Intra‐Seasonal Crop Management and the Potential Benefit of Seasonal Precipitation Forecasts: Farm‐Level Embedded Risk Analysis in Ethiopia
研究评估了季节性降水预报对埃塞俄比亚雨养农业农户的潜在收益，发现考虑整个生长周期的作物管理决策后，预报可提高风险调整后预期现金盈余2%-3%。
ABSTRACT How large is the potential benefit for farmers from obtaining forecasts of total rainfall in the upcoming season? This critically depends on the local farm system and the crop management actions available to farmers to respond to the forecasts issued. Studies assessing the financial value of seasonal precipitation forecasts have so far focused almost exclusively on start‐of‐season crop sowing decisions using approaches for non‐embedded risk analysis. However, crop management decisions are spread over the entire growing cycle, and considering this realistically could either increase or diminish the financial value of seasonal forecast information from a theoretical perspective. Our simulation analysis demonstrates how this research gap can be closed: we employ a state‐contingent embedded risk approach combining multi‐stage discrete stochastic programming and high‐performance computing to determine optimal crop management responses (crop choice, sowing date, tied‐ridging, relay cropping and fertilization) to seasonal precipitation forecasts throughout the full crop growth cycle. For rain‐fed agriculture in the Central Rift Valley of Ethiopia, we find seasonal forecasts to increase risk‐adjusted expected cash surplus by about 2%–3% at realistic forecast skill levels. For a typical risk‐averse subsistence farming household (0.5 ha), we calculated an increase in long‐term expected cash surplus of 58 USD PPP at 2023 prices. Intra‐seasonal crop management plays an important role in forecast response. A non‐embedded risk approach simulated not more than 35% of the forecast's economic value simulated with the embedded risk approach.