A new growth subroutine was developed for CERES-Wheat, a computer model of wheat (Triticum aestivum) growth and development. The new subroutine simulates canopy photosynthetic response to CO2 concentrations and light levels, and includes the effects of temperature on canopy light-use efficiency. Its performance was compared to the original CERES-Wheat V-2 10 in 30 different cases. Biomass and yield predictions of the two models were well correlated (correlation coefficient r > 0.95). As an application, summer growth of spring wheat was simulated at one site. Modeled crop responses to higher mean temperatures, different amounts of minimum and maximum warming, and doubled CO2 concentrations were compared to observations. The importance of irrigation and nitrogen fertilization in modulating the wheat crop climatic responses were also analyzed. Specifically, in agreement with observations, rainfed crops were found to be more sensitive to CO2 increases than irrigated ones. On the other hand, low nitrogen applications depressed the ability of the wheat crop to respond positively to CO2 increases. In general, the positive effects of high CO2 on grain yield were found to be almost completely counterbalanced by the negative effects of high temperatures. Depending on how temperature minima and maxima were increased, yield changes averaged across management practices ranged from -4% to 8%.

中文翻译：

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CO2、温度和管理实践的相互作用：使用修改版 CERES-Wheat 进行模拟

为 CERES-Wheat 开发了一个新的生长子程序，它是小麦 (Triticum aestivum) 生长和发育的计算机模型。新的子程序模拟冠层光合作用对 CO2 浓度和光照水平的响应，并包括温度对冠层光利用效率的影响。在 30 种不同情况下，将其性能与原始 CERES-Wheat V-2 10 进行了比较。两种模型的生物量和产量预测具有良好的相关性（相关系数 r > 0.95）。作为一种应用，在一个地点模拟了春小麦的夏季生长。将模拟作物对较高平均温度、不同的最小和最大变暖量以及二氧化碳浓度加倍的反应与观察结果进行了比较。还分析了灌溉和施氮肥在调节小麦作物气候响应中的重要性。具体而言，与观察结果一致，发现雨育作物比灌溉作物对 CO2 增加更敏感。另一方面，低氮应用抑制了小麦作物对二氧化碳增加做出积极反应的能力。一般而言，发现高 CO2 对谷物产量的积极影响几乎完全被高温的负面影响所抵消。根据温度最小值和最大值的增加方式，管理实践中的平均产量变化范围从 -4% 到 8%。发现高 CO2 对谷物产量的积极影响几乎完全被高温的负面影响抵消了。根据温度最小值和最大值的增加方式，管理实践中的平均产量变化范围从 -4% 到 8%。发现高 CO2 对谷物产量的积极影响几乎完全被高温的负面影响抵消了。根据温度最小值和最大值的增加方式，管理实践中的平均产量变化范围从 -4% 到 8%。