中国农业科学 ›› 2020, Vol. 53 ›› Issue (20): 4237-4247.doi: 10.3864/j.issn.0578-1752.2020.20.012

• 土壤肥料·节水灌溉·农业生态环境 • 上一篇    下一篇

秸秆还田后效对玉米氮肥利用率的影响

邹文秀(),韩晓增,陆欣春,陈旭,郝翔翔,严君()   

  1. 中国科学院东北地理与农业生态研究所,哈尔滨150081
  • 收稿日期:2020-02-10 接受日期:2020-03-12 出版日期:2020-10-16 发布日期:2020-10-26
  • 通讯作者: 严君
  • 作者简介:邹文秀,E-mail: zouwenxiu@iga.ac.cn
  • 基金资助:
    国家重点研发计划(2016YFD0200309-6);国家重点研发计划(2017YFD0300605);国家现代农业产业技术体系建设专项(CARS04);国家自然科学基金(41771327);国家自然科学基金(41807085);国家自然科学基金(41671299);黑龙江省应用技术研究与开发计划(GY2017ZB006);黑龙江省应用技术研究与开发计划(GA19B10);中国科学院野外台站联盟项目(KFJ-SW-YW035-4)

Effect of Maize Straw Return Aftereffect on Nitrogen Use Efficiency of Maize

ZOU WenXiu(),HAN XiaoZeng,LU XinChun,CHEN Xu,HAO XiangXiang,YAN Jun()   

  1. Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081
  • Received:2020-02-10 Accepted:2020-03-12 Online:2020-10-16 Published:2020-10-26
  • Contact: Jun YAN

摘要:

【目的】玉米秸秆还田已经成为培肥土壤的重要农艺措施之一,研究玉米秸秆还田后效对氮肥利用率的影响,旨在为提出提高氮肥利用率的秸秆还田方式提供理论依据。【方法】以中国科学院海伦农业生态实验站为研究平台,以质地黏重的黑土为研究对象,运用15N同位素示踪技术,以2011年进行秸秆还田的田间试验为基础,于2016年开展不同秸秆还田方式后效对化肥氮利用率影响的研究。以未进行秸秆还田的处理为对照(CK),在同等秸秆还田量下(10 000 kg·hm-2)设置免耕秸秆覆盖(D0),粉碎后的秸秆均匀混于0—20 cm土层(D0-20)、0—35 cm土层(D0-35)和20—35 cm土层(D20-35),秸秆平铺于35 cm深度(D35)和50 cm深度(D50)7个处理。【结果】不同秸秆还田方式后效通过促进玉米干物质积累,提高玉米对氮素的吸收,增加玉米的氮素积累进而提高氮素利用率。不同处理对玉米各器官干物质积累的影响表现为D0-35>D20-35>D0-20>CK≥D0>D35>D50,其中D0-35和D20-35(秸秆深混还田后效)处理比其他处理分别显著提高了7.1%—47.7%和2.0%—39.1%(P<0.05)(叶子除外)。不同秸秆还田方式后效对玉米各器官氮含量没有显著影响(P>0.05),但是D0-35、D20-35和D0-20处理显著增加了玉米各器官氮素积累量(P<0.05),与CK、D0、D35、D50处理相比分别提高了15.8%—20.2%、8.5%—18.2%和27.9%—39.5%(P<0.05)。与其他处理相比,D0-35和D20-35处理玉米各器官15N累积量分别显著提高了5.1%—38.4%和9.3%—31.8%。74.1%以上的15N累积在玉米的籽粒中,不同秸秆还田方式后效没有显著影响15N在玉米各器官的分配比例,说明玉米秸秆还田后效通过促进玉米植株整体对肥料氮的吸收来提高氮肥的利用率。D0-35处理氮肥利用率和15N肥料氮的残留率与其他处理相比分别提高了1.9—12.7个百分点和6.9—21.2个百分点,而氮肥损失率则降低了8.8—31.3个百分点;但是与CK处理相比,D0、D35和D50(秸秆层铺后效)处理没有显著增加氮肥利用率,同时D0和D50处理氮素损失率提高了3.6和4.4个百分点;说明秸秆层铺后效有增加氮素损失的风险,而通过秸秆深混还田后效构建肥沃耕层是一种提高氮肥利用率的有效地途径。与CK处理相比,D20-35、D35和D50处理的氮肥贡献率分别显著提高了3.74、4.26、3.79和4.51个百分点(P<0.05),但是不同秸秆还田方式后效之间没有显著查差异(P>0.05)。Pearson相关分析结果表明秸秆还田后效通过促进玉米根系生长、增加土壤中轻组有机碳含量及改善土壤物理性质来提高氮肥利用率。【结论】对于质地黏重的黑土,可以通过增加秸秆还田混合深度,构建肥沃耕层提升土壤肥力和改善土壤结构,能够有效提高氮肥的利用率。

关键词: 玉米, 秸秆还田后效, 氮肥利用率, 干物质积累, 氮素积累

Abstract:

【Objective】Maize straw return has been one of agronomic practices for improving soil fertility. The effect of straw return aftereffect on Nitrogen use efficiency (NUE) was considered, with the objective of suppling the theoretical guidance for proposing the straw return patterns being favorable to enhance the NUE.【Method】Based on the black soil with heavy clay content in the Hailun agro-ecosystem experimental station of Chinese Academy of Sciences, the micro-plot experiment was carried out using 15N isotope techniques in 2016 under the treatment of the straw return (10 000 kg·hm-2) only once established in 2011. Seven treatments were set up, including control without maize straw return (CK), maize straw cover (D0), maize straw incorporated within 0-20 cm soil depth (D0-20), 0-35 cm soil depth (D0-35), 20-35 cm soil depth (D20-35), respectively, as well as maize straw placed on the 35 cm depth (D35) and 50 cm depth (D50).【Result】The aftereffect of maize straw return increased NUE by enhancing the cumulation of dry biomass and nitrogen in maize organs. The maize dry biomass shown in the decreasing trend of D0-35>D20-35>D0-20>CK≥D0>D35>D50, D0-35 and D20-35 treatments (Maize straw incorporated within deep soil) significantly increased by 7.1%-47.7% and 2.0%-39.1% (with exception of leaf), respectively (P<0.05), compared with other treatments. The different treatments didn’t impact the nitrogen (N) contents of maize organs, but D0-35, D20-35 and D0-20 treatments significantly increased the N cumulation in maize organs (P<0.05) with the increase of 15.8%-20.2%, 8.5%-18.2% and 27.9%-39.5%, respectively (P<0.05), compared with CK, D0, D35, and D50. The cumulation of 15N under D0-35 and D20-35 treatments significantly increased by 5.1%-38.4% and 9.3%-31.8%, respectively, compared with other treatments. 15N of more than 74.1% were accumulated in the grain, different treatments didn’t impact the 15N distribution in maize organs, indicating that NUE was increased by improving the N uptake of whole maize. The NUE and N retention rate reached the largest value under D0-35 with the increase of 1.9-12.7 percentage and 6.9-21.2 percentage, respectively, However, the N loss under D0-35 reached the lowest value with the decrease of 8.8-31.3 percentage. D0, D35 and D50 treatments (straw return in some soil layer) didn’t significantly increased the NUE compared with CK treatment, meanwhile the N loss was higher 3.6 and 4.4 percentages than that in CK treatment. The result indicated that straw return in some soil layer had potential risk in the increase of N loss, constructing fertile cultivated soil layer by straw incorporation within deep soil depth was effective agronomic practice with high NUE. The correlation analysis demonstrated that root biomass, light fraction organic carbon and soil physical properties contributed the increase of NUE in study site. N contribution rate was significantly higher 3.74, 4.26, 3.79 and 4.51percentages in D20-35, D35 and D50 treatments than that in CK treatment, no significantly difference was observed among treatments with straw return. 【Conclusion】NUE could be increased by enhancing soil fertility and improving soil structure under maize straw incorporated within deep soil, and constructing fertile soil layer in black soil with heavy clay content.

Key words: maize, maize straw return aftereffect, nitrogen use efficiency, dry biomass cumulation, maize straw incorporated within deep soil, nitrogen accumulation