Research Project: Agricultural Water Management in Poorly Drained Midwestern Agroecosystems

Location: Soil Drainage Research

2021 Annual Report

Objectives
The overall objective of this project is to address the hydrologic, biogeochemical, and ecological processes and impacts of crop production agriculture and conservation practices in the poorly drained Midwestern US while sustaining increased productivity. Specific objectives include: Objective 1: Develop technology to identify the location and density of tile drainage systems. Objective 2: Characterize the coupling of hydrologic and chemical/biogeochemical processes in tile drained landscapes and its impact on water quality in the Mississippi River and Western Lake Erie Basins. Objective 3: Develop water management and treatment technologies for subsurface drainage that provide strategies to help farmers, ranchers, and other land managers adapt to climate variability and change at a variety of spatial and temporal scales. Objective 4: As part of the LTAR network, and in concert with similar long-term, land-based research infrastructure in the Midwest region, use the Eastern Corn Belt 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 Midwest 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.

Approach
Water quantity and quality continue to be major natural resource concerns in the United States. As the pressure to produce more food, feed, fiber and fuel from our agricultural lands increases, the need for protecting soil and water resources and ecosystem services within poorly drained watersheds accelerates exponentially. In the Midwestern United States, excess water is rapidly removed through subsurface drainage and agricultural drainage ditches to facilitate agricultural crop production. Excessive levels of nutrients exported with drainage water from agricultural landscapes contribute to downstream algal blooms and hypoxic zones. Sediment, nutrient and pesticide mixtures found in waterways adjacent to agricultural production may also disrupt stream ecosystem function and have deleterious effects on aquatic biota. Information on the primary transport pathways of nutrients and the temporal delivery through these pathways at the field and watershed scales is sparse. Conservation practices (i.e., 4Rs, cover crops, drainage water management, grassed filter strips) are being implemented at a rapid rate across many watersheds to mitigate the effects of agricultural production, but their effectiveness has not been fully evaluated. The research consists of location specific and cross location research projects that investigate the impacts of agricultural land use, production management, and conservation practices on edge-of-field water quality (surface and subsurface flow pathways) and aquatic biota. Additionally, technologies and approaches to address these issues under a changing climate will be evaluated. The research will primarily be conducted in three high priority watersheds in Ohio: 1) Upper Big Walnut Creek; 2) Grand Lake St. Mary; and 3) Western Lake Erie Basin. Understanding the watershed scale transport pathways, timing, and ecological impact within these agricultural landscapes will facilitate the identification, design, and implementation of conservation practices to mitigate or reduce the environmental impact of agricultural land use

Progress Report
Objective 1 – An unmanned Aerial Vehicle (UAV) mounted with visible, multispectral (green, red, red edge, near infrared), and thermal infrared cameras continue to be tested for mapping subsurface drainage systems at sites in Indiana, Michigan, and Ohio. This large amount of accumulated imagery is providing insight on field conditions under which UAV imagery does and does not work regarding location of buried agricultural drainage pipes. A manuscript describing the time of day impact on UAV thermal infrared mapping of subsurface drainage was submitted and accepted by the scientific journal, Agricultural Water Management. Working with collaborators from Aarhus University, a manuscript focused on the complimentary employment of ground penetrating radar (GPR) and UAV surveys for drainage mapping was prepared, submitted, and published in the scientific journal, Sensors. Data (UAV surveys, handheld thermal imaging cameras, and stream temperature measurements) have been collected at five Ohio sites in a new study focused on evaluating the potential of using UAV thermal infrared imagery to locate drainage system outlets in streams and ditches. Because crop establishment and health is often best over drain lines, a second new study was initiated to determine if UAV imagery (visible, multispectral, and/or thermal infrared) collected during the middle to late growing season can provide insight on subsurface drainage system patterns. Objective 2 - The effect of recent phosphorus fertilizer applications on edge-of-field water quality is being analyzed using an advanced statistical approach (weighted regression on time, discharge, and season). The analysis will quantify the relative contributions of recently applied P fertilizer and legacy soil phosphorus to phosphorus export at the edge-of-field and will translate findings into predictive models for characterization of phosphorus export at the field scale. All the data is collected; statistical model building and analyses are ongoing. Experiments examining nitrogen and phosphorus uptake in tile drain flow paths on two-stage ditch floodplains during two seasons (spring and summer) have been completed. Data processing of the data has been completed and statistical analyses are on-going with draft publication targeted for later this year. Progress is being made on quantifying nitrogen and phosphorus uptake, as well as ecosystem metabolism (i.e., gross primary production, (GPP) and ecosystem respiration, (ER)), in streams adjacent to agricultural fields with a gradient of historical management practices. One set of nutrient uptake experiments at each stream site have been completed and the second set of nutrient uptake experiments at each stream site is scheduled to be completed in the next month. Additionally, logging oxygen sensors were deployed at each stream site in winter 2021 and will be retrieved at the end of summer 2021. Ecosystem metabolism will be quantified and metrics of both GPP and ER will be correlated with nutrient uptake metrics in each stream site. Objective 3 – Drainage water management as a practice to address water quality if being assessed. An initial manuscript summarizing findings from two paired edge-of-field sites has been submitted for publication review. Additionally, a new assessment of drainage water management as affected by subsurface tile spacing has been initiated. Through collaboration with University partners, simulation technologies are being improved to more accurately capture the effects of drainage water management and quantify its ability to address water quality in the Lake Erie watershed. In collaboration with ARS in West Lafayette, Indiana, a field scale phosphorus removal structure was installed on a private farm to assess its ability to reduce soluble phosphorus loss originating in tile drainage. In addition, plans are underway to establish another phosphorus removal structure using a different design and filter media. Objective 4 - Progress continues on the conservation effects assessment project (CEAP) and the Long-Term Agroecosystem Research (LTAR) common experiment. Experiments are underway on 16 plus established paired edge-of-field (EOF) sites that exist on private farms in central and northwest Ohio. Sites range in age from three to nine years. New precipitation and soil moisture and temperature sensors were recently installed. Current practices being evaluated for addressing excess phosphorus issues include: 4Rs (right source, right rate, right time, right placement) of nutrient stewardship, cover crops, drainage water management, and structural practices. All show promise in reducing agriculture’s footprint in the Eastern Corn Belt. Placement and timing practices within the 4R framework have shown significant reductions in phosphorus loss. An assessment of cover crops across the edge-of-field (EOF) network have shown cover crops to be great nitrogen scavengers; however, results show no benefit with respect to addressing phosphorus (specifically dissolved reactive phosphorus) loss. Plans are underway to isolate the effects of cover crops on one to two paired sites within the EOF network. A recent analysis of drainage water management was shown to positively reduce nitrogen loss, but the effects on phosphorus were minimal. Additionally, the losses of phosphorus in surface runoff following drainage water management implementation increased and could potentially negate any benefits measured in the surface tile drainage. Current emphasis is on quantifying the benefits of practices being promoted within Ohio’s H2Ohio initiative (a statewide initiative to promote adoption of conservation management practices to reduce agricultural nutrient loss). Specifically, plans are underway to isolate the impacts of subsurface nutrient placement, conservation crop rotation, cover crops, drainage water management and variable rate application as well as quantify the impact of combining two or more practices. Across a subset of the paired EOF sites, soil health indicators are being assessed. Soil health impacts of management systems will be assessed, and the relationships between in-field soil health properties and EOF nitrogen and phosphorus losses will be analyzed. Collaborative partnerships have been established with university partners, agencies, and nongovernment organizations (NGOs) to share and interpret the findings. Current research findings have been shared with local, state, national, and international stakeholders to identify crop production practices that can address the excess phosphorus transport that is leading to harmful and nuisance algal blooms in Lake Erie and other inland waters. The research efforts have led to opportunities for collaboration on several grants aimed at expanding the research network and scope. Considerable progress has been made on sampling snakes and measuring riparian habitat variables in the Upper Big Walnut Creek watershed to evaluate the effects of planting grass filter strips on terrestrial animals within riparian corridors of agricultural headwater streams. Initial results suggest that widening of riparian corridors by planting grass filter strips increases snake species richness and likely benefits snake species that prefer open canopied herbaceous habitats. A second snake has been initiated to determine if cover board materials (wood or metal) differ in snake capture effectiveness and if capture effectiveness is influenced by canopy cover. Additionally, ARS scientists in Columbus, Ohio, West Lafayette, Indiana, and Oxford, Mississippi, and a Purdue University-Fort Wayne research scientist continue CEAP Ecology Research collaboration. Recently published manuscripts document: 1) the effects of sediment chemistry and sediment physical characteristics on macroinvertebrates within agricultural headwater streams and 2) the synthesis of available information globally on the effects of conservation practices on aquatic ecosystem structure and function. Notably, the published literature review identified that the majority of available information from 2000 to 2020 on the ecological effects of conservation practices is derived from CEAP ecology research conducted in the three CEAP watersheds (Upper Big Walnut Creek, Ohio; Saint Joseph River, Indiana, Beasley Lake, Mississippi). Additionally, these scientists currently have two manuscripts in preparation: one that will identify the best environmental predictors of crayfish community structure in agricultural headwater stream and one that will quantify the influence of nutrient and pesticide mixtures on fish morphology and physiology within agricultural headwater streams.

Accomplishments
1. Governing controls for nutrient loss in the tile drained landscape of the Western Lake Erie Basin watershed. Nutrient source and transport, specifically phosphorus is at the core of understanding and addressing the re-eutrophication of Lake Erie. Nutrient losses from agricultural fields impact water quality at local, regional, and national scales, particularly by fueling algal blooms in downstream water bodies. Understanding the governing controls and mechanisms is paramount for developing and/or identifying practices to address eutrophication. ARS researchers in Columbus, Ohio, and West Lafayette, Indiana, in collaboration with University partners estimated the effects of transport and source controls while accounting for interactions among other factors (e.g., weather, field, soil, and management characteristics). Tile discharge and nutrient sources in the soil profile as well as preferential flow increase tile nitrogen and phosphorus loss, demonstrating that managing transport (e.g., by controlling flow or disconnecting hydrologic pathways) and source (e.g., by reducing inputs or addressing legacy P) are important to mitigate nutrient loss via subsurface tile drainage. The results from this study have been delivered to the federal, state, and local action agencies, policy makers, NGOs, and the general agricultural community and should be beneficial in development and promotion of practices and programs aimed at addressing agricultural nutrient loss.

2. Effectiveness of conservation practices for addressing nutrient transport from tile drained crop production fields. The recent extent and toxicity of algal blooms within the Western Lake Erie Basin (WLEB) led to the binational agreement between the U.S. and Canada calling for a 40% reduction in phosphorus loadings. Millions of federal (USDA, NRCS) and state (H2Ohio Initiative) dollars have been set aside to promote adoption and widespread implementation of conservation practices to meet the 40% reduction goals. However, the efficacy and efficiency of many of these practices, especially application in tile drained landscapes, is not documented. ARS scientists in Columbus, Ohio, in collaboration with ARS scientists in West Lafayette, Indiana, along with University partners assessed the ability of phosphorus removal structures, cover crops, and drainage water management practices to reduce nutrient loss. P removal structures were shown to be an effective approach for addressing P transport in tile drainage. Cover crops and drainage water management were effective for N mitigation, but the effects on phosphorus were mixed and may be site-specific depending on the dominant pathway of loss (i.e., tile vs. surface) and additional management or field characteristics that influence P losses. Achieving the 40% reduction goal will require multiple practices to be implemented. The findings have been shared and delivered to NRCS, Ohio Department of Agriculture, and Lake Erie stakeholders (e.g., The Nature Conservancy, Farm Bureau, and producers) and will be used to inform conservation policy. Furthermore, these findings are critical to the USDA Conservation Effects Assessment Project (CEAP) and the Long-Term Agroecosystem Research (LTAR) network sustainable intensification objectives.

3. Concentration of soil phosphorus at the soil surface contributes to phosphorus losses from crop fields into waterways. Soil phosphorus is a major source of phosphorus losses from cropland that cause harmful and nuisance algal blooms. Understanding the factors that control the contribution of soil phosphorus to phosphorus losses is important for reducing the environmental footprint of agriculture. ARS researchers in Columbus, Ohio, used edge-of-field network data to assess the importance of soil sampling depth for understanding the risk of phosphorus loss. Results showed concentration of phosphorus in the soil surface resulted in greater phosphorus loss, and measurement of soil phosphorus in shallower soil samples improved predictions of phosphorus losses compared to traditional depth samples. In addition, the best predictions of phosphorus losses used the ratio of soil phosphorus at the shallower depth compared to the deeper depth. Therefore, measurement of phosphorus in shallow soil sample can be a useful approach for improving understanding of phosphorus losses from crop fields. These findings have been published as a peer-reviewed article and are of interest to researchers, extension and NRCS, and regional stakeholders including producers and environmental organizations.

4. Comparison of proximal and remote sensing technologies for mapping agricultural subsurface drainage systems. In order modify or repair subsurface drainage systems, or to evaluate environmental impacts of drainage practices, an effective, efficient, and non-destructive approach is needed for locating pre-existing drainage pipes. Prior research indicates that both ground penetrating radar (GPR – a proximal soil sensing technology) and Unmanned Aerial Vehicles (UAVs) with visible, multispectral, and/or thermal infrared cameras (a remote sensing technology) exhibit promise for mapping buried drainage pipes. ARS researchers in Columbus, Ohio, tested and compared both technologies at four farm field sites, two in Ohio and two in Michigan. At two of the sites, UAV imagery worked better than GPR for mapping drain lines. At a third site, GPR had greater success finding drainage pipes in some parts of the field, while UAV imagery provided superior drainage mapping results in other parts of the field. Drainage pipes were detected far more clearly with GPR than UAV imagery at the fourth site. The efficiency of mapping subsurface drainage systems in farm fields was found to be much greater with UAVs than GPR. Consequently, GPR and UAV technologies can be complementary for drainage mapping, especially in cases where one works better than the other, and furthermore, where GPR can be used to confirm drainage pipe detection results obtained in large farm fields with UAV imagery. This research will be of value to farmers, drainage contractors, and watershed environmental coordinators needing information on subsurface drainage at field to watershed scales.

5. Time of day impact on mapping agricultural subsurface drainage systems with UAV thermal infrared imagery. Due to economic and environmental considerations, there exists a need for effective, efficient, and nondestructive methods for locating buried agricultural drainage pipes. Previous research indicates that thermal infrared (TIR) imagery obtained with an unmanned aerial vehicle (UAV) has potential for mapping agricultural subsurface drainage systems, thereby warranting further investigation to determine the best time of day to conduct these UAV TIR surveys. Accordingly, a set of sunrise to sunset UAV TIR surveys were carried out by ARS researchers in Columbus, Ohio, at four different farm field sites in Ohio. Overall research results indicate that strictly on a consistency of success basis alone, late morning through late afternoon are the best times for locating drainage pipes with UAV TIR surveys; however, under certain circumstances, especially when relative humidity is low (<60%), UAV TIR surveys at sunrise/sunset can likewise provide exceptional drainage pattern recognition. This research provides valuable guidance for those (farmers, drainage contractors, and watershed environmental coordinators) considering UAV TIR drainage mapping surveys.

6. Joint influence of physical and chemical sediment characteristics on macroinvertebrates within agricultural headwater streams. Agricultural land use alters the physical and chemical characteristics of stream sediments, which results in reductions of macroinvertebrate biodiversity and abundance in agricultural streams. The combined influence of physical and chemical sediment conditions on stream macroinvertebrates has not been assessed because previous research focused on the influence of physical sediment variables or chemical sediment variables. An ARS scientist at Columbus, Ohio, collaborated with scientists from Fort Wayne, Indiana, and West Lafayette, Indiana, and documented invertebrate-habitat relationships in headwater streams in the Midwestern United States. They documented that most sites were dominated by sand or silt and overall chemical conditions suggested suitable conditions for macroinvertebrates. It was observed that increasing amounts of silt corresponded with increases in selected plant nutrients within the stream sediments. Macroinvertebrate biotic integrity declined with increasing simazine concentrations, decreasing calcium concentrations, increasing substrate heterogeneity, and decreasing amounts of sand. Results represent the first documentation of the joint influence of sediment physical and chemical variables on macroinvertebrates in agricultural headwater streams in the Midwestern United States. The conservation implications of these results are that watershed management plans need to address physical and chemical degradation within the stream sediments to improve macroinvertebrate biotic integrity in agricultural headwater streams in the Midwestern United States. The results will be of interest to state agencies, federal agencies, private consulting companies, and non-profits involved with the management of agricultural watersheds in the United States because they provide information that can assist with developing effective watershed conservation plans. Results of these research projects were transferred via a peer review journal article.

7. Global synthesis of the available information on aquatic ecological responses to conservation practices. Conservation practices have been internationally promoted and used for decades to enhance soil health, reduce soil loss, and to mitigate agricultural runoff impacts on aquatic ecosystems. Increasingly there is a need to demonstrate that conservation practices can provide ecological improvements in aquatic ecosystems within agricultural watersheds. Yet, the ecological effects of conservation practices on aquatic ecosystems at the watershed scale is limited. ARS scientists from Columbus, Ohio, and Oxford, Mississippi, collaborated with scientists from Fort Wayne, Indiana, and University, Mississippi, to conduct a literature review to synthesize the available information in the scientific literature since 2000 on the ecological responses of aquatic ecosystems to conservation practices. They identified 88 relevant studies, the majority of which were conducted in the United States as part of the USDA Conservation Effects Assessment Project. Additionally, most studies documented macroinvertebrate, fish, and algal responses to riparian, wetland, or combinations of conservation practices and/or responses to eutrophication and pesticide contamination. Notable research gaps identified included: 1) biogeochemical responses to conservation practices; 2) documentation of the combinations of conservation practices provide the greatest ecological benefits; and 3) quantifying the minimum implementation of conservation practices needed to mitigate the effects of agriculture on the biota. These results will be of interest to state agencies, federal agencies, private consulting companies, and non-profits involved with the management of agricultural watersheds in the United States because they provide information that can assist with developing watershed conservation plans capable of improving ecosystem structure and function within lentic and lotic ecosystems within agricultural watersheds. Results of this research were transferred via a peer review journal article.

8. Implications of glacial invertebrate-habitat relationships for conservation of agricultural headwater streams. In developed and undeveloped landscapes throughout the world information on invertebrate-habitat relationships is lacking for extreme ecosystem types (i.e., headwater streams, ephemeral wetlands) that experience cycles of drying and freezing. This ecological information can guide the conservation of extreme ecosystems. An ARS scientist at Columbus, Ohio, collaborated with scientists from Kenyon, Ohio, Columbus, Ohio and Chengdu, China and documented invertebrate-habitat relationships in glacial headwater streams and ephemeral wetlands in Tibet. They conducted two research projects lasting between two and four years that involved the measurement of physical variables, chemical variables, and sampling macroinvertebrates from headwater streams and ephemeral wetlands in Tibet. These research efforts resulted in the first documentation of the: 1) invertebrate-habitat relationships in glacier streams in Tibet, and 2) invertebrate-habitat relationships in supraglacial pools on debris-covered glaciers. The scientific and conservation implications of these results are: 1) to provide critical information for the development of a new regional theoretical model of invertebrate-habitat relationships in glacier streams in Asia, and 2) to provide information that can be applied to predict changes in water quality that will impact invertebrate biodiversity and abundance within glacier streams and ephemeral wetlands in Asia. These results combined with information from other studies will also be of interest to U.S. customers/stakeholders involved with the management of agricultural headwater streams because they confirm the importance of a combination of chemical, physical, and landscape variables as determinants of invertebrate biodiversity within disturbance-prone aquatic ecosystems. Results of these research projects were transferred via two peer review journal articles.

Review Publications
Shuman, T.C., Smiley, P.C., Gillespie, R.B., Gonzalez, J.M. 2020. Influence of physical and chemical charicteristics of sediment on macroinvertebrate communities in agricultural headwater streams. Water. 12(11). Article 2976. https://doi.org/10.3390/w12112976.
Osterholz, W.R., Dias, J.L.C.S., Grabber, J.H., Renz, M.J. 2020. Pre- and post-applied herbicides options for alfalfa interseeded with corn silage. Weed Technology. 35(2):263-270. https://doi.org/10.1017/wet.2020.104.
Osterholz, W.R., King, K.W., Williams, M.R., Hanrahan, B.R., Duncan, E.W. 2020. Stratified soil sampling improves predictions of P concentration in surface runoff and tile discharge. Soil Systems. 4(4). Article 67. https://doi.org/10.3390/soilsystems4040067.
Koganti, T., Ghane, E., Martinez, L.R., Iversen, B.V., Allred, B.J. 2021. Mapping of agricultural subsurface drainage systems using unmanned aerial vehicle imagery and ground penetrating radar. Sensors. 21(8). Article 2800. https://doi.org/10.3390/s21082800.
Hanrahan, B.R., King, K.W., Williams, M.R. 2020. Controls on subsurface nitrate and dissolved reactive phosphorus losses from agricultural fields during precipitation-driven events. Science of the Total Environment. 754. Article 142047. https://doi.org/10.1016/j.scitotenv.2020.142047.
Franks, M., Duncan, E., King, K.W., Vasquez-Ortega, A. 2020. Role of Fe- and Mn-(oxy)hydroxides on carbon and nutrient dynamics in agricultural soils: A chemical sequential extraction approach. Chemical Geology. 561. Article 120035. https://doi.org/10.1016/j.chemgeo.2020.120035.
Hanrahan, B.R., King, K.W., Duncan, E.W., Shedekar, V.S. 2021. Cover crops differentially influenced nitrogen and phosphorus loss in tile drainage and surface runoff from agricultural fields in Ohio, USA. Journal of Environmental Management. 293. Article 112910. https://doi.org/10.1016/j.jenvman.2021.112910.
Macrae, M., Jarvie, H., Brouwer, R., Gunn, G., Reid, K., Joosse, P., King, K.W., Kleinman, P.J., Smith, D.R., Williams, M.R., Zwonitzer, M. 2021. One size does not fit all: towards regional conservation practice guidance to reduce phosphorus loss risk in the Lake Erie watershed. Journal of Environmental Quality. 50(3):529-546. https://doi.org/10.1002/jeq2.20218.
Apostel, A., Kalcic, M., Dagnew, A., Evenson, G., Kast, J., King, K.W., Martin, J., Logsdon Muenich, R., Scavia, D. 2020. Simulating internal watershed processes using multiple SWAT models. Science of the Total Environment. 759. Article 143920. https://doi.org/10.1016/j.scitotenv.2020.143920.
Shedekar, V.S., King, K.W., Fausey, N.R., Islam, R.R., Soboyejo, A.B., Kalcic, M., Brown, L.C. 2020. Exploring the effectiveness of drainage water management on water budgets and nitrate loss using three evaluation approaches. Agricultural Water Management. 243. Article 106501. https://doi.org/10.1016/j.agwat.2020.106501.
Lizotte Jr, R.E., Smiley, P.C., Gillespie, R.B., Knight, S.S. 2021. Agricultural conservation practices and aquatic ecological responses: a synthesis of perspectives across ecosystem types and watersheds. Agriculture Ecosystems and the Environment. 13(12). Article 1687. https://doi.org/10.3390/w13121687.
Fair, H., Smiley, P.C., Lanno, R. 2021. Determinants of invertebrate community structure in glacial-melt streams of southeast Tibet. Freshwater Biology. 66(7):1282-1295. https://doi.org/10.1111/fwb.13716.
Fair, H., Smiley, P.C., Liu, Q. 2020. Physical, chemical, and biological characteristics of supraglacial pools on a debris-covered glacier in Mt. Gongga, Tibetan Plateau. Arctic, Antarctic, and Alpine Research (AAAR). 52(1):635-649. https://doi.org/10.1080/15230430.2020.1839165.
Askar, M.H., Youssef, M.A., Chescheir, G.M., Negm, L.M., King, K.W., Hesterberg, D.L., Amoozegar, A., Skaggs, R.W. 2020. DRAINMOD simulation of macropore flow: model modification and field testing. Agricultural Water Management. 242. Article 106401. https://doi.org/10.1016/j.agwat.2020.106401.
Allred, B.J., Martinez, L.R., Fessehazion, M., Rouse, G., Koganti, T., Freeland, R., Eash, N., Wishart, D., Featheringill, R. 2021. Time of day impact on mapping agricultural subsurface drainage systems with UAV thermal infrared imagery. Agricultural Water Management. 256: Article 107071. https://doi.org/10.1016/j.agwat.2021.107071.