Abstract Planting date and cultivar selection are major factors in determining the yield potential of any crop and in any region. However, there is a knowledge gap in how climate scenarios affect these choices. To explore this gap, we performed a regional scale analysis (11 planting dates × 8 cultivars × 281 fields × 36 weather years × 6 climate scenarios) using the APSIM model and pSIMS software for Iowa, the leading US maize (Zea mays L.) producing state. Our objectives were to determine how the optimum planting date (optPD) changes with weather scenarios and cultivars and the potential economic implications of planting outside the optimum windows. Results indicated that the mean optPD corresponds to the US Department of Agriculture, National Agriculture Statistics Service (USDA-NASS) 18.4% planting progress (April 28th) in Iowa. The optPD was found to be advancing by –0.13 d yr−1 from 1980 to 2015. A 1 °C increase in mean temperature increased the length of the growing season by 10 days while the optPD changed by –2 to + 6 days, depending on cultivar. Under a more realistic scenario of increasing the minimum temperature by 0.5 °C, decreasing the maximum temperature by 0.5 °C, increasing spring rainfall by 10% and decreasing summer rainfall by 10%, the optPD only changed by –2 days compared to current trends, however, yield increased by 6.6%. Analysis of historical USDA-NASS planting durations indicated that on average, the planting duration (1–99% statewide reported planting progress) is 44 days, while it can be as low as 21 days in years with favorable weather. A simple economic analysis illustrated a potential revenue loss up to $340 million per year by planting maize outside the optimum window. We conclude that future investments in planting technologies to accelerate planting, especially in challenging weather years, as well as improved optPD × cultivar recommendations to farmers, will provide economic benefits and buffer climate variability.

中文翻译：

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气候变化对美国中部玉米带不同玉米品种最佳种植日期的影响

摘要 种植日期和品种选择是决定任何作物和任何地区产量潜力的主要因素。然而，在气候情景如何影响这些选择方面存在知识差距。为了探索这一差距，我们使用 APSIM 模型和 pSIMS 软件对美国领先的美国玉米 (Zea mays L.) 进行了区域尺度分析（11 个种植日期 × 8 个栽培品种 × 281 个田地 × 36 个天气年 × 6 个气候情景）生产状态。我们的目标是确定最佳种植日期 (optPD) 如何随天气情况和品种而变化，以及在最佳窗口外种植的潜在经济影响。结果表明，平均 optPD 对应于美国农业部、国家农业统计局 (USDA-NASS) 18.4% 的爱荷华州种植进度（4 月 28 日）。发现 optPD 从 1980 年到 2015 年推进了 –0.13 d yr−1。平均温度升高 1 °C 会使生长季节的长度增加 10 天，而 optPD 变化 –2 至 + 6 天，具体取决于在栽培品种上。在最低气温升高 0.5 °C、最高气温降低 0.5 °C、春季降雨量增加 10% 和夏季降雨量减少 10% 的更现实情景下，optPD 与当前趋势相比仅变化了 –2 天然而，产量增加了 6.6%。对美国农业部-NASS 历史种植持续时间的分析表明，平均种植持续时间（全州报告的种植进度的 1-99%）为 44 天，而在天气好的年份可以低至 21 天。一项简单的经济分析表明，在最佳窗口外种植玉米可能会导致每年高达 3.4 亿美元的收入损失。我们得出的结论是，未来对种植技术的投资以加速种植，尤其是在充满挑战的天气年份，以及向农民提供改进的 optPD × 栽培品种建议，将提供经济效益并缓冲气候变化。