Hu Lei, Liu Yun, Zhu Bo
Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Huan Jing Ke Xue. 2017 Aug 8;38(8):3442-3450. doi: 10.13227/j.hjkx.201612250.
NO and NO emissions from a winter wheat-summer maize rotation system in purple soil were measured on a long-term fertilization platform of purple soil for two consecutive cropping years (from November 2014 to September 2016) by using a closed-chamber and gas chromatography-based system. Chemical fertilizer (NPK), pig manure (OM), incorporation of crop residues plus synthetic NPK fertilizer (RSDNPK), pig manure plus synthetic NPK fertilizer (OMNPK), and nitrification inhibitor with NPK fertilizer (DCDNPK) under the same rate of total nitrogen were involved in monitoring NO and NO emissions. Short-term fertilizer-free treatment (CK) was used as a control for emission coefficient calculation. The results showed that NO emission peaks appeared in the early stage of fertilization and in the period of heavy rainfall for all fertilization regimes. The NO emission process was similar to that of NO, in that emission peaks appeared at the early stage of fertilization, yet no obvious emission peaks were observed during heavy rainfall. The annual cumulative emissions of NO from NPK, OM, RSDNPK, OMNPK, and DCDNPK were 1.35, 4.38, 1.43, 2.46, and 0.92 kg·hm, respectively, and the emission coefficients were 0.33%, 1.41%, 0.36% 0.73%, and 0.18%. The annual emissions of NO from NPK, OM, RSDNPK, OMNPK, and DCDNPK were 0.11, 0.38, 0.10, 0.27, and 0.04 kg·hm, respectively, and the cumulative emission coefficients were 0.03%, 0.13%, 0.03%, 0.09%, and 0.01%. Amendment of organic material was the main stimulator for NO and NO emissions, as they significantly increased 226% and 262% (for OM) and 83% and 157% (for OMNPK), respectively (<0.01), compared with conventional synthetic fertilizers. The application of synthetic fertilizers combined with nitrification inhibitor (DCDNPK) significantly reduced NO emissions 32% and NO emissions 62% (<0.01), whereas straw returning with NPK application increased NO emissions 6% and reduced NO emissions 5% (>0.05). Furthermore, statistical analyses showed that soil inorganic N content was the main regulating factor of NO and NO emissions together, whereas soil water-filled pore space (WFPS) and temperature were the respective main regulating factors of NO and NO emissions individually.
在紫色土长期施肥试验平台上，采用密闭箱 - 气相色谱系统，连续两个种植年份（2014年11月至2016年9月）对紫色土冬小麦 - 夏玉米轮作系统中的一氧化氮（NO）和氧化亚氮（N₂O）排放进行了测定。在总氮用量相同的情况下，监测了化肥（NPK）、猪粪（OM）、作物秸秆还田配施化肥（RSDNPK）、猪粪配施化肥（OMNPK）以及在化肥中添加硝化抑制剂（DCDNPK）处理下的NO和N₂O排放。短期不施肥处理（CK）作为排放系数计算的对照。结果表明，所有施肥处理的NO排放峰值均出现在施肥初期和强降雨时期。N₂O的排放过程与NO相似，即在施肥初期出现排放峰值，但在强降雨期间未观察到明显的排放峰值。NPK、OM、RSDNPK、OMNPK和DCDNPK处理的NO年累积排放量分别为1.35、4.38、1.43、2.46和0.92 kg·hm⁻²，排放系数分别为0.33%、1.41%、0.36%、0.73%和0.18%。NPK、OM、RSDNPK、OMNPK和DCDNPK处理的N₂O年排放量分别为0.11、0.38、0.10、0.27和0.04 kg·hm⁻²，累积排放系数分别为0.03%、0.13%、0.03%、0.09%和0.01%。有机物料的添加是NO和N₂O排放的主要促进因素，与传统化肥相比，它们分别使NO排放显著增加226%和262%（OM处理）以及83%和157%（OMNPK处理）（P < 0.01）。施用化肥并添加硝化抑制剂（DCDNPK）显著降低了32%的NO排放和62%的N₂O排放（P < 0.01），而秸秆还田配施NPK使NO排放增加了6%，N₂O排放减少了5%（P > 0.05）。此外，统计分析表明，土壤无机氮含量是NO和N₂O排放的共同主要调节因子，而土壤充水孔隙率（WFPS）和温度分别是NO和N₂O排放各自的主要调节因子。
