Role of gypsum and intermittent leaching in reclaiming saline-sodic soils in El-Qantara Gharb region, Ismailia, Egypt

Salt-affected soils have undesirable properties for crop production. However, these problematic regions can be improved and regained for cultivation. A field experiment was conducted to evaluate the impact of different rates of gypsum application on the salinity, reaction (pH) and sodicity of the saline-sodic soil under intermittent leaching conditions. The experiment was carried out over two years in a clayey saline-sodic soil site at El-Qantara Gharb region, Ismailia Governorate, Egypt. The treatments were distributed in four randomized blocks of 20 x 15 m and the soil was subjected to intermittent leaching for fifth leachates, and evaluated for salinity, reaction (pH) and sodicity before and after gypsum application and leaching. Gypsum was applied at rates of zero, 50, 75 and 100% of the predetermined gypsum requirements (50 t ha-1) (0.0, 25. 37.5 and 50 t ha-1) respectively. Five intermittent leaching cycles were performed with proper drainage. Generally, gypsum addition at all rates pronouncedly improved the salinity, reaction (pH) and sodicity of the saline-sodic soil compared to the control treatment (without gypsum addition). Where the best values were recorded due to the gypsum addition rate of 100% followed by 50% and 25%, respectively for soil characteristics. Also, the results confirm that agricultural gypsum application in Egypt is beneficial for improving saline-sodic soils due to its high content of calcium.