The implementation of crop models for water and nitrogen management are important in preserving water resources and reducing groundwater pollution. The Decision Support System for Agrotechnology Transfer (DSSAT) is a collection of field-scale process-based crop models that simulate crop growth and yield in response to water and nitrogen management as well as many other factors. The objective of this study was to improve the simulation of irrigation and nitrogen fertilizer effects on growth and yield of winter wheat using locally modified Penman-Monteith (PM) equation. Specifically, we focused on improving the estimation of using a locally modified Penman-Monteith (PM) equation in the CSM-CERES-Wheat model. Field measured data from a two-year experiment (2009–2010 and 2010–2011) in a semi-arid region were used to calibrate and evaluate the CSM-CERES-Wheat model in a region with strong advective condition. In this experiment, the irrigation treatments were 1.2, 1.0, 0.8, 0.5 times by full irrigation requirements and rain-fed, and nitrogen treatments were 0, 46, 92, and 136 kg N ha Using the CSM-CERES-Wheat model with the unmodified PM equation resulted in some growth variables such as: aboveground dry matter, grain yield, and grain nitrogen uptake with high normalized root mean square error (NRMSE) of 0.51, 0.35, and 0.32, respectively. However, using the modified PM equation for module under semi-arid condition improved the soil water content estimation and the model outputs, such as the above ground dry matter, grain yield and grain nitrogen uptake with NRMSE of 0.2, 0.15 and 0.16, respectively, that are accurate. This modification provided more accurate estimations, particularly in our experimental site in semi-aid region with strong advective conditions. The findings of this study indicated that the locally modified PM equation in the CSM-CERES-Wheat model enhanced the accuracy of estimating irrigation and nitrogen fertilizer on the growth and yield of winter wheat. By improving the estimation of value, the model's performance in simulating crop responses to water and nitrogen management was significantly enhanced. The utilization of the accurately estimated value of the modified PM equation has significant importance in the practical application of the CSM-CERES-Wheat model. Furthermore, this modification greatly enhances the accuracy of model outputs, particularly at our experimental site located in a semi-arid region with robust advective conditions.

中文翻译：

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使用修正的 Penman-Monteith 方程提高半干旱地区水氮响应 CSM-CERES-Wheat 模型的预测精度

实施水和氮管理作物模型对于保护水资源和减少地下水污染具有重要意义。农业技术转让决策支持系统 (DSSAT) 是一系列基于田间规模过程的作物模型，可模拟作物生长和产量对水和氮管理以及许多其他因素的响应。本研究的目的是使用局部修改的 Penman-Monteith (PM) 方程改进灌溉和氮肥对冬小麦生长和产量影响的模拟。具体来说，我们专注于改进在 CSM-CERES-Wheat 模型中使用局部修改的 Penman-Monteith (PM) 方程的估计。利用半干旱地区两年实验（2009-2010年和2010-2011年）的现场实测数据，对强平流条件地区的CSM-CERES-Wheat模型进行了校准和评估。本试验中，灌水处理为满灌要求和雨养的1.2、1.0、0.8、0.5次，施氮处理为0、46、92和136 kg N ha。采用CSM-CERES-Wheat模型，未修改的 PM 方程导致一些生长变量，例如：地上干物质、谷物产量和谷物氮吸收量，归一化均方根误差 (NRMSE) 分别为 0.51、0.35 和 0.32。然而，在半干旱条件下，使用修正的 PM 方程模块改进了土壤含水量的估算和模型输出，例如地上干物质、谷物产量和谷物氮吸收量，NRMSE 分别为 0.2、0.15 和 0.16，是准确的。这一修改提供了更准确的估计，特别是在我们位于半援助地区的具有强平流条件的实验地点。本研究结果表明，CSM-CERES-Wheat 模型中局部修改的 PM 方程提高了估算灌溉和氮肥对冬小麦生长和产量影响的准确性。通过改进价值估计，该模型在模拟作物对水和氮管理的响应方面的性能显着增强。修正PM方程准确估计值的利用对于CSM-CERES-Wheat模型的实际应用具有重要意义。此外，这种修改极大地提高了模型输出的准确性，特别是在我们位于半干旱地区、平流条件强劲的实验地点。