Key Takeaways
- String Bio and CLRRI completed the first field trial of CleanRise® in Vietnam’s Mekong Delta.
- CleanRise improved grain yield by 12% and maintained yields even with 25% reduced nitrogen use.
- Trials reported 30–40% lower greenhouse gas emissions.
- CLRRI researchers highlighted compatibility with national low-carbon rice initiatives.
- Additional multi-location trials are recommended before national scale-up.
String Bio Completes First CleanRise® Field Trial with CLRRI in Vietnam
String Bio has completed its first field trials of CleanRise® in Vietnam in partnership with the Cuu Long Delta Rice Research Institute (CLRRI), marking a key milestone in the company’s expansion of low-carbon agricultural solutions across Asia. The trial was conducted in the Mekong Delta during the Summer–Autumn 2025 season and tested the performance of the foliar microbial biostimulant in real-world paddy systems.
CleanRise®, developed using String Bio’s patented platform, is designed to enhance nutrient-use efficiency and stimulate systemic plant responses that support productive tillering and reduce grain sterility. According to previous studies in India, the product has also demonstrated the potential to reduce methane and nitrous oxide emissions by up to 50%.
Field Trial Findings
CLRRI evaluated CleanRise under four treatment scenarios, including full and reduced nitrogen applications with and without the product. Key outcomes included:
- 12% yield increase compared to farmers’ traditional practice.
- Comparable yields with 25% less nitrogen, indicating improved nitrogen-use efficiency.
- 30–40% reduction in greenhouse gas emissions, confirmed through field-based measurements.
- Improved grain quality, with reduced sterility and enhanced grain fullness.
These results support CleanRise’s suitability for integration into Vietnam’s diverse rice cultivation systems, including AWD, TPR, DSR, and Single Drainage.
Alignment with National Low-Carbon Rice Targets
Researchers at CLRRI emphasized the strategic relevance of the findings. Dr. Thach and Dr. Cuong noted that CleanRise is “compatible with existing cultivation techniques and aligns with Vietnam’s national ‘One Million Hectare Low-Carbon Rice Program.’ Its ease of use and infrastructure-free adoption position it as a promising tool for scale-out across diverse rice farming landscapes in Vietnam.”
CLRRI leadership recommended expanding the research. According to Dr. Tran Ngoc Thach, Director General of CLRRI, multi-season and multi-location trials are needed “to confirm and strengthen the evidence for the product’s performance.”
String Bio’s Perspective on Regional Expansion
String Bio said the results reinforce CleanRise’s consistency across varying geographies. “The validation data from CLRRI extends the consistent performance, scaling and benefits of CleanRise witnessed with rice farmers across India,” said Dr. Ezhil Subbian, CEO of String Bio. “To have studies completed with Dr. Cuong’s lab at CLRRI in the Mekong Delta provides a high level of confidence for us to bring CleanRise… to the rice farmers of Vietnam.”
The company is expanding partnerships to support Vietnam’s climate resilience ambitions and smallholder livelihood improvements.
