Soil salinity is a big problem in many irrigation systems around the world due to poor quality water and lack of natural drainage. Studies in China, Mali, Pakistan, and Uzbekistan show different approaches to managing this issue. In China, over-irrigation led to soil salinity in some areas, while in Mali, changes in water management improved soil alkalinity. In Pakistan, using low-quality groundwater decreased soil salinity but increased sodicity. In Uzbekistan, a drainage system helped control soil salinity. Overall, different strategies are being used to manage soil salinity in irrigation systems, with varying levels of success.