水分胁迫对冬小麦生长后效影响的模拟研究

以Logistic方程为基础框架,建立了具有土壤水分胁迫后效影响的作物生长模型,实现了胁迫后效影响在生长模型中的定量化。利用模型模拟了小麦冠根干物质积累动态。经与实测值相比较,模拟与实测值吻合良好,表明所建模型结构合理,为作物水分关系模拟提供了一种新方法。所建模型不仅可以模拟单调上升的生长过程,也可模拟先上升后下降的过程,具有一定普适性。模型中的时变和非时变参数,都具有明确的物理意义。对冠根两种不同动态过程的后效影响参数对比显示,胁迫对冠生长的后效影响明显大于对根系的后效影响,表明对水分胁迫较敏感的生长过程,胁迫对它的后效影响也较大。

Simulation of after-effect of water stress on growth of winter wheat

Based on the framework of logistic equation, a crop model considering the after-effect of water stress was established. It was then used to simulate the dry matter accumulation of shoot and root of winter wheat. Comparison between the simulated and the measured value showed good agreement between them, indicating the correct model structure. The model can simulate not only the process of monotonic rise as shoot growth, but also the process of first rise and then down as the root growth, suggesting its general applicability. It contains both time-constant and time-dependent parameters that have clear practical meanings. Comparative study on the time-dependent parameters of shoot and root showed that the water stress had greater after-effect on shoot growth than on root growth, suggesting the more sensitive growth process to water stress was affected to a larger extent by after effect.