Explanation:

Salt-affected soils are characterized by a strongly alkaline soil reaction.The soils containing sodic salts have an enhanced content of exchangeable Na+ and pH > 8.5. The soil profile S shows a pH between 9.5 and 10.0 in the upper soil horizons.The chief characteristic of sodic soils from the agricultural stand point is that they contain sufficient exchangeable sodium to adversely affect the growth of most crop plants. For the purpose of definition, sodic soils are those which have an exchangeable sodium percentage (ESP) of more than 15.

Desert soils have sparse vegetative cover that varies with temperature and elevation. Desert soils form in arid climates, where evaporation is more than five times the annual precipitation from rain and snow. Deserts can be hot (like the Sahara or the Mohave) or cold (like Antarctica or at high elevations) or in between (like in Wyoming, Idaho and Oregon. Soil formation is usually limited to near the surface because water is not moving through the soil.