Economic Analysis of Segmented Soil Salinity Management Using Current Irrigation Technology

Due to significant initial investments, adopting complex reactive irrigation technologies to manage salinity can be financially risky for farmers. This paper explores using existing irrigation systems to manage salinity by adjusting irrigation timing and amounts to manage salt and water stress. An integrated bioeconomic model, combining a crop model and an economic model, was developed to simulate the impact of irrigation decisions on crop yield and profitability. This paper used secondary data to develop the case study used in the analysis. The results indicated that the margin above specified costs for a segmented irrigation approach was consistently higher than for the uniform approach. The economic benefit varied depending on the soil salinity category that made up the uniform approach, with a maximum potential benefit of 161 ZAR/ha. Increasing irrigation in high-salinity zones to dilute salts enhanced crop yields through improved osmotic and matric potentials, leading to higher total soil water potential. Interestingly, despite higher irrigation applications, there was minimal leaching of salts. The conclusion is that farmers can effectively manage salt and water stress using their current irrigation technology, avoiding costly reactive technologies. Adjusting irrigation timing and amounts offers a viable, cost-effective solution for managing salinity and optimising crop yields.