Which practice best mitigates soil salinization in irrigated agriculture?

• A. Increasing irrigation frequency.
• B. Allowing soil to dry completely.
• C. Continuous monoculture with no drainage.
• D. Leaching and proper irrigation management.

Answer: (D)

In irrigated farming, salts build up in the root zone when water brings dissolved minerals and evaporation concentrates them near the surface; without a way to remove these salts, crop performance declines as osmotic stress reduces water uptake. The best way to mitigate this is leaching and proper irrigation management: apply enough water to push a portion of the salts below the root zone and ensure good drainage so those salts can exit the field. This keeps soil salinity at levels that crops can tolerate and prevents perched water that can worsen salinization. Frequent irrigation or letting soil dry out completely both tend to concentrate salts at the surface, and continuing monoculture without drainage allows salts to accumulate, all of which worsen the problem.