干旱区研究 ›› 2022, Vol. 39 ›› Issue (2): 493-501.doi: 10.13866/j.azr.2022.02.17

• 土壤资源 • 上一篇    下一篇

保护性耕作对黄土高原半干旱区农田土壤N2O排放的影响

杜梦寅1(),袁建钰1,李广1(),闫丽娟2,刘兴宇1,祁小平1,庞晔1   

  1. 1.甘肃农业大学林学院,甘肃 兰州 730070
    2.甘肃农业大学农学院,甘肃 兰州 730070
  • 收稿日期:2021-10-10 修回日期:2021-10-31 出版日期:2022-03-15 发布日期:2022-03-30
  • 通讯作者: 李广
  • 作者简介:杜梦寅(1998-),男,硕士研究生,主要从事土壤氮循环. E-mail: 920446333@qq.com
  • 基金资助:
    国家自然科学基金(32160416);甘肃省重点研究发展计划(20YF8NA135);甘肃省财政专项(GSCZZ 20160909);甘肃省重点人才项目(LRYCZ-2020-1);甘肃省教育厅产业支撑计划项目(2021CYZC-15)

Effects of protective measures on N2O emission from farmland soil in a semi-arid area of the Loess Plateau

DU Mengyin1(),YUAN Jianyu1,LI Guang1(),YAN Lijuan2,LIU Xingyu1,QI Xiaoping1,PANG Ye1   

  1. 1. College of Forestry, Gansu Agricultural University, Lanzhou 730070, Gansu, China
    2. College of Agriculture, Gansu Agricultural University, Lanzhou 730070, Gansu, China
  • Received:2021-10-10 Revised:2021-10-31 Online:2022-03-15 Published:2022-03-30
  • Contact: Guang LI

摘要:

一氧化二氮(N2O)是大气中重要的温室气体之一,在全球气候变暖问题中备受关注,而农田土壤是其主要排放源。在影响农田N2O排放的诸多因子中,耕作措施作为关键因素,其对旱地农田土壤N2O的排放规律尚不明确。为此,本试验以传统耕作(T)为对照、布设免耕(NT)、传统耕作+秸秆覆盖(TS)、免耕+秸秆覆盖(NTS)3种保护性耕作,采用静态箱-气相色谱法对春小麦地土壤N2O排放通量进行测定,并对影响N2O排放的相关因子及春小麦产量进行同期测定。结果表明:(1) 春小麦地不同耕作措施下土壤N2O累计排放量大小顺序为:T>NT>TS>NTS,其中T处理显著高于其他处理,分别较NT、TS、NTS处理增加了15.87%、28.08%和39.58%,另外相比于T处理,保护性耕作有助于表层土壤NH4+-N含量及春小麦产量的增加,并减少NO3--N含量的积累。(2) 相关关系表明,土壤温度、土壤含水量及NH4+-N含量是影响土壤N2O排放的关键因素。其中,土壤含水量、NH4+-N含量与春小麦地土壤N2O排放量均呈极显著负相关关系,土壤温度与N2O排放量呈极显著正相关关系。因此,以经济效益和环境效益为基础,综合考虑N2O排放量和作物产量,黄土高原半干旱区以NTS处理为最优耕作措施。

关键词: 温室气体, 保护性耕作, 耕作措施, 春小麦, 相关关系, 黄土高原

Abstract:

Nitrous oxide (N2O) is an important greenhouse gas. It has attracted much attention as a factor in climate change, and farmland soil is the main source of emissions. Among many variables affecting N2O emission from farmland, tillage is a key factor but exactly how it regulates N2O emission from dryland farmland soil is unclear. In this study, traditional tillage (T) was used as a control, and three kinds of conservation tillage were used: no tillage (NT), traditional tillage + straw mulch (TS), and no tillage + straw mulch (NTS). The soil N2O emission flux of a spring wheat field was measured by static box gas chromatography, and factors affecting N2O emission and spring wheat yield were measured concurrently. Soil N2O cumulative emissions under different tillage measures in the spring wheat field decreased in the order T > NT > TS > NTS. Emissions under treatment T were significantly higher than those under other treatments (by 15.87%, 28.08%, and 39.58%, respectively, compared with NT, TS, and NTS). In addition, compared with treatment T, conservation tillage helped to increase the surface soil content of NH4+-N and the yield of spring wheat, and reduce the accumulation of NO3--N. Correlation analysis showed that soil temperature, soil water content, and NH4+-N content were associated with soil N2O emission. Of these, soil water content and NH4+-N content showed significant negative correlations with soil N2O emission, and soil temperature showed a highly significant positive correlation with N2O emission. Based on economic and environmental benefits and considering N2O emission and crop yield, we suggest that NTS is the best tillage strategy in semi-arid areas of the Loess Plateau.

Key words: greenhouse gases, conservation tillage, farming practices, spring wheat, correlation, Loess Plateau