The potential impacts of climate change on wheat were assessed for Kulmsa area in central highlands of Ethiopia using the Agricultural Production Systems sIMulator (APSIM)—wheat model. The objectives were to (i) evaluate the performance of wheat under increased temperatures with or without changes in rainfall and carbon dioxide (CO 2 ) levels and (ii) assess the response of different wheat cultivars to projected future climates under improved management practices (optimal nitrogen rate, planting date, and density) (IMPs). The model was first calibrated and used to identify ranges of IMPs. Then, the model was used to (i) conduct sensitivity analysis of wheat in response to assumed elevated temperature (T), with and without change in rainfall and CO 2 level, and to (ii) evaluate average effect of future worst-case climate change scenarios as predicted by an ensemble of three global climate models (GCM) under highest Representative Concentration Pathways (RCP8.5) for three future time frames, NF (2010–2039), MC (2040–2069), and EC (2070–2099). The simulation was evaluated for three wheat cultivars (“early”, “medium”, and “late”) relative to their corresponding baseline values under the selected IMPs. The baseline climate was represented by the long-term (1980–2009) dataset and CO 2 of 360 μmol/mol. Results showed that increased temperature above 4 °C alone had strong negative impacts on yields under the IMPs when CO 2 staying constant at the baseline level. In contrast, climate change simulations with GCM projections under IMPs and elevated CO 2 effect showed that wheat yield remained unchanged (− 0.4 to + 9%) for all three genotypes. This suggests that the IMPs and elevated CO 2 were able to reduce the negative effect of elevated T on wheat yield as T stress did not go beyond optimal T range for wheat. Overall, climate change may not reduce wheat production in the climate of the location of study in the near future, midcentury, or end century.

中文翻译：

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气候变化因素和农艺适应策略对埃塞俄比亚中部高地小麦产量的潜在影响

使用农业生产系统模拟器 (APSIM) - 小麦模型评估了气候变化对埃塞俄比亚中部高地库尔姆萨地区小麦的潜在影响。目标是 (i) 在降雨量和二氧化碳 (CO 2 ) 水平发生或不发生变化的情况下，评估小麦在升高的温度下的表现，以及 (ii) 在改进的管理实践（最佳施氮量、种植日期和密度）（IMP）。该模型首先被校准并用于识别 IMP 的范围。然后，该模型用于 (i) 对小麦响应假设升高的温度 (T) 进行敏感性分析，无论降雨量和 CO 2 水平有无变化，(ii) 评估未来最坏情况气候变化情景的平均影响，如三个全球气候模型 (GCM) 在最高代表性浓度路径 (RCP8.5) 下预测的三个未来时间框架，NF (2010-2039) )、MC (2040–2069) 和 EC (2070–2099)。模拟评估了三个小麦品种（“早”、“中”和“晚”）相对于它们在所选 IMP 下的相应基线值。基线气候由长期（1980-2009 年）数据集和 360 μmol/mol 的 CO 2 表示。结果表明，当 CO 2 保持在基线水平不变时，仅将温度升高到 4 °C 以上就会对 IMP 下的产量产生强烈的负面影响。相比之下，在 IMP 和升高的 CO 2 效应下使用 GCM 预测的气候变化模拟表明，小麦产量保持不变（- 0. 4 到 + 9%）对于所有三种基因型。这表明 IMP 和升高的 CO 2 能够减少升高的 T 对小麦产量的负面影响，因为 T 胁迫没有超出小麦的最佳 T 范围。总体而言，在不久的将来、本世纪中叶或本世纪末，气候变化可能不会减少研究地点气候下的小麦产量。