Simplified Evaluation of Salt Affected Soils Using 1:5 Soil-Water Extract

Because of the global increase in salt-affected soils, rapid and cost-effective remediations and easily measurable soil salinity evaluations are required. Soil salinity, through EC, and soil sodicity through exchangeable sodium percentage values, were predicted using a 1:5 soil-water extract. To determine the differences of soil salinity evaluations between arid regions, 48 soil samples (Inceptisols and Entisols) from China and 120 soil samples (Aridisol) from Sudan were used in this study. Positive correlations between the EC of a soil saturation extract and EC, exchangeable sodium percentage, and sodium adsorption ratio of a 1:5 soil-water extract were observed in all the soil samples. A simplified evaluation of salt-affected soils was possible using these relational expressions. Although the correlations differed by region, each correlation was strong. This was due to the differences in soil clay content and mineral composition between China and Sudan, but it also affected the salt content and composition in the soils. In addition, a strong correlation of soil salinity evaluations between saturated extract method and 1:5 soil-water extract method was observed even in the same area even when the salt content varied. Since accumulated salts were affected by the salt composition in irrigation water used in each region, soil salinity, and soil sodicity could be evaluate via simplified method based on the irrigation area. This results can be useful for farmland management in arid regions.