Location: Soil Drainage Research2012 Annual Report
1a. Objectives (from AD-416):
The overall objective of this project is to quantify the environmental effects and services resulting from prevailing and innovative land use and management practices within poorly drained Midwest landscapes. This research was initially undertaken to meet a request from Congress to quantify the benefits of federally funded, voluntary conservation programs. Progress during the previous 5-year cycle revealed the need to expand and continue the work. Objective 1: Elucidate and quantify the surface and subsurface hydrology and water quality impacts of innovative conservation management practices, water management practices, and land use at multiple spatial scales in mixed-use watersheds that include combinations of agriculture, urban, turf, and forested/wetland land uses. Sub-objective 1a: Quantify the influence of conservation practices on surface discharge and water chemistry in the agricultural landscape. Sub-objective 1b: Conduct field and watershed-scale studies of hydrology, nutrient, and agrichemical contributions originating from subsurface drainage. Sub-objective 1c: Assess and characterize the environmental aspects of urban and golf course turf. Objective 2: Conduct field studies to document ecological responses to improved water quality as a result of conservation practices. Field studies will encompass both evaluation of responses to specific conservation practices and the evaluation of the relationships of the aquatic biota with water chemistry and physical habitat. Sub-objective 2a: Determine the relationship between aquatic biota and nutrient/pesticide mixtures. Sub-objective 2b: Document the relationships of fish biodiversity with short term weather conditions (i.e., air temperature and precipitation) and watershed characteristics. Sub-objective 2c: Quantify the impacts of conservation practices on the biota within headwater streams.
1b. Approach (from AD-416):
A before-after-control-impact (BACI) paired design will be used to elucidate and quantify the surface and subsurface hydrology and water quality impacts of conservation practices, water management practices and land use. The research will be conducted at two different scales, edge-of-field (EOF) and watershed. EOF studies will be conducted in two different watersheds within Ohio, Upper Wabash and Upper Scioto. Four pair (eight fields) in each watershed have been identified for the study. The paired watershed study will be conducted in the Upper Big Walnut Creek watershed, a sub-watershed of the Upper Scioto, and build on an existing framework and dataset. All sites will be instrumented with automated Isco sampling equipment to collect discharge and water quality samples. Samples will be collected on both time and flow proportional approaches. The samples will be analyzed for nutrients using colorimetric flow injection analysis and for pesticides using a combination of gas chromatography and Ultra Performance Liquid Chromatography (UPLC). A mass balance approach will be used to quantify the impact of subsurface drainage on watershed hydrology and water quality. A before-after design on managed turf systems in MN and OH will be used to quantify land use impacts. Hydrology and water quality data will be collected in a manner consistent with those previously outlined. Field studies will encompass both evaluation of aquatic biota responses to specific conservation practices and the evaluation of the relationships with water chemistry and physical habitat. Fish biomarkers and community assessments will be used to evaluate the relationships of fishes to nutrient-pesticide mixtures within channelized agricultural headwater streams in Ohio and Indiana. Biochemical, physiological, and morphological biomarkers will be used as indicators of sublethal responses of selected fish species from exposure to agricultural contaminants. Additionally, fish, in situ physicochemical variables, and physical habitat will be collected in 18 UBWC watershed Conservation Effects Assessment Project (CEAP) study sites in the spring and fall of each year to determine the impacts of buffer treatments that represent a range of environmental conditions from the worst case (i.e., the control treatment) to the best case (i.e., forested buffers) management strategies for headwater streams in this region. Indirect gradient analyses will be conducted by combining the use of ordination and multiple regression analyses to determine the relationships between fish community structure with nutrient-pesticide mixtures and to evaluate the relative influence of physical habitat and water chemistry on fish community structure within agricultural drainage ditches in Ohio and Indiana. Using the paired watershed approach, aquatic ecology metrics will be measured to assess the impacts of watershed scale implementation of conservation practices.
3. Progress Report:
The Soil Drainage Research Unit (SDRU) continues to make advances in quantifying the watershed scale environmental and ecologic impacts of conservation practices as well as assessing and characterizing the environmental aspects of managed turf. Additionally the SDRU is making significant progress in determining the role of subsurface (tile) drainage in watershed hydrology and chemical transport. The watershed and edge-of-field (EOF) research being conducted by the SDRU is critical to the Conservation Effects Assessment Project (CEAP), Mississippi River Basin Initiative (MRBI), and Agricultural Drainage Management Systems (ADMS) Task Force. CEAP, MRBI, and ADMS efforts are designed to identify, develop, and assess the impact of conservation practices and technologies on water quantity and quality. EOF research has been initiated in two high priority watersheds (Upper Scioto and Upper Wabash) and we are establishing contacts in the Western Lake Erie Basin (WLEB) watershed for additional EOF research sites. This network of sites will serve as the foundation for the EOF research objectives outlined in the project plan. We continue to be sought out for expertise on phosphorus transport from agricultural systems, specifically related to the eutrophication issues in Lake Erie and Grand Lake St. Mary. We continue to make progress on quantifying the role and contribution of tile drainage to watershed hydrology and nutrient transport. We have presented to multiple audiences preliminary results from six years of watershed scale surface and subsurface discharge and associated nutrients. We continue to make progress on identifying the key transport pathways for nutrient transport from managed turf. Ecological studies continue in an effort to relate water quality and habitat characteristics to multiple aquatic ecology metrics. A fish tissue biomarker study was initiated and the first samples collected.
1. Paired edge-of-field (EOF) data collection network established in two high priority watersheds. Quantifying effects of conservation practices continues to be an emphasis by multiple state and federal agencies to understand the processes governing pollutant transport from agriculture. The eight paired EOF sites (16 fields) sites are representative of both surface and subsurface (tile) water and pollutant transport pathways. Data collected from the sites will provide critical insight to the mechanisms and pathways leading to nutrient transport and provide a platform for measuring the effects of different management practices intended to reduce or eliminate those pollutant discharges.
2. Thirty percent practices adoption threshold required for watershed response. We documented the need for greater adoption of atrazine reduction practices within watersheds of channelized agricultural headwater streams. The watershed scale impacts of conservation practices that lead to the reduction of pesticide usage has not been quantified. Understanding the effects of reducing pesticide usage at the watershed scale will assist with developing watershed management guidelines for headwater streams within the Midwestern United States. Watershed management practices intended to reduce atrazine usage did not influence atrazine concentrations, pesticide mixtures, or fish communities within channelized agricultural headwater streams in central Ohio during the spring and summer. Our results suggest the implementation of watershed management practices within 30% or less of the watersheds of channelized agricultural headwater streams may not be sufficient to reduce pesticide levels in these small streams. This information can be used by state, federal, and private agencies responsible for managing agricultural watersheds and restoring streams.
Smiley, P.C., King, K.W., Gillespie, R.B., Fausey, N.R. 2012. Watershed scale influence of pesticide reduction practices on pesticides and fishes within channelized agricultural headwater streams. Journal of Sustainable Watershed Science & Management. 1:61-75.