不同水分条件下土壤N2O排放的动力学方程模拟
作者:
作者单位:

作者简介:

通讯作者:

中图分类号:

X511,X16

基金项目:

国家重点研发计划项目“黄土高原旱作适水改土与产能提升技术模式及应用”(2021YFD1900700);高等学校学科创新引智计划项目(B12007)


Simulation of Soil N2O Emissions Under Different Soil Moisture Conditions by Using Mixed Dynamic Equation
Author:
Affiliation:

Fund Project:

  • 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:

    [目的] 水分对土壤N2O排放有重要影响。运用混合动力学方程模拟不同水分条件下土壤N2O累积排放的过程,分析土壤水分对N2O产生途径的影响及其变化规律,为通过改善土壤管理降低N2O气体排放提供理论和实践指导。[方法] 通过室内培养试验,研究了不同水分条件〔40% WHC,60% WHC,80% WHC,100% WHC和淹水处理,WHC(田间持水量)〕下土壤N2O排放特征、硝铵态氮含量和氧气消耗动态变化。[结果] ①N2O排放速率24 h时达到最大,淹水处理〔3.46 μg/(kg·h)〕是其他处理的54.5~178.9倍。②土壤N2O累积排放量均随着培养时间的延长而增加,淹水处理的快速上升阶段为前48 h,而其他处理为前96 h。培养结束时的土壤N2O累积排放量,淹水处理(44.6 μg/kg)分别是40% WHC,60% WHC,80% WHC和100% WHC的67.1,29.2,20.8,10.4倍。③除淹水条件下,伪二级动力学方程的决定系数(R2)为0.878以外,其余均在0.92以上。培养初期24 h时,反硝化过程的N2O排放所占比例9.3%~13.2%,硝化过程为86.8%~90.7%;培养结束480 h时,反硝化过程的N2O排放所占比例为37.8%~47.5%,硝化过程为52.5%~62.2%。[结论] 土壤水分含量越高N2O的排放量越大,并且在24 h出现排放速率脉冲。淹水条件下N2O主要由反硝化过程产生,而40% WHC~100% WHC条件下主要由硝化过程产生。混合动力学方程可以很好地模拟培养过程中土壤N2O的累积排放过程,并且可以用来区分反硝化和硝化过程的N2O排放量和所占比例。这为研究土壤N2O产生和排放途径提供了一种新的思路和方法,结果还有待通过田间试验以及同位素示踪方法等进一步验证。

    Abstract:

    [Objective] Soil moisture has an important impact on N2O emissions. This study attempted to simulate the cumulative process of soil N2O emission under different soil moisture conditions by using a mixed dynamic equation, and to analyze the influence of soil water on N2O production pathway and its variation rule in order to provide theoretical and practical guidance for reducing N2O gas emissions through improving soil management. [Methods] Soil N2O emission characteristics, the dynamics of ammonium and nitrate nitrogen content, and oxygen consumption were studied under different soil moisture conditions [40% water-holding capacity (WHC), 60% WHC, 80% WHC, 100% WHC, and flooded]. [Results] ① The N2O emission rates reached maximum values at 24 h. Emissions from the flooded treatment [3.46 μg/(kg·h)] were 54.5-178.9 times greater than from the other treatments. ② The cumulative emission of soil N2O increased with increasing incubation time, and the rapid rise stage occurred in the first 48 h for the flooded treatment. The rapid rise stage occurred in the first 96 h for other treatments. The cumulative N2O emissions for soil under the flooded treatment (44.6 μg/kg) were 67.1, 29.2, 20.8, and 10.4 times greater than under 40% WHC, 60% WHC, 80% WHC and 100% WHC, respectively, at the end of incubation. ③ Except for the coefficient of determination (R2) of 0.878 for the pseudo-second-order dynamic equation under the flooded treatment, all coefficients of determination were greater than 0.920 for all dynamic equations under all soil moisture treatments. The denitrification process accounted for 9.3%~13.2% of the N2O emissions, and the nitrification process accounted for 86.8%~90.7% of the N2O emissions at the initial 24 h of incubation. At the end of incubation (480 h), the denitrification process accounted for 37.8%~47.5% of the N2O emissions, and the nitrification process accounted for 52.5%~62.2% of the N2O emissions. [Conclusion] The higher the soil moisture content, the greater the emission of N2O, and an emission rate pulse appeared at 24 h. N2O was mainly generated by denitrification under flooded conditions. N2O was mainly generated by nitrification under the 40%~100% WHC conditions. The mixed dynamic equation was able to well simulate the cumulative emission process of soil N2O during the incubation experiment, and can be used to distinguish the amount and proportion of N2O emissions occurring by denitrification and nitrification processes. These results provide a new idea and method for studying the pathways of soil N2O production and emission. The results need to be further verified by field experiments and isotope tracing methods etc.

    参考文献
    相似文献
    引证文献
引用本文

唐坤,郑艺欣,赵成政,段淑方,高明霞,冯浩,孙本华.不同水分条件下土壤N2O排放的动力学方程模拟[J].水土保持通报,2023,43(6):106-114

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:2023-03-14
  • 最后修改日期:2023-05-16
  • 录用日期:
  • 在线发布日期: 2024-01-29
  • 出版日期: