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Abstract Rice paddies are one of the major sources of anthropogenic methane (CH4) emissions. The alternate wetting and drying (AWD) irrigation management has been shown to reduce CH4emissions and total global warming potential (GWP) (CH4and nitrous oxide [N2O]). However, there is limited information about utilizing AWD management to reduce greenhouse gas (GHG) emissions from commercial‐scale continuous rice fields. This study was conducted for five consecutive growing seasons (2015–2019) on a pair of adjacent fields in a commercial farm in Arkansas under long‐term continuous rice rotation irrigated with either continuously flooded (CF) or AWD conditions. The cumulative CH4emissions in the growing season across the two fields and 5 years ranged from 41 to 123 kg CH4‐C ha−1for CF and 1 to 73 kg CH4‐C ha−1for AWD. On average, AWD reduced CH4emissions by 73% relative to CH4emissions in CF fields. Compared to N2O emissions, CH4emissions dominated the GWP with an average contribution of 91% in both irrigation treatments. There was no significant variation in grain yield (7.3–11.9 Mg ha−1) or growing season N2O emissions (−0.02 to 0.51 kg N2O‐N ha−1) between the irrigation treatments. The yield‐scaled GWP was 368 and 173 kg CO2eq. Mg−1season−1for CF and AWD, respectively, showing the feasibility of AWD on a commercial farm to reduce the total GHG emissions while sustaining grain yield. Seasonal variations of GHG emissions observed within fields showed total GHG emissions were predominantly influenced by weather (precipitation) and crop and irrigation management. The influence of air temperature and floodwater heights on GHG emissions had high degree of variability among years and fields. These findings demonstrate that the use of multiyear GHG emission datasets could better capture variability of GHG emissions associated with rice production and could improve field verification of GHG emission models and scaling factors for commercial rice farms.
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This content will become publicly available on April 2, 2026
Global warming potential of farming systems across England: possible mitigation and co-benefits for water quality and biodiversity
Abstract Agriculture is a key contributor to gaseous emissions causing climate change, the degradation of water quality, and biodiversity loss. The extant climate change crisis is driving a focus on mitigating agricultural gaseous emissions, but wider policy objectives, beyond net zero, mean that evidence on the potential co-benefits or trade-offs associated with on-farm intervention is warranted. For novelty, aggregated data on farm structure and spatial distribution for different farm types were integrated with high-resolution data on the natural environment to generate representative model farms. Accounting for existing mitigation effects, the Catchment Systems Model was then used to quantify global warming potential, emissions to water, and other outcomes for water management catchments across England under both business-as-usual and a maximum technically feasible mitigation potential scenario. Mapped spatial patterns were overlain with the distributions of areas experiencing poor water quality and biodiversity loss to examine potential co-benefits. The median business-as-usual GWP20 and GWP100, excluding embedded emissions, were estimated to be 4606 kg CO2eq. ha−1(inter-quartile range 4240 kg CO2eq. ha−1) and 2334 kg CO2eq. ha−1(inter-quartile range 1462 kg CO2eq. ha−1), respectively. The ratios of business-as-usual GHG emissions to monetized farm production ranged between 0.58 and 8.89 kg CO2eq. £−1for GWP20, compared with 0.53–3.99 kg CO2eq. £−1for GWP100. The maximum mitigation potentials ranged between 17 and 30% for GWP20 and 19-27% for GWP100 with both corresponding medians estimated to be ~24%. Here, we show for the first time that the co-benefits for water quality associated with reductions in phosphorus and sediment loss were both equivalent to around a 34% reduction, relative to business-as-usual, in specific management catchment reporting units where excess water pollutant loads were identified. Several mitigation measures included in the mitigation scenario were also identified as having the potential to deliver co-benefits for terrestrial biodiversity.
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- Award ID(s):
- 2330502
- PAR ID:
- 10647347
- Publisher / Repository:
- Agronomy for Sustainable Development
- Date Published:
- Journal Name:
- Agronomy for Sustainable Development
- Volume:
- 45
- Issue:
- 2
- ISSN:
- 1774-0746
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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