Journal of Integrative Agriculture ›› 2024, Vol. 23 ›› Issue (9): 3159-3173.DOI: 10.1016/j.jia.2024.03.047

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有机肥替代化肥降低节水灌溉稻田N2O排放的潜力及微生物学机制研究

  

  • 收稿日期:2023-08-18 接受日期:2024-01-31 出版日期:2024-09-20 发布日期:2024-08-21

Mitigation of N2O emissions in water-saving paddy fields: Evaluating organic fertilizer substitution and microbial mechanisms

Delei Kong1, 2*, Xianduo Zhang3*, Qidong Yu2, Yaguo Jin2, Peikun Jiang1, Shuang Wu2, 4#, Shuwei Liu2, 4, Jianwen Zou2, 4   

  1. 1 College of Environment and Resources/College of Carbon Neutrality, Zhejiang A&F University, Hangzhou 311300, China
    2 Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
    3 Department of Biochemistry and Molecular Biology, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
    4 Jiangsu Key Lab and Engineering Center for Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing 210095, China

  • Received:2023-08-18 Accepted:2024-01-31 Online:2024-09-20 Published:2024-08-21
  • About author:Delei Kong, E-mail: deleikong@zafu.edu.cn; Xianduo Zhang, E-mail: 2017216034@njau.edu.cn; #Correspondence Shuang Wu, E-mail: wushuang@njau.edu.cn * These authors contributed equally to this study.
  • Supported by:
    This work was supported by the National Key Research and Development Program of China (2022YFD2300300), the National Natural Science Foundation of China (41907072), the Scientific Research Foundation of Zhejiang A&F University, China (2022LFR003) and the Jiangsu Agriculture Science and Technology Innovation Fund, China (CX(21)3007).

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摘要：

节水灌溉策略可以有效减少稻田甲烷排放，但由于土壤含氧量和氧化还原电位的变化，会强烈刺激氧化亚氮（N2O）的排放。然而，目前有关不同施肥措施下节水灌溉稻田土壤N2O排放与氮（N）循环功能基因之间的关系却很少被研究。此外，有机肥替代化肥对稻田N2O排放的减排潜力及微生物学机制有待进一步阐明。本研究分析了我国东南部连续两年不同施肥措施对稻田土壤N2O排放和相关功能微生物【氨氧化古菌（AOA）、氨氧化细菌（AOB）、nirS、nirK和nosZ】的影响。共设置了三个试验处理：不施氮肥（Control）、化学氮肥（Ni）和有机肥部分替代化学氮肥（Ni+No）。研究结果表明，平均两个水稻生长季，Control、Ni和Ni+No处理的N2O累积排放量分别为0.47、4.62和4.08 kg ha−1。与Ni处理相比，Ni+No施肥措施在保障水稻产量的同时，显著降低了土壤N2O排放量11.6%，其N2O排放因子（EF）为0.95%。与Control处理相比，施用氮肥可以显著提高AOB、nirS、nirK和nosZ基因丰度。有机肥部分替代化学氮肥显著降低了AOB和nirS基因丰度，但增加了nosZ基因丰度。AOB对氮肥的响应比AOA更敏感。N2O累积排放量与AOB、nirS基因丰度呈正相关关系，而与nosZ基因丰度、nosZ/nirS比值呈负相关关系。综上所述，在节水灌溉稻田中，有机肥替代化学氮肥可以减少土壤N2O排放，主要通过改变土壤NO3--N、pH和DOC含量，从而抑制硝化过程的氨氧化和反硝化过程的亚硝酸盐还原，以及增强反硝化过程的N2O还原。

Abstract:

Water-saving irrigation strategies can successfully alleviate methane emissions from rice fields, but significantly stimulate nitrous oxide (N2O) emissions because of variations in soil oxygen level and redox potential.  However, the relationship linking soil N2O emissions to nitrogen functional genes during various fertilization treatments in water-saving paddy fields has rarely been investigated.  Furthermore, the mitigation potential of organic fertilizer substitution on N2O emissions and the microbial mechanism in rice fields must be further elucidated.  Our study examined how soil N2O emissions were affected by related functional microorganisms (ammonia-oxidizing archaea (AOA), ammonia-oxidizing bacteria (AOB), nirS, nirK and nosZ) to various fertilization treatments in a rice field in southeast China over two years.  In this study, three fertilization regimes were applied to rice cultivation: a no nitrogen (N) (Control), an inorganic N (Ni), and an inorganic N with partial N substitution with organic manure (Ni+No).  Over two rice-growing seasons, cumulative N2O emissions averaged 0.47, 4.62 and 4.08 kg ha−1 for the Control, Ni and Ni+No treatments, respectively.  In comparison to the Ni treatment, the Ni+No fertilization regime considerably reduced soil N2O emissions by 11.6% while maintaining rice yield, with a lower N2O emission factor (EF) from fertilizer N of 0.95%.  Nitrogen fertilization considerably raised the AOB, nirS, nirK and nosZ gene abundances, in comparison to the Control treatment.  Moreover, the substitution of organic manure for inorganic N fertilizer significantly decreased AOB and nirS gene abundances and increased nosZ gene abundance.  The AOB responded to N fertilization more sensitively than the AOA.  Total N2O emissions significantly correlated positively with AOB and nirS gene abundances while having a negative correlation with nosZ gene abundance and the nosZ/nirS ratio across N-fertilized plots.  In summary, we conclude that organic manure substitution for inorganic N fertilizer decreased soil N2O emissions primarily by changing the soil NO3−-N, pH and DOC levels, thus inhibiting the activities of ammonia oxidation in nitrification and nitrite reduction in denitrification, and strengthening N2O reduction in denitrification from water-saving rice paddies.


Key words: organic manure substitution , inorganic fertilizer ,  N2O ,  functional microbe ,  rice paddy