Risk-based evaluations of competing agronomic climate adaptation strategies: The case of rice planting strategies in the indo-Gangetic Plains

Mkondiwa, M., & Urfels, A. (2024). Risk-based evaluations of competing agronomic climate adaptation strategies: The case of rice planting strategies in the indo-Gangetic Plains. Agricultural Systems, 218, 104014. https://doi.org/10.1016/j.agsy.2024.104014

CONTEXT: Adjusting crop planting dates and variety durations is emerging as a crucial climate change adaptation strategy for many cereal systems. Such strategies include harmonizing crop planting with the onset of the rainy season or planting at specific recommended calendar dates. Evaluations of these strategies mostly consider yield and yield variability, but focus less on financial risks associated with different planting strategies and importance of risk aversion behaviour of the farmers in their decision to adopt the strategies. OBJECTIVE: Here, we present a novel framework that uses a computational spatial ex-ante approach for risk-based evaluations of agronomic adaptation options. This framework allows development agronomic adaptation recommendations that consider climate risks for risk-averse famrers. METHODS: We use a second order stochastic dominance approach that is paired with computational optimization—Golden section search algorithm. This approach allows a distributional assessment of risk and uncertainty by providing bounds at which even a risk averse would benefit from changing practices. This contrasts with conventional methods that do not consider farmers' risk aversion, e.g. mean-variance or conditional value at risk optimization methods. To demonstrate our approach, we compare the yield risks and economic risks associated with readily available gridded crop simulation outputs for various rice planting strategies across the Indo-Gangetic Plains (IGP)– a major region experiencing food insecurity and climate impacts. RESULTS AND CONCLUSIONS: The findings provide quantitative evidence about the riskiness of previously recommended rice planting date strategies. The risk-based assessment corroborates the recommendation for planting long-duration varieties at the monsoon onset with or without supplemental irrigation (covering about 22% of IGP area) in the Eastern IGP, and at state-recommended planting dates (covering about 38% of IGP area) in most of the Western and Middle IGP. Importantly, our risk-based assessment shows where the results are not as clear cut and which strategy is the least risky. This is especially important in the Middle IGP where farmers appear to have more flexibility to achieve comparable outcomes with several planting strategies. SIGNIFICANCE: In conclusion, the proposed approach provides a useful and novel tool for comparing different agronomic climate adaptation strategies from an economic risk perspective in a spatial framework.