<p>Poultry manure urea can undergo hydrolysis by urease to produce ammonia, which contributes to air pollution. To reduce ammonia emissions from urea, we targeted the inhibition of urease activity, the key enzyme responsible for the rapid hydrolysis of urea, using organic acids as sustainable alternatives to chemical compounds. Organic acids are biodegradable fermentation products and they have minimal negative effect on soil microbiota, plant metabolism and human health. The organic acids tested for their inhibitory effect on urease activity include malic, succinic, lactic, acetic, and citric acids, all of which exhibited potential inhibitory effects, with malic acid showing the potent inhibitory effect on urease activity. The results of the docking analysis revealed that organic acids could interact with the nickel atoms in the active site of urease through their carboxyl groups, confirming their high anti-urease potential by chelating nickel. Additionally, treating poultry manure with organic acids reduced the NH₄⁺ production rate for 4&#xa0;days longer than sulfuric acid, which is commonly used for manure acidification. It also alleviated the increase in pH and conductivity, which are indicators of urea hydrolysis.</p><p>Based on our results, malic acid emerged as the most effective urease inhibitor, demonstrating for the first time a significant reduction in NH₄⁺ production from poultry manure. In addition to its urease-inhibitory effect, malic acid is known to enhance nutrient uptake and improve fruit quality. Therefore, its use in poultry manure management represents an innovative and environmentally friendly strategy to mitigating ammonia emissions. This approach offers a sustainable alternative to conventional chemical inhibitors, with potential benefits for both agricultural productivity and environmental protection.</p>