Nitrate as an alternative electron acceptor destabilizes the mineral associated organic carbon in moisturized deep soil depths
Numerous studies have investigated the effects of nitrogen (N) addition on soil organic carbon (SOC) decomposition. However, most studies have focused on the shallow top soils <0.2 m (surface soil), with a few studies also examining the deeper soil depths of 0.5–1.0 m (subsoil). Studies inves...
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| Format: | Article |
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Frontiers Media S.A.
2023-02-01
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| Series: | Frontiers in Microbiology |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fmicb.2023.1120466/full |
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| author | Wei Song Chunsheng Hu Yu Luo Tim J. Clough Nicole Wrage-Mönnig Tida Ge Jiafa Luo Shungui Zhou Shuping Qin |
| author_facet | Wei Song Chunsheng Hu Yu Luo Tim J. Clough Nicole Wrage-Mönnig Tida Ge Jiafa Luo Shungui Zhou Shuping Qin |
| author_sort | Wei Song |
| collection | DOAJ |
| description | Numerous studies have investigated the effects of nitrogen (N) addition on soil organic carbon (SOC) decomposition. However, most studies have focused on the shallow top soils <0.2 m (surface soil), with a few studies also examining the deeper soil depths of 0.5–1.0 m (subsoil). Studies investigating the effects of N addition on SOC decomposition in soil >1.0 m deep (deep soil) are rare. Here, we investigated the effects and the underlying mechanisms of nitrate addition on SOC stability in soil depths deeper than 1.0 m. The results showed that nitrate addition promoted deep soil respiration if the stoichiometric mole ratio of nitrate to O2 exceeded the threshold of 6:1, at which nitrate can be used as an alternative acceptor to O2 for microbial respiration. In addition, the mole ratio of the produced CO2 to N2O was 2.57:1, which is close to the theoretical ratio of 2:1 expected when nitrate is used as an electron acceptor for microbial respiration. These results demonstrated that nitrate, as an alternative acceptor to O2, promoted microbial carbon decomposition in deep soil. Furthermore, our results showed that nitrate addition increased the abundance of SOC decomposers and the expressions of their functional genes, and concurrently decreased MAOC, and the ratio of MAOC/SOC decreased from 20% before incubation to 4% at the end of incubation. Thus, nitrate can destabilize the MAOC in deep soils by stimulating microbial utilization of MAOC. Our results imply a new mechanism on how above-ground anthropogenic N inputs affect MAOC stability in deep soil. Mitigation of nitrate leaching is expected to benefit the conservation of MAOC in deep soil depths. |
| first_indexed | 2024-04-10T16:42:08Z |
| format | Article |
| id | doaj.art-6d4e6375f1e748b69cecc4e4ba3a6044 |
| institution | Directory Open Access Journal |
| issn | 1664-302X |
| language | English |
| last_indexed | 2024-04-10T16:42:08Z |
| publishDate | 2023-02-01 |
| publisher | Frontiers Media S.A. |
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| series | Frontiers in Microbiology |
| spelling | doaj.art-6d4e6375f1e748b69cecc4e4ba3a60442023-02-08T05:44:18ZengFrontiers Media S.A.Frontiers in Microbiology1664-302X2023-02-011410.3389/fmicb.2023.11204661120466Nitrate as an alternative electron acceptor destabilizes the mineral associated organic carbon in moisturized deep soil depthsWei Song0Chunsheng Hu1Yu Luo2Tim J. Clough3Nicole Wrage-Mönnig4Tida Ge5Jiafa Luo6Shungui Zhou7Shuping Qin8Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, Fujian, ChinaHebei Provincial Key Laboratory of Soil Ecology, Center for Agricultural Resources Research, Institute of Genetic and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei, ChinaZhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Institute of Soil and Water Resources and Environmental Science, Zhejiang University, Hangzhou, ChinaFaculty of Agriculture and Life Sciences, Lincoln University, Lincoln, New ZealandFaculty of Agricultural and Environmental Sciences, Grassland and Fodder Sciences, University of Rostock, Rostock, GermanyState Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-Products, Key Laboratory of Biotechnology in Plant Protection of Ministry of Agriculture and Zhejiang Province, Institute of Plant Virology, Ningbo University, Ningbo, ChinaAgResearch Ltd., Hamilton, New ZealandFujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou, Fujian, ChinaHebei Provincial Key Laboratory of Soil Ecology, Center for Agricultural Resources Research, Institute of Genetic and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei, ChinaNumerous studies have investigated the effects of nitrogen (N) addition on soil organic carbon (SOC) decomposition. However, most studies have focused on the shallow top soils <0.2 m (surface soil), with a few studies also examining the deeper soil depths of 0.5–1.0 m (subsoil). Studies investigating the effects of N addition on SOC decomposition in soil >1.0 m deep (deep soil) are rare. Here, we investigated the effects and the underlying mechanisms of nitrate addition on SOC stability in soil depths deeper than 1.0 m. The results showed that nitrate addition promoted deep soil respiration if the stoichiometric mole ratio of nitrate to O2 exceeded the threshold of 6:1, at which nitrate can be used as an alternative acceptor to O2 for microbial respiration. In addition, the mole ratio of the produced CO2 to N2O was 2.57:1, which is close to the theoretical ratio of 2:1 expected when nitrate is used as an electron acceptor for microbial respiration. These results demonstrated that nitrate, as an alternative acceptor to O2, promoted microbial carbon decomposition in deep soil. Furthermore, our results showed that nitrate addition increased the abundance of SOC decomposers and the expressions of their functional genes, and concurrently decreased MAOC, and the ratio of MAOC/SOC decreased from 20% before incubation to 4% at the end of incubation. Thus, nitrate can destabilize the MAOC in deep soils by stimulating microbial utilization of MAOC. Our results imply a new mechanism on how above-ground anthropogenic N inputs affect MAOC stability in deep soil. Mitigation of nitrate leaching is expected to benefit the conservation of MAOC in deep soil depths.https://www.frontiersin.org/articles/10.3389/fmicb.2023.1120466/fullnitrate leachingglobal warminggreenhouse gas emissionMAOCdeep soil |
| spellingShingle | Wei Song Chunsheng Hu Yu Luo Tim J. Clough Nicole Wrage-Mönnig Tida Ge Jiafa Luo Shungui Zhou Shuping Qin Nitrate as an alternative electron acceptor destabilizes the mineral associated organic carbon in moisturized deep soil depths Frontiers in Microbiology nitrate leaching global warming greenhouse gas emission MAOC deep soil |
| title | Nitrate as an alternative electron acceptor destabilizes the mineral associated organic carbon in moisturized deep soil depths |
| title_full | Nitrate as an alternative electron acceptor destabilizes the mineral associated organic carbon in moisturized deep soil depths |
| title_fullStr | Nitrate as an alternative electron acceptor destabilizes the mineral associated organic carbon in moisturized deep soil depths |
| title_full_unstemmed | Nitrate as an alternative electron acceptor destabilizes the mineral associated organic carbon in moisturized deep soil depths |
| title_short | Nitrate as an alternative electron acceptor destabilizes the mineral associated organic carbon in moisturized deep soil depths |
| title_sort | nitrate as an alternative electron acceptor destabilizes the mineral associated organic carbon in moisturized deep soil depths |
| topic | nitrate leaching global warming greenhouse gas emission MAOC deep soil |
| url | https://www.frontiersin.org/articles/10.3389/fmicb.2023.1120466/full |
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