以水稻和小麦为研究对象，通过解析和提炼稻麦适宜氮素营养指标与品种类型、栽培技术、生态环境之间的定量关系，以基于生理发育时间（PDT）的相对生长度日和相对氮素营养指标为参数，建立了稻麦适宜氮素营养指标动态模型，并利用南京3年的大田试验资料对所建模型的可靠性和适应性进行了验证.结果表明：模型生成的水稻植株氮积累量和氮含量与实际观测值之间的平均根均方差（RMSE）分别为0.1245和0.1316；模拟的小麦植株氮积累量和氮含量与实际观测值之间的平均RMSE分别为0.1166和0.1301，表明模型对稻麦氮素营养指标动态具有较好的指导性，可为不同生态环境、品种类型和生产条件下的稻麦氮素营养诊断与管理调控提供定量化和精确化的指导.
By analyzing and extracting the quantitative relationships of suitable nitrogen index dynamics of rice and wheat to their cultivar types, cultural techniques, and eco-environments, a design model for the suitable nitrogen index dynamics of rice and wheat was developed. The model was driven by the physiological development time-based relative growing degree days, with the relative nitrogen indices as modeling parameters, and could be used to generate the time-course indices such as the nitrogen accumulation and concentration of rice and wheat under different growth conditions. Case studies with the datasets from 3-year field experiments in Nanjing showed that the average RMSEs of the simulated to measured plant nitrogen accumulation and concentration were 0.1245 and 0.1316 for rice, and 0.1166 and 0.1301 for wheat, respectively. It was suggested that this model could reliably guide the dynamics of major nitrogen indices of rice and wheat, which would help with the quantitative nitrogen diagnosis and precision nitrogen management of rice and wheat under different eco-environments, cultivar types, and production conditions.