Active Nitrogen Fixation by Iron-Reducing Bacteria in Rice Paddy Soil and Its Further Enhancement by Iron Application
In rice paddy soil, biological nitrogen fixation is important for sustaining soil nitrogen fertility and rice growth. <i>Anaeromyxobacter</i> and <i>Geobacteriaceae</i>, iron-reducing bacteria belonging to Deltaproteobacteria, are newly discovered nitrogen-fixing bacteria dom...
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MDPI AG
2023-07-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/13/14/8156 |
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| author | Zhengcheng Zhang Yoko Masuda Zhenxing Xu Yutaka Shiratori Hirotomo Ohba Keishi Senoo |
| author_facet | Zhengcheng Zhang Yoko Masuda Zhenxing Xu Yutaka Shiratori Hirotomo Ohba Keishi Senoo |
| author_sort | Zhengcheng Zhang |
| collection | DOAJ |
| description | In rice paddy soil, biological nitrogen fixation is important for sustaining soil nitrogen fertility and rice growth. <i>Anaeromyxobacter</i> and <i>Geobacteriaceae</i>, iron-reducing bacteria belonging to Deltaproteobacteria, are newly discovered nitrogen-fixing bacteria dominant in paddy soils. They utilize acetate, a straw-derived major carbon compound in paddy soil, as a carbon and energy source, and ferric iron compounds as electron acceptors for anaerobic respiration. In our previous paddy field experiments, a significant increase in soil nitrogen-fixing activity was observed after the application of iron powder to straw-returned paddy field soil. In addition, combining iron application with 60–80% of the conventional nitrogen fertilizer rate could maintain rice yields similar to those with the conventional nitrogen fertilization rate. It was thus suggested that iron application to paddy soil increased the amount of nitrogen fixed in the soil by enhancing nitrogen fixation by diazotrophic iron-reducing bacteria. The present study was conducted to directly verify this suggestion by <sup>15</sup>N-IRMS analysis combined with <sup>15</sup>N-DNA-stable isotope probing of iron-applied and no-iron-applied plot soils in an experimental paddy field. In no-iron-applied native paddy soil, atmospheric <sup>15</sup>N<sub>2</sub> was incorporated into the soil by biological nitrogen fixation, in which diazotrophic iron-reducing bacteria were the most active drivers of nitrogen fixation. In iron-applied paddy soil, the amount of <sup>15</sup>N incorporated into the soil was significantly higher due to enhanced biological nitrogen fixation, especially via diazotrophic iron-reducing bacteria, the most active drivers of nitrogen fixation in the soil. Thus, our previous suggestion was verified. This study provided a novel picture of active nitrogen-fixing microorganisms dominated by diazotrophic iron-reducing bacteria in paddy soil, and directly proved the effectiveness of iron application to enhance their nitrogen fixation and increase the incorporation of atmospheric nitrogen into soil. The enhancement of biological nitrogen fixation in paddy fields by iron application may lead to novel and unique paddy soil management strategies to increase soil nitrogen fertility and ensure rice yields with reduced nitrogen fertilizer input and lower environmental nitrogen burdens. |
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| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-11T01:20:50Z |
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| spelling | doaj.art-9c1e11c8e96a4435a3f961ab7ad8f5e42023-11-18T18:09:06ZengMDPI AGApplied Sciences2076-34172023-07-011314815610.3390/app13148156Active Nitrogen Fixation by Iron-Reducing Bacteria in Rice Paddy Soil and Its Further Enhancement by Iron ApplicationZhengcheng Zhang0Yoko Masuda1Zhenxing Xu2Yutaka Shiratori3Hirotomo Ohba4Keishi Senoo5Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, JapanDepartment of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, JapanDepartment of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, JapanNiigata Agricultural Research Institute, Nagaoka 940-0826, JapanNiigata Agricultural Research Institute, Nagaoka 940-0826, JapanDepartment of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, JapanIn rice paddy soil, biological nitrogen fixation is important for sustaining soil nitrogen fertility and rice growth. <i>Anaeromyxobacter</i> and <i>Geobacteriaceae</i>, iron-reducing bacteria belonging to Deltaproteobacteria, are newly discovered nitrogen-fixing bacteria dominant in paddy soils. They utilize acetate, a straw-derived major carbon compound in paddy soil, as a carbon and energy source, and ferric iron compounds as electron acceptors for anaerobic respiration. In our previous paddy field experiments, a significant increase in soil nitrogen-fixing activity was observed after the application of iron powder to straw-returned paddy field soil. In addition, combining iron application with 60–80% of the conventional nitrogen fertilizer rate could maintain rice yields similar to those with the conventional nitrogen fertilization rate. It was thus suggested that iron application to paddy soil increased the amount of nitrogen fixed in the soil by enhancing nitrogen fixation by diazotrophic iron-reducing bacteria. The present study was conducted to directly verify this suggestion by <sup>15</sup>N-IRMS analysis combined with <sup>15</sup>N-DNA-stable isotope probing of iron-applied and no-iron-applied plot soils in an experimental paddy field. In no-iron-applied native paddy soil, atmospheric <sup>15</sup>N<sub>2</sub> was incorporated into the soil by biological nitrogen fixation, in which diazotrophic iron-reducing bacteria were the most active drivers of nitrogen fixation. In iron-applied paddy soil, the amount of <sup>15</sup>N incorporated into the soil was significantly higher due to enhanced biological nitrogen fixation, especially via diazotrophic iron-reducing bacteria, the most active drivers of nitrogen fixation in the soil. Thus, our previous suggestion was verified. This study provided a novel picture of active nitrogen-fixing microorganisms dominated by diazotrophic iron-reducing bacteria in paddy soil, and directly proved the effectiveness of iron application to enhance their nitrogen fixation and increase the incorporation of atmospheric nitrogen into soil. The enhancement of biological nitrogen fixation in paddy fields by iron application may lead to novel and unique paddy soil management strategies to increase soil nitrogen fertility and ensure rice yields with reduced nitrogen fertilizer input and lower environmental nitrogen burdens.https://www.mdpi.com/2076-3417/13/14/8156nitrogen-fixing bacteriairon-reducing bacteriaamount of fixed nitrogeniron applicationrice paddy soil |
| spellingShingle | Zhengcheng Zhang Yoko Masuda Zhenxing Xu Yutaka Shiratori Hirotomo Ohba Keishi Senoo Active Nitrogen Fixation by Iron-Reducing Bacteria in Rice Paddy Soil and Its Further Enhancement by Iron Application Applied Sciences nitrogen-fixing bacteria iron-reducing bacteria amount of fixed nitrogen iron application rice paddy soil |
| title | Active Nitrogen Fixation by Iron-Reducing Bacteria in Rice Paddy Soil and Its Further Enhancement by Iron Application |
| title_full | Active Nitrogen Fixation by Iron-Reducing Bacteria in Rice Paddy Soil and Its Further Enhancement by Iron Application |
| title_fullStr | Active Nitrogen Fixation by Iron-Reducing Bacteria in Rice Paddy Soil and Its Further Enhancement by Iron Application |
| title_full_unstemmed | Active Nitrogen Fixation by Iron-Reducing Bacteria in Rice Paddy Soil and Its Further Enhancement by Iron Application |
| title_short | Active Nitrogen Fixation by Iron-Reducing Bacteria in Rice Paddy Soil and Its Further Enhancement by Iron Application |
| title_sort | active nitrogen fixation by iron reducing bacteria in rice paddy soil and its further enhancement by iron application |
| topic | nitrogen-fixing bacteria iron-reducing bacteria amount of fixed nitrogen iron application rice paddy soil |
| url | https://www.mdpi.com/2076-3417/13/14/8156 |
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