Responses of N[sub.2]O, CO[sub.2], and NH[sub.3] Emissions to Biochar and Nitrification Inhibitors Under a Delayed Nitrogen Application Regime

• Published in: Agriculture (Basel) 2024-11, Vol.14 (11)
• Main Authors: Wu, Haizhong, Wang, Daichang, Zhang, Dengxiao, Rao, Wei, Yuan, Qingsong, Shen, Xiaobo, Ma, Guozhen, Jie, Xiaolei, Liu, Shiliang
• Format: Article
• Language: English
• Subjects: Air pollution; Air quality management; Ammonia; Fertilizers; Greenhouse gases; Nitrification
• ISSN: 2077-0472; 2077-0472
• DOI: 10.3390/agriculture14111986

Greenhouse gas and NH[sub.3] emissions are exacerbated by the inappropriate timing and excessive application of nitrogen (N) fertilizers in wheat cultivation in China. In this study, the impacts on N[sub.2]O, CO[sub.2], and NH[sub.3] emissions of a delayed and reduced N application regime on the Huang-Huai-Hai Plain were investigated. The treatments comprised the control (N[sub.0]), conventional N at 270 kg N ha[sup.−1] (N[sub.270]) and optimized N application of 180 kg N ha[sup.−1] (N[sub.180]), N[sub.180] + biochar at 7.5 t ha[sup.−1] (N[sub.180]B[sub.7.5]), N[sub.180] + biochar at 15 t ha[sup.−1] (N[sub.180]B[sub.15]), N[sub.180] + DMPP (a nitrification inhibitor; N[sub.180]D), N[sub.180]D + biochar at 7.5 t ha[sup.−1] (N[sub.180]DB[sub.7.5]), and N[sub.180]D + biochar at 15 t ha[sup.−1] (N[sub.180]DB[sub.15]). Reduced N application (N[sub.180]) lowered N[sub.2]O and NH[sub.3] emissions. Biochar application resulted in a 4–25% and 12–16% increase in N[sub.2]O and NH[sub.3] emissions, respectively. Application of DMPP significantly decreased N[sub.2]O emissions by 32% while concurrently inducing a 9% increase in NH[sub.3] emissions. Co-application of DMPP and biochar significantly reduced the activity of nitrification enzymes (HAD, NOO), resulting in a reduction of 37–38% in N[sub.2]O emissions and 13–14% in NH[sub.3] emissions. No significant differences in CO[sub.2] emissions were observed among the various N treatments except the N[sub.0] treatment. Application of DMPP alone did not significantly affect grain yield. However, biochar, in combination with DMPP, effectively increases grain yield. The findings suggest that the N[sub.180]DB[sub.15] treatment has the potential to reduce emissions of N[sub.2]O and NH[sub.3] while concurrently enhancing soil fertility (pH, SOC) and wheat yield.