Resolution of the Richards Equation for the Water Transport in a Growing Substrate

Abstract The soil less crop substrates should be a starting point for management models that can be used to obtain growth systems, with minimal input of water, nutrients, and pesticides, with a high production of good quality and with a minimal nuisance to the environment. These systems are better defined and controllable. For describing the water movement in a growing substrate, the h based form of Richards equation in two dimensions is obtained by combination of continuity equation and Darcy's law, this equation is implicitly solved using the control volume finite element method. The hydraulic conductivity, the water retention characteristic, and the differential moisture capacity have been described by the mathematical models known. A numerical model is developed for this aim and validated, by comparing the results of water transport with the numerical results obtained by CFD which are validated by experimental results. A growing substrate with specific dimensions, two drippers on top of the planting and the drain at lower right corner is tested by this model.