Moisture transport in a soil-plant system: a mathematical model and finite element analysis

A mathematical model and approximate analysis using finite elements are developed to simulate the transport of moisture from a soil medium through a small seedling or plant to the atmosphere. An intrinsic part of the mathematical model is analysis of the characteristic diffusion rates of different components in the soil-plant system. This leads to consideration of the non-linear coupling of the component soil and plant regimes and effective numerical solution of the problem using a Galerkin semi-discrete finite element method: Details concerning the mathematical model and approximate analysis are described. Numerical experiments are conducted to examine the performance of the model. Relaxation and iterative acceleration techniques and an adaptive timestepping strategy are devised to improve the solution algorithms. Comparisons of model predictions with results of laboratory and field experiments indicate that the model provides useful information on plant-water relations.