THE EFFECT OF SALINITY ON NUTRIENT AVAILABILITY AND UPTAKE IN CROP PLANTS
Crops are influenced by many climatic and environmental factors that can be of abiotic and biotic factors and they respond directly to changes in temperature, CO2 concentration, moisture, light intensity, condition of the soil, and so on. Salinity is a major factor that reduces plant growth and productivity throughout the world. Salinity usually occurs when high concentration of soluble salts is present in soil and water; it mainly occur in arid or semi-arid regions as well as in coastal regions. Excessive salts damage plants by disrupting the uptake of water by plant roots and by interfere with the uptake of competitive nutrients. It is well known that nutrient availability and uptake by plants are influenced by salinity. Some soil and plant factor influence nutrient uptake and availability. This review provides an update about soil factors and plant factors that affect nutrients availability and uptake. Soil factors such as soil pH and water availability have a significant role in controlling nutrients availability and uptake. Regarding plant factors, plant species vary in how well they tolerate saline soils; some plants will stand high levels of salinity while others cannot stand salinity. In addition, plants differ in their salinity tolerances depending on the plant growth stages. Physiologically, salinity may have negative impact on many processes, but the most important impacts are in the form of reduced cell growth and decreased leaf area, biomass and yield.