Enhancing nitrogen use efficiency and yield of maize ( Zea mays L.) through Ammonia volatilization mitigation and nitrogen management approaches

Management of nitrogen (N) fertilizer is a critical factor that can improve maize ( Zea mays L. ) production. On the other hand, high volatilization losses of N also pollute the air. A field experiment was established using a silt clay soil to examine the effect of sulfur-coated urea and sulfur from gypsum on ammonia (NH 3 ) emission, N use efficiency (NUE), and the productivity of maize crop under alkaline calcareous soil. The experimental design was a randomized complete block (RCBD) with seven treatments in three replicates: control with no N, urea 150 alone (150 kg N ha −1 ), urea 200 alone (200 kg N ha −1 ), urea 150 + S (60 kg ha −1 S from gypsum), urea 200 + S, SCU 150 (sulfur-coated urea) and SCU 200 . The results showed that the urea 150 + S and urea 200 + S significantly reduced the total NH 3 by (58 and 42%) as compared with the sole application urea 200 . The NH 3 emission reduced further in the treatment with SCU 150 and SCU 200 by 74 and 65%, respectively, compared to the treatment with urea 200 . The maize plant biomass, grain yield, and total N uptake enhanced by 5–14%, 4–17%, and 7–13, respectively, in the treatments with urea 150 + s and urea 200 + S, relative to the treatment with urea 200 alone. Biomass, grain yield, and total N uptake further increased significantly by 22–30%, 25–28%, and 26–31%, respectively, in the treatments with SCU 150 and SCU 200 , relative to the treatment with urea 200 alone. The applications of SCU 150 enhanced the nitrogen use efficiency (NUE) by (72%) and SCU 200 by (62%) respectively, compared with the sole application of urea 200 alone. In conclusion, applying S-coated urea at a lower rate of 150 kg N ha −1 compared with a higher rate of 200 kg N ha −1 may be an effective way to reduce N fertilizer application rate and mitigate NH 3 emission, improve NUE, and increase maize yield. More investigations are suggested under different soil textures and climatic conditions to declare S-coated urea at 150 kg N ha −1 as the best application rate for maize to enhance maize growth and yield.