Explanation

Saline-alkaline soils have high pH and EC. Adding water dilutes the salts, causing Electrical Conductivity (EC) to decrease. The pH may slightly increase or remain high due to sodium hydrolysis, but the primary effect of leaching is a reduction in salt concentration (EC). However, standard agronomy texts often state that irrigation with good quality water on saline-alkaline soil initially might show a slight pH increase due to dispersion and sodium activity before leaching reduces it, or simply EC decreases significantly. Let's re-evaluate. Saline soils: High EC, low pH (<8.5). Alkaline/Sodic soils: Low EC, high pH (>8.5). Saline-alkaline: High EC, High pH. Adding water dilutes salts -> EC decreases. The pH of saline-alkaline soil is usually controlled by the presence of sodium carbonate/bicarbonate. Dilution can sometimes lead to a slight increase in pH due to the dissociation of sodium salts or dispersion effects before leaching removes them, but often the pH is considered to decrease as salts are leached away over time. However, immediate effect: EC definitely decreases. Option C says pH increase & EC decrease. This matches the dilution effect on sodic components where pH can rise slightly due to increased water activity for sodium hydrolysis before leaching occurs. Many sources confirm that upon wetting, saline-alkaline soils show a drop in EC and a rise or stable high pH initially.