LAUSR

The main objective of this study was to investigate the sensitivity of the output parameters of SIRMOD software relative to initial soil water content. The treatments consisted of three irrigation water qualities, two types of soil water content management (FC and 30% FC; FC is field capacity) and three irrigation events. The HYDRUS‐1D software was calibrated to simulate infiltration under different initial soil water contents. Subsequently, the infiltration coefficients obtained from the HYDRUS model were used to simulate the border irrigation system under the different border lengths and inflow rates using the SIRMOD software. The results showed that soil was more permeable under FC management than under 30% FC. The sensitivity of the output parameters of the SIRMOD software under FC was more sensitive compared to 30% FC. The high‐ and low‐sensitive treatments were in the FC and 30% FC management with high saline‐sodic water, respectively. Due to the high permeability under FC, in order to increase the irrigation application efficiency and reduce its sensitivity, the inflow rate should be greater while border length has to be less, compared to 30% FC. Sensitivity analysis of the output parameters showed that the advance time and tailwater fraction were identified as the most and least sensitive parameters, respectively. © 2019 John Wiley & Sons, Ltd.