Abstract Adaptation measures are required to enhance climate change resilience of agricultural systems and reduce risks associated with climate change at both regional and global scales. The Texas High Plains is a semi-arid region that faces major challenges from climate change risks and dwindling groundwater supply from the exhaustible Ogallala Aquifer for sustaining irrigated agriculture. The overall goal of this study was to assess the impacts of climate change on yield and water use of grain sorghum and identify optimum climate change adaptation strategies for three study sites in the Texas High Plains. Future climate data projected by nine Global Circulation Models (GCMs) under two Representative Concentration Pathways (RCPs) of greenhouse gas emissions (RCPs 4.5 and 8.5) were used as input for the DSSAT CSM-CERES-Sorghum model. The climate change adaptation strategies were designed by modifying crop genotype parameters to incorporate drought tolerance, heat tolerance, high yield potential, and long maturity traits. Irrigated and dryland grain sorghum yield and irrigation water use were projected to decrease at varying percentages at the study sites in the future. On an average (of 9 GCMs), irrigated grain sorghum yield is expected to decrease by 5–13 % and 16–27 % by mid-century (2036–2065) and late-century (2066–2095), respectively under RCP 8.5 compared to the baseline (1976–2005). The irrigation water use is expected to decrease by 7–9% and 14–16 % by the mid-century and late-century, respectively. Among the adaptation strategies, an ideotype with high yield potential trait (10 % higher partitioning to the panicle, radiation use efficiency, and relative leaf size than the reference cultivar) resulted in maximum grain sorghum yield gains in the future under both irrigated (6.9 %–17.1 %) and dryland (7.5 %–17.1 %) conditions, when compared to the reference cultivar. Enhancing drought tolerance by increasing root density at different soil depths also resulted in a significantly higher irrigated grain sorghum yield than the reference cultivar. A longer maturity cultivar will likely increase irrigation water use and, therefore, is not recommended for water limited conditions.

中文翻译：

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气候变化下基于基因型的适应策略对德克萨斯高原高粱生产的潜在益处

摘要 需要采取适应措施来增强农业系统的气候变化适应能力，并在区域和全球范围内降低与气候变化相关的风险。德克萨斯高原是一个半干旱地区，面临着气候变化风险和来自可枯竭的奥加拉拉含水层的地下水供应减少以维持灌溉农业的重大挑战。本研究的总体目标是评估气候变化对高粱产量和用水的影响，并确定德克萨斯高原三个研究地点的最佳气候变化适应策略。九个全球环流模型 (GCM) 在温室气体排放的两个代表性浓度路径 (RCP)（RCP 4.5 和 8.5）下预测的未来气候数据被用作 DSSAT CSM-CERES-高粱模型的输入。气候变化适应策略是通过修改作物基因型参数来设计的，以结合耐旱、耐热、高产潜力和长成熟性状。预计未来研究地点的灌溉和旱地高粱产量和灌溉用水量将以不同的百分比下降。平均而言（9 个 GCM），在 RCP 8.5 下，预计到本世纪中叶（2036-2065）和本世纪末（2066-2095）灌溉谷物高粱产量将分别下降 5-13% 和 16-27%与基线（1976-2005）相比。到本世纪中叶和本世纪末，灌溉用水预计将分别减少 7-9% 和 14-16%。在适应策略中，具有高产潜力性状（对穗的分配高 10%、辐射利用效率、和相对叶片大小）导致未来在灌溉 (6.9 %–17.1 %) 和旱地 (7.5 %–17.1 %) 条件下，与参考品种相比，谷物高粱产量最大。通过增加不同土壤深度的根密度来增强耐旱性也导致灌溉谷物高粱产量显着高于参考品种。成熟期较长的品种可能会增加灌溉用水，因此不推荐用于水资源有限的条件。通过增加不同土壤深度的根密度来增强耐旱性也导致灌溉谷物高粱产量显着高于参考品种。成熟期较长的品种可能会增加灌溉用水，因此不推荐用于水资源有限的条件。通过增加不同土壤深度的根密度来增强耐旱性也导致灌溉谷物高粱产量显着高于参考品种。成熟期较长的品种可能会增加灌溉用水，因此不推荐用于水资源有限的条件。