中国农业科学 ›› 2016, Vol. 49 ›› Issue (1): 120-131.doi: 10.3864/j.issn.0578-1752.2016.01.011

• 土壤肥料·节水灌溉·农业生态环境 • 上一篇    下一篇

少免耕及秸秆还田小麦间作玉米的碳排放与水分利用特征

胡发龙1,柴强1,甘延太2,殷文1,赵财1,冯福学1

 
  

  1. 1甘肃农业大学农学院/甘肃省干旱生境作物学重点实验室, 中国兰州 730070
    2Agriculture and Agri-Food Canada, Semiarid Prairie Agricultural Research Centre, Swift Current, SK, S9H 3X2, Canada
  • 收稿日期:2015-05-19 出版日期:2016-01-01 发布日期:2016-01-01
  • 通讯作者: 柴强,E-mail:Chaiq@gsau.edu.cn
  • 作者简介:胡发龙,Tel:18793112959;E-mail:falong_hu@126.com
  • 基金资助:
    国家自然科学基金(31360323)、国家科技支撑计划(2012BAD14B10)、伏羲杰出人才培育计划(FXRC20130101)

Characteristics of Soil Carbon Emission and Water Utilization in Wheat/Maize Intercropping with Minimal/Zero Tillage and Straw Retention

HU Fa-long1, CHAI Qiang1 , GAN Yan-tai2, YIN Wen1, ZHAO Cai1, FENG Fu-xue1   

  1. 1 Faculty of Agronomy, Gansu Agricultural University/Gansu Provincial Key Laboratory of Arid Land Crop Science, Lanzhou 730070, China
    2Agriculture and Agri-Food Canada, Semiarid Prairie Agricultural Research Centre, Swift Current, SK, S9H 3X2, Canada
  • Received:2015-05-19 Online:2016-01-01 Published:2016-01-01

摘要: 目的】利用间作和保护性耕作对土壤碳减排及水分高效利用的潜力,将二者集成于同一系统中以发挥各自的优势并催生彼此间的协同效应,从而建立减排与节水双赢的间作高效种植模式。【方法】以河西绿洲灌区长期规模化种植的小麦间作玉米为研究对象,集成应用保护性耕作的理论与技术,利用带状耕作和秸秆覆盖建立免耕立茬(NTSSI)、免耕秸秆覆盖(NTSI)、少耕秸秆翻压(TISI)和传统收割(CTI)4种处理,并以传统收割单作小麦(SW)和单作玉米(SM)作为对照,系统研究了不同处理土壤呼吸与作物耗水状况。应用土壤呼吸测定系统EGM-4(environmental gas monitor-4,UK,PP system)测定土壤呼吸速率,以此计算不同处理生育期内土壤碳排放总量。用产量与耗水和土壤碳排放量与耗水两种方法计算水分利用效率,客观评价间作系统的水分利用状况。【结果】不同种植模式中,单作玉米土壤呼吸速率最大(1.57 μmol CO2·m-2·s-1),间作次之(0.83 μmol CO2·m-2·s-1),单作小麦最小(0.72 μmol CO2·m-2·s-1);4种秸秆还田方式中,NTSI处理土壤呼吸速率最低,2011与2012年分别较CTI降低了20.4%和11.9%,由此减少碳排放量12.4%。在间作中集成应用带状耕作和秸秆覆盖能有效降低系统耗水总量、增加产量、提高水分利用效率(WUEGY),与CTI处理相比,NTSI处理平均减少耗水量达4.1%,增产29.7%,水分利用效率提高15.6%。同时,间作系统的单位耗水碳排放平均降低了5.9%,碳排放效率提高了28.2%。【结论】小麦间作玉米与保护性耕作结合,并集成应用带状耕作及秸秆覆盖技术可使系统的产量、碳排放和耗水得到有效协调,能促进耗水更多转化为作物产量并降低在该转化过程中产生的碳排放,实现碳减排与水分高效利用的协同促进。

关键词: 绿洲灌区, 带状耕作, 小麦间作玉米, 碳排放, 水分利用效率

Abstract: 【Objective】 This study exploited the potential of intercropping and conservation tillage on optimizing carbon emission and water utilization, and integrated them into one cropping system to promote their respective and coordination effect. Thereby, to establish an effective intercropping system with double-wins on carbon emission reduction and water conservation. 【Method】 The study employed wheat (Triticum aestivum)/maize (Zea mayz) intercropping, which was cultivated as a long-term and large-scale cropping mode in Hexi irrigation areas, as the research object. The field experiment was conducted by integrating minimal/zero tillage into wheat/maize intercropping and established four tillage and straw retention patterns, which were: (a) no-till with 25 cm wheat stubble standing in the field (NTSSI, stubble standing), (b) no-till with 25 cm height of wheat straw chopped and spread evenly on the soil surface (NTSI, straw mulching), (c) tillage with 25 cm height of straw was incorporated in the soil (TISI, straw incorporated), and conventional tillage (CTI, tillage without straw retention). Meanwhile, the study also applied conventional-tilled sole wheat (SW) and sole maize (SM) as the controls, and investigated the conditions of soil respiration and crop water consumption in various treatments. An EGM-4 system (Environmental gas monitor-4, UK, PP system) was used to measure soil respiration and there from calculating the carbon emission during the growing season. Two methods of water use efficiency were determined, i.e., based on grain yield (WUEGY) and carbon emission (WUECE, that is carbon emission per unit of water) in order to make a proper assessment of water use condition in the intercropping system. 【Result】 Among the three cropping systems, the sole maize had the highest soil respiration rate (1.57 μmol CO2·m-2·s-1), which was almost twice as higher as the intercropping (0.83 μmol CO2·m-2·s-1), while among four straw retention patterns, NTSI had the lowest soil respiration, which was decreased by 20.4% in 2011 and 11.9% in 2012 as compared to CTI. Accordingly, carbon emission of NTSI was reduced by 12.4% compared to CTI. Integration of no-till and straw mulching into wheat/maize intercropping effectively lowered the crop water consumption while improving grain yield and WUEGY. Compared to CTI, the water consumption of NTSI was reduced by 4.1%, while grain yield and WUEGY was respectively increased by 29.7% and 15.6%. Furthermore, the carbon emission per unit of water was decreased by 5.9%, although carbon emission efficiency was promoted by 28.2%. 【Conclusion】 The results suggested that the integration of no-till and straw mulching into wheat/maize intercropping optimized the relationship between grain yield, carbon emission, and crop water consumption in this cropping system. The cropping mode could promote more water to produce more grain yield, meanwhile reducing the carbon emission during the crop production process. Consequently, it achieved a win-win effect on coordinating carbon emission reduction and efficient use of soil water in a wheat/maize intercropping system.

Key words: oasis irrigation area, strip tillage, wheat/maize intercropping, carbon emission, water use efficiency