Potential effect of irrigation conversion on rice yields and self-sufficiency in the Philippines under future climate

Understanding the effect of irrigation is critical for ensuring future food security in the Philippines. While previous analysis has focused on national-level irrigation conversion targets to achieve 98% rice self-sufficiency, this study offers a more comprehensive assessment. We integrated 11,003 provincial-level rice statistics (5211 for the dry season; 5792 for the wet season) to quantify differences in the yield sensitivity of irrigated and rainfed rice to climate. Furthermore, we projected the effect of irrigation conversion under future climate conditions. Our findings indicate that converting rainfed rice to irrigated presents substantial potential to offset negative climate impacts on rice yields in the future. However, despite these gains, the rice self-sufficiency ratio is projected to remain below 87%, suggesting that adverse climate impacts may constrain the adaptive limits of irrigation conversion. These results imply that irrigation conversion should be treated as one component of a broader adaptation strategy rather than a standalone solution to safeguard food security in the Philippines.