Nitrous Oxide Emissions and Its Influencing Factors from an Agricultural Headwater Ditch During a Maize Season in the Hilly Area of Central Sichuan Basin

• Published in: Huanjing kexue Vol. 38; no. 5; p. 2074
• Main Authors: Tian, Lin-Lin, Zhu, Bo, Wang, Tao, Zhao, Yuan, Dong, Hong-Wei, Ren, Guang-Qian, Hu, Lei
• Format: Journal Article
• Language: Chinese
• Published: China 08.05.2017
• Subjects: rain; N2O; nitrogen cycling; nitrate; indirect N2O emission factor; ditch ecosystem
• ISSN: 0250-3301
• DOI: 10.13227/j.hjkx.201611163

Agricultural headwater ditches, the important locations for retaining and transforming nitrogen derived from the adjacent farmlands, have been regarded as the potential source of nitrous oxide (N O) emission. In this study, N O emissions from a typical agricultural ditch in the Hilly Area of Central Sichuan Basin, were observed by closed static chamber-GC technique during the maize season (rainy season), from June to the end of September. During the study period, cumulative N O emissions in the sediment-water interface without vegetation (NV) and the ditch ecosystem with natural vegetation (V) were 0.07 and 0.43 kg·hm , respectively. Meanwhile, the mean N O flux from the agricultural headwater ditch ecosystem[14.7 μg·(m ·h) ] was comparable to the magnitude of direct N O flux from the maize cropland in this region. Nitrate concentration in the overlying water could be the main factor governing N O emission from the ditch, especially in the rainy season. The existence of vegetation increased the indirect N O e