基于Richards方程的不同氮肥处理的旱地小麦茎秆生长的动态模拟

Dynamic Simulation of Stem Growth of Dryland Wheat Treated with Nitrogen Fertilizer Based on Richards Equation

以实测试验数据为基础,分析旱地小麦茎秆生长的动态变化,用Richards方程描述茎秆的节间长度和粗度的动态变化过程,并以不同氮肥处理的旱地小麦对模型进行了检验。针对Richards方程参数多且参数估计复杂的问题,用粒子群优化算法进行Richards方程参数估计,将经验性和机理性有机结合。检验结果表明：茎秆的节间长度和粗度测量值与模拟值表现了很好的一致性,长度的RMSE范围为0.124～0.932,粗度的RMSE范围为0.012～0.076,模型具有很好的适用性和预测性。

Based on the experimental data,this paper analyzed the dynamic changes in stem growth of dryland wheat,described the dynamic change process of stem internode length and thickness by using Richards equation,and examined the model through dryland wheat which was treated with different nitrogen fertilizers. Aiming at the problems of more parameters and complex parameter estimation of Richards equation,we used the particle swarm optimization algorithm to estimate the parameters of Richards equation,which could combine the experience with the mechanism. The statistical analysis of the model examination showed that： there was a good consistency between the measured value and simulated value of stem internode length and thickness; the RMSE of internode length was between 0.124 and 0.932,and the RMSE of internode thickness was 0.012 ~ 0.076. Therefore,the model had very good applicability and predictability.