Effects of salt stress on nitrification and denitrification rates and N2O emissions in soil using a 15N isotope tracing approach

Authors

  • Linjuan Du 1. State Key Laboratory of Efficient Utilization of Agricultural Water Resources, Beijing 100083, China; 2. China Center for Agricultural Water Research, China Agricultural University, Beijing 100083, China
  • Cunzhen Pan 1. State Key Laboratory of Efficient Utilization of Agricultural Water Resources, Beijing 100083, China; 2. China Center for Agricultural Water Research, China Agricultural University, Beijing 100083, China
  • Caiyun Wang 1. State Key Laboratory of Efficient Utilization of Agricultural Water Resources, Beijing 100083, China; 2. China Center for Agricultural Water Research, China Agricultural University, Beijing 100083, China
  • Zhijun Chen 1. State Key Laboratory of Efficient Utilization of Agricultural Water Resources, Beijing 100083, China; 2. China Center for Agricultural Water Research, China Agricultural University, Beijing 100083, China
  • Yunwu Xiong 1. State Key Laboratory of Efficient Utilization of Agricultural Water Resources, Beijing 100083, China; 2. China Center for Agricultural Water Research, China Agricultural University, Beijing 100083, China
  • Guanhua Huang 1. State Key Laboratory of Efficient Utilization of Agricultural Water Resources, Beijing 100083, China; 2. China Center for Agricultural Water Research, China Agricultural University, Beijing 100083, China

Keywords:

Denitrification, Nitrification, Salinized soil, Sources of N2O, Stable isotope tracer

Abstract

Nitrous oxide (N2O), a long-lived greenhouse gas, is primarily produced in agricultural soils through biological nitrification and denitrification processes. However, the effects of soil salinity on nitrogen transformation processes remain insufficiently understood, hindering the development of effective nitrogen management in salt-affected farmlands. In this study, laboratory incubation experiments combined with a 15N stable isotope tracing technique were conducted to quantify the effects of salt stress on nitrification and denitrification rates and their contributions to N2O emissions. The results showed that during the first week of incubation, slight and moderate salinity (NaCl contents of 0.04% and 0.10%; EC1:5≤1.10 dS/m) enhanced both nitrification and denitrification rates, whereas strong salinity (0.20% NaCl; EC1:5≥1.42 dS/m) inhibited these processes. In the first week of incubation, nitrification and denitrification contributed approximately 65%-70% and 30%-35% to the total N2O emissions under 60% water-filled pore space, respectively. These results indicate that nitrification represents the predominant source of N2O production in saline soils during the first week following fertigation. The findings suggest that nitrogen management practices for inhibiting the nitrification process (e.g., the addition of nitrification inhibitors in companion with fertigation) may mitigate N2O emissions in saline fields. This provides a scientific basis for optimizing nitrogen management in saline soils and reducing greenhouse gas emissions.      

Keywords: nitrogen transformation, soil salinity, soil N2O emissions, stable isotope tracer

DOI: 10.25165/j.ijabe.20261903.10307

Citation: Du L J, Pan C Z, Wang C Y, Chen Z J, Xiong Y W, Huang G H. Effects of salt stress on nitrification and denitrification rates and N2O emissions in soil using a 15N isotope tracing approach. Int J Agric & Biol Eng, 2026; 19(3): 191–197.

References

[1] Intergovernmental Panel on Climate Change （IPCC）. Climate Change 2021: The Physical Science Basis. 2021. Available: https://www.ipcc.ch/report/sixth-assessment-report-working-group-i/. Accessed on [2026-04-09].

[2] Yang L Q, Zhang X J, Ju X T, Wu D. Oxygen-depletion by rapid ammonia oxidation regulates kinetics of N2O, NO and N2 production in an ammonium fertilised agricultural soil. Soil Biol Biochem, 2021; 163: 108460.

[3] Tian H Q, Xu R T, Canadell J G, Thompson R L, Winiwarter W, Suntharalingam P, et al. A comprehensive quantification of global nitrous oxide sources and sinks. Nature, 2020; 586: 248–256.

[4] Li S X, Wang Z H, Hu T T, Gao Y J, Stewart B A. Nitrogen in dryland soils of China and its management. Adv Agron, 2009; 101: 123–181.

[5] Voss M, Baker A, Cornell S, Bange H, Conley D, Deutsch B, et al. The European nitrogen assessment: Sources, effects and policy perspectives. Cambridge University Press. 2011.

[6] Zhang X, Davidson E A, Mauzerall D, Searchinger T D, Dumas P, Shen Y. Managing nitrogen for sustainable development. Nature, 2015; 528: 51–59.

[7] Lassaletta L, Billen G, Grizzetti B, Garnier J, Leach A M, Galloway J N. Food and feed trade as a driver in the global nitrogen cycle: 50-year trends. Biogeochemistry, 2014; 118: 225–241.

[8] Cassman K, Dobermann A. Nitrogen and the future of agriculture: 20 years on. Ambio, 2022; 51: 17–24.

[9] Hassani A, Azapagic A, Shokri N. Global predictions of primary soil salinization under changing climate in the 21st century. Nat Commun, 2021; 12: 6663.

[10] Food and Agriculture Organization of the United Nations （FAO）. Salt-affected soils are a global issue. 2021. Available: https://openknowledge.fao.org/handle/20.500.14283/cb4809en. Accessed on [2026-04-09].

[11] Stavi I, Thevs N, Priori S. Soil salinity and sodicity in drylands: a review of causes, effects, monitoring, and restoration measures. Front Environ Sci, 2021; 9: 712831.

[12] Devkota K P, Devkota M, Rezaei M, Oosterbaan R. Managing salinity for sustainable agricultural production in salt-affected soils of irrigated drylands. Agric Syst, 2022; 198: 103390.

[13] Lodhi A, Arshad M, Azam F, Sajjad M H. Changes in mineral and mineralizable N of soil incubated at varying salinity, moisture and temperature regimes. Pak J Bot, 2009; 41: 967–980.

[14] Iwaoka C, Imada S, Taniguchi T, Du S, Yamanaka N, Tateno R. The impacts of soil fertility and salinity on soil nitrogen dynamics mediated by the soil microbial community beneath the halophytic shrub tamarisk. Microb Ecol, 2018; 75: 985–996.

[15] Bateman E J, Baggs E M. Contributions of nitrification and denitrification to N2O emissions from soils at different water-filled pore space. Biol Fertil Soils, 2005; 41: 379–388.

[16] Ghosh U, Thapa R, Desutter T, He Y B, Chatterjee A. Saline-sodic soils: potential sources of nitrous oxide and carbon dioxide emissions? Pedosphere, 2017; 27（1）: 65–75.

[17] Zhang L H, Song L P, Wang B C, Shao H B, Zhang L W, Qin X C. Co-effects of salinity and moisture on CO2 and N2O emissions of laboratory-incubated salt-affected soils from different vegetation types. Geoderma, 2018; 332: 109–120.

[18] Jia J, Bai J H, Wang W, Yin S, Zhang G L, Zhao Q Q, et al. Salt stress alters the short-term responses of nitrous oxide emissions to the nitrogen addition in salt-affected coastal soils. Sci Total Environ, 2020; 742: 140124.

[19] Li Y W, Xu J Z, Liu S M, Qi Z M, Wang H Y, Wei Q, et al. Salinity-induced concomitant increases in soil ammonia volatilization and nitrous oxide emission. Geoderma, 2020; 361: 114053.

[20] Huang Q Z, Xu X, Lyu L J, Ren D Y, Ke J Y, Xiong Y W, et al. Soil salinity distribution based on remote sensing and its effect on crop growth in Hetao Irrigation District. Trans CSAE, 2018; 34（1）: 102–109.

[21] Chen Z J, Zhou T L, Huang G H, Xiong Y W. Soil microbial community and associated functions response to salt stresses: Resistance and resilience. Sci Total Environ, 2024; 954: 176475.

[22] Li C J, Xiong Y W, Zou J Y, Dong L, Ren P, Huang G H. Impact of biochar and lignite-based amendments on microbial communities and greenhouse gas emissions from agricultural soil. Vadose Zone J, 2021; 20（2）: e20105.

[23] Lin W, Ding J J, Li Y Z, Zhang W, Ahmad R, Xu C Y, et al. Partitioning of sources of N2O from soil treated with different types of fertilizers by the acetylene inhibition method and stable isotope analysis. Eur J Soil Sci, 2019; 70（5）: 1037–1048.

[24] Stevens R J, Laughlin R J, Burns L C, Arah J R M, Hood R C. Measuring the contributions of nitrification and denitrification to the flux of nitrous oxide from soil. Soil Biol Biochem, 1997; 29: 139–151.

[25] Di H J, Cameron K C, McLaren R G. Isotopic dilution methods to determine the gross transformation rates of nitrogen, phosphorus, and sulfur in soil: a review of the theory, methodologies, and limitations. Aust J Soil Res, 2000; 38: 213–230.

[26] Azam F, Müller C. Effect of sodium chloride on denitrification in glucose amended soil treated with ammonium and nitrate nitrogen. J Plant Nutr Soil Sci, 2003; 166（5）: 594–600.

[27] Gonzalez-Silva B M, Jonassen K R, Bakke I, Østgaard K, Vadstein O. Nitrification at different salinities: biofilm community composition and physiological plasticity. Water Res, 2016; 95: 48–58.

[28] Skujins J J, Mclaren A D. Enzyme reaction rates at limited water activities. Science, 1967; 158（3808）: 1569.

[29] Adviento-Borbe M A A, Doran J W, Drijber R A, Dobermann A. Soil electrical conductivity and water content affect nitrous oxide and carbon dioxide emissions in intensively managed soils. J Environ Qual, 2006; 35（6）: 1999–2010.

[30] Mahmood M Z, Bibi S, Shahzad M, Fakhar A, Rafique M, Qayyum A. Mechanisms of microbes to combat salinity in soil by producing secondary metabolites. Arab J Geosci, 2022; 15: 45.

[31] Zeng W Z, Xu C, Wu J W, Huang J S, Ma T. Effect of salinity on soil respiration and nitrogen dynamics. Ecol Chem Eng S, 2013; 20（3）: 519–530.

[32] Windey K, Bo I D, Verstraete W. Oxygen-limited autotrophic nitrification–denitrification （OLAND） in a rotating biological contactor treating high-salinity wastewater. Water Res., 2005; 39（18）: 4512–4520.

[33] Aslan S, Simsek E. Influence of salinity on partial nitrification in a submerged biofilter. Bioresour Technol, 2012; 118: 24–29.

[34] Li J C, Cai L, Lu H F, Ma B, Chen G S, Kong D D, et al. Effects of ion combinations and their concentrations on denitrification performance and gene expressions of an aerobic strain marinobacter hydrocarbonoclasticus RAD-2. Environ Microbiol, 2023; 11: 1867.

[35] Wang X Y, Zhu H, Yan B X, Shutes B, Bañuelos G, Cheng R. Response of the microbial community to salt stress and its stratified effect in constructed wetlands. Environ Sci Pollut R, 2021; 28: 18089–18101.

[36] Halverson L J, Jones T M, Firestone M K. Release of intracellular solutes by four soil bacteria exposed to dilution stress. Soil Sci Soc Am J, 2000; 64: 1630–1637.

[37] Schlüter S, Lucas M, Grosz B, Ippisch O, Zawallich J, He H, et al. The anaerobic soil volume as a controlling factor of denitrification: A review. Biol Fert Soils, 2024; 61: 343–365.

[38] Bai J H, Gao H F, Xiao R, Wang J J, Huang C. A review of soil nitrogen mineralization as affected by water and salt in coastal wetlands: issues and methods. Clean Soil Air Water, 2012; 40（10）: 1099–1105.

[39] Wei Q, Li X T, Xu J G, Dai H X, Li B, Xu J Z, et al. Responses of soil N2O and CO2 emissions and their global warming potentials to irrigation water salinity. Atmosphere, 2022; 13（11）: 1777.

[40] Miao Y, Liao R H, Zhang X X, Liu B, Li Y, Wu B, et al. Metagenomic insights into salinity effect on diversity and abundance of denitrifying bacteria and genes in an expanded granular sludge bed reactor treating high-nitrate wastewater. Chem Eng J, 2015; 277: 116–123.

[41] Chen J H, Han Y, Wang Y M, Gong B Z, Zhou J, Qing X X. Start-up and microbial communities of a simultaneous nitrogen removal system for high salinity and high nitrogen organic wastewater via heterotrophic nitrification. Bioresour Technol, 2016; 216: 196–202.

[42] Xue D M, Li J, Yu H, Jin K, Wang Z L. Effects of oxytetracycline on denitrification and anammox processes in riparian buffer zone soil. Int J Agric & Biol Eng, 2024; 17（6）: 286–295.

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Published

2026-07-14

How to Cite

(1)
Du, L.; Pan, C.; Wang, C.; Chen, Z.; Xiong, Y.; Huang, G. Effects of Salt Stress on Nitrification and Denitrification Rates and N2O Emissions in Soil Using a 15N Isotope Tracing Approach. Int J Agric & Biol Eng 2026, 19, 191–197.

Issue

Vol. 19 No. 3 (2026): IJABE

Section

Natural Resources and Environmental Systems

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