Assessing climate change impacts and adaptation strategies for key crops in the Republic of Moldova using the AquaCrop model

Abstract

Impact-based models are an essential tool to better understand the effects of climate change on crop production and to aid in the adaptation planning processes. However, in the Republic of Moldova (RoM), there is limited integration of crop simulation findings into adaptation policies and plans (see National Adaptation Plan (NAP) adopted in 2024). To bring novelty to this topic, the Food and Agriculture Organization (FAO), in conjunction with the State Hydrometeorological Service and the State Commission for Plant Variety Testing of the RoM, aims to assess the effect of future climate on five crops of national importance (maize, tomatoes, sunflowers, green peas, and wheat). We use state-of-the-art climate (Coordinated Regional Downscaling Experiment (CORDEX) and Coordinated Output for Regional Evaluations (CORE)) and crop models (AquaCrop) for two climate change scenarios: Representative Concentration Pathways (RCPs) 2.6 and 8.5. Adaptation solutions across the RoM are explored by advancing or delaying the sowing dates and enhancing field management decisions by improving soil fertility and reducing weed stress. Statistically significant (p < 0.05) higher yields are simulated when advancing the sowing date of maize and when growing medium cycle varieties as opposed to short cycle. A CO₂-enriched environment (RCP 8.5) leads to statistically significantly higher yields among C3 crops (wheat and green peas) but has detrimental effects on C4 crops (maize). Limiting climatic drivers include decreasing seasonal rainfall, a higher number of dry days and heat-stress conditions during the summertime, and, conversely, fewer cold days during the wintertime necessary for wheat vernalization. As a result, this research not only provides valuable insights for stakeholders mandated to provide evidence-based adaptation, such as the National Commission on Climate Change, but also uncovers potential adaptation solutions to mitigate the adverse effects of climate change.