Model Application of Water Flow and Solute Transport During Non-steady Diffusion From Subsurface Emitter Source

A model developed by the authors is used to describe flow of soil water and transport of solute during subsurface drip irrigation and fertigation. Impacts on flow of water and transport of solute of factors such as soil texture and structure, discharge rate of emitters, depth of laterals and time lasted in a single irrigation are simulated. Results show that for a specific soil, discharge rate of emitter and depth of lateral are, among others, two potential factors that have more powerful impacts on the performance of SDI system. To improve fertigation efficiency, appropriate strategy of fertigation should be adopted. Changing the fertigation strategy for coarse textured soils to involve application of nutrients at the beginning of an irrigation cycle can help maintain larger amounts of solute close to and above the emitter thereby making them less susceptible to leaching losses.