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草业学报 ›› 2018, Vol. 27 ›› Issue (9): 1-13.DOI: 10.11686/cyxb2017530

• 研究论文 • 上一篇    下一篇

黄土高原雨养农业区不同种植模式土壤温室气体排放特征

邓长芳1, 罗珠珠1, 2, *, 李玲玲2, 牛伊宁2, 蔡立群1, 2, 张仁陟2, 谢军红2   

  1. 1.甘肃农业大学资源与环境学院,甘肃 兰州 730070;
    2.甘肃省干旱生境作物学省部共建国家重点实验室,甘肃 兰州730070
  • 收稿日期:2017-12-28 修回日期:2018-03-28 出版日期:2018-09-20 发布日期:2018-09-20
  • 通讯作者: E-mail: luozz@gsau.edu.cn
  • 作者简介:邓长芳(1991-), 女, 山东枣庄人, 在读硕士。E-mail: 568002432@qq.com
  • 基金资助:
    国家自然科学基金项目(41461067,31171513),甘肃省财政厅高校基本科研业务费项目(037-041014)和甘肃省自然科学基金(1606RJZA076)资助

Characterization of greenhouse gases emissions from rainfed soils in different cropping systems on the Loess Plateau

DENG Chang-fang1, LUO Zhu-zhu1, 2, *, LI Ling-ling2, NIU Yi-ning2, CAI Li-qun1, 2, ZHANG Ren-zhi2, XIE Jun-hong2   

  1. 1.College of Resources and Environmental, Gansu Agricultural University, Lanzhou 730070, China;
    2.Gansu Key Laboratory of Aridland Crop Science, Lanzhou 730070, China
  • Received:2017-12-28 Revised:2018-03-28 Online:2018-09-20 Published:2018-09-20

摘要: 研究陇中黄土高原旱作农田,设置了苜蓿-苜蓿(L-L)、苜蓿-休闲(L-F)、苜蓿-小麦(L-W)、苜蓿-玉米(L-C)、苜蓿-马铃薯(L-P)和苜蓿-谷子(L-M)6个处理,采用静态箱-气相色谱法和碳通量测量系统LI-8100对苜蓿后茬轮作不同作物土壤温室气体排放动态及其影响因素进行了测定与分析。研究结果表明,农田土壤表现为CO2源、N2O源和CH4吸收汇,且呈现夏秋高,春冬低的季节性变化特征。L-L处理的CO2累积排放量最高,L-W处理较之降低了42.43%;L-C处理的N2O累积排放量最高,L-P处理最低;CH4吸收量以L-M处理最高,较L-F和L-L分别增加了62.71%和31.87%,综合增温潜势表现为L-L>L-M>L-C>L-P>L-F>L-W。相关分析结果表明,CO2、CH4、N2O排放量与脲酶、过氧化氢酶活性及土壤温度呈极显著相关(P<0.01),与土壤水分在不同土层有显著相关性;逐步回归分析发现,土壤温度、过氧化氢酶是CO2和CH4排放的主导因素,土壤温度极显著影响气体排放,N2O排放主要受到环境因子的影响。综合来看,与长期苜蓿连作相比,黄土高原地区苜蓿种植一定年限之后轮作粮食作物能减少土壤温室气体排放量,减弱农田温室气体的增温效应,其中以小麦效果最佳。

关键词: 苜蓿-作物, 温室气体, 排放通量, 脲酶, 过氧化氢酶

Abstract: This paper compares the effects of different lucerne planting patterns on the dynamic flux of soil greenhouse gases (CO2, CH4 and N2O) in dry farmlands of the Loess Plateau.Effects of soil temperature, soil water content, and soil enzyme activities on greenhouse gas emissions were studied, using static chamber gas chromatographic techniques to measure CH4 and N2O and a LI-8100 measurement system to determine CO2 flux. The research included 6 treatments: lucerne-lucerne (L-L), lucerne-fallow (L-F), lucerne-wheat (L-W), lucerne-corn (L-C), lucerne-potato (L-P) and lucerne-millet (L-M). The results showed that farmland soil served not only as source of atmospheric CO2 and N2O,but also as sink of atmospheric CH4, with seasonal gas fluxes higher in summer and autumn than in spring and winter. L-L had the highest cumulative emission of CO2 and L-W had decreased 42% compared with it, while L-C had the highest cumulative emission of N2O and L-P had the lowest. The CH4 absorption of L-M was higher by 62.71% and 31.87%, respectively, than L-F and L-L.The calculated global warming potential was L-L>L-M>L-C>L-P>L-F>L-W. Correlation analysis showed there were significant relationships between greenhouse gas fluxes and activities of soil enzymes urease, and catalase, and with soil temperature (P<0.01).Gas fluxes were also correlated with soil water content in some soil layers; stepwise regression analysis found that soil temperature and catalase activities were the dominant factors affecting CO2 and CH4 flux. Soil temperature influenced greenhouse gas emission significantly. N2O flux displayed no significant correlation with biological factors, but was positively correlated with soil temperature and soil water content. In general, planting of other crop species after lucerne cropping reduced intensity of soil greenhouse gas emission, and the overall greenhouse gas emission of the farmland, and the treatment L-W was the most effective.

Key words: lucerne-crop, greenhouse gases, emission flux, urease, catalase