Rice cultivation is a major contributor to greenhouse gas (GHG) emissions as flooded paddies create ideal conditions for methane production, while overuse of nitrogen fertiliser increases nitrous oxide emissions.
With rice covering roughly 75% of Bangladesh’s agricultural land, finding practical, low-emission cultivation methods is critical for climate mitigation and food security.
A team of researchers from the Bangladesh Rice Research Institute (BRRI), International Rice Research Institute (IRRI), International Fertiliser Development Center (IFDC), and Japan’s National Agriculture and Food Research Organisation (NARO) aimed to identify climate-smart practices that reduce emissions without reducing yields.
The researchers conducted multi-location field trials across non-saline and coastal saline soils over consecutive dry and wet seasons.
Practical climate-smart strategies
The study found that selecting the right rice variety was one of the most effective ways to lower methane emissions.
It identified BRRI dhan67 and BRRI hybrid dhan3 as climate-smart choices.
During the dry seasons, the former reduced methane emissions by 9 to 14 per cent compared to other varieties. The latter reduced emissions by 6 per cent to 14 per cent compared to other varieties.
The Global Warming Potential (GWP) was reduced by 10 to 13 per cent with BRRI dhan67 and 8 to 11 per cent with BRRI hybrid dhan3, demonstrating their strong potential for climate mitigation.
Meanwhile, during the wet season, BRRI dhan75 and BRRI hybrid dhan6 reduced methane emissions by approximately 7 to14 per cent compared to BRRI dhan87 and BRRI dhan90.
When it came to inputs, the study found that reducing nitrogen fertiliser by 20 per cent lowered methane emissions by 6 per cent and nitrous oxide by 17 per cent.
Importantly, grain yields remained stable, demonstrating that farmers can reduce input costs and carbon footprint without compromise.
The research demonstrated that simple and scalable interventions could make rice cultivation more sustainable, helping farmers meet both productivity and environmental goals.
For rice-growing delta regions like Bangladesh, these findings offer a practical roadmap for reducing agriculture’s carbon footprint without compromising food security.
Soil influence
The study also evaluated the role of saline soil as a significant area of Bangladesh’s cultivable land were coastal saline soils.
According to the findings, coastal saline soil was found to significantly reduce the overall GWP by 9 per cent compared to non-saline soil while emitting about 10 per cent less methane.
This was likely due to the microbial inhibition under high salt concentrations, which slows down the process of methanogenesis.
However, non-saline soils proved to be better for crop productivity, resulting in 11 per cent more yield and 13 per cent higher total nitrogen uptake compared to the coastal saline soils.
These insights underscore the importance of site-specific management strategies in cutting emissions and improving productivity.
Science of The Total Environment; https://doi.org/10.1016/j.scitotenv.2025.180192; Reducing greenhouse gas emissions and improving rice yield: The influence of cultivars, soil salinity, and nitrogen management; Authors: S.M Mofijul Isalam et al.
