Ammonia-oxidation as an engine to generate nitrous oxide in an intensively managed calcareous Fluvo-aquic soil

作者：Huang Tao; Gao Bing; Hu Xiao Kang; Lu Xing; Well Reinhard; Christie Peter; Bakken Lars R; Ju Xiao Tang^*

来源：Scientific Reports, 2014, 4(1): 3950.

DOI：10.1038/srep03950

We combine field observations, microcosm, stoichiometry, and molecular and stable isotope techniques to quantify N2O generation processes in an intensively managed low carbon calcareous fluvo-aquic soil. All the evidence points to ammonia oxidation and linked nitrifier denitrification (ND) being the major processes generating N2O. When NH4+-based fertilizers are applied the soil will produce high N2O peaks which are inhibited almost completely by adding nitrification inhibitors. During ammonia oxidation with high NH4+ concentrations (%26gt;80 mg N kg(-1)) the soil matrix will actively consume oxygen and accumulate high concentrations of NO2-, leading to suboxic conditions inducing ND. Calculated N2O isotopomer data show that nitrification and ND accounted for 35-53% and 44-58% of total N2O emissions, respectively. We propose that slowing down nitrification and avoiding high ammonium concentrations in the soil matrix are important measures to reduce N2O emissions per unit of NH4+-based N input from this type of intensively managed soil globally.

• 出版日期2014-2-4
• 单位中国农业科学院