玉米和大豆根系吸收土壤磷的模型验证研究

为了验证养分吸收机制模型对作物根系磷吸收模拟的适用性和有效性,以玉米和大豆为研究对象,通过盆栽试验获取15个与土壤、根形态、根生理和水分相关的模型参数,采用NST 3.0软件对玉米和大豆地上磷吸收进行模型模拟和验证。结果表明,随着培养时间的延长,玉米和大豆磷吸收模拟值呈现指数曲线增长的趋势。在45 d的培养期间,玉米具有比大豆更高的磷吸收。对模拟值和实测值进行比较发现,NST模型能够较好地模拟玉米对土壤磷的吸收,但对大豆磷吸收的模拟值偏低。回归分析结果表明,磷吸收模拟值和实测值存在显著的回归关系(P0.05),模拟磷吸收解释了实测磷吸收70.22%的信息,说明模拟的磷吸收在很大程度上能够代表2个种类的磷吸收。总体来说,NST模型能够很好地模拟玉米和大豆的磷吸收。

Model Simulation of Soil Phosphorus Uptake by Root System of Maize and Soybean

Simulating phosphorus (P) uptake by crop roots is of great significance for crop fertilization manage-ment.In order to validate the applicability and effectiveness of nutrient uptake model for phosphorus (P) uptake by crop roots,a pot experiment in this study was carried out to obtain 15 model parameters associated with soil charac-teristics,root morphology,root physiology and water in maize and soybean.Aboveground P uptake of maize and soy-bean was simulated and validated by NST 3.0 soft.The results showed that P uptake of maize and soybean exhibited an increased trend,similar to exponential curve,with prolonged growth time.During the 45 d growth,the maize had a higher P uptake than soybean.A comparison between the simulated and measured P uptake revealed that the NST model could well simulate the P uptake by maize roots,but simulated P uptake was lower than measured value in soybean.Regression analysis showed that the simulated and measured values exhibited a significant regression rela-tionship (P <0.05).Simulated P uptake explained 70.22% of measured P uptake,suggesting that simulated P up-take,to a large extent,can represent measured P uptake of two species.Overall,NST model can well simulated the P uptake of maize and soybeans.