoplankton and crustacean responses to a nitrogen-permethrin mixture? Bulletin of Environmental Contamination and Toxicology. 98(1):58-64.

Jenkins, M., Locke, M.A., Reddy, K.N., McChesney, D.S., Steinriede Jr, R.W. 2017. Impact of glyphosate resistant corn, glyphosate applications, and tillage on soil nutrient ratios, exoenzyme activities, and nutrient acquisition ratios. Pest Management Science. 73:78-86.

Lizotte Jr, R.E., Locke, M.A., Bingner, R.L., Steinriede Jr, R.W., Smith, S. 2017. Effectiveness of integrated best management practices on mitigation of atrazine and metolachlor in an agricultural lake watershed. Bulletin of Environmental Contamination and Toxicology. 98(4):447-453.

Momm, H.G., Bingner, R.L., Yuan, Y., Kostel, J., Monchak, J., Locke, M.A., Giley, A. 2016. Characterization and placement of wetlands for integrated watershed conservation practice planning. Transactions of the ASABE. 59(5):1345-1357.

Lizotte Jr, R.E., Moore, M.T. 2017. Effectiveness of emergent and submergent aquatic plants in mitigating a nitrogen-permethrin mixture. Chemistry and Ecology. 33(5):420-530.

Moore, M.T., Locke, M.A., Kroger, R. 2016. Mitigation of atrazine, S-metolachlor, and diazinon using common aquatic emergent vegetation. Journal of Environmental Science. 56:114-121.

Mcneal, J., Krutz, L., Locke, M.A., Kenty, M., Atwill Ii, R., Pickelmann, D., Bryant, C., Wood, C., Golden, B., Cox, M. 2017. Application of polyacrylamide (PAM) through lay-flat polyethylene 1 tubing: effects on infiltration, erosion, N and P transport, and corn yield. Journal of Environmental Quality. 46:855-861 doi:10.2134/jeq2016.08.0299.

Runkle, B., Rigby Jr, J.R., Reba, M.L., Anapalli, S.S., Bhattacharjee, J., Krauss, K.W., Liang, L., Locke, M.A., Novick, K., Sui, R., Suvocarev, K., White Jr, P.M. 2017. Delta-Flux: An eddy covariance network for a climate-smart lower Mississippi basin. Agricultural and Environmental Letters. 2:170003. doi:10.2134/ael2017.01.0003.

Yasarer, L.M., Sinnathamby, S., Sturm, B.S. 2016. Impacts of biofuel-based land-use change on water quality and sustainability in a Kansas watershed. Agricultural Water Management. 175:4-14. doi:10.1016/j.agwat.2016.05.002.

Buchanan, B.P., Auerbach, D.A., McManamay, R.A., Taylor, J.M., Flecker, A.S., Archibald, J.A., Fuka, D.R., Walter, M. 2016. Environmental flows in the context of unconventional natural gas development in the Marcellus Shale. Ecological Applications. doi:10.1002/eap.1425.

Tyler, H.L., Locke, M.A., Moore, M.T., Steinriede Jr, R.W. 2016. Impact of conservation land management practices on soil microbial function in an agricultural watershed. Journal of Soil and Water Conservation. 71:396-403.

Faust, D.R., Moore, M.T., Emison, G.A., Rush, S.A. 2016. Potential implications of climate change on the proposed 'Waters of the United States' rule. Bulletin of Environmental Contamination and Toxicology. 96(5):565-572.