Environmental sustainability of future fertilizers: Tradeoffs between ammonia volatilization and nitrate leaching for 11 enhanced efficiency fertilizers

Authors: CLARK, CHRISTOPHER - Environmental Protection Agency (EPA); DODLA, SYAM - International Fertilizer Development Center (IFDC); UPENDRA, SINGH - International Fertilizer Development Center (IFDC); DELGADO, JORGE - Retired ARS Employee; HOPKINS, BRYAN - Brigham Young University; Olk, Daniel; PAVULURI, KIRAN - International Fertilizer Development Center (IFDC); ROY, AMIT - International Fertilizer Development Center (IFDC); VENTEREA, RODNEY - Retired ARS Employee; WILSON, MICHAEL - Wabash Valley Service Company; FUGICE, JOB - International Fertilizer Development Center (IFDC)

Submitted to: Journal of Plant Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/20/2025
Publication Date: 1/7/2026
Citation: Clark, C.M., Dodla, S., Upendra, S., Delgado, J.A., Hopkins, B.G., Olk, D.C., Pavuluri, K., Roy, A., Venterea, R.T., Wilson, M.H., Fugice, J. 2026. Environmental sustainability of future fertilizers: Tradeoffs between ammonia volatilization and nitrate leaching for 11 enhanced efficiency fertilizers. Journal of Plant Nutrition. https://doi.org/10.1080/01904167.2025.2595092.
DOI: https://doi.org/10.1080/01904167.2025.2595092

Interpretive Summary: Nitrogen is often the most important nutrient for plant growth. It must be added to the soil at high fertilizer rates to enable maximum crop growth. However, it can be transported from the soil to pollute air and water bodies if the crops do not take it up quickly enough. To reduce its losses to the environment, special nitrogen fertilizers can be made that are more stable in the soil. But their effectiveness in reducing environmental losses has not been carefully compared in multiple soils for different types of stable nitrogen fertilizers. Working with two Midwestern soils in greenhouse conditions, we found that stable nitrogen fertilizers differed in their rates of loss from the soil through gas or liquid pathways, depending on their type. These results will guide continuing work into the development of stable nitrogen fertilizers. This work will be of value to researchers of stable fertilizers, land managers who desire more efficient use of their applied nitrogen fertilizers, and crop advisors.

Technical Abstract: Nitrogen (N) fertilizers are critical to modern society and human well-being. However, these benefits are not without consequences, as excess N fertilizer can lead to environmental impacts. There are more and more new technologies that aim to reduce N losses to the environment and increase nitrogen use efficiency (NUE), but many studies only evaluate a few technologies, and most field campaigns are difficult to cross-compare due to the strong effect of site conditions. Here we “stress tested” 11 enhanced efficiency fertilizers (EEFs) under common greenhouse conditions using two different soil types (a clay loam from Iowa and a sandy loam from Minnesota) against two conventional fertilizers for performance in two key areas – NH3 volatilization and N leaching. This included three nitrification inhibitors (DMPSA, Pronitridine, Nitrapyrin), one urease inhibitor (NBPT), two dual inhibitors (DCD+NBPT+Urea, DCD+NBPT+UAN), five polymer coated fertilizers, and two conventional fertilizers (UAN and urea). We found performance tradeoffs among EEFs; and, considering both tests, there were six EEFs that performed well: two inhibitors (DMPSA, DCD+NBPT+Urea), and four polymer coated fertilizers (all three polyurethane and the PLA/PBS coated fertilizers). We also found that the same class of EEF (e.g., nitrification inhibitor) could perform very differently based on the substrate (e.g., Urea vs. UAN). Given that the polymer coated fertilizers all likely biodegrade very slowly (years) under field conditions and could accumulate microplastics in the environment, the two inhibitor-class EEFs may be promising as candidates for additional agronomic testing in the field until more biodegradable polymers are developed.