Simulation of soil water and salt transfer under mulched furrow irrigation with saline water

- Model for water and salt transfer under mulched furrow irrigation is presented.
- More water was maintained below the ridge after irrigation.
- Soil salt concentration was small in surface soil layer below the ridge.
- Soil salt below the ridge was more uniform than below the furrow.

A mathematical model for simulating soil water and salt transfer under mulched furrow irrigation with saline water was presented. The model performance was evaluated by comparing the simulated values with observed data from the field experiment. The results demonstrated that the model performed reliably in the simulation of water and salt transfer under field conditions. In addition, the model was also used to simulate the process of soil water and salt transfer after saline water irrigation. The simulation demonstrated that the increment of soil water storage below the bottom of the furrow was nearly equal to the value below the top of the ridge immediately after the end of the irrigation (17 h) when the downward movement of irrigation water was restricted by the clay interlayer in soil. However, during the irrigation interval (192 h and 384 h after the irrigation), more water was maintained below the top of the ridge due to a considerable reduction of evaporation under mulched furrow irrigation. Soil salt mainly comes from saline water irrigation and the soil salt below the top of the ridge mainly increased at the redistribution phase (17 h). During the irrigation interval, soil conductivity in surface soil layer below the top of the ridge was smaller than that below the bottom of the furrow, which indicated that the distribution of soil salt below the top of the ridge was more uniform than below the furrow. The model presented here offers an efficient approach to estimate environmental effects of mulched furrow irrigation technology associated to saline water utilization.