Existing agro-hydrological models to explore the effects of paddy management practices on hydrology and water quality suffer from multiple shortcomings because they were developed using upland characteristics. The Agricultural Policy/Environmental eXtender (APEX)-Paddy model was recently developed to improve the agro-hydrological characteristics of paddy ecosystems. This study explores the hydrology, total nitrogen (T-N) content, and rice yield behaviors of the APEX-Paddy model by simultaneously considering multiple parameters associated with different agricultural activities. Model performances with respect to runoff, T-N, and rice yield were assessed as good level of approved statistical criteria over the calibration and validation periods. Results showed that the APEX-Paddy model can simulate the behavior differences of soil nutrients between different agricultural activities, such as treatment with commercial mineral fertilizer or liquid manure application. Changes in mineral-nitrogen levels in root zones caused by fertilizers can affect T-N load and crop uptake. A high degree of correlation was observed between the amount of nutrients remaining after crop uptake and sediment-transported nitrogen. These findings suggest that the crop-growth parameters of the model can significantly affect biomass, evapotranspiration rate, and T-N load on farmland. The results may help decision makers evaluate water-saving and pollutant-reduction options in paddy fields under future climate scenarios and conservation strategies.

探索稻田管理实践对水文和水质影响的现有农业水文模型存在多个缺点，因为它们是利用高地特征开发的。最近开发了农业政策/环境扩展 (APEX)-稻谷模型，以改善稻谷生态系统的农业水文特征。本研究通过同时考虑与不同农业活动相关的多个参数，探讨了 APEX-Paddy 模型的水文、总氮 (TN) 含量和水稻产量行为。在校准和验证期间，模型在径流、TN 和水稻产量方面的性能被评估为批准的统计标准的良好水平。结果表明，APEX-Paddy 模型可以模拟不同农业活动之间土壤养分的行为差异，例如商业矿物肥料处理或液体肥料施用。由肥料引起的根区矿物质氮水平的变化会影响 TN 负荷和作物吸收。在作物吸收后剩余的养分量与沉积物输送的氮之间观察到高度相关。这些发现表明，该模型的作物生长参数可以显着影响农田的生物量、蒸散率和 TN 负荷。研究结果可能有助于决策者评估未来气候情景和保护策略下稻田的节水和污染物减排方案。例如用商业矿物肥料或液体肥料处理。由肥料引起的根区矿物质氮水平的变化会影响 TN 负荷和作物吸收。在作物吸收后剩余的养分量与沉积物输送的氮之间观察到高度相关。这些发现表明，该模型的作物生长参数可以显着影响农田的生物量、蒸散率和 TN 负荷。结果可能有助于决策者评估未来气候情景和保护策略下稻田节水和减少污染物的选择。例如用商业矿物肥料或液体肥料处理。由肥料引起的根区矿物质氮水平的变化会影响 TN 负荷和作物吸收。在作物吸收后剩余的养分量与沉积物输送的氮之间观察到高度相关。这些发现表明，模型的作物生长参数可以显着影响农田的生物量、蒸散率和总氮负荷。研究结果可能有助于决策者评估未来气候情景和保护策略下稻田的节水和污染物减排方案。在作物吸收后剩余的养分量与沉积物输送的氮之间观察到高度相关。这些发现表明，该模型的作物生长参数可以显着影响农田的生物量、蒸散率和 TN 负荷。结果可能有助于决策者评估未来气候情景和保护策略下稻田节水和减少污染物的选择。在作物吸收后剩余的养分量与沉积物输送的氮之间观察到高度相关性。这些发现表明，该模型的作物生长参数可以显着影响农田的生物量、蒸散率和 TN 负荷。结果可能有助于决策者评估未来气候情景和保护策略下稻田节水和减少污染物的选择。