ABSTRACT
Years of research have gone into the impact of soil salinity and sodicity as a plant stress factor. Soil salinity and sodicity can potentially affect several traits in plants, including nutrient absorption and use, water uptake and plant water relations, physiological processes such as seed germination and emergence, plant growth rates, photosynthesis, fresh and dry matter production, yield and yield components, and eventually, plant senescence. Soil salinity and sodicity problems usually occur in climates with little to no rain, generally when evapotranspiration is higher than precipitation, so that salts accumulate at the soil surface. In dry and semi-dry areas, factors such as low precipitation, high evaporation, and high temperature as well as poor management of water resources result in increased soil salinity. Saline soils affect the development of plants because of the osmotic stress caused by the high salt concentration in both the liquid phase and the solid phase. Also, chlorides as toxic elements are a compound of saline soil that hinders the development of crops. Sodic soils, also known as alkaline soils, show unfavorable physical conditions (low permeability, high dispersion, low aggregation and flocculation), which negatively affect the water and air movement within the soil. Soil salinity and sodicity are among the major agricultural problems limiting plant growth and development throughout the world [2–4,7–9, 14, 15, 17–20, 25], [31, 33, 34, 36, 39, 43, 44, 46, 47, 49], [51–53, 56, 58, 60, 71, 72, 74, 75], [80–84,87–89, 93, 94, 99, 100], [102, 104–111, 114, 115, 120–127], [133, 136, 139–141,143–146, 148], [151, 153, 154, 156, 185, 187, 191–193,198–202], [207, 208, 210, 211, 215, 216, 223–228], [231–233, 237, 239–257, 259, 264–268, 270]. Salinity and sodicity problems in agriculture have an ancient history and have now become a very difficult problem in agricultural and farming activities [270]. The salinity and sodicity problems are more severe, and the situation is catastrophic, especially in arid regions with high soil salinity, hot and dry conditions, and limited water resources [1, 10, 13, 21, 24, 28, 101, 242, 255]. The use of Landsat data (LD), satellite-based detection (SBD), remote sensing (RS), and global positioning system (GPS) technologies has made the identification and measurement of salt-affected land easy and relatively accurate [1, 13, 35, 66, 78, 85, 91, 92, 138, 149, 194, 211, 261]. These problems are of particular concern for countries whose economies rely to a great extent on agriculture [214, 222].
