Source: OHIO STATE UNIVERSITY submitted to
ADVANCING KNOWLEDGE AND PREDICTION OF PHOSPHORUS DYNAMICS IN TILE DRAINED LANDSCAPES
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
ACTIVE
Funding Source
AFRI COMPETITIVE GRANT
Reporting Frequency
Annual
Accession No.
1028288
Grant No.
2022-67019-36697
Cumulative Award Amt.
$749,997.00
Proposal No.
2021-09263
Multistate No.
(N/A)
Project Start Date
Feb 1, 2022
Project End Date
Jan 31, 2026
Grant Year
2022
Program Code
[A1411]- Foundational Program: Agricultural Water Science
Recipient Organization
OHIO STATE UNIVERSITY
1680 MADISON AVENUE
WOOSTER,OH 44691
Performing Department
Food, Ag and Biol Engineering
Non Technical Summary
Phosphorus (P) transported via surface and subsurface flows from agricultural systems plays a major role in water quality impairments downstream, including harmful algal blooms (HABs). In heavily tile-drained agricultural landscapes such as the Western Lake Erie Basin (WLEB), understanding and quantifying dynamics of dissolved P (DP) transport through tile drainage is critical. While the transport of total P (TP) and DP have been extensively studied, knowledge and modeling gaps exist in relating soil properties with sorption dynamics and P transport through matrix and preferential flow pathways. While P transport through surface runoff is fairly well-represented in commonly-applied models, P transport to tile drainage is either ignored or poorly represented. Poor representation of P sorption and transport processes impact the usefulness of watershed models in guiding environmental policy. To fill this knowledge gap, we aim to characterize the process of P desorption from topsoils and sorption by subsoils using novel, proven methods. We will then fill the modeling gap by using knowledge from laboratory studies to improve the theoretical framework of a watershed model (Soil Water Assessment Tool - SWAT), by adopting mathematical models of P dynamics and improving the representation of preferential and matrix flow to tile drains. Finally, we will evaluate model improvements by conducting sensitivity analysis and comparing model outputs of a field-scale SWAT model against field-measured water quantity and quality data. Expected outcomes include (1) robust evidence of the mechanisms controlling P transport to tile drains, (2) a transferable method of simulating P transport and dynamics within hydrologic models.Our research will be impactful in providing farmers and other stakeholders with more accurate estimations of phosphorus loads in the WLEB, which will promote better management of nutrient pollution. Further, a transferable method of simulating phosphorus transport within a hydrologic model will facilitate better management of this pollution and eutrophication it causes in watersheds beyond the WLEB. Further, our project will improve the capacity to represent and evaluate P transport processes within watershed-scale hydrologic models, which are commonly applied to inform stakeholder decision making and policy development.
Animal Health Component
40%
Research Effort Categories
Basic
30%
Applied
40%
Developmental
30%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1020110200030%
4050199205030%
1120320202040%
Knowledge Area
102 - Soil, Plant, Water, Nutrient Relationships; 112 - Watershed Protection and Management; 405 - Drainage and Irrigation Systems and Facilities;

Subject Of Investigation
0320 - Watersheds; 0110 - Soil; 0199 - Soil and land, general;

Field Of Science
2020 - Engineering; 2050 - Hydrology; 2000 - Chemistry;
Goals / Objectives
Our long-term goal is to provide science-based information to farmers and other stakeholder groups to support sustainable agricultural production while promoting water quality. The principal goal of this project is to improve our understanding of phosphorus (P)loss in tile drainage systems and improve tile P simulation in an existing nutrient transport model. Our central hypothesis is that the ratio and time of soil-water contact will dramatically impact P losses, and that this dynamic between hydrology and soil P will dictate the ability of a soil to behave as a sink or source of P. The following objectives will test this hypothesis:Quantify how dissolved P (DP) transport in tile-drained fields is impacted by soil properties and hydrology.Improve simulation of macropore and matrix P contributions to tile drainage and P dynamics in the soil matrix in the Soil Water Assessment Tool (SWAT) model.Evaluate SWAT model improvements by comparing the simulated tile DP and total P (TP) outputs against edge-of-field monitoring data.
Project Methods
To test our central hypothesis, we will adopt novel flow-through P desorption and sorption techniques utilizing a short and long contact time (i.e., fast and slow flow rate) on a diverse group of soils collected from the WLEB.Stakeholder engagement is important to successful implementation of this project, and has already contributed to the problem definition leading up to this proposal. Stakeholders will continue to serve in advisory roles throughout the project and we have laid out plans to disseminate results widely through the edge-of-field monitoring network, to the region, and to the scientific community through publication and presentation of results.The specific project tasks under each objective are outlined below:Objective 1: Quantify how DP transport in tile-drained fields is impacted by soil properties and hydrologyTask 1.1 Collect and characterize soil samplesTask 1.2 Conduct flow-through desorption tests on collected topsoilsTask 1.3 Conduct flow-through P sorption tests on subsoilsTask 1.4 Analyze flow-through and soil characterization dataObjective 2: Improve simulation of macropore and matrix P components of tile drainage and P dynamics in the soil matrix in the SWAT modelTask 2.1 Represent sediment-bound P transport through crack flow in SWATTask 2.2 Partition tile DP transporting from crack flow and matrix flow pathwaysTask 2.3 Represent sorption and desorption mechanisms of P transport within the soil profile as a function of soil properties and flow ratesObjective 3: Evaluate the model improvements by comparing the simulated tile DP and TP outputs with edge-of-field monitoring data.To evaluate the performance of the proposed SWAT model improvements, we will conduct sensitivity analysis and validation of a field-scale SWAT model in two subwatersheds that contain the edge-of-field monitoring sites (viz. Auglaize and Blanchard River watersheds).Task 3.1 Site and watershed model selectionTask 3.2 Run baseline scenarios for select field sites representing a range of soil test P and managementTask 3.3 Conduct sensitivity analysis of improved SWAT modelTask 3.4 Validate the performance of improved SWAT for tile drainage P simulationsTask 3.5Assess the watershed-scale impact of model improvements on estimates and effectiveness of BMPs

Progress 02/01/22 to 01/31/23

Outputs
Target Audience:During this reporting period, various audiences were reached through dissemination of findings related to water quality from monitoring activities, through oral presentations, and through a written publication. This target audience included conservationists, NRCS personnel, scientists, and representatives of various agricultural and environmental organizations.? Changes/Problems:The project activities at OSU and University of Wisconsin slowed down due to transition of the PIs Shedekar and Kalcic in new roles and severe delays in the hiringprocess for postdoctoral scholar. However, these issues have not caused us to consider any major changes to the approach and deliverables. In fact, the project has been able to provide a platform for intellectual interactions among the scientific and modeling communitiesand has led to synergistic advances of the P transport theory and model improvements. What opportunities for training and professional development has the project provided?The project has provided a number of opportunities to students and staff. Students learned new laboratory practices and procedures through the various extractions conducted on the soils and have how to operate analytical equipment such as colorimetric nutrient analyzers. Additionally, a graduate student was able to attend a national conference (American Society of Agronomy) to present results. An undergraduate student conducted the analysis of P loss by soil P and texture data as part of an undergraduate thesis. The postdoctoral researcher at UW-Madison has networked and prepared presentations related to the project. How have the results been disseminated to communities of interest?Various audiences have been reached through project activities completed thus far. Objective 1 activities were communicated through a graduate student presentation of the results of soil characterization and the comparison of water extractable phosphorus methods. Representing Objective 2 activities, Margaret Kalcic (UW-Madison) presented findings from this and another USDA-NIFA project at the WI-AWRA Conference in March 2023. For Objective 3, results from water quality monitoring have been disseminated to the 4R Nutrient Stewardship Council and to farmers whose properties are being monitored. What do you plan to do during the next reporting period to accomplish the goals? The next steps towards meeting project objectives are as follows: Objective 1 Tasks 1.2 and 1.3: Conduct flow-through desorption and sorption experiments on the collected soil samples (topsoils and subsoils). Objective 2 Task 2.3: Incorporate the new findings coming out from Objective 1 (i.e., mathematical relationships resulting from flow-through tests and established relationships between flow rate and P sorption/desorption) into source code and parameterization improvements. Objective 3 Tasks 3.2 and 3.3: Assess baseline scenarios for selected SWAT model HRUs and test the model using edge-of- field data obtained from the USDA-ARS Drainage Unit in Columbus, OH. These modifications will improve the accuracy of our estimates of phosphorus traveling through tile drainage systems and will contribute to more effective management of agricultural land and water quality.

Impacts
What was accomplished under these goals? Objective 1 Task 1.1: Thirty soils of diverse properties were collected, mostly possessing elevated agronomic P levels and from within the Western Lake Erie Basin. Topsoils (0-6 inches) and their respective subsoils (16-24 inches) were collected. All soils were characterized for agronomic P level (Mehlich-3 P), pH, water extractable P, organic matter, particle size distribution, amorphous Al and Fe, and total dissolved carbon. Objective 2 Tasks 2.1 and 2.2: We have investigated options for improving simulation of phosphorus to tile drains and modified the SWAT2012 source code to include phosphorus contribution from matrix flow through soils.Some preliminary source code modifications were implemented to test SWAT model's sensitivity to changes in the routing of tile drainage flow through crack volume versus soil matrix. Objective 3 Task 3.1: Water quality data has been collected using edge-of-field monitoring from agricultural fields with elevated soil test phosphorus concentrations. This data was analyzed using soil P concentration and soil textures to predict P concentrations.

Publications

  • Type: Journal Articles Status: Published Year Published: 2022 Citation: Penn, C. J., Williams, M. R., Camberato, J., Wenos, N., & Wason, H. (2022). Desorption kinetics of legacy soil phosphorus: Implications for non-point transport and plant uptake. Soil Systems, 6(1), 6.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Kalcic, M., Mehan, S., Prasad, L., Thompson, A. Improving Watershed Model (SWAT) Simulation of Wintertime Nutrient Transport. Oral presentation at the 46th Annual Meeting of the American Water Resources Association  Wisconsin Section, Wisconsin Dells, March 16-17, 2023