Control of Salinity

Resumen

Salinity threatens the sustainability of many agricultural systems, especially irrigated areas in arid and semiarid zones. Salt concentration in the soil is measured as electric conductivity (EC) of the saturated extract (ECe). Besides the possible specific toxicity, the main effect of salts is the reduction of soil osmotic potential causing an effect similar to that of water deficit. The expected yield under saline conditions can be calculated with a simple model whose parameters are the threshold ECe and the yield loss per unit increase in ECe. The salt balance equation may be used to deduce soil salinity as a function of the EC of the irrigation water and the leaching fraction (LF). The required LF is calculated as a function of the irrigation frequency, the EC of the irrigation water and the desired ECe. The presence of Na deteriorates soil structure, but the effect depends on other factors, especially the salinity of irrigation water.