Effect of future climate on crop production in Bhutan

Authors

DOI:

https://doi.org/10.36253/ijam-2782

Keywords:

Agricultural Meteorology, crop modelling, food security, climate change

Abstract

Understanding the relationship between adverse weather conditions and crop productivity is the backbone of risk assessments on food security. It is paramount in countries like Bhutan, which has a limited number of impact assessment studies in agriculture. The work presented here highlights agricultural production trends under a changing climate and the attribution of yield changes to a specific weather hazard. Thus, the relationship between climate and yields is improved by running the Food and Agriculture Organization (FAO) Python Agroecological Zoning (PyAEZ) model with state-of-the-art climate projections from the Coordinated Regional Climate Downscaling Experiment (CORDEX-CORE). At the national level, we analyze climate change impacts on yields for ten crops (grain maize, foxtail millet, buckwheat, wheat, wetland rice, common beans, cabbage, white potatoes, carrots, and citrus). The main simulation findings point to higher yield variations, either a gain or a loss, under rainfed conditions for the Representative Concentration Pathway (RCP) 8.5 as opposed to irrigated conditions and RCP 2.6; for example, by +17.4% (white potatoes), +15.3% (wheat), +12.8% (cabbage), -5.8% (citrus), and -6.7% (buckwheat) under RCP 8.5 by 2070-2099. Yield results show the potential of irrigation to modulate adverse weather conditions and to improve crop performance by +43.4% on average for all crops as opposed to rainfed crops which are more exposed to weather hazards (i.e., heat stress and dry spells). This study also sheds light on the most impactful weather perils describing 28% (RCP 2.6) and 33% (RCP 8.5) of the yield variability over time. Thus, our findings support smallholder farmers, decision-makers, and project formulators in developing adaptation solutions that minimize the effects of growing adverse weather conditions on crop yields.

Understanding the relationship between weather extremes and crop productivity is the backbone of risk assessments on food security. The former is paramount in countries (i.e., Bhutan) where there are a limited number of impact assessments in agriculture. The analysis performed in this work highlights the trends in agricultural production under a changing climate and the attribution of yield change to a specific climatic hazard. We improve the understanding between the two (climate and yields) by applying an FAO eco-physiological model (PyAEZ) and by relying on state-of-the-art downscaled climate projections (CORDEX-CORE). We analyze climate change impacts on ten crops (maize, foxtail millet, buckwheat, wheat, rice, common beans, cabbage, white potatoes, carrots, and citrus) at national level. The main simulation findings point to a higher yield gain and loss under rainfed conditions as opposed to irrigated conditions by the end-century (2070-2099) compared to the baseline period (2010-2039), particularly under RCP 8.5 for white potatoes (+17.7%), wheat (+15.5%), cabbage (+12.8%), buckwheat (-6.6%), and citrus (-5.8%). The irrigation potential to modulate climate change impacts is reflected in a yield gain of +43.4% on average for all crops and RCP’s when compared to rainfed conditions. On average, weather extremes explain 28% and 33% of the yield variability over time, respectively under RCP’s 2.6 and 8.5. Overall, this study supports smallholder farmers, decision-makers, and project developers to implement adaptation solutions that minimize growing weather extremes such as heat-stress and dry-spells.

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Published

2024-11-06

How to Cite

Alvar-Beltrán, J., & Franceschini, G. (2024). Effect of future climate on crop production in Bhutan. Italian Journal of Agrometeorology, (2), 101–119. https://doi.org/10.36253/ijam-2782

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RESEARCH ARTICLES

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