植物生长条件下土壤水分与养分资源动态分布的模拟研究

借助根系功能-结构机理模型,在动态描述根系空间生长发育的基础上,采用根系空间吸水速率函数耦合三维土壤水动力学模型,描述根系吸收条件下土壤水分的时空分布;以根个体为中心,采用扩散方式,描述了由于根系吸收土壤中磷元素而引起的土壤中有效磷分布的动态变化。通过小麦苗期根系结构与生物量的动态观测试验,获取了根系生长参数,利用文献资料获取了土壤水分运移参数、土壤有效磷扩散参数。在设定的灌溉与蒸散情景下,模拟了根长密度与根系吸收速率在三维空间的动态分布、根系吸水条件下土壤水分三维时空变化以及根系吸收磷元素的条件下土壤中有效磷的亏缺区域变化过程。模拟结果显示,根系-土壤系统能够实时地模拟根系生长下土壤环境资源的动态变化。

Dynamic Simulation of Soil Water and Nutrients under the Condition of Development and Growth of Plant Root

It is an important key to quantitatively study the dynamic distribution of soil water and nutrients for effective utilization of agricultural resources.This study integrated the three-dimensional Richards equation,diffusion model of effective phosphorus and development and growth of root system by the uptake of root for soil water and nutrients.The culture experiments of wheat seedling for measuring structure and biomass were carried out to obtain the parameters of growth and development of root system,and the soil water movement and diffusion of soil effective phosphorus parameters were from the literature data.Under the given scenarios of irrigations and evapotranspirations,the dynamic distributions of spatial density of root system,uptake water rate of root system,soil water contents considering root uptake water and changes of deficient area of phosphorus by the uptake of root were implemented by the visual way.The simulation results showed that the system of root and soil can describe the dynamic processes of agricultural soil resources by the uptake of plant root system.