Soil processes affecting crop production in salt-affected soils

Salts can be deposited in the soil from wind and rain, as well as through the weathering of rocks. These processes, combined with the influence of climatic and landscape features and the effects of human activities, determine where salt accumulates in the landscape. When the accumulated salt in soil layers is above a level that adversely affects crop production, choosing salt-tolerant crops and managing soil salinity are important strategies to boost agricultural economy. Worldwide, more than 800 million hectares of soils are salt-affected, with a range of soils defined as saline, acidic–saline, alkaline–saline, acidic saline–sodic, saline–sodic, alkaline saline–sodic, sodic, acidic–sodic and alkaline–sodic. The types of salinity based on soil and groundwater processes are groundwater-associated salinity (dryland salinity), transient salinity (dry saline land) and irrigation salinity. This short review deals with the soil processes in the field that determine the interactions between root-zone environments and plant responses to increased osmotic pressure or specific ion concentrations. Soil water dynamics, soil structural stability, solubility of compounds in relation to pH and pE and nutrient and water movement all play vital roles in the selection and development of plants tolerant to salinity.