Progress 06/01/19 to 12/31/24
Outputs
Target Audience:The main audience for this work is scientists and researchers from universities (includes students), state or federal agencies, or non-profit organizations. We are also reaching technical service providers including Certified Crop Advisers; these individuals help farmers make nutrient management decisions on their operations. Changes/Problems:We opted to collect additional soil samples to obtain supporting grain size and soil phosphorus data that was needed to explain results of the 2024 tracer study. All other changes/problems were outlined in previous reports. What opportunities for training and professional development has the project provided?Rutgers University Newark: Joshua Thompson continued work with project personnel todeveloppeer-reviewed manuscripts that will comprise his PhD thesisexploring the use of field-scale electrical geophysical methods to investigate flow and transport processes in dual domain systems. Mr. Thompson also leared to prepare scientific presentations for dissemination to non-science audiences at theMid-Atlantic Crop Management School How have the results been disseminated to communities of interest?Presentation of our research findings at the Mid-Atlantic Crop Management School exposed 94 attendees to information about how near surface geophysics can guide crop management practices. At this presentation, Mr. Thompsons engaged with crop consultants, Extension educators, and governmental agency personnel. Evaluation data showed that 95% of respondents (35 of 37) indicated they learned something new and 73% (27 of 37 respondents) indicated they will use the information presented in the future. Project results have also been disseminated to scientific audiences through peer-reviewed publications and oral/poster presentations at scinetific conferences as outlined in the products section. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
All project activities through May 2024 were described in previous progress reports. The following accomplishments reflect work completed between June 2024 and December 2024. At the Society of Experimental Geophysics IMAGE 2024 in August, Joshua Thompson (graduate student, Rutgers University - Newark) delivered a presentation titled Time-lapse 3D electrical resistivity imaging coupled with induced polarization for monitoring solute transport in flat, agricultural landscapes. This talk was designed for a research-oriented audience, including geophysicists and environmental scientists. He presented findings from a field study where time-lapse ERI and induced polarization (IP) were used to track solute transport in a low-relief agricultural field with artificial drainage ditches. The study highlighted the role of high-permeability pathways in nutrient-rich groundwater movement and its potential contributions to phosphorus loading in drainage networks. By integrating geophysical monitoring with hydrological modeling, this research provided insights into subsurface nutrient transport mechanisms, which are critical for refining field-scale nutrient management strategies. At the Mid-Atlantic Crop Management School on November 19, 2024, Joshua Thompson (graduate student, Rutgers University - Newark) presented on the use of geophysical methods to support field-scale nutrient risk assessment. This talk was tailored for an audience of farmers and crop consultants, focusing on practical applications of geophysics in agricultural water and nutrient management. He discussed how techniques like electromagnetic induction (EMI) and electrical resistivity imaging (ERI) can help assess soil properties, identify subsurface flow paths, and improve nutrient management strategies. The session encouraged discussion on how these tools could be integrated into existing farm management practices to mitigate nutrient runoff and reduce environmental impacts on water bodies like the Chesapeake Bay. In November2024, we completed one last soil sampling campaign. Soil samples were collected from the fields at University of Delaware Carvel Research and Education Center in Georgetown DE, where the 2024 tracer study was conducted. These samples were collected and analyzed for grain size and soil P; this supporting information was requested by peer-reviewers to support publication of a manuscript detailing the results of the 2024 tracer experiment.
Publications
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2024
Citation:
Thompson, J., Buda, A., Shober, A., Triantafilis, J., Ntarlagiannis, D., Collick, A, Kennedy, C., Mosesso, L., & Slater, L. 2024. Time-lapse 3D electrical resistivity imaging coupled with induced polarization for monitoring solute transport in flat, agricultural landscapes. Society of Exploration Geophysics International Meeting for Applied Geoscience and Energy (IMAGE), Houston, TX.
- Type:
Other
Status:
Published
Year Published:
2024
Citation:
Thompson, J. 2024. Geophysical methods in support of field-scale nutrient risk assessment. Mid Atlantic Crop Management School, Ocean City, MD. November 19-21, 2024.
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Progress 06/01/23 to 05/31/24
Outputs
Target Audience:Scientists and researchers from universities (includes students), state or federal agencies, or non-profit organizations. Changes/Problems:We were awarded a 6-month no cost extension to complete dissemination efforts for both research and Extension objectives. What opportunities for training and professional development has the project provided?Rutgers University Newark: Joshua Thompson continued to benefit from the experience of interacting with a diverse range of scientists that make up the project team. The team is currently assisting him with development of peer-reviewed manuscripts that will comprise hisPhD thesis that isexploring the use of field-scale electrical geophysical methods to investigate flow and transport processes in dual domainsystems. University of Delaware: Sapana Pohkrel (postdoctoral researcher) gained knowledge on the use of geophysical tools to assist with nutrient management decisions. She gained useful field experience and has participated in the dessemination efforts for this project. How have the results been disseminated to communities of interest?Rutgers University Newark (Thompson) submitted an abstract and delivered a poster at the Fall 2021 American Geophysical Union (AGU) meeting describing results of the large-scale electrical geophysical surveys to map soil structures controlling solute transport across agricultural fields. He also delivered a seminar on the use of electrical geophysics for noninvasive characterization of solute transport in dual domain systems. He presented to a group of geophysicists and soil scientists as part of the Hydrogeophysics Knowledge Exchange webinar series organized between Lancaster University (UK) and Rutgers University Newark. Faculty from other academic institutions in the US and in Europe engaged in the webinar. What do you plan to do during the next reporting period to accomplish the goals?All major field and data analysis activities are complete. For the remainder of the funding period, we are focused on dissemination of results via conference proceedings,journal publications, and Extension meetings. Crop consultants and agency personnel will be engaged during the 2024 Mid-Atlantic Crop Management School in November in Ocean City, MD. This event attracts nearly 300 technical service providers. We will also develop written Extension outputs to help guide the use of geophysical tools for phosphorus management.
Impacts
What was accomplished under these goals?
The research team finalized plans for and executed a field-scale tracer test. We selected adjacent field sites with differing hydrology that were located near a ditch at the Carvel Research and Education Center in Georgetown, DE. Both fields were mapped using an apparent electrical conductivity (VERIS) sensor and a Duelem (EM) to verify differences in soil texture and potential hydrology. Soil core samples and water table depth estimates were completed and corroborated with geophysical field surveys.This background information was used to select the location for two intensive sprinkling events with a conservative KBr tracer, which was executed in October 2023. Briefly, a KBr tracer solution was injected into a shallow well; water table levels were monitored in several wells located within the tracer experimental area. Electrical resistivity imaging was then applied to at 12-m x 8-mgrid withing the evaluation area every 2 hours or so following tracer injection. Data analysis from this tracer event was completed in early 2024. Dissemination activities are ongoing.
Publications
- Type:
Journal Articles
Status:
Under Review
Year Published:
2024
Citation:
Thompson, J. H., Buda, A. R., Shober, A. L., Collick, A. S., Kennedy, C., Reiner, M., Mosesso, L. Malayil, A., Triantafillis, J., Ntarlagiannis, D., & Slater, L. (2024). Electrical geophysical monitoring of subsurface solute transport in low-relief agricultural landscapes in response to a simulated major rainfall event. Journal of Hydrology, In Review.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2023
Citation:
Thompson, J. H., Buda, A. R., Shober, A. L., Triantafillis, J., Ntarlagiannis, D., Collick, A. S., Kennedy, C., Mosesso, L., & Slater, L. (2023). Time-lapse 3D electrical resistivity imaging coupled with induced polarization for monitoring solute transport in flat, agricultural landscapes. 2023 American Geophysical Union Annual Meeting, San Francisco, CA.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2023
Citation:
Thompson, J., Pokhrel, S., Shober, A. L., Buda, A. R., Slater, L., Ntarlagiannis, D., Collick, A. S., Kennedy, C., & Mosesso, L. (2024). Enhancing site assessments of agricultural surface phosphorus loss using geophysical surveys and conservative tracers. FY2024 (A1401) Soil Health
Project Directors Meeting. Kansas City, MO.
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Progress 06/01/22 to 05/31/23
Outputs
Target Audience:Scientists and researchers from universities (including students), state or federal agencies, or non-profit organizations. Crop advisors or technical service providers working with farmers. Changes/Problems:No significant changes at this point outside of significant COVID delays. A no-cost extension was granted for 1-year to allow for continued progress toward project completion. What opportunities for training and professional development has the project provided?Rutgers University Newark: Joshua Thompson continued to benefit from the experience of interacting with a diverse range of scientists that make up the project team. The work being performed by Thompson continues to contribute content to his PhD thesis that is exploring the use of field-scale electrical geophysical methods to investigate flow and transport processes in dual domain systems. University of Delaware: Several undergraduate students received training and assisted with sampling from the multiport samplers. Studies at UMES are supporting a UDpostdoc Pokhrel. USDA-ARS team members are actively involved in mentoring students and postdocs who are funded by the project. How have the results been disseminated to communities of interest?Two presentations led by colleagues from Rutgers University Newark:(1) one led by Thompson at the Fall 2023 American Geophysical Union (AGU) meeting, and (2) one led by Slater at the 2023 Australasian Geoscience Exploration Conference (AEGC), in Brisbane, Australia. Faculty from other academic institutions in the US and in Europe engaged in the webinar. Mossesso from University of Delaware completed a Ph.D. program that included this work. What do you plan to do during the next reporting period to accomplish the goals?The next reporting period will focus on the field-scale tracer test that was designed and modeled during this project period. The major field activities are scheduled for one week during July 2023. The next period will focus on the development of manuscripts from the tracer experiment. In addition, preparations are being made for two additional tracer experiments that will test the near-surface geophysics methods on ditch-drained farms elsewhere on the Delmarva.Thompson is expected to complete Ph.D. programs that include this work during the next project reporting period.Extension activities are planned for the next project reporting period, including development of educational materials and workshops/training events.
Impacts
What was accomplished under these goals?
Research team members visited the Research Farm at the University of Maryland Eastern Shore (UMES) and collected a set of ten 10-ft soil cores in fields that were previously surveyed using large-scale geophysics (electromagnetic induction, EMI; induced polarization, IP) on 2/2022. These soil cores were analyzed for particle size distributions at Rutgers University Newark (RUN) and the resultant data were used to corroborate geophysical estimations of soil properties in the surveyed fields. A separate set of five 5-foot soil cores was collected in the vicinity of the tracer plot that was established for the field-scale tracer test using simulated rainfall. These soil cores were also analyzed for particle size distributions at Rutgers-Newark. Monthly research team meetings were held in the spring of 2022 to prepare for the field-scale tracer test using simulated rainfall. Meetings covered a wide range of topics, including: (1) design and testing of the sprinkling system; (2) identifying a water source for the sprinkling system; (3) hydrologic instrumentation needed for the tracer plot; (3) procurement of needed tracers (potassium bromide and deuterium oxide); (4) planning for reconnaissance field work and site establishment; and (5) developing protocols for salt tracer injection, hydrologic monitoring, and field sampling of soil water and groundwater. Research team members visited UMES on 8-10 June 2022 to conduct reconnaissance field work at the tracer plot. Field work focused on installing a set of four shallow monitoring wells, conducting pump tests to determine an appropriate pump rate for the tracer injection, and collecting background water samples from the proposed water source. Also, a 5000-gallon tanker truck was delivered to University of Delaware's Carvel Center in Georgetown, Delaware in preparation for the field experiment that was scheduled for June 20-23, 2022. We also installed time-domain reflectometry (TDR) probes adjacent to the suction cup lysimeter arrays, sampled water from the multiport samplers, and cleaned the tubing of the suction cup lysimeters. Research team members returned to UMES on 19 June 2022, to lay the groundwork for the field-scale tracer test with simulated rainfall. Groundwater monitoring wells were instrumented with water level sensors, and sampling equipment was prepped for the experiment. The tanker was filled with irrigation water from the UMES Farm and mixed with roughly 200 mL of deuterium oxide (D2O). We collected several samples of the irrigation water for stable water isotope analysis. Suction was applied to the suction lysimeters. The sodium bromide salt tracer solution was mixed on 20 June 2022, and subsequently injected into a shallow well over a period of 3 hours. On 21 June 2022, six sprinkler heads were arrayed around the outer boundary of the 10 x 15 m plot. We started the sprinkling system at 10:15 AM. Four sets of soil water samples were collected from suction lysimeters near the top of the plot, and eleven sets of precipitation samples were collected over the course of the 11-hour event. On the morning of 22 June 2022, all hydrologic sensors were downloaded and another set of lysimeter samples was collected. In addition, a complete set of groundwater samples (n = 80) was taken from the 15 multiport samplers that were situated throughout the tracer plot. Each multiport sampler was installed to a depth of 10 feet and had ten sampling ports at 1-foot depth intervals. All water samples were sent to The USDA-ARS (Kennedy) lab in East Wareham, Massachusetts where they were analyzed for dissolved nutrients, bromide, and stable water isotopes. Colleagues from University of Delaware visited the tracer plot at roughly bimonthly intervals between August and December 2022 to collect additional sets of samples from the multiport samplers and download data from the water level sensors in the shallow monitoring wells. As with the previous sets of samples, all water quality and isotopic analyses were performed at the USDA-ARS lab in East Wareham, Massachusetts. USDA-ARS co-PIs met regularly with colleagues from Rutgers University Newark (Thompson, Slater) to review results from the tracer experiment, including geophysical findings, as well as findings from water quality and isotopic analyses of shallow groundwater. Preliminary results from the time-lapse electrical resistivity imaging (ERI) data suggest that a preferential flow pathway developed during the experiment; the location and general extent of this pathway was corroborated by bromide measurements from the multiport samplers shortly after the sprinkling experiment was concluded. Further examination of the tracer transport data is being done via flow and transport modeling that is being led by colleagues from Rutgers University Newark. The research team recently conducted two meetings leading up to the summer and early fall (2023) for another intensive sampling campaign at a second research site.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2023
Citation:
Thompson, J., Buda, A, Shober, A,, Triantafilis, J., Ntarlagiannis, D., Collick, A., Kennedy, C, Mosesso, L. and Slater, L. (2023). Electrical imaging of solute transport dynamics to understand nutrient transport from flat agricultural landscapes, 2023 Australasian Exploration Geoscience Conference, 13-18 March, 2023, Brisbane, Australia.
- Type:
Other
Status:
Published
Year Published:
2022
Citation:
Thompson, J., Buda, A. R., Shober, A., Triantafilis, J., Ntarlagiannis, D., Collick, A., ... & Slater, L. D. (2022, December). Characterizing Solute Transport in Flat Agricultural Landscapes During a Simulated Storm Event with Time-lapse 3D and 1D Electrical Resistivity. In AGU Fall Meeting Abstracts (Vol. 2022, pp. NS34A-07).
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2022
Citation:
Mosesso, L. R., Shober, A., Buda, A., Kennedy, C., & Collick, A. (2022). Characterization of legacy phosphorus and quantification of subsurface losses under artificial drainage. University of Delaware (Doctoral, Dissertation, University of Delaware).
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Progress 06/01/21 to 05/31/22
Outputs
Target Audience:Scientists and researchers from universities (includes students), state or federal agencies, or non-profit organizations. Changes/Problems:Nothing to report beyond COVID-related delays to field activities What opportunities for training and professional development has the project provided?Rutgers University Newark: Joshua Thompson continued to benefit from the experience ofinteracting with a diverse range of scientists that make up the project team. In particular,Thompson received critical guidance from Buda on hydrological model development andcalibration. The work being performed by Thompson continues to contribute content to his PhDthesis that is exploring the use of field-scale electrical geophysical methods to investigate flowand transport processes in dual domain systems. University of Delaware: Several undergraduate students received training and assisted withsampling from the multiport samplers. How have the results been disseminated to communities of interest?Rutgers University Newark (Thompson) submitted an abstract and delivered a poster at the Fall2021 American Geophysical Union (AGU) meeting describing results of the large-scaleelectrical geophysical surveys to map soil structures controlling solute transport acrossagricultural fields.He also delivered a seminar on the use of electrical geophysics for non-invasivecharacterization of solute transport in dual domain systems. He presented to a group ofgeophysicists and soil scientists as part of the Hydrogeophysics Knowledge Exchange webinarseries organized between Lancaster University (UK) and Rutgers University Newark. Facultyfrom other academic institutions in the US and in Europe engaged in the webinar. What do you plan to do during the next reporting period to accomplish the goals?The next reporting period will focus on the field-scale tracer test that wasdesigned and modeled during this project period. The major field activities are scheduled forone week during June 2022, with follow up occasional measurements through the remainder ofthe summer and fall of 2022. The remainder of the next project reporting period will focus oninterpretation of the electrical geophysical amd hydrologic datasets acquired during and after this tracer test,followed by dissemination of results via conference proceedings and a journal publication.Thompson and Mosesso areexpected to completePh.D. programsthat includes this work during the next project reporting period.
Impacts
What was accomplished under these goals?
Geophysics Team: (Thompson, Slater) and USDA ARS (Buda) collaborated on the hydrologicalmodel development to constrain the design parameters of a major tracer test experimentplanned for 06/2022. Thompson led the model development, implemented in FlowPy (python wrapper for MODFLOW & MT3D-USGS). The model predicts 2D advection/dispersion in a dualdomain, with diffusion occurring between the two domains. Representative values for thepermeability and porosity of the shallow sediments, along with average hydraulic gradients,were obtained from previous field experiments performed by the project team. Buda utilized themodel to constrain key parameters of the planned field tracer experiment, including the tracervolume, infiltration rate and location. Thompson also utilized the model simulations to design theelectrical geophysical data acquisition strategy to be used during the planned tracer experiment.Rutgers University Newark (Thompson, Slater) analyzed grain size characteristics of +200 soilsamples acquired by UMES collaborators (Collick) across one intensively studied field at theUMES experimental farm. Thompson assisted USDA ARS with coring activities to acquiresamples down to 10 ft from locations selected based on previously acquired geophysicaldatasets. Rutgers University Newark (Thompson, Ntarlagiannis, Slater) inverted and processedfield-scale electromagnetic and resistivity datasets acquired on this field to evaluate the use ofgeophysics for informing on soil texture patterns controlling subsurface flow from fields todrainage ditches. Soils Team: We team planned the protocol for the irrigation experiment that was scheduled for June 2022.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
J. Thompson et al., 2021, Proximal mapping of surface conductivity through integration of electromagnetic and induced polarization datasets: implications for improved understanding of agricultural hydrogeology. AGU Fall Meeting 2021, Abstract NS35C-0372
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Mosesso, L. R., Buda, A., Collick, A., Kennedy, C., Folmar, G., & Shober, A. (2021). Examining sources and pathways of phosphorus transfer in a ditch-drained field. Journal of Environmental Quality, 50(3), 680 693. https://doi.org/10.1002/jeq2.20226
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Progress 06/01/20 to 05/31/21
Outputs
Target Audience:Scientists and researchers from universities (includes students), state or federal agencies, or non-profit organizations. Changes/Problems:During this project period, we continued to experience COVID-related delays to field data acquisition. These delays were driven by travel restrictions that limited the project team's ability to travel to the field site until late in the project period (May 2021).We added laboratory analysis of 38 soils from UMES as a change to the project scope to allow Ph.D. student Thompson to pursue research when travel restrictions were in place. What opportunities for training and professional development has the project provided?Both Lauren Mossesso (UD) andJoshua Thompson (Rutger's) continued with Ph.D. research under the supervision of co-PIs Shober (Mosesso) andSlater and Ntarlagiannis (Thompson). Co-PI Buda is serving as a member of both Ph.D. committee and has provided assistance to students. Co-PDs Collick and Kennedy serve as a member of L. Mosesso's Ph.D. committee. Both students continued to increase their research and and written communication skills during the project period as a result of participating in this project. How have the results been disseminated to communities of interest?Results were not disseminated during the project period, mainly due to COVID-related limitations and setbacks that limited data collection activities. Students will be presenting preliminary results at upcoming professional meetings. What do you plan to do during the next reporting period to accomplish the goals?In the next grant year, we plan to execute the irrigation experiment. We are currently developing our water sampling protocol. We plan to set up five pumps with five peristaltic pumps each to allow us to quickly sample the multiport wells. We are working out the logistics for sampling in the field which may involve setting up a vacuum manifold on a folding table near our wells. We plan to bring into tanker trucks for our irrigation experiment that can be moved in and out of the field when the tanks empty. We are still working on how to add our deuterated water to the water in the tanks so that all irrigated water has the same isotopic signature. A priority is to perform the geophysical monitoring of the tracer test at the UMES farm and to finish development of the coupled hydrogeophysical model needed to interpret the results.
Impacts
What was accomplished under these goals?
A coupled hydrological and geophysical model is in development that will model the tracer test. The hydrological component of the model has been constructed in VS2DTI and is currently being used to inform on tracer test design. The model has been populated with hydrological parameters based on known soil profiles from the UMES site. On a UMES field, 38 soil samples were collected by A. Collick and colleagues, each divided into 4 depth ranges down to a depth of 1 meter. These samples were taken from a field that an electromagnetic induction (EM) survey was completed in 2019. Sample locations were selected based on the patterns of electrical conductivity recorded in the EM survey. Laser particle size and sieve measurements were conducted on the soil samples. Surface area and cation exchange measurements are currently in progress. We determined the injection rate for our tracers into the experimental plot's injection well in May 2021by pumping water from a 65 gallon carboy into a 1 L graduated cylinder using aperistaltic pump with silicone tubing. Our power source was from our ATV's battery using a power inverter. We adjusted the speed of the pump and measured how much water was pumped into the graduated cylinder during a minute to determine the rate. For each tested injection rate (50, 75, 100, 125, 145, 195, 495 mL/min), we lowered a pressure transducer into the injection well to measure water pressure head. We waited five minutes to allow the pressure transducer to equilibrate before injecting the water. We also placed a second pressure transducer next to the injection well in the shade (to not increase the temperature measurement) to measure the background atmospheric pressure. We then injected water at our predetermined rate for 15 minutes and then the pump was turned off. We allowed the pressure transducer to sit in the well for another 10 minutes before removing the transducer and downloading the data to determine the change in water level before, during, and after water injection. Our goal was to find the fastest injection rate that did not raise the water level. We determined this rate to be 50 mL/min.
Publications
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Progress 06/01/19 to 05/31/20
Outputs
Target Audience:Scientists and researchers from universities (includes students), state or federal agencies, or non-profit organizations. Changes/Problems:Unfortunately, we had to suspend our field plans for spring/summer 2020 due to the COVID-19 pandemic.As such, data collection slated for Spring 2020 was not completed. What opportunities for training and professional development has the project provided?During this period, we trained two graduate students and a post-doctoral researchers to complete field-scale geophysical mappingand on the fabrication and installation of multilevel hydrological monitoring equipment. How have the results been disseminated to communities of interest?Results of this project have not yet been disseminated to communities of interest. The project team collected some preliminary data in fall 2019 and early spring 2020. Unfortunately, field site visits and data collection was cut of abruptly due to travel bans related to the community spread of COVID-19. What do you plan to do during the next reporting period to accomplish the goals?The geophysics team at Rutgers University Newark plans tocontinue processing of the ECa data is ongoing to improve inversion results. A resistivity/induced polarization survey conducted at UMES in 2018 has been used to investigate ways to improve the interpretation of the large-scale ECa datasets in terms of soil properties. In addition, the hydrologic team intends to begin routine background sampling of the lysimeters and multilevel samplers in fall 2020, with the hopes of conducting our sprinkling experiments in spring/summer 2021, should conditions permit.
Impacts
What was accomplished under these goals?
Electromagnetic induction surveys were conducted across nine agricultural fields in Maryland and Delaware including 3 fields at University of Maryland Eastern Shore (UMES), 3 farmer-owned fields in Marion Station, Maryland, 1 field at the University of Delaware Carvel Research and Education Center, and 2 farmer owned fields in Sudlersville, Maryland (1 irrigated and 1 dryland). These surveys were conducted using a Dualem 421S electromagnetic induction instrument between October 2019 to March 2020. All data has been imported into an inversion software for initial processing. The apparent electrical conductivity (ECa) data of each field has been initially inverted using a smooth inversion process. Strategies for a coupled electrical and transport modeling approach to the planned geoelectrical tracer tests at the selected sites (to be determined) was investigated. The current approach is focused on using the Comsol coupled physics modeling package. On October 9-11, 2019, we established a 10 × 15 m experimental plot adjacent to an open field ditch that drains 1.5-ha field at the UMES Research Farm. Within the plot, we installed an array of fifteen multilevel samplers to enable hydrochemical monitoring of shallow groundwater. Each multilevel sampler was 3-m long with sampling ports at roughly 0.3-m intervals. We also installed five nests of suction lysimeters at 0.2-, 0.4-, and 0.8-m depths in the upper portion of the plot (see images below). We allowed the experimental plot to rest for approximately six months before attempting any background sampling of soil water and groundwater prior to our planned sprinkling experiments with groundwater tracers and geophysics in the spring/summer of 2020. During the winter/spring 2020, we designed and built a sprinkling system to simulate a 10-year, 48-hr storm event (roughly 150 mm of rain) for the experimental plot at UMES. The system features four 1,500-gallon storage tanks aligned in series, along with a submersible pump (installed in the first tank in the series) to deliver water to a network of sprinkler heads connected by garden hoses. The pump is powered by a propane generator, and the sprinkler heads are attached to plastic stakes that are arrayed in a grid-like pattern to enable uniform irrigation of the plot. We also purchased two 100-gram bottles of deuterium oxide (D20, 99.9%), which will be used to label the tank waters with heavy water for the unsaturated zone study with suction lysimeters and electrical resistivity. ?
Publications
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