Evaluation of modeling of water ecohydrologic dynamics in soil–root system

Soil water movement due to root water uptake is a key process for plant growth and transport of water in the soil plant system. The accuracy of prediction extraction rate by plants depends on selection of proper mathematical models. The water uptake by plant roots has been simulated both at the microscopic and macroscopic levels. The microscopic approach requires detailed information about the dynamic geometry of the plant root system that is practically not available. In the macroscopic approach, a sink term, representing water extraction by plant roots is included in the dynamic water flow equation and the spatial and temporal uptake is controlled by the soil moisture and the plant demand. Different pattern of moisture uptake including constant, linear and exponential are available in various models. Relevant literature points out that a non-linear, exponential and logarithmic macroscopic root water uptake model is popular due to their improved prediction efficiency. In this paper most commonly used models which are suitable for the estimation of moisture uptake by plants in different agro-climatic regions are reviewed and a field study of macroscopic model has been given. Model predicted soil-moisture parameters i.e. , moisture depletion, moisture status at various depths and soil moisture profile in root zone are compared with experimental results.