秸秆生物质炭对稻田土壤剖面N2O和N2浓度的影响
作者:
作者单位:

作者简介:

通讯作者:

中图分类号:

S151.9

基金项目:

国家自然科学基金项目(41771338、41807088、41807096)资助


Effect of Application of Straw-derived Biochar on Concentrations of N2O and N2in Paddy Soil Profile
Author:
Affiliation:

Fund Project:

the National Natural Science Foundation of China

  • 摘要
  • |
  • 图/表
  • |
  • 访问统计
  • |
  • 参考文献
  • |
  • 相似文献
  • |
  • 引证文献
  • |
  • 资源附件
  • |
  • 文章评论
    摘要:

    氧化亚氮(N2O)和氮气(N2)是淹水稻田土壤剖面反硝化过程的重要气态产物,可通过土水界面向大气排放,也可随水向下淋溶。秸秆生物质炭施入稻田后会改变土壤理化及微生物学性质,影响反硝化过程及N2O和N2产排。依托2010年夏建立的连续秸秆生物质炭还田的稻麦轮作农田试验,通过埋设淋溶管收集土壤剖面溶液,采用气相色谱和膜进样质谱分别定量溶液中N2O和exN2(反硝化产生N2量),观测2018和2019年水稻季不同秸秆生物质炭施用量(CK:每季0 t·hm-2;1BC:每季2.25 t·hm-2;5BC:每季11.3 t·hm-2;10BC:每季22.5 t·hm-2)0~1 m土壤剖面溶液中N2O和exN2浓度的时空变化,评估长期施用秸秆生物质炭对稻田土壤剖面反硝化作用及其主要气态氮产物exN2随水流失的影响。结果表明,两个稻季CK处理N2O浓度以60 cm处较高,exN2浓度则随土壤深度增加呈降低趋势。秸秆生物质炭处理能降低剖面N2O和exN2浓度,以10BC处理最为明显。其中,N2O浓度降低以60 cm处较大,exN2浓度降低随土壤深度增加而加大。施用秸秆生物质炭对土壤剖面溶液无机氮(NO3-+NH4+)含量无明显影响,但5BC和10BC处理增加了可溶性有机碳(DOC)和溶解氧(DO)浓度以及氧化还原电位(Eh)。CK处理下土壤剖面溶液N2O和exN2浓度变化与DOC、硝态氮(NO3-)及DO有关;秸秆生物质炭处理下则主要受DO和Eh控制。exN2淋溶量(按1 m深度计算)CK处理下为2.3~5.5 kg·hm-2,相当于无机氮和有机氮(DON)淋溶量的32%~34%,5BC和10BC处理则降低为1.7~3.7 kg·hm-2和1.1~1.9 kg·hm-2。综上,反硝化产生N2随水淋溶量不容忽视,秸秆生物质炭还田可改善淹水稻田土壤剖面的通气状况,增加DO,提高Eh,进而有效减少深层反硝化及其主要气态产物exN2随水流失的风险。

    Abstract:

    [Objective] Nitrous oxide (N2O) and nitrogen (N2) are important gaseous products of denitrification in soil profile of flooded rice field, which may be discharged directly into the atmosphere through soil-water interface, or leached into groundwater and eventually into the atmosphere. Application of biochar can alter denitrification process in the paddy field by changing physicochemical and microbiological properties of the paddy soil and then affect the generation and emission of N2 and N2O in the field.[Method] In this study, based on a long-term (since 2010) rice-wheat rotation field experiment on biochar amendment. Soil solutions (0-1 m depth) were collected through specially designed piezometers imbedded in the paddy soil. And concentrations of dissolved N2O and exN2(N2 produced by denitrification) in soil solution were determined by gas chromatography and membrane inlet mass spectronmeter. The experiment was designed to have 4 treatments (CK:each season 0 t·hm-2; 1BC:each season 2.25 t·hm-2; 5BC:each season 11.3 t·hm-2; 10BC:each season 22.5 t·hm-2) for the two rice seasons in 2018 and 2019, and aimed to investigate spatial and temporal variations of N2O and exN2 concentrations in soil solution as affected by biochar application rate. The effects of long-term application of biochar on denitrification in paddy soil profile and the exN2, which was the main gaseous nitrogen product, was washed away by water were evaluated.[Result] The concentration of N2O is higher in the soil 60 cm in depth in CK and exN2 concentration decreased with soil depth. N2O and exN2 concentrations in profile decreased with rising biochar application rate, thus being the lowest in treatment 10BC. Among them N2O concentration decreased the most significantly in the soil 60 cm in depth and exN2concentration decreased with increasing soil depth. Biochar amendments had no obvious effect on inorganic nitrogen (NO3- +NH4+) in the soil profile, but increased the concentrations of soluble organic carbon (DOC), dissolved oxygen(DO) and redox potential (Eh) in 5BC and 10BC. The variations of N2O and exN2 was related to DOC, NO3- and DO in CK, and to DO and Eh in the biochar treatments. The leaching amount of exN2(calculated by 1 m depth) is 2.3-5.5 kg·hm-2 in CK, which was equivalent to 32%~34% of the leaching amount of inorganic nitrogen and organic nitrogen (DON), while it was reduced to 1.7-3.7 kg·hm-2 and 1.1-1.9 kg·hm-2 in 5BC and 10BC.[Conclusion] All the findings show that the leaching amount of N2 produced by denitrification with water can not be ignored, the amendment of biochar can improve aeration of the soil profile and increase DO and Eh, thus inhibiting denitrification and reducing the risk of leaching loss of its main gaseous products, exN2.

    参考文献
    相似文献
    引证文献
引用本文

马芸芸,周伟,何莉莉,赵旭,王林权.秸秆生物质炭对稻田土壤剖面N2O和N2浓度的影响[J].土壤学报,2021,58(6):1540-1551. DOI:10.11766/trxb202005110231 MA Yunyun, ZHOU Wei, HE Lili, ZHAO Xu, WANG Linquan. Effect of Application of Straw-derived Biochar on Concentrations of N2O and N2in Paddy Soil Profile[J]. Acta Pedologica Sinica,2021,58(6):1540-1551.

复制
分享
文章指标
  • 点击次数:
  • 下载次数:
  • HTML阅读次数:
  • 引用次数:
历史
  • 收稿日期:2020-05-11
  • 最后修改日期:2020-08-29
  • 录用日期:2020-10-20
  • 在线发布日期: 2020-12-07
  • 出版日期: 2021-11-11