Abstract:

【Objective】 Modelling grain protein composition in barley is of significant importance for establishing production management decision support system. 【Method】 Based on time-course observations on the nitrogen accumulation, assignment, absorption and remobilization under various nitrogen rate regimes with different cultivars, a dynamic model was developed to simulate the nitrogen accumulation and assignment before anthesis and the nitrogen absorption and remobilization model after anthesis in barley. The critical nitrogen content in heading period was used to calculate the biggest accumulation quantity of nitrogen. The latent distribution index of leaf and stem, which was the variety heredity parameter, were used to distinguish the difference in nitrogen assignment in different varieties. The dynamic content of the nitrogen accumulation before anthesis could be described with a Richards model. The dynamic content of the nitrogen remobilization in leaf with leaf area index (LAI) could be described with a power model, and the nitrogen absorption of grain from soil with dry weight could be described with a power model. The dynamic content of nitrogen density in stem and spike with physiological development time(PDT) could be described with a nonlinear model. The model was validated with independent experiment data. 【Result】 The results showed that the absolute prediction error ranges for grain protein contents were 0.04%-1.27%, and RMSEs were 0.20%-0.72%. 【Conclusion】 The present model with empirical and mechanism appears to provide a reliable prediction.

Key words: barley, nitrogen accumulation, protein, simulation