Modeling soil wetting with subsurface drip irrigation using curved wetted geometry

The wetted soil geometry play important role in design and management of subsurface drip irrigation (SDI) towards delivering desired amount of water to the plants. A model based on curved wetted geometry was developed for predicting depths and widths of wetted soil under SDI with line sources of water application. The predicted values of wetted depths and widths were compared with those obtained through field experiments under sandy loam soil. The experimentation included determination of maximum depths and widths of wetted zone of soil after 0.5, 1, 2, 3, 5, and 7 hours of water application under SDI with lateral placed at depths 0.05, 0.10 and 0.15 m below soil surface. The performance of developed model was evaluated using t-test, root mean square, mean error and model efficiency. Statistical analysis revealed that values predicted through developed model and experimentation were similar. The developed model had efficiency of 97.3 and 94.9% to predict wetted width and depth, respectively. Therefore, developed model can be used for simulation of wetted zone soil depths and widths with different duration of water application, discharge rate and placement depths of laterals. Analysis revealed that developed model can also be used to describe wetting of soil under surface drip with line source of water application by neglecting lateral placement depth.