Articles | Volume 29, issue 22
https://doi.org/10.5194/hess-29-6703-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/hess-29-6703-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Technical note: Extending the SWAT2012 and SWAT+ models to simulate pesticide plant uptake processes
Hendrik Rathjens
Stone Environmental, 535 Stone Cutters Way, 05602 Montpelier (VT), USA
Stone Environmental, 535 Stone Cutters Way, 05602 Montpelier (VT), USA
Jeffrey Arnold
USDA-ARS, Grassland Soil and Water Research Laboratory, 808 East Blackland Rd., 76502 Temple (TX), USA
Gerald Reinken
Bayer AG Crop Science Division, Regulatory Science, Environmental Safety Assessment & Strategy, Monheim, Germany
Robin Sur
Bayer AG Crop Science Division, Regulatory Science, Environmental Safety Assessment & Strategy, Monheim, Germany
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Cited articles
Arnold, J. G., Srinivasan, R., Muttiah, R. S., and Williams, J. R.: Large-area hydrologic modeling and assessment: part I. model development, Am. Wat. Res., 34, 73–89, 1998.
Arnold, J.G., Rathjens, H., and Kiesel, J.: SWAT source code including pesticide plant update routines [Code], https://github.com/StoneEnv/SwatPestPlantUptake (last access: 18 November 2025), 2023
Bouraoui, F.: Testing the PEARL model in the Netherlands and Sweden, Environmental Modelling & Software, 22, 937–950, https://doi.org/10.1016/j.envsoft.2006.06.004, 2007.
Bieger, K., Arnold, J. G., Rathjens, H., White, M. J., Bosch, D. D., Allen, P. M., Volk, M., and Srinivasan, R.: Introduction to SWAT+, a Completely Restructured Version of the Soil and Water Assessment Tool, Journal of the American Water Resources Association (JAWRA), 53, 115–130, https://doi.org/10.1111/1752-1688.12482, 2017.
Carsel, R. F., Mulkey, L. A., Lorber, M. N., and Baskin, L. B.: The Pesticide Root Zone Model (PRZM): A procedure for evaluating pesticide leaching threats to groundwater, Ecological Modelling 30, 49–69, 1985.
Daggupati, P., Pai, N., Ale, S., Douglas-Mankin, K. R., Zeckoski, R. W., Jeong, J., Parajuli, P. B., Saraswat, D., and Youssef, M. A.: A recommended calibration and validation strategy for hydraulic and water quality models, Transactions of the ASABE, 58, 1705–1719, 2015.
Eze, M. O. and Amuji, C. F.: Elucidating the significant roles of root exudates in organic pollutant biotransformation within the rhizosphere, Sci. Rep., 14, 2359, https://doi.org/10.1038/s41598-024-53027-x, 2024.
Fantke, P., Wieland, P., Wannaz, C., Friedrich, R., and Jolliet, O.: Dynamics of pesticide uptake into plants: From system functioning to parsimonious modeling, Environmental Modelling & Software 40, 316–324, 2013.
FAO: Assessing soil contamination, A reference manual, FAO Pesticide disposal series 8, Food and Agricultural Organization of the United Nations, https://www.fao.org/3/X2570E/X2570E00.htm#TOC (last access: 15 January 2024), 2000.
Feddes, R. A., Kowalik, P., Kolinska-Malinka, K., and Zaradny, H.: Simulation of field water uptake by plants using a soil water dependent root extraction function, J. Hydrol., 31, 13–26, 1976.
Gassman, P. W., Sadeghi, A. M., and Srinivasan, R.: Applications of the SWAT Model Special Section: Overview and Insights, J. Environ. Qual., 43, 1–8, 2014.
Hanson, J. D., Ahuja, L. R., Shaffer, M. D., Rojas, K. W., DeCoursey, D. G., Farahani, H., and Johnson, K.: RZWQM: Simulating the effects of management on water quality and crop production, Agricultural Systems 57, 161–195, 1998.
Holvoet, K. A., Gevaert, V., van Griensven, A., Seuntjens, P., and Vanrolleghem, P. A.: Modeling the effectiveness of agricultural measures to reduce the amount of pesticides entering surface waters, Water Resour. Manage., 21, 2027–2035, 2007.
Jackson, R. B., Canadell, J., Ehleringer, J. R., Mooney, H. A., Sala, O. E., and Schulze, E. D.: A global analysis of root distributions for terrestrial biomes, Oecologia, 108, 389–411, 1996.
Jorda, H., Huber, K., Kunkel, A., Vanderborght, J., Javaux, M., Oberdörster, C., Hammel, K., and Schnepf, A.: Mechanistic modeling of pesticide uptake with a 3D plant architecture model, Environmental Science and Pollution Research, 28, 55678–55689, https://doi.org/10.1007/s11356-021-14878-3, 2021.
Kling, H., Fuchs, M., and Paulin, M.: Runoff conditions in the upper Danube basin under an ensemble of climate change scenarios, Journal of Hydrology 424–425, 264–277, 2012.
Lamshoeft, M., Gao, Z., Resseler, H., Schriever, C., Sur, R., Sweeney, P., Webb, S., Zillgens, B., and Reitz, M. U.: Evaluation of a novel test design to determine uptake of chemicals by plant roots, Science of the Total Environment, 613–614, 10–19, 2018.
Leistra, M., Boesten, J. J. T. I., van der Linden, A. M. A., Tiktak, A., and van den Berg, F.: PEARL model for pesticide behaviour and emissions in soil-plant systems: Description of the processes in FOCUS PEARL v 1.1.1, Alterra-rapport 013, Wageningen, The Netherlands: Alterra, https://edepot.wur.nl/26563 (last access: 15 May 2025), 2001.
Neitsch, S. L., Arnold, J. G., Kiniry, J. R., and Williams, J. R.: Soil and Water Assessment Tool theoretical documentation, Version 2009, College Station (TX), USA, TX Water Res. Inst. Tech. Rep, No. 406, p. 647, https://swat.tamu.edu/media/99192/swat2009-theory.pdf (last access: 18 November 2025), 2011.
Rathjens, H., Kiesel, J., Miguez, M. B., Winchell, M., Arnold, J. G, and Sur, R.: Simulation of pesticide and metabolite concentrations using SWAT+ landscape routing and conditional management applications, Water, 14, 1332, https://doi.org/10.3390/w14091332, 2022.
Rathjens, H., Kiesel, J., Winchell, M., Arnold, J., and Sur, R.: Technical note: Extending the SWAT model to transport chemicals through tile and groundwater flow, Hydrol. Earth Syst. Sci., 27, 159–167, https://doi.org/10.5194/hess-27-159-2023, 2023.
Schriever, C. and Lamshoeft, M.: Lipophilicity matters – A new look at experimental plant uptake data from literature, Science of the Total Environment 713, 136667, https://doi.org/10.1016/j.scitotenv.2020.136667, 2020.
Shen, H., Tolson, B. A., and Mai, J.: Time to update the split-sample approach in hydrological model calibration, Water Resources Research, 58, e2021WR031523, https://doi.org/10.1029/2021WR031523, 2022.
USDA-ARS and TAMU: Official SWAT+ Source Code repository including pesticide plant uptake routines, US Department of Agriculture and Agricultural Research Service Texas A&M AgriLife Research [Code], https://github.com/swat-model/swatplus (last access: 18 November 2025), 2025.
van den Berg, F., Tiktak, A., Boesten, J. J. T. I., and van der Linden, A. M. A.: PEARL model for pesticide behaviour and emissions in soil-plant systems, WOt-technical report 61, WOT Natuur & Milieu, https://edepot.wur.nl/377664 (last access: 15 January 2024), 2016.
Short summary
We improved the widely used SWAT (Soil and Water Assessment Tool) model to better predict how pesticides move through the environment. We added a new process that considers how plants take-up chemicals from the soil. Testing this updated model in two catchments showed very good prediction capabilities and a reduction of chemicals in river water by up to 17 % due to the plant uptake. The enhanced model offers a valuable tool for assessing the environmental impacts of agricultural management.
We improved the widely used SWAT (Soil and Water Assessment Tool) model to better predict how...