Peduruhewa H Jeewani, Emmanuella Oghenefejiro Agbomedarho, Chris D Evans, David R Chadwick, Davey L Jones
{"title":"Wetter farming: raising water table and biochar for reduced GHG emissions while maintaining crop productivity in agricultural peatlands.","authors":"Peduruhewa H Jeewani, Emmanuella Oghenefejiro Agbomedarho, Chris D Evans, David R Chadwick, Davey L Jones","doi":"10.1007/s42773-025-00487-7","DOIUrl":null,"url":null,"abstract":"<p><p>Despite their high agricultural productivity, drained and cultivated peats are highly susceptible to degradation and significant sources of greenhouse gas (GHG) emissions. This study investigates the potential of water table manipulation and biochar application to mitigate GHG losses from agricultural peats. However, balancing the need for agricultural production with securing the ecosystem function of the peat under high water table (WT) conditions poses a significant challenge. Therefore, we grew lettuce in a controlled mesocosm experiment with either a high (HW) or low (LW) water table and monitored emissions of CO<sub>2</sub>, CH<sub>4</sub> and N<sub>2</sub>O over 4 months using a mesocosm method. Concurrent measurements of soil solution, plant measurements and microbial sequencing allowed identification of the key controls on GHG emissions. Raising the WT significantly reduced CO<sub>2</sub> emissions (18%), and N<sub>2</sub>O emission (40%), but eventually increased CH<sub>4</sub> emission (2.5-fold) compared to the Control + LW. Biochar amendment with raised WT provided the strongest reduction in CO<sub>2</sub> equivalent GHG emission (4.64 t CO<sub>2</sub>eq ha<sup>-1</sup> yr<sup>-1</sup>), compared to Control + LW. We found that biochar amendment modified the microbial community composition and diversity (Shannon index 8.9-9.3), lowering the relative abundance of peat decomposers (such as Ascomycota). Moreover, biochar amendments produced 38-56% greater lettuce biomass compared to the unamended controls, irrespective of water table level, suggesting that biochar application could generate economic benefits in addition to reduced GHG emissions. Mechanisms responsible for these effects appeared to be both abiotic (e.g. via effects of the biochar physicochemical composition) and biotic via changing the soil microbiome. Overall, the combination of high-water table and biochar amendment enhanced total soil C, reduced peat decomposition, suppressed CH<sub>4</sub> and N<sub>2</sub>O emissions, and enhanced crop yields.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s42773-025-00487-7.</p>","PeriodicalId":8789,"journal":{"name":"Biochar","volume":"7 1","pages":"110"},"PeriodicalIF":13.5000,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12433923/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Biochar","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.1007/s42773-025-00487-7","RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/9/15 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Despite their high agricultural productivity, drained and cultivated peats are highly susceptible to degradation and significant sources of greenhouse gas (GHG) emissions. This study investigates the potential of water table manipulation and biochar application to mitigate GHG losses from agricultural peats. However, balancing the need for agricultural production with securing the ecosystem function of the peat under high water table (WT) conditions poses a significant challenge. Therefore, we grew lettuce in a controlled mesocosm experiment with either a high (HW) or low (LW) water table and monitored emissions of CO2, CH4 and N2O over 4 months using a mesocosm method. Concurrent measurements of soil solution, plant measurements and microbial sequencing allowed identification of the key controls on GHG emissions. Raising the WT significantly reduced CO2 emissions (18%), and N2O emission (40%), but eventually increased CH4 emission (2.5-fold) compared to the Control + LW. Biochar amendment with raised WT provided the strongest reduction in CO2 equivalent GHG emission (4.64 t CO2eq ha-1 yr-1), compared to Control + LW. We found that biochar amendment modified the microbial community composition and diversity (Shannon index 8.9-9.3), lowering the relative abundance of peat decomposers (such as Ascomycota). Moreover, biochar amendments produced 38-56% greater lettuce biomass compared to the unamended controls, irrespective of water table level, suggesting that biochar application could generate economic benefits in addition to reduced GHG emissions. Mechanisms responsible for these effects appeared to be both abiotic (e.g. via effects of the biochar physicochemical composition) and biotic via changing the soil microbiome. Overall, the combination of high-water table and biochar amendment enhanced total soil C, reduced peat decomposition, suppressed CH4 and N2O emissions, and enhanced crop yields.
Supplementary information: The online version contains supplementary material available at 10.1007/s42773-025-00487-7.
期刊介绍:
Biochar stands as a distinguished academic journal delving into multidisciplinary subjects such as agronomy, environmental science, and materials science. Its pages showcase innovative articles spanning the preparation and processing of biochar, exploring its diverse applications, including but not limited to bioenergy production, biochar-based materials for environmental use, soil enhancement, climate change mitigation, contaminated-environment remediation, water purification, new analytical techniques, life cycle assessment, and crucially, rural and regional development. Biochar publishes various article types, including reviews, original research, rapid reports, commentaries, and perspectives, with the overarching goal of reporting significant research achievements, critical reviews fostering a deeper mechanistic understanding of the science, and facilitating academic exchange to drive scientific and technological development.