Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, PR China.
Sci Total Environ. 2013 May 1;452-453:302-8. doi: 10.1016/j.scitotenv.2013.03.002. Epub 2013 Mar 22.
A field experiment was conducted to evaluate the influences of long-term applications of organic amendments and chemical fertilizers on nitrous oxide (N2O) emissions from Mollisols in northeast China and to relate soil N2O fluxes to soil moisture and temperature. A closed-chamber method was used to determine soil N2O flux during the maize growing season in 2011. In the entire maize growing period, cumulative N2O emissions were significantly (all P<0.05) increased by 66, 86 and 83% under the applications of 4.5 Mg ha(-1) maize straw combined with NPK, 7.5 and 22.5 Mg ha(-1) pig manure combined with NPK, respectively, compared with the control (0.64±0.01 kg N2O-N ha(-1)), whereas NPK fertilizer alone and 2.25 Mg ha(-1) maize straw combined with NPK had no remarkable influences (P>0.05). Nonetheless, even increasing nitrogen inputs, the cumulative microbial N2O emission over 126 days had an upper threshold around 1.2 kg N2O-N ha(-1). Approximately 25-44% of N2O was emitted from the applied organic amendments, and the emission factor (EF) of applied organic amendments as N2O based on 126 days was between 0.07 and 1.52%, higher than NPK fertilizer-induced EF (0.03%). Soil temperature explained 38-96% of the seasonal variation in soil N2O fluxes using exponential models, with a Q10 of 2.01-3.48. Our results suggest that the influences of organic amendments on soil N2O emissions from Mollisols primarily vary with the type of the applied organic amendments, whereas great nitrogen inputs at maximum asymptotically double baseline cumulative emissions.
一项田间试验评估了长期施用有机肥和化肥对中国东北黑土区一氧化二氮（N2O）排放的影响，并将土壤 N2O 通量与土壤水分和温度相关联。在 2011 年玉米生长季期间，采用密闭室法测定土壤 N2O 通量。在整个玉米生长期间，与对照（0.64±0.01 kg N2O-N ha(-1))相比，施用 4.5 Mg ha(-1)玉米秸秆与 NPK 结合、7.5 和 22.5 Mg ha(-1)猪粪与 NPK 结合分别显著（均 P<0.05）增加了 66%、86%和 83%的累积 N2O 排放，而单独施用 NPK 肥料和施用 2.25 Mg ha(-1)玉米秸秆与 NPK 结合则没有显著影响（P>0.05）。然而，即使增加氮素投入，126 天内累积的微生物 N2O 排放也有一个约 1.2 kg N2O-N ha(-1)的上限。约 25-44%的 N2O 来自施用的有机肥料，以 126 天为基础，施用有机肥料的排放因子（EF）为 N2O，介于 0.07-1.52%之间，高于 NPK 肥料诱导的 EF（0.03%）。土壤温度用指数模型解释了土壤 N2O 通量季节变化的 38-96%，Q10 为 2.01-3.48。我们的研究结果表明，有机肥料对黑土区土壤 N2O 排放的影响主要取决于施用有机肥料的类型，而大量氮素投入则最大程度地使基线累积排放量加倍。
