where does salt in the soil come from naturally
Soil salinity Over long periods of time, as soil minerals weather and release salts, these salts are flushed or leached out of the soil by drainage water in areas with sufficient precipitation. In addition to mineral weathering, salts are also deposited via dust and precipitation. In dry regions salts may accumulate, leading to naturally saline soils. This is the case, for example, in large parts of Australia. Human practices can increase the salinity of soils by the addition of salts in irrigation water. Proper irrigation management can prevent salt accumulation by providing adequate drainage water to leach added salts from the soil. Disrupting drainage patterns that provide leaching can also result in salt accumulations. An example of this occurred in Egypt in 1970 when the Aswan High Dam was built. The change in the level of ground water before the construction had enabled soil erosion, which led to high concentration of salts in the water table. After the construction, the continuous high level of the water table led to the salination of the arable land.
Mineral (nutrient) In the context of nutrition, a mineral is a chemical element required as an essential nutrient by organisms to perform functions necessary for life.[1][2] Minerals originate in the earth and cannot be made by living organisms.[3] Plants get minerals from soil.[3] Most of the minerals in a human diet come from eating plants and animals or from drinking water.[3] As a group, minerals are one of the four groups of essential nutrients, the others of which are vitamins, essential fatty acids, and essential amino acids.[4]