Improving irrigated maize (Zea mays L.) production with saline agricultural drainage water using drip irrigation system and organic mulches: Field study and simulation modelling

Due to the scarcity of fresh water in dry areas, including Egypt, emphasis has been placed on the importance of studying non-traditional water sources as an alternative source of irrigation. Therefore, this research aimed at investigating the impact of saline agricultural drainage water, drip irrigation and organic mulching using rice straw on maize water productivity under Egypt’s arid condition. The field experiment included sixteen treatments during two seasons, 2022 and 2023. Irrigation systems were [Furrow irrigation system (FIS) and drip irrigation system (DIS)] while saline agricultural drainage water strategies were [FW (0.55 dS/m), SW1 (1.35 dS/m), SW2 (3 dS/m) and SW3 (5 dS/m)] represented as sub main plot and organic mulching using rice straw (OMRS) was also investigated. The highest MY values were achieved with DIS with FW and also with irrigation with salty agricultural drainage water, with the necessity of using organic mulches of rice straw. The highest MY values were achieved as a result of achieving the best water-salt balance within the root propagation zone. The highest values were 10.89 t/ha with FW and there were no significant differences between them and the values of 10.83 t/ha when irrigated with saline agricultural drainage water for 2022 and the similar results were achieved during the 2023 season. Based on the above, SW1 can be used directly without mixing with FW1 if the ability of the grown plant to tolerate the level of salinity concentration, with the necessity of using organic mulches. The SALTMED model simulated reasonably well the soil moisture and soil salinity as well as maize yield and for all treatments, with R2 of 0.87, 0.98 and 0.96, respectively.