• ISSN 1008-505X
  • CN 11-3996/S
叶桂香, 史永晖, 王良, 陈玉洁, 辛延斌, 刘文茹, 陈国庆. 秸秆还田的小麦–玉米农田 N2O 周年排放的量化分析[J]. 植物营养与肥料学报, 2017, 23(3): 589-596. DOI: 10.11674/zwyf.16324
引用本文: 叶桂香, 史永晖, 王良, 陈玉洁, 辛延斌, 刘文茹, 陈国庆. 秸秆还田的小麦–玉米农田 N2O 周年排放的量化分析[J]. 植物营养与肥料学报, 2017, 23(3): 589-596. DOI: 10.11674/zwyf.16324
YE Gui-xiang, SHI Yong-hui, WANG Liang, CHEN Yu-jie, XIN Yan-bin, LIU Wen-ru, CHEN Guo-qing. Quantitative analysis of straw returning on annual soil N2O emission in the wheat–maize rotation system[J]. Journal of Plant Nutrition and Fertilizers, 2017, 23(3): 589-596. DOI: 10.11674/zwyf.16324
Citation: YE Gui-xiang, SHI Yong-hui, WANG Liang, CHEN Yu-jie, XIN Yan-bin, LIU Wen-ru, CHEN Guo-qing. Quantitative analysis of straw returning on annual soil N2O emission in the wheat–maize rotation system[J]. Journal of Plant Nutrition and Fertilizers, 2017, 23(3): 589-596. DOI: 10.11674/zwyf.16324

秸秆还田的小麦–玉米农田 N2O 周年排放的量化分析

Quantitative analysis of straw returning on annual soil N2O emission in the wheat–maize rotation system

  • 摘要:
    目的N2O 是重要的温室气体之一,主要来源于农田土壤。华北平原是我国的粮食主产区,秸秆还田是该地区主要的农田管理措施,明确不同秸秆还田量对小麦玉米农田周年土壤温度和含水量的影响以及与 N2O 排放之间的量化关系,对发挥秸秆还田的生态效应,明确硝化和反硝化作用机制具有重要意义。
    方法以冬小麦、夏玉米为研究对象,设置 5 种不同秸秆还田量处理:小麦、玉米秸秆均不还田 (T0);小麦秸秆 1875 kg/hm2 + 玉米秸秆 2000 kg/hm2 还田 (T1);小麦秸秆 3750 kg/hm2 + 玉米秸秆 4000 kg/hm2 还田 (T2);小麦秸秆 5625 kg/hm2 + 玉米秸秆 6000 kg/hm2 还田 (T3);小麦秸秆 7500 kg/hm2 + 玉米秸秆 8000 kg/hm2 还田 (T4)。于 2014 年 10 月~2015 年 10 月,采用静态箱–气相色谱法对农田 N2O 排放进行测定,探究不同秸秆还田量下小麦玉米农田 N2O 排放的周年变化,并量化分析土壤温度、含水量与 N2O 排放的关系。
    结果秸秆还田量显著影响 N2O 的排放,随着秸秆还田量的增加,周年内 N2O 排放总量呈增加的趋势,增加量为 1.33~3.50 kg/hm2,增加率为 32.3%~85.0%;通量增加量为 15.52~40.87 μg/(m2·h),增加率为 32.3%~85.1%。玉米季 N2O 排放通量和总量分别是小麦季的 2.42~2.62 和 1.05~1.14 倍。秸秆还田可提高 0—10 cm 土壤温度和 0—20 cm 土壤含水量,增加范围分别为 0.63~2.14℃ 和 0.6%~1.8%。相关性分析表明,各处理土壤温度和 N2O 排放通量无相关关系(P > 0.05)。T0、T1、T2 处理土壤含水量与 N2O 排放通量呈显著正相关(P < 0.05),而 T3、T4 处理与 N2O 排放通量之间不相关(P > 0.05)。
    结论随着秸秆还田量的增加,N2O 排放通量和总量均呈现增加趋势,且玉米季高于小麦季。秸秆还田显著促进 N2O 排放并可提高 0—20 cm 土壤含水量和 0—10 cm 土壤温度,周年秸秆还田量在 7750 kg/hm2 及以下时,N2O 排放通量与土壤含水量之间呈显著正相关,而与土壤温度之间不相关。

     

    Abstract:
    ObjectivesNitrous oxide (N2O) is one of the important greenhouse gases that mainly come from farmland soils. Straw returning is an effective ecological management in North China. Quantitative analysis of the N2O emission and the affecting factors is of great significance for deep understanding of nitrification and denitrification mechanism in the wheat-maize system.
    MethodsA field experiment with five different amounts of straw incorporation was carried out in the winter wheat and summer maize, including without straw returning (T0), returning 1875 kg/hm2 wheat straw and 2000 kg/hm2 maize straw (T1), returning 3750 kg/hm2 wheat straw and 4000 kg/hm2 maize straw (T2), returning 5625 kg/hm2 wheat straw and 6000 kg/hm2 maize straw (T3), and returning 7500 kg/hm2 wheat straw and 8000 kg/hm2 maize straw (T4). From October 2014 to October 2015, the N2O flux was determined using static chamber technology combined with gas chromatography, the annual variation of N2O flux and their relationships with soil temperature and moisture were analyzed.
    ResultsThe straw returning amounts affected the N2O flux significantly, which was increased with the increase of straw returning amounts. The seasonal N2O emission was increased by 1.33–3.50 kg/hm2 in amount, or 32.3%–85.1% in rates. The average N2O flux were increased by 15.52–40.87 μg/(m2·h) in amount, or 32.3%–85.1% in rates. The average N2O flux and total emission during the maize season were respectively 2.42–2.62 times and 1.05–1.14 times of those in the wheat season. The straw returning increased the temperature in 0–10 cm layer of soil by 0.63–2.14℃ and moisture in 0–20 cm layer of soil by 0.6%–1.8%, respectively. The correlation analysis showed that the N2O flux had no correlation with soil temperature, had an exponential correlation with soil moisture in treatment T0, T1 and T2 (P < 0.05), but not with those in treatment T3 or T4.
    ConclusionsWith the increase of straw returning amounts, the average N2O flux and seasonal emission will be increased, which are higher in the maize season than in the wheat season. The straw returning could increase soil temperature in 0–10 cm layer and soil moisture in 0–20 cm layer significantly. The N2O flux has an exponential correlation with soil moisture when the annual straw returning amounts are less than 7500 kg/hm2, while had no correlation with soil temperature.

     

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