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草业学报 ›› 2021, Vol. 30 ›› Issue (2): 32-45.DOI: 10.11686/cyxb2020226

• 研究论文 • 上一篇    下一篇

培肥措施对旱地农田土壤CO2排放和碳库管理指数的影响

王晓娇1,3(), 蔡立群1,2,4(), 齐鹏1,2,4(), 王雅芝1, 陈晓龙1, 武均1,2,4, 张仁陟1,2,4()   

  1. 1.甘肃农业大学资源与环境学院,甘肃 兰州 730070
    2.甘肃农业大学甘肃省干旱生境作物学重点实验室,甘肃 兰州 730070
    3.甘肃农业大学管理学院,甘肃 兰州 730070
    4.甘肃省节水农业工程技术研究中心,甘肃 兰州 730070
  • 收稿日期:2020-05-21 修回日期:2020-07-29 出版日期:2021-02-20 发布日期:2021-01-19
  • 通讯作者: 蔡立群,齐鹏,张仁陟
  • 作者简介:zhangrz@gsau.edu.cn
    gsauqip@163.com
    E-mail:cailq@gsau.edu.cn
    王晓娇(1980-),女,甘肃平凉人,讲师,在读博士。 E-mail: 42321964@qq.com
  • 基金资助:
    甘肃农业大学盛彤笙基金(GSAU-STS-1706);甘肃农业大学学科建设基金(GAU-XKJS-2018-205);青年研究生导师扶持基金(GAU-QNDS-201704)

Effects of alternative fertilizer options on soil CO2 emission and carbon pool management index in a dryland soil

Xiao-jiao WANG1,3(), Li-qun CAI1,2,4(), Peng QI1,2,4(), Ya-zhi Wang1, Xiao-long CHEN1, Jun Wu1,2,4, Ren-zhi ZHANG1,2,4()   

  1. 1.College of Resources and Environmental Sciences,Gansu Agricultural University,Lanzhou 730070,China
    2.Gansu Provincial Key Laboratory of Arid Land Crop Science,Gansu Agricultural University,Lanzhou 730070,China
    3.College of Management,Gansu Agricultural University,Lanzhou 730070,China
    4.Gansu Engineering Research Center for Agriculture Water-saving,Lanzhou 730070,China
  • Received:2020-05-21 Revised:2020-07-29 Online:2021-02-20 Published:2021-01-19
  • Contact: Li-qun CAI,Peng QI,Ren-zhi ZHANG

摘要:

阐明长期有机物料施肥下土壤CO2排放特征及其影响机制以及碳库管理指数对黄土高原旱作农业区固碳减排及施肥模式选择的影响尤为重要。基于2012年设置在陇中黄土高原旱作区的长期定位试验,通过不施肥(CK)、氮肥(NF)、有机肥(OM)、秸秆(ST)、有机肥结合无机肥(OMNF)5个处理,测定并计算了2018年不同施肥措施下全年土壤CO2排放、作物碳排放效率和碳库管理指数的变化,并运用结构方程模型分析了0~30 cm土壤温度、水分、微生物量碳氮、易氧化有机碳、蔗糖酶、脲酶与土壤CO2排放速率的关系。结果表明:1)与不施肥相比,秸秆、有机结合无机肥和有机肥处理使生育期土壤CO2排放平均速率提高了42.72%、30.82%和29.79%,秸秆、有机肥处理分别使生育期土壤CO2排放量显著提高36.35%、32.45%(P<0.05),有机结合无机肥处理使碳排放效率显著降低41.10%(P<0.05);2)有机物料处理均能显著提高0~5 cm土层易氧化有机碳、微生物量碳氮、蔗糖酶活性和碳库管理指数,相比不施肥和氮肥处理,有机结合无机肥处理分别使0~30 cm土壤碳库管理指数提高127.41%,99.33%(P<0.05);3)结构方程模型表明,环境因子对土壤CO2排放速率的总解释度为53%,对土壤CO2排放速率总效应较大的影响因素包括土壤温度(2.36)、微生物量碳(1.59)和土壤水分(1.18),且均间接地影响着土壤CO2排放速率,土壤温度促进了微生物量碳和蔗糖酶活性的提高,微生物量碳促进了微生物量氮和易氧化有机碳的增加。综合来看,有机结合无机肥处理可以提升土壤碳库管理指数,保持微生物活性,增加作物产量,降低土壤碳排放效率,是陇中黄土高原旱作农业区比较适宜的农田培肥措施。

关键词: 旱地土壤, CO2排放, 作物碳排放效率, 碳库管理指数, 培肥措施

Abstract:

In 2015, the Ministry of Agriculture in China announced a ‘zero increase action plan’ for national fertilizer use, to be implemented by 2020, with the aim of reducing the environmental costs associated with food production. This ‘zero increase’ plan highlights the need to adopt reasonable fertilizer policies with organic materials to alleviate the environmental problems (e.g., global warming, air pollution, and eutrophication). Hence, this research aimed to clarify the influence of various fertilization options on soil CO2 emission and carbon pool management index under different fertilization options. Collection of such data is an essential component of research on carbon sequestration and carbon emission reduction and is also necessary to identify best fertilization practice in unirrigated farming on the Loess Plateau. A long-term field experiment with five fertilization treatments in the Longzhong Loess Plateau was set up in 2012. Fertilization treatments included no fertilizer (CK), nitrogen fertilizer (NF), organic fertilizer (OM), straw (ST), and organic fertilizer combined with inorganic fertilizer (OMNF). The annual soil CO2 emissions, crop carbon emission efficiency (CEE) and carbon pool management index (CPMI) were analyzed in 2018, and the relationships between relevant factors [soil temperature, moisture content, microbial biomass carbon and nitrogen (MBC, MBN), readily oxidizable organic carbon (ROOC), urease and invertase for the soil depth of 0-30 cm] and soil CO2 flux were determined by the structural equation model (SEM). It was found that: 1) Compared with CK, ST, OMNF and OM treatments increased the soil CO2 flux by 42.72%, 30.82% and 29.79%, respectively, while ST and OM treatments increased the soil CO2 emission by 36.35%, 32.45%(P<0.05), respectively, and OMNF reduced carbon emission efficiency by 41.10% (P<0.05). 2) The OM treatment significantly increased the soil ROOC, MBC, MBN, invertase activity and CPMI in the 0-5 cm soil layer. Compared with CK and NF, the OMNF treatment significantly increased the soil CPMI (0-30 cm) by 127.41% and 99.33% (P<0.05), respectively. 3) SEM showed that the environmental factors explained in total 53% of soil CO2 flux, and the factors that had the largest cumulative effect were soil temperature (2.36), microbial biomass carbon (1.59) and soil moisture content (1.18). These three factors also indirectly affected soil CO2 flux. Higher soil temperature promoted increased MBC and invertase activity, and increased MBC further enhanced the rate of change of MBN and ROOC. Overall, OMNF was found to be a sustainable and effective management practice to improve CPMI, maintain microbial activity, increase crop yield, and at the same time also reduce CEE in dryland farming on the Loess Plateau.

Key words: dry land soil, CO2 emission, crop carbon emission efficiency, carbon pool management index, fertilization options