Micro-nano bubbles revitalize waterlogged paddy fields, supporting agricultural carbon neutrality
Higher Education Press
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Waterlogged paddy fields are widely distributed in rainy and low-lying areas of southern China, accounting for 15%–20% of the local rice planting area. The strongly reducing environment formed by long-term flooding not only reduces rice yields by 30%–50% compared with normal paddy fields, but also makes waterlogged soils a core source of agricultural methane emissions, creating a real contradiction with the green and low-carbon development of agriculture and the advancement of carbon neutrality strategies. Oxygen deficiency and the accumulation of ferrous ions and organic acids in waterlogged soils both poison crop roots and immobilize key nutrients such as phosphorus and potassium, becoming a prominent problem constraining the coordinated development of food security and farmland ecology.
The research group led by Yonghong WU at the Institute of Soil Science, Chinese Academy of Sciences, published a research paper titled “Multidimensional effects and mechanisms of micro-nano bubbles in regulating waterlogged soil microenvironments” in ENGINEERING Agriculture (DOI: 10.15302/J-FASE-2026673). Through pot experiments, this study confirmed that oxygen micro-nano bubbles (MNBs) can reshape the micropore structure of waterlogged soil, increase redox potential, enhance the abundance of carbon, nitrogen, and phosphorus cycling genes, and reduce greenhouse gas emissions, achieving dual benefits of soil quality improvement and ecological emission reduction. This provides a brand-new technical pathway for low-cost green remediation of waterlogged farmland.
This study applied MNB technology to the remediation of waterlogged paddy fields for the first time and revealed its unique mechanisms, which differ from conventional amendments. The study established an air micro-nano bubble group (air-MNBs) and an oxygen micro-nano bubble group (O₂-MNBs). After a 40-day pot experiment, the key findings were reflected at three levels:
Physical reshaping was the starting point: O₂-MNBs increased the number of soil micropores by 2.4 times and nearly doubled the specific surface area, but the coordination number of pores and throats decreased by more than 60%, forming numerous isolated “micro-air pockets” that achieved slow oxygen release rather than rapid loss. Pore connectivity did not improve significantly.
Chemical transformation followed: soil redox potential rose from 230 to 374 mV, and total reducing substances decreased by 22.4%. Alkali-hydrolyzable nitrogen increased to 216 mg/kg, available phosphorus rose from 35.6 to 72.2 mg/kg, and available potassium increased to 284 mg/kg. Soil pH did not change significantly.
Ecological benefits were the outcome: methane emissions plummeted by 60.6%. Although carbon dioxide emissions doubled, the integrated global warming potential still decreased by 26.2%, and ammonia oxidation genes showed no change, avoiding nitrogen loss. Path analysis confirmed that micropore volume proportion—rather than macropores or connectivity—is the core variable driving nutrient release and ecological improvement.
MNB technology provides a new paradigm for green remediation of waterlogged soils and is deeply aligned with the needs of food security assurance and agricultural low-carbon transformation. Using air and oxygen as raw materials, the technology leaves no chemical residues, does not alter soil pH, and is compatible with existing irrigation systems. It features low equipment investment and simple operation and maintenance, and can be scaled up for the improvement of low-yield fields in southern China, helping enhance farmland quality and efficiency. At the same time, by inhibiting methane emissions and activating soil carbon, nitrogen, and phosphorus cycling, it provides an operational pathway for transforming rice cultivation from “high-carbon” to “low-carbon.” It addresses the pain point of traditional improvement practices that “emphasize production while neglecting ecology,” promotes the coordinated development of agricultural production and ecological protection, and offers a replicable and scalable new path for green agricultural technology innovation.
Journal
ENGINEERING Agriculture
Method of Research
Experimental study
Subject of Research
Not applicable
Article Title
Multidimensional effects and mechanisms of micro-nano bubbles in regulating waterlogged soil microenvironments
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