Nitrogen input promotes denitrifying methanotrophs' abundance and contribution to methane emission reduction in coastal wetland and paddy soil

Anaerobic oxidation of methane driven by different electron acceptors: A review

Methane, the most significant reduced form of carbon on Earth, acts as a crucial fuel and greenhouse gas. Globally, microbial methane sinks encompass both aerobic oxidation of methane (AeOM), conducted by oxygen-utilizing methanotrophs, and anaerobic oxidation of methane (AOM), performed by anaerobic methanotrophs employing various alternative electron acceptors. These electron acceptors involved in AOM include sulfate, nitrate/nitrite, humic substances, and diverse metal oxides. The known anaerobic methanotrophic pathways comprise the internal aerobic oxidation pathway found in NC10 bacteria and the reverse methanogenesis pathway utilized by anaerobic methanotrophic archaea (ANME). Diverse anaerobic methanotrophs can perform AOM independently or in cooperation with symbiotic partners through several extracellular electron transfer (EET) pathways. AOM has been documented in various environments, including seafloor methane seepages, coastal wetlands, freshwater lakes, soils, and even extreme environments like hydrothermal vents. The environmental activities of AOM processes, driven by different electron acceptors, primarily depend on the energy yields, availability of electron acceptors, and environmental adaptability of methanotrophs. It has been suggested that different electron acceptors driving AOM may occur across a wider range of habitats than previously recognized. Additionally, it is proposed that methanotrophs have evolved flexible metabolic strategies to adapt to complex environmental conditions. This review primarily focuses on AOM, driven by different electron acceptors, discussing the associated reaction mechanisms and the habitats where these processes are active. Furthermore, it emphasizes the pivotal role of AOM in mitigating methane emissions.

Aromatic compound 2-acetyl-1-pyrroline coordinates nitrogen assimilation and methane mitigation in fragrant rice

Rice paddy has been the main source of anthropogenic methane (CH4) emissions, with significant variations among rice varieties. 2-Acetyl-1-pyrroline (2-AP) is the key component of the pleasant aroma in fragrant rice. Here, we show that fragrant rice is metabolically active in nitrogen assimilation and exhibits high levels of 2-AP and that CH4 fluxes at the booting stage and cumulative emissions are 25.5% and 14.8% lower, respectively, in fragrant rice paddies compared with nonfragrant rice paddies. Three precursors involved in 2-AP synthesis-proline, glutamic acid, and ornithine-are identified as crucial nitrogen compounds that significantly promote CH4 oxidation in the rhizosphere. Augmenting 2-AP synthesis, either through foliar spraying or by utilizing CRISPR-Cas9 technology to generate knockout lines of BETAINE ALDEHYDE DEHYDROGENASE 2 gene, effectively enhances CH4 oxidation and reduces CH4 fluxes. Our findings reveal that the 2-AP metabolic pathway coordinates the carbon/nitrogen cycle to improve nitrogen assimilation along with high 2-AP levels and mitigate CH4 emissions in paddy ecosystems.

Simultaneous methane mitigation and nitrogen removal by denitrifying anaerobic methane oxidation in lake sediments

Methane (CH4) is a potent greenhouse gas, with lake ecosystems significantly contributing to its global emissions. Denitrifying anaerobic methane oxidation (DAMO) process, mediated by NC10 bacteria and ANME-2d archaea, links global carbon and nitrogen cycles. However, their potential roles in mitigating methane emissions and removing nitrogen from lake ecosystems remain unclear. This study explored the spatial variations in activities of nitrite- and nitrate-DAMO and their functional microbes in Changdanghu Lake sediments (Jiangsu Province, China). The results showed that although the average abundance of ANME-2d archaea (5.0 × 106 copies g-1) was significantly higher than that of NC10 bacteria (2.1 × 106 copies g-1), the average potential rates of nitrite-DAMO (4.59 nmol 13CO2 g-1 d-1) and nitrate-DAMO (5.01 nmol 13CO2 g-1 d-1) showed no significant difference across all sampling sites. It is estimated that nitrite- and nitrate-DAMO consumed approximately 6.46 and 7.05 mg CH4 m-2 d-1, respectively, which accordingly achieved 15.07-24.95 mg m-2 d-1 nitrogen removal from the studied lake sediments. Statistical analyses found that nitrite- and nitrate-DAMO activities were both significantly related to sediment nitrate contents and ANME-2d archaeal abundance. In addition, NC10 bacterial and ANME-2d archaeal community compositions showed significant correlations with sediment organic carbon content and water depth. Overall, this study underscores the dual roles of nitrite- and nitrate-DAMO processes in CH4 mitigation and nitrogen elimination and their key environmental impact factors (sediment organic carbon and inorganic nitrogen contents, and water depth) in shallow lake, enhancing the understanding of carbon and nitrogen cycles in freshwater aquatic ecosystems.

Active anaerobic methane oxidation in the groundwater table fluctuation zone of rice paddies

Rice paddies are globally important sources of methane emissions and also active regions for methane consumption. However, the impact of fluctuating groundwater levels on methane cycling has received limited attention. In this study, we delved into the activity and microbial mechanisms underlying anaerobic oxidation of methane (AOM) in paddy fields. A comprehensive approach was employed, including 13C stable isotope assays, inhibition experiments, real-time quantitative reverse transcription PCR, metagenomic sequencing, and binning technology. Geochemical profiles revealed the abundant coexistence of both methane and electron acceptors in the groundwater table fluctuation (GTF) zone, at a depth of 40-60 cm. Notably, the GTF zone exhibited the highest rate of AOM, potentially linked to the reduction of iron oxides and nitrate. Within this zone, Candidatus Methanoperedens (belonging to the ANME-2d group) dominated the Archaea population, accounting for a remarkable 85.4 %. Furthermore, our results from inhibition experiments, RT-qPCR, and metagenome-assembled genome (MAG) analysis highlighted the active role of Ca. Methanoperedens GTF50 in the GTF zone. This microorganism could independently mediate AOM process through the intriguing "reverse methanogenesis" pathway. Considering the similarity in geochemical conditions across different paddy fields, it is likely that Ca. Methanoperedens-mediated AOM is prevalent in the GTF zones.

Soil methane emissions from plain poplar (Populus spp.) plantations with contrasting soil textures

The forest soil methane (CH4) flux exhibits high spatiotemporal variability. Understanding these variations and their driving factors is crucial for accurately assessing the forest CH4 budget. In this study, we monitored the diurnal and seasonal variations in soil CH4 fluxes in two poplar (Populus spp.) plantations (Sihong and Dongtai) with different soil textures using the static chamber-based method. The results showed that the annual average soil CH4 flux in the Sihong and Dongtai poplar plantations was 4.27 ± 1.37 kg CH4-C ha-1 yr-1 and 1.92 ± 1.07 kg CH4-C ha-1 yr-1, respectively. Both plantations exhibited net CH4 emissions during the growing season, with only weak CH4 absorption (-0.01 to -0.007 mg m-2 h-1) during the non-growing season. Notably, there was a significant difference in soil CH4 flux between the clay loam of the Sihong poplar plantation and the sandy loam of the Dongtai poplar plantation. From August to December 2019 and from July to August and November 2020, the soil CH4 flux in the Sihong poplar plantation was significantly higher than in the Dongtai poplar plantation. Moreover, the soil CH4 flux significantly increased with rising soil temperature and soil water content. Diurnally, the soil CH4 flux followed a unimodal variation pattern at different growing stages of poplars, with peaks occurring at noon and in the afternoon. However, the soil CH4 flux did not exhibit a consistent seasonal pattern across different years, likely due to substantial variations in precipitation and soil water content. Overall, our study emphasizes the need for a comprehensive understanding of the spatiotemporal variations in forest soil CH4 flux with different soil textures. This understanding is vital for developing reasonable forest management strategies and reducing uncertainties in the global CH4 budget.

Regulation of nitrite-dependent anaerobic methane oxidation bacteria by available phosphorus and microbial communities in lake sediments of cold and arid regions

As global anthropogenic nitrogen inputs continue to rise, nitrite-dependent anaerobic methane oxidation (N-DAMO) plays an increasingly significant role in CH4 consumption in lake sediments. However, there is a dearth of knowledge regarding the effects of anthropogenic activities on N-DAMO bacteria in lakes in the cold and arid regions. Sediment samples were collected from five sampling areas in Lake Ulansuhai at varying depth ranges (0-20, 20-40, and 40-60 cm). The ecological characterization and niche differentiation of N-DAMO bacteria were investigated using bioinformatics and molecular biology techniques. Quantitative PCR confirmed the presence of N-DAMO bacteria in Lake Ulansuhai sediments, with 16S rRNA gene abundances ranging from 1.72 × 104 to 5.75 × 105 copies·g-1 dry sediment. The highest abundance was observed at the farmland drainage outlet with high available phosphorus (AP). Anthropogenic disturbances led to a significant increase in the abundance of N-DAMO bacteria, though their diversity remained unaffected. The heterogeneous community of N-DAMO bacteria was affected by interactions among various environmental characteristics, with AP and oxidation-reduction potential identified as the key drivers in this study. The Mantel test indicated that the N-DAMO bacterial abundance was more readily influenced by the presence of the denitrification genes (nirS and nirK). Network analysis revealed that the community structure of N-DAMO bacteria generated numerous links (especially positive links) with microbial taxa involved in carbon and nitrogen cycles, such as methanogens and nitrifying bacteria. In summary, N-DAMO bacteria exhibited sensitivity to both environmental and microbial factors under various human disturbances. This study provides valuable insights into the distribution patterns of N-DAMO bacteria and their roles in nitrogen and carbon cycling within lake ecosystems.

Nitrite-dependent anaerobic methane oxidation (N-DAMO) in global aquatic environments: A review

The vast majority of processes in the carbon and nitrogen cycles are driven by microorganisms. The nitrite-dependent anaerobic oxidation of methane (N-DAMO) process links carbon and nitrogen cycles, offering a novel approach for the simultaneous reduction of methane emissions and nitrite pollution. However, there is currently no comprehensive summary of the current status of the N-DAMO process in natural aquatic environments. Therefore, our study aims to fill this knowledge gap by conducting a comprehensive review of the global research trends in N-DAMO processes in various aquatic environments (excluding artificial bioreactors). Our review mainly focused on molecular identification, global study sites, and their interactions with other elemental cycling processes. Furthermore, we performed a data integration analysis to unveil the effects of key environmental factors on the abundance of N-DAMO bacteria and the rate of N-DAMO process. By combining the findings from the literature review and data integration analysis, we proposed future research perspectives on N-DAMO processes in global aquatic environments. Our overarching goal is to advance the understanding of the N-DAMO process and its role in synergistically reducing carbon emissions and removing nitrogen. By doing so, we aim to make a significant contribution to the timely achievement of China's carbon peak and carbon neutrality targets.

Equal importance of humic acids and nitrate in driving anaerobic oxidation of methane in paddy soils

Methane (CH4) is both generated and consumed in paddy soils, where anaerobic oxidation of methane (AOM) serves as a crucial process for mitigating CH4 emissions. Although the participation of humic acids (HA) and nitrate in AOM has been recognized, their relative roles and significance in paddy soils remain insufficiently investigated. In this study, we explored the potential activity of AOM driven by HA and nitrate, as well as the composition of archaeal communities in paddy soils across different rice growth periods and fertilization treatments. AOM activity ranged from 0.81 to 1.33 and 1.26 to 2.38 nmol of 13CO2 g-1 (dry soil) day-1 with HA and nitrate, respectively. No significant differences (p < 0.05) were observed between the AOM activity driven by HA and nitrate across the three fertilization treatments. According to AOM activity, the annual consumption of CH4 was estimated at approximately 0.49 ± 0.06 and 0.83 ± 0.19 Tg for AOM processes driven by HA and nitrate in Chinese paddy soils. Nitrate-driven AOM activity exhibited a positive (p < 0.05) correlation with the abundance of the ANME-2d mcrA gene but a negative (p < 0.05) correlation with the content of dissolved organic carbon. Intriguingly, HA-driven AOM activity was only correlated positively with the nitrate-driven AOM activity. Soil water content, soil organic carbon, nitrate and nitrite contents were significantly correlated with the relative abundance of methanogenic and methanotrophic archaea. These results identified the potential importance of HA and nitrate in driving AOM processes within paddy soils, providing a comprehensive understanding of the complex microbial processes regulating greenhouse gas emissions from paddy soils.

Methane-dependent complete denitrification by a single Methylomirabilis bacterium

Methane-dependent nitrate and nitrite removal in anoxic environments is thought to rely on syntrophy between ANME-2d archaea and bacteria in the genus 'Candidatus Methylomirabilis'. Here we enriched and purified a single Methylomirabilis from paddy soil fed with nitrate and methane, which is capable of coupling methane oxidation to nitrate reduction via nitrite to dinitrogen independently. Isotope labelling showed that this bacterium we name 'Ca. Methylomirabilis sinica' stoichiometrically performed methane-dependent complete nitrate reduction to dinitrogen gas. Multi-omics analyses collectively demonstrated that 'M. sinica' actively expressed a well-established pathway for this process, especially including nitrate reductase Nap. Furthermore, 'M. sinica' exhibited a higher nitrate affinity than most denitrifiers, implying its competitive fitness under oligotrophic nitrogen-limited conditions. Our findings revise the paradigm of methane-dependent denitrification performed by two organisms, and the widespread presence of 'M. sinica' in public databases suggests that the coupling of methane oxidation and complete denitrification in single cells substantially contributes to global methane and nitrogen budgets.

Anaerobic oxidation of methane in terrestrial wetlands: The rate, identity and metabolism

The recent discovery of anaerobic oxidation of methane (AOM) in freshwater ecosystems has caused a great interest in "cryptic methane cycle" in terrestrial ecosystems. Anaerobic methanotrophs appears widespread in wetland ecosystems, yet, the scope and mechanism of AOM in natural wetlands remain poorly understood. In this paper, we review the recent progress regarding the potential of AOM, the diversity and distribution, and the metabolism of anaerobic methanotrophs in wetland ecosystems. The potential of AOM determined through laboratory incubation or in situ isotopic labeling ranges from 1.4 to 704.0 nmol CH4·g-1 dry soil·d-1. It appears that the availability of electron acceptors is critical in driving different AOM in wetland soils. The environmental temperature and salinity exert a significant influence on AOM activity. Reversal methanogenesis and extracellular electron transfer are likely involved in the AOM process. In addition to anaerobic methanotrophic archaea, the direct involvement of methanogens in AOM is also probable. This review presented an overview of the rate, identity, and metabolisms to unravel the biogeochemical puzzle of AOM in wetland soils.

Effects of Long-Term (17 Years) Nitrogen Input on Soil Bacterial Community in Sanjiang Plain: The Largest Marsh Wetland in China

Increased nitrogen (N) input from natural factors and human activities may negatively impact the health of marsh wetlands. However, the understanding of how exogenous N affects the ecosystem remains limited. We selected the soil bacterial community as the index of ecosystem health and performed a long-term N input experiment, including four N levels of 0, 6, 12, and 24 gN·m-2·a-1 (denoted as CK, C1, C2, and C3, respectively). The results showed that a high-level N (24 gN·m-2·a-1) input could significantly reduce the Chao index and ACE index for the bacterial community and inhibit some dominant microorganisms. The RDA results indicated that TN and NH4+ were the critical factors influencing the soil microbial community under the long-term N input. Moreover, the long-term N input was found to significantly reduce the abundance of Azospirillum and Desulfovibrio, which were typical N-fixing microorganisms. Conversely, the long-term N input was found to significantly increase the abundance of Nitrosospira and Clostridium_sensu_stricto_1, which were typical nitrifying and denitrifying microorganisms. Increased soil N content has been suggested to inhibit the N fixation function of the wetland and exert a positive effect on the processes of nitrification and denitrification in the wetland ecosystem. Our research can be used to improve strategies to protect wetland health.

Spatio-temporal variations of activity of nitrate-driven anaerobic oxidation of methane and community structure of Candidatus Methanoperedens-like archaea in sediment of Wuxijiang river

Nitrate-driven anaerobic oxidation of methane (AOM), catalyzing by Candidatus Methanoperedens-like archaea, is a new addition in the global CH₄ cycle. This AOM process acts as a novel pathway for CH₄ emission reduction in freshwater aquatic ecosystems; however, its quantitative importance and regulatory factors in riverine ecosystems are nearly unknown. Here, we examined the spatio-temporal changes of the communities of Methanoperedens-like archaea and nitrate-driven AOM activity in sediment of Wuxijiang River, a mountainous river in China. These archaeal community composition varied significantly among reaches (upper, middle, and lower reaches) and between seasons (winter and summer), but their mcrA gene diversity showed no significant spatial or temporal variations. The copy numbers of Methanoperedens-like archaeal mcrA genes were 1.32 × 10⁵-2.47 × 10⁷ copies g^-1 (dry weight), and the activity of nitrate-driven AOM was 0.25-1.73 nmol CH₄ g^-1 (dry weight) d^-1, which could potentially reduce 10.3% of CH₄ emissions from rivers. Significant spatio-temporal variations of mcrA gene abundance and nitrate-driven AOM activity were found. Both the gene abundance and activity increased significantly from upper to lower reaches in both seasons, and were significantly higher in sediment collected in summer than in winter. In addition, the variations of Methanoperedens-like archaeal communities and nitrate-driven AOM activity were largely impacted by the sediment temperature, NH₄⁺ and organic carbon contents. Taken together, both time and space scales need to be considered for better evaluating the quantitative importance of nitrate-driven AOM in reducing CH₄ emissions from riverine ecosystems.

Aerobic and denitrifying methanotrophs: Dual wheels driving soil methane emission reduction

The greenhouse gas methane in soils has been considered to be consumed mainly by aerobic methane-oxidizing bacteria for a long time. In the last decades, the discovery of anaerobic methanotrophs greatly complemented the methane cycle, but their contribution rates and ecological significance in soils remain undescribed. In this work, the soil samples from forest, grassland and cropland in four different climatic regions were collected to investigate these conventional and novel methanotrophs. A dual-core microbial methane sink, responsible for over 80 % of soil methane emission reduction, was unveiled. The aerobic core was performed by aerobic methanotrophic bacteria in topsoil, who played important roles in stabilizing bacterial communities. The anaerobic core was denitrifying methanotrophs in anoxic soils, including denitrifying methanotrophic bacteria from NC10 phylum and denitrifying methanotrophic archaea from ANME-2d clade. They were ubiquitous in terrestrial soils and potentially led to around 50 % of the total methane removal. Human activities such as livestock farming and rice cultivation further promoted the contribution rates of these denitrifying methanotrophs. This work elucidated the emission reduction contribution of different methanotrophs in the continental setting, which would help to reduce uncertainties in the estimations of the soil methane emission.

Role and regulation of anaerobic methane oxidation catalyzed by NC10 bacteria and ANME-2d archaea in various ecosystems

Freshwater wetlands, paddy fields, inland aquatic ecosystems and coastal wetlands are recognized as important sources of atmospheric methane (CH₄). Currently, increasing evidence shows the potential importance of the anaerobic oxidation of methane (AOM) mediated by NC10 bacteria and a novel cluster of anaerobic methanotrophic archaea (ANME)-ANME-2d in mitigating CH₄ emissions from different ecosystems. To better understand the role of NC10 bacteria and ANME-2d archaea in CH₄ emission reduction, the current review systematically summarizes different AOM processes and the functional microorganisms involved in freshwater wetlands, paddy fields, inland aquatic ecosystems and coastal wetlands. NC10 bacteria are widely present in these ecosystems, and the nitrite-dependent AOM is identified as an important CH₄ sink and induces nitrogen loss. Nitrite- and nitrate-dependent AOM co-occur in the environment, and they are mainly affected by soil/sediment inorganic nitrogen and organic carbon contents. Furthermore, salinity is another key factor regulating the two AOM processes in coastal wetlands. In addition, ANME-2d archaea have the great potential to couple AOM to the reduction of iron (III), manganese (IV), sulfate, and even humics in different ecosystems. However, the study on the environmental distribution of ANME-2d archaea and their role in CH₄ mitigation in environments is insufficient. In this study, we propose several directions for future research on the different AOM processes and respective functional microorganisms.

Nitrate-dependent anaerobic methane oxidation (N-DAMO) as a bioremediation strategy for waters affected by agricultural runoff

Agricultural drainage ditches are subjected to high anthropogenic nitrogen input, leading to eutrophication and greenhouse gas emissions. Nitrate-dependent anaerobic methane oxidation (N-DAMO) could be a promising remediation strategy to remove methane (CH4) and nitrate (NO3-) simultaneously. Therefore, we aimed to evaluate the potential of N-DAMO to remove excess NO3- and decrease CH4 release from agricultural drainage ditches. Microcosm experiments were conducted using sediment and surface water collected from three different sites: a sandy-clay ditch (SCD), a freshwater-fed peatland ditch (FPD), and a brackish peatland ditch (BPD). The microcosms were inoculated with an N-DAMO enrichment culture dominated by Candidatus Methanoperedens and Candidatus Methylomirabilis and supplemented with 13CH4 and 15NO3-. A significant decrease in CH4 and NO3- concentration was only observed in the BPD sediment. In freshwater sediments (FPD and SCD), the effect of N-DAMO inoculation on CH4 and NO3- removal was negligible, likely because N-DAMO microorganisms were outcompeted by heterotrophic denitrifiers consuming NO3- much faster. Overall, our results suggest that bioaugmentation with N-DAMO might be a potential strategy for decreasing NO3- concentrations and CH4 emission in brackish ecosystems with increasing agricultural activities where the native microbial community is incapable of efficient denitrification.

Regulatory strategies for inhibiting horizontal gene transfer of ARGs in paddy and dryland soil through computer-based methods

Antibiotic resistance genes (ARGs) have been regarded as emerging pollutants due to their potential risk of resistance. Horizontal gene transfer (HGT) is the main pathway for ARGs to lead to environmental threats. Therefore, the inhabitation of ARGs' HGT can effectively inhibit ARGs' potential drug resistance risk within a single strain. In this paper, the characteristics of ARGs' HGT in paddy and dryland soils were identified and regulated by a combination of ARGs' HGT feature identification, transfer mechanism analysis and transfer process regulation. The homology modeling algorithm was used to simulate the construction of the Tn5 plasmid transposase of Escherichia coli (E. coli) for identifying ARGs' HGT characteristics. The GCG (212.617 Å) was thus determined as the target codon. Through integrated computer-based methods, results showed that the most important environmental disturbance factors for the HGT of ARGs in the paddy and dryland soils were rough farmyard manure/sewage irrigation and mining pollution, respectively. Under the disturbance of key environmental factors, the inhibitory effect of HGT of ARGs in paddy and dryland soil was reduced by 35.01 % and 34.74 %, respectively. Results demonstrated that the proposed theoretical mechanism and control strategies could effectively inhibit the HGT of E. coli ARGs in the soil environment.

Rapid enrichment of denitrifying methanotrophs in a series hollow-fiber membrane biofilm reactor

Denitrifying anaerobic methane oxidation (DAMO) process uses methane as electron donor to reduce nitrate/nitrite to dinitrogen, which is a potentially efficient, low-cost and clean biological nitrogen removal technology. However, slow microbial growth rate severely limits the application of this promising process. In this study, a series hollow-fiber membrane biofilm reactor (HfMBR) was operated for 90 days to achieve rapid enrichment of these denitrifying methanotrophs. Finally, the highest relative abundance of denitrifying methanotrophic archaea and bacteria (DAMO archaea and bacteria) reached 47.5% and 11.3%, respectively. And the average abundance of DAMO archaea and bacteria increased 92.9 and 136.6 times respectively during the 90-day enrichment. High growth rate of DAMO archaea with a doubling time of 11.6 days was achieved in the second HfMBR according to quantitative PCR results. The results implied that dissolved oxygen would inhibit the growth of DAMO archaea, but the series HfMBR could effectively counteract this unfavorable factor. This work provided theoretical guidance for the rapid enrichment of denitrifying methanotrophs and contributed to the application of methane-dependent denitrification process.

Effect of Plant Buffer Zone–Antifouling Curtain Wall on Reducing Non-Point Source Pollution in Paddy Fields, China

In view of the nitrogen and phosphorus non-point source pollution caused by paddy field drainage in southern China, two paddy fields in Nanjing and Yuyao cities were selected to study the effect of plant buffer zone–antifouling curtain walls on reducing non-point source pollution. The results showed that the designed plant buffer zone–antifouling curtain wall systems could significantly reduce the concentration of total nitrogen (TN) and total phosphorus (TP) in drainage of the two paddy fields. Compared with paddy field drainage in Nanjing, the interception rate of TN in the plant buffer zone and antifouling curtain wall were 33.0% and 59.3%, respectively; the removal rates of TP were about 18.4% and 40.3%, respectively. In addition, the contents of ammoniacal nitrogen (NH3-N), nitrate nitrogen (NO3-N) and Chemical Oxygen Demand (COD) were also significantly reduced. For the Yuyao experimental area, compared to the paddy field without the soil plant buffer zone (the control), the concentration of each indicator in the discharge water of the paddy fields with the soil plant buffer system operation mode was significantly reduced, the rejection rate of the TP, TN, total dissolved phosphorus (TDP), NO3-N and NH3-N were 64.28%, 70.66%, 83.73%, 65.22% and 80.69%, respectively. In summary, the construction of a plant buffer zone–antifouling curtain wall (soil plant buffer zone) has an obvious effect on the reduction of non-point source pollution in paddy fields, which could improve yield and fertilizer utilization. The plant buffer zone–antifouling curtain wall could be popularized and applied in local areas and southern China.