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ARS Home » Pacific West Area » Maricopa, Arizona » U.S. Arid Land Agricultural Research Center » Water Management and Conservation Research » Research » Research Project #441595
Research Project: Improving Water Management for Arid Irrigated Agroecosystems

Location: Water Management and Conservation Research

2025 Annual Report


Objectives
The overall goals of this project are to 1) improve knowledge of water, nutrient, and crop growth processes in arid agroecosystems, 2) to develop sensing, computing, and decision support technologies that improve water and nutrient use efficiency for crop production, and 3) provide science-based data to ensure that treated municipal wastewater used for irrigation poses minimal threat to people and the environment. Objective 1: Design, test, improve and integrate sensor data and simulation models to improve irrigation and fertilization decision support for irrigated cropping systems. Objective 2: Create and evaluate suites of satellite-based hydrology models that enable accurate monitoring and forecasting of evapotranspiration and other soil water balance components over irrigated agriculture, leading to improved irrigation scheduling. Objective 3: Design, test and/or improve sensors and technologies for optimizing surface irrigation systems. Objective 4: Determine the processes that govern the environmental fate and transport of emerging contaminants and other constituents found in treated wastewater used for irrigation to provide a research basis for potential regulation of these constituents. Objective 5: Develop and optimize low input treatment systems to reduce emerging contaminants and nutrients found in degraded waters to increase water resources used for food production.


Approach
Objective 1: Design, test, improve and integrate sensor data and simulation models to improve irrigation and fertilization decision support for irrigated cropping systems. Sub-objective 1A: Develop remote, proximal, and in-situ sensing technologies for estimating crop, water, and nutrient status of irrigated agroecosystems. Sub-objective 1B: Develop and evaluate simulation models, machine learning algorithms, and data integration strategies that better inform crop management decisions. Sub-objective 1C: Develop and field-test decision support tools that integrate data and models for improving in-season crop management. Sub-objective 1D: Develop irrigation guidelines, tools, and models for direct-seeded guayule. Objective 2: Create and evaluate suites of satellite-based hydrology models that enable accurate monitoring and forecasting of evapotranspiration and other soil water balance components over irrigated agriculture, leading to improved irrigation scheduling. Sub-objective 2A: Develop and test crop coefficient models driven by remote sensing data. Sub-objective 2B: Develop and test algorithms that use remote sensing to track water budgets across multiple cropping seasons. Objective 3: Design, test and/or improve sensors and technologies for optimizing surface irrigation systems. Sub-objective 3A. Evaluate and improve infiltration modeling approaches for irrigation design and management, tied to the Natural Resources Conservation Service (NRCS) soils database. Sub-objective 3B. Develop design and management strategies that account for the spatial and temporal variability of conditions, including infiltration, hydraulic resistance, and flow rate. Objective 4: Increase water supplies available for irrigation and managed aquifer recharge through safely reusing treated wastewater. Sub-objective 4A will determine the effect of temperature on the sorption, fate, and transport of pharmaceuticals in soil. Sub-objective 4B will determine the effects of long-term wastewater irrigation on soil contaminant concentration and the soil microbiome. Sub-objective 4C will optimize removal of pharmaceuticals from water. Objective 5 Will be a modeling exercise to determine the potential for using reclaimed wastewater as a supplemental irrigation source in rainfed agricultural systems. The volume of produced wastewater in regions of the Midwest will be spatially matched to potential crop needs. Crop irrigation needs will be modeled using historical weather data and then spatially matched to wastewater availability.


Progress Report
Note that project 2020-13000-005-000D (which is being terminated) has merged into this project, 2020-13660-009-000D. For updates on FY2025 accomplishments and all future research, please reference future annual reports for 2020-13660-009-000D. Critical retirements and resignations of four SY’s in 2023 and 2024 prevented progress for Objectives 1 and 3. In support of Objective 2, eddy covariance flux towers were deployed in grower fields along the lower Colorado River in cooperation with the collaborators at the University of Arizona through a non assistance cooperative agreement (NACA). In support of Sub-objective 4A, it was also found that microplastics can provide a transport mechanism for antibiotics through soil systems. Microplastics found in wastewater can absorb antibiotics as they move through the wastewater treatment system providing protection from degradation. Microplastics carrying antibiotics were transported through the soil to accumulate at root surfaces where they act as a source slowly releasing antibiotics to the soil solution where they are taken up by crops being irrigated with wastewater. Microplastics were also taken up by plants and translocated throughout the plants’ vascular system. Both microplastics and antibiotic fate and transport in soil can be limited by the application of waste derived biochar. This provides a management option for limiting pharmaceuticals and microplastic transport in soil systems to protect food crops grown in reclaimed wastewater. In support of Sub-objective 4B, paired water retention basins were identified. One basin receives reclaimed effluent for irrigation, and one receives potable water for irrigation. Both basins are planted with Bermuda grass and have similar management. Samples have been collected from the top 50 cm and will be sectioned into 10 cm samples for nutrient, contaminants of emerging concern, and microbial community analysis. Undisturbed columns are being collected one at a time and leached to characterize the leaching characteristics of the soil. Contaminant leaching potential will be determined.


Accomplishments
1. Water use by cotton can be reduced using deficit irrigation. Improved irrigation guidelines are needed to maximize crop water use efficiency. Combining field data with simulation models can provide information for better irrigation management. In 2024, U.S. cotton was valued at $4.7 billion with 67% of cotton being grown in areas requiring irrigation. With competition for water becoming more prevalent, reducing water use while maintaining production is important. ARS researchers in Maricopa, Arizona, and at the University of Arizona, used the freely available model AquaCrop, developed by the Food and Agricultural Organization, to simulate cotton yield, water use, and total soil water content. It was found that AquaCrop is an effective tool for irrigation scheduling and predicting yield with a standard error less than 15%, allowing farmers in arid climates to optimize yield in a water limiting situation.

2. Microplastics and antibiotics can reduce rice yield. The world's population is growing, which means we need more food and water. An alternative to help growing more food is using recycled water from treatment plants to irrigate crops. However, this water can contain tiny pieces of plastic and chemicals that can harm plants. Chemicals adsorbed to microplastics are protected from degradation and can be desorbed and pharmacokinetically available at a future time. ARS researchers in Maricopa, Arizona, conducted a study to see how the frequently used antibiotic sulfamethoxazole, when sorbed to microplastics, affects rice plant growth and health. The results showed that the pollutants slowed down the growth of the plants, made them produce less biomass, and caused stress. The study also found changes in the genes that might help the plants deal with stress and use nutrients. This research shows that the presence of microplastics and antibiotics could jeopardize the $3.4 billion rice sector in the United States.


Review Publications
Eisa, M., Brondi, M., Williams, C.F., Hejl, R.W., Baltrusaitis, J. 2025. From urea to urea cocrystals: A critical view of conventional and emerging nitrogenous fertilizer materials for improved environmental sustainability. Sustainable Chemistry for the Environment. 9. Article 100209. https://doi.org/10.1016/j.scenv.2025.100209.
 Silva, M., Eisa, M., Ragauskaite, D., Mcminn, M.H., Tian, Z., Williams, C.F., Knopf, A.L., Zhang, L., Baltrusaitis, J. 2023. Treatment of emerging contaminants in simulated wastewater via tandem photo-Fenton-like reaction and nutrient recovery. Environmental Science: Water Research & Technology. 9(2):508-522. https://doi.org/10.1039/D2EW00209D.
 Gonzalez, H.A., Qiao, X., D'Alessio, M., Dissanayake, D., Heeren, D., Biswas, S., Williams, C.F., Ray, C. 2023. Growing corn and sugar beets with feedlot effluent, air injection, and subsurface drip irrigation system in western Nebraska. Journal of Irrigation and Drainage Engineering. 149(3). https://doi.org/10.1061/JIDEDH.IRENG-9949.
 Zerihun, D., Sanchez, C., Rock, C., Williams, C.F. 2023. Modeling solute transport in sprinkler irrigation laterals. Journal of Irrigation and Drainage Engineering. 150(2). https://doi.org/10.1061/JIDEDH.IRENG-10176.
 Ndoun, M., Knopf, A.L., Preisendanz, H.E., Vozenilek, N., Elliott, H.A., Mashtare, M.L., Velegol, S.B., Veith, T.L., Williams, C.F. 2023. Fixed bed column experiments using cotton gin waste and walnut shells-derived biochar as low-cost solutions to removing pharmaceuticals from aqueous solutions. Chemosphere. 330. Article 138591. https://doi.org/10.1016/j.chemosphere.2023.138591.
 Hamilton, K., Harrison, J.C., Mitchell, J., Weir, M., Verhougstraete, M., Haas, C., Nejadhashemi, P.A., Libarkin, J., Aw, T.G., Williams, C.F., et al. 2024. Research gaps and priorities for quantitative microbial risk assessment (QMRA). Risk Analysis. 44(11):2521-2536. https://doi.org/10.1111/risa.14318.
 Ullah, R., Stiles, J.F., Feyissa, B.A., Tsui, M.T., Chow, A., Williams, C.F., Karanfil, T., Ligaba-Osena, A. 2024. Combined effects of polyamide microplastic and sulfamethoxazole in modulating the growth and transcriptome profile of hydroponically grown rice (Oryza sativa L.). Science of the Total Environment. 952. Article 175909. https://doi.org/10.1016/j.scitotenv.2024.175909.
 Nguyen, T., Nsiah, G.A., Crowder, E., Garland, S., Williams, C.F., Conroy-Ben, O. 2024. Predicted endocrine disrupting activity of unregulated drinking water contaminants. ACS Environmental Science & Technology Water. 4(3):1000-1013. https://doi.org/10.1021/acsestwater.3c00156.
 Yalin, D., Craddock, H., Assouline, S., Mordechay, E., Ben-Gal, A., Bernstein, N., Chaudhry, R., Chefetz, B., Fatta-Kassinos, D., Williams, C.F., et al. 2023. Mitigating risks and maximizing sustainability of treated wastewater reuse for irrigation. Water Research. 21. Article 100203. https://doi.org/10.1016/j.wroa.2023.100203.
 Eisa, M., Ragauskaite, D., Shi, J., Shimizu, S., Bucko, T., Williams, C.F., Baltrusaitis, J. 2023. Interactions of urea surfaces with water as relative humidity obtained from dynamic vapor sorption experiments, in situ single-particle Raman spectroscopy, and ab initio calculations. ACS Earth and Space Chemistry. 7(10):2139-2153. https://doi.org/10.1021/acsearthspacechem.3c00210.
 Brondi, M.G., Bortoletto-Santos, R., Stiles, J.F., Sanchez Farinas, C., Ammar, M., Ribeiro, C., Williams, C.F., Baltrusaitis, J. 2024. Mechanochemically synthesized nitrogen-efficient Mg- and Zn-ammonium carbonate fertilizers. ACS Sustainable Chemistry & Engineering. 12(16):6182-6193. https://doi.org/10.1021/acssuschemeng.3c07785.
 Nusair, A., Barber, M., Pramanik, A., Ethridge, C., Williams, C.F., Alkhateb, H., Ucak-Astarlioglu, M., Ray, P.C., D'Alessio, M. 2024. Graphene-coated sand for enhanced water reuse: Impact on water quality and chemicals of emerging concern. Science of the Total Environment. 945. Article 174078. https://doi.org/10.1016/j.scitotenv.2024.174078.
 Pathiranage, W.B., Sharp, C., Williams, C., McKnight, A., Algharibeh, O., Hong, Y., Williams, C.F., Rushing, G., Alkhateb, H., D'Alessio, M. 2025. Enhanced ability of 3D-printed bricks to treat wastewater under variable conditions. Journal of Environmental Management. 386. Article 125690. https://doi.org/10.1016/j.jenvman.2025.125690.
 Elsadek, E., Elshikha, D.M., Awad, A., Hamoud, Y., Elsheikha, A., Williams, C.F., Orr, E., Shaghaleh, H., Hamad, A., Thorp, K.R., Elbeltagi, A. 2025. Projecting rice water footprint for different shared socioeconomic pathways under arid climate conditions. Irrigation Science. 43:955-969. https://doi.org/10.1007/s00271-025-01019-8.