Enhanced Efficiency Nitrogen Fertilizers Reduced Ammonia Emissions in Rainfed Cotton

ABSTRACT Ammonia volatilization is a nitrogen (N) loss pathway with severe environmental impacts, such as ecosystem eutrophication and secondary particulate formation. Rainfed agricultural systems and sandy soils in the Florida panhandle provide ideal conditions for ammonia (NH 3 ) losses. This study investigated the potential of enhanced efficiency nitrogen fertilizers (EENFs) to reduce NH 3 losses under rainfed cotton production. The experiment was conducted in 2023 and 2024 using a randomised complete block design. The experiment included four fertilizers: urea (U), urea coated with urease inhibitor (U + NBPT), urea coated with urease and nitrification inhibitor (U + NBPT + DCD), and polymer‐coated urea (PCU [41‐0‐0]) applied at rate of 102 kg N/ha. Our results indicate that cumulative NH 3 emissions were 50%–87.5% higher under U than U + NBPT, U + NBPT + DCD, and PCU (41‐0‐0) in 2023. In 2024, U and U + NBPT had 83%–87% higher emissions than U + NBPT + DCD and PCU (41‐0‐0). There was no significant effect of EENFs on lint yield compared to U. This study underscores the potential of EENFs to reduce NH 3 losses under rainfed conditions.