• ISSN 1008-505X
  • CN 11-3996/S
刘一戈, 胡家帅, 王朝, 彭子倩, 郝珖存, 卢瑛, 李博. 不同温度条件下生物质炭陈化对华南集约化菜地土壤反硝化过程的影响[J]. 植物营养与肥料学报, 2022, 28(9): 1641-1651. DOI: 10.11674/zwyf.2022053
引用本文: 刘一戈, 胡家帅, 王朝, 彭子倩, 郝珖存, 卢瑛, 李博. 不同温度条件下生物质炭陈化对华南集约化菜地土壤反硝化过程的影响[J]. 植物营养与肥料学报, 2022, 28(9): 1641-1651. DOI: 10.11674/zwyf.2022053
LIU Yi-ge, HU Jia-shuai, WANG Chao, PENG Zi-qian, HAO Guang-cun, LU Ying, LI Bo. Effects of field-aged biochar on denitrification of vegetable soils under different temperature conditions in south China[J]. Journal of Plant Nutrition and Fertilizers, 2022, 28(9): 1641-1651. DOI: 10.11674/zwyf.2022053
Citation: LIU Yi-ge, HU Jia-shuai, WANG Chao, PENG Zi-qian, HAO Guang-cun, LU Ying, LI Bo. Effects of field-aged biochar on denitrification of vegetable soils under different temperature conditions in south China[J]. Journal of Plant Nutrition and Fertilizers, 2022, 28(9): 1641-1651. DOI: 10.11674/zwyf.2022053

不同温度条件下生物质炭陈化对华南集约化菜地土壤反硝化过程的影响

Effects of field-aged biochar on denitrification of vegetable soils under different temperature conditions in south China

  • 摘要:
    目的 比较不同温度下新鲜生物质炭与陈化生物质炭对华南集约化菜地土壤N2O排放的影响,以深化对生物质炭减排机理的认识。
    方法 本研究采用乙炔抑制法进行室内培养试验,共设置3个温度梯度(10℃、20℃和30℃)和3个生物质炭处理:无生物质炭(CK)、新鲜生物质炭(FB)以及田间陈化生物质炭(FAB),共9个处理。同时,各处理分别设置不加乙炔和添加10%体积含量乙炔的平行处理,以测定N2O排放量并作差计算N2排放量。对不含乙炔处理则测定土壤pH、电导率(EC)、可溶性有机碳(DOC)、 \rmNO_3^-、\rmNH_4^+、 \rmNO_2^-含量,以及土壤中反硝化功能基因nirSnirKnosZnosZII的丰度。
    结果 温度升高显著增加了菜地土壤N2O和N2的排放量,显著提高了土壤pH 和土壤\rmNH_4^+ 含量,并明显降低了DOC和\rmNO_3^- 含量(P<0.01),但是并未明显影响反硝化过程的功能基因nirKnirSnosZnosZII的丰度。FB、FAB在30℃时分别显著降低了菜地土壤N2O排放量的18.8%、22.3%,并且显著降低了反硝化总脱氮量(N2O+N2) (P<0.001)。FAB处理在30℃下能显著增加土壤中nirKnosZII基因丰度(P<0.05)。冗余分析显示,土壤pH、\rmNO_2^- 、DOC是影响反硝化功能基因的主要因素,以pH贡献率最高。逐步回归分析表明,N2O排放量在CK处理中主要受土壤DOC含量影响,在FB处理中主要受土壤\rmNO_3^- 含量影响,在FAB处理中则受到土壤\rmNO_3^- 和\rmNO_2^- 含量影响。
    结论 升温对菜地土壤N2O排放的影响呈非线性增长,以10℃增至20℃时增幅最大。在反硝化过程中,新鲜生物质炭通过持留\rmNO_3^- 以减少其参与反硝化过程,进而减少N2O排放量。陈化生物质炭则通过影响反硝化过程的底物\rmNO_3^- 、\rmNO_2^- 含量及反硝化功能基因nirKnosZII的丰度,从而导致土壤氮以NO或N2形式损失,减少N2O的排放量。低温抑制微生物的活性,因此,在30℃时生物质炭对N2O减排效果更好,且陈化生物质炭的减排效果优于新鲜生物质炭。

     

    Abstract:
    Objectives In order to improve the understanding of how biochar reduces N2O emissions, we compared the effects of fresh and aged biochar at different temperatures on N2O emissions from intensive vegetable soils in southern China.
    Methods An incubation experiment was conducted, and the treatments were soil without biochar addition control (CK), addition of fresh biochar (FB), and addition of field-aged biochar (FAB) at 10°C, 20°C, and 30°C. A parallel treatment was set up for each treatment with and without the addition of 10% volume content of acetylene to measure the N2O emission, and the difference was made to obtain N2 emissions. For the treatments without acetylene addition, soil pH, electrical conductivity (EC), dissolved organic carbon (DOC), \rmNO_3^- , \rmNH_4^+ , and \rmNO_2^- , as well as functional genes for denitrification (nirS, nirK, nosZ, and nosZII) were measured.
    Results The elevation of incubation temperature significantly increased N2O and N2 emissions, increased soil pH and \rmNH_4^+ -N content, decreased soil DOC and \rmNO_3^- -N contents (P<0.01), but did not affect the abundance of nirK, nirS, nosZ and nosZII. FB and FAB treatments significantly reduced N2O emissions by 18.8% and 22.3% at 30℃ respectively and the total denitrifying nitrogen amount (N2O + N2) (P<0.01). FAB significantly increased the nirK and nosZII gene abundance at 30℃ (P<0.05). The redundancy analysis showed that soil pH, NO2 and DOC were the main factors affecting denitrification function genes, among which pH was the most important factor. Stepwise regression analysis showed that N2O emission was mainly affected by DOC content in CK treatment, N2O emissions in the FB treatment were mainly influenced by soil \rmNO_3^- content, and N2O emissions in the FAB treatment were influenced by soil \rmNO_3^- and \rmNO_2^- content.
    Conclusions N2O emissions increased with temperature nonlinearly, and the greatest increment occurred from 10°C to 20°C. Fresh biochar enhanced soil pH and retain \rmNO_3^- from participating in denitrification process, thus reduced N2O emission. FAB decreased soil \rmNO_3^- and \rmNO_2^- contents, nirK and nosZII genes abundance, and soil N loss as NO or N2, not in form of N2O emission. Low temperature inhibited microbial activity, therefore, both fresh and aged biochar perform better in reducing N2O emissions at 30°C than at lower temperatures. Aged biochar can achieve better N2O mitigation effects than fresh biochar.

     

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