• ISSN 1008-505X
  • CN 11-3996/S
刘敏, 张翀, 何彦芳, 高兵, 苏芳, 江荣风, 巨晓棠. 追氮方式对夏玉米土壤N2O和NH3排放的影响[J]. 植物营养与肥料学报, 2016, 22(1): 19-29. DOI: 10.11674/zwyf.15108
引用本文: 刘敏, 张翀, 何彦芳, 高兵, 苏芳, 江荣风, 巨晓棠. 追氮方式对夏玉米土壤N2O和NH3排放的影响[J]. 植物营养与肥料学报, 2016, 22(1): 19-29. DOI: 10.11674/zwyf.15108
LIU Min, ZHANG Chong, HE Yan-fang, GAO Bing, SU Fang, JIANG Rong-feng, JU Xiao-tang. Impact of fertilization method on soil nitrous oxide emissions and ammonia volatilization during summer maize growth period[J]. Journal of Plant Nutrition and Fertilizers, 2016, 22(1): 19-29. DOI: 10.11674/zwyf.15108
Citation: LIU Min, ZHANG Chong, HE Yan-fang, GAO Bing, SU Fang, JIANG Rong-feng, JU Xiao-tang. Impact of fertilization method on soil nitrous oxide emissions and ammonia volatilization during summer maize growth period[J]. Journal of Plant Nutrition and Fertilizers, 2016, 22(1): 19-29. DOI: 10.11674/zwyf.15108

追氮方式对夏玉米土壤N2O和NH3排放的影响

Impact of fertilization method on soil nitrous oxide emissions and ammonia volatilization during summer maize growth period

  • 摘要: 【目的】研究氮肥与硝化抑制剂撒施及条施覆土三种追施氮肥方式下土壤N2O和NH3排放规律、 O2浓度及土壤NH4+-N、 NO2--N和NO3--N的时空动态,揭示追氮方式对两种重要环境气体排放的影响及机制。【方法】试验设置3个处理: 1)农民习惯追氮方式撒施(BC); 2)撒施添加10%的硝化抑制剂(BC+DCD); 3) 条施后覆土(Band)。 3个处理均在施肥后均匀灌水20 mm。在夏玉米十叶期追施氮肥后的15天(2014年7月23日至8月8日)进行田间原位连续动态观测,并在玉米成熟期测定产量及吸氮量。采用静态箱-气相色谱法测定土壤N2O排放量,土壤气体平衡管-气相色谱法测定土壤N2O浓度,PVC管-通气法测定土壤NH3挥发,土壤气体平衡管-泵吸式O2浓度测定仪测定土壤O2浓度。【结果】农民习惯追氮方式N2O排放量为N 395 g/hm2,NH3挥发损失为N 22.9 kg/hm2,同时还导致土壤在一定程度上积累了NO2--N。与习惯追氮方式相比,添加硝化抑制剂显著减少N2O排放89.4%,使NH3挥发略有增加,未造成土壤NO2--N的累积。条施覆土使土壤N2O排放量显著增加将近1倍,但使NH3挥发显著减少69.4%,同时造成施肥后土壤局部高NO2--N累积。条施覆土的施肥条带上土壤NO2--N含量与N2O排放通量呈显著正相关。土壤气体的O2和N2O浓度受土壤含水量控制,当土壤WFPS大于60%时,020 cm土层中的O2浓度明显降低,而N2O浓度增加,土壤N2O浓度和土壤O2浓度间呈极显著负相关。各处理地上部产量及总吸氮量差异不显著。【结论】土壤NO2--N的累积与铵态氮肥施肥方式密切相关,NO2--N的累积能够促进土壤N2O的排放,且在条施覆土时达到显著水平(P0.05)。追氮方式对N2O和NH3两种气体的排放存在某种程度的此消彼长,添加硝化抑制剂在减少N2O排放的同时会增加NH3挥发,条施覆土在显著减少NH3挥发的同时会显著增加土壤N2O排放。在条施覆土基础上添加硝化抑制剂,有可能同时降低N2O排放和NH3挥发损失,此推论值得进一步研究。

     

    Abstract: 【Objectives】The temporal and spatial patterns of soil NH4+-N, NO2--N and NO3--N content variation under different nitrogen fertilization methods, and the soil air N2O and O2 concentrations were investigated in the present study. The aim is to explore the mechanism of soil NH3 volatilization and N2O emission. 【Methods】The tested N fertilization methods were: 1) local farmers' conventional practices in which urea is broadcasted on soil surface followed by irrigation (BC), 2) broadcasting urea on soil surface and followed by the application of nitrification inhibitor DCD on soil surface (BC+DCD), 3) band application of urea in the middle of two adjacent maize rows and backfilled with soil (Band). Field experiment was conduct in a summer maize field from July 23 to August 8, 2014. Crop yield and nitrogen uptake were measured in the ripe period. Soil N2O emissions were measured with static chamber-gas chromatograph (GC) method and NH3 volatilizations with PVC tube-venting method. Soil N2O and O2 content were measured with soil-air equilibration tube-GC and soil-air equilibration tube-pump determinator, respectively. 【Results】 The N2O emission and NH3 volatilization induced by farmers' practice was N 395 g/hm2 and N 22.9 g/hm2 respectively, the soil NO2--N showed accumulation to some extend. Compared with BC, the application of DCD precluded the accumulation of soil NO2--N in soil, reduced N2O emission by 89.4%,whereas increased NH3 volatilization by 27.1%; By contrast, band application of urea induced high soil NO2--N accumulation in the fertilizer band, doubled N2O emission, whereas reduced NH3 volatilization by 69.4%. O2 and N2O concentration is soil air was regulated by WFPS. When WFPS was over 60%, O2 concentration reduced while N2O concentration increased significantly in the 0-20 cm soil layer. A negative relationship was observed between N2O and O2 concentration in soil air. There was nether significant difference among the three treatments in maize yield, nor total N uptake of aboveground part. 【Conclusions】 The accumulation of NO2--N in soil induced by ammonium fertilizer relies on N management strategies. Band application of ammonium fertilizer increased NO2--N accumulation in soil and soil N2O emission significantly (P0.05). There is a trade-off between the nitrogen fertilizer management strategies with different mitigation objectives. The application of DCD reduced N2O emission while it increased NH3 volatilization on the other hand, whereas the band application of urea reduced NH3 volatilization but it increased N2O emission. The N2O emission and NH3 volatilization were both high in farmers' traditional practices. Band application with DCD may reduce N2O emission and NH3 volatilization in the same time, which needs further research.

     

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