DSR is a more sustainable way of growing rice that replaces the traditional practice of transplanting nursery-grown seedlings into continuously flooded fields.
This method also requires less labour, encouraging farmers like those in labour-stressed places like Savannakhet, Laos to adopt it.
However, the shift to DSR presented a new problem: weeds.
These fast-growing weeds competed with rice, lowered grain quality and forced farmers to remove weeds by hand or use costly herbicides.
To address this, an Australian Centre for International Agricultural Research (ACIAR) funded a project led by UQ to solve the problem
The team, which included extension staff and farmers across Laos and Cambodia, co-designed a package of solutions that combined certified seed, improved land preparation, drill or drum seeding, timely early flooding, mungbean intercropping in rainfed lowlands, and context-appropriate herbicides or mechanical weeders.
These interventions were able to reduce weeds while increasing rice yield by about one-third. Additionally, profits more than double compared with local practices.
With integrated weed management, irrigated systems in both Laos and Cambodia, were able to cut weed biomass by roughly half, reduced weed seed contamination in harvested grain, and boosted profits by 40 to 120 per cent per hectare
This contributed directly to food security and enabled households to support the essentials such as their children’s education.
Skills that go beyond the farms
Women were central beneficiaries of this initiative as they were the ones mostly responsible for weeding.
They experienced the benefits of labour reduction first and were able to pursue diversified income and participate more confidently in farm decision-making.
The project also actively supported women’s leadership. Nearly half of the 49 Master Trainers trained in weed identification and integrated weed management were women, many of whom now lead farmer field days and provide technical guidance in their districts.
Beyond on-farm impacts, the project influenced Cambodia’s Royal University of Agriculture to update its weed science curriculum using field-based examples.
This ensured a stronger knowledge of DSR, safe herbicide use and integrated weed management among graduates.
The project provides a strong foundation for further investment in climate‑smart and weed‑smart rice systems across the Mekong region, said ACIAR.
Next steps include scaling up proven DSR packages, accelerating adoption of weed-competitive and climate-resilient varieties, strengthening post-harvest and grain quality systems, and deepening gender-responsive extension so women and men can adopt innovations equitably.
The project’s visibility has also opened policy discussions on herbicide regulation, drone use, grain quality standards and improving women’s representation in extension and decision-making.
“Importantly, the project has shown that when farmers, researchers, extension staff and policymakers work together, weeds don’t have to ‘steal the harvest’. With the right mix of practices, they can be managed in ways that protect people, profits and the environment across the Mekong’s rice bowls.”
