Nine rice varieties tested in farmers’ fields in Preah Vihear, Cambodia, reveal how strongly yields are shaped by interactions between climate, variety and crop management. Conducted in Rovieng district, the research examines yield variability across different ecosystems and management systems. High temperatures above 33 °C and humidity emerged as major climatic drivers of variability, highlighting the importance of matching rice varieties to increasingly variable production conditions.

Local rice varieties demonstrated broad adaptability across environments, while improved varieties performed better under irrigated conditions. Five of the nine varieties also achieved better results when grown with green manure management. These findings indicate that varietal performance depends on both environmental conditions and agroecological practices. The limited suitability of some improved varieties for agroecological systems points to the value of local genetic diversity for developing rice varieties that combine resilience, adaptability and productivity.

Published in 2025, the research was conducted by specialists from CIRAD and Cambodia’s General Directorate of Agriculture, including DALRM/CARDEC, with contributions from ASSET. By drawing on on-farm trials, it provides evidence relevant to rice breeding and crop management under climate change. The results support greater consideration of locally adapted genetic resources when developing varieties for diversified agroecological systems, including systems using green manure and other practices intended to reduce external inputs and strengthen soil health.