Which practices maximize irrigation efficiency and minimize pollution?

• A. Scheduling based on evapotranspiration and soil moisture; use of efficient irrigation (drip/trickle); soil and crop management; leaching management.
• B. Only flood irrigation with no soil management.
• C. Using sprinkler but ignoring soil salinity.
• D. Applying fertilizers at high rates during rain events.

Answer: (A)

Maximizing irrigation efficiency and minimizing pollution comes from matching water delivery and nutrient inputs to what the crop actually needs, using delivery methods that reduce losses and practices that keep soils healthy.

Scheduling irrigation based on evapotranspiration and soil moisture ensures water is applied when the plant needs it and only in the amount needed, which minimizes waste, deep percolation of water beyond the root zone, and runoff. Pairing this with an efficient delivery method, like drip or trickle irrigation, keeps water right at the root zone with minimal evaporation and surface runoff, greatly reducing both water use and the potential for nutrient and salt leaching into waterways.

Soil and crop management supports this by maintaining good soil structure, promoting infiltration, reducing erosion, and sustaining crop health, which together improve water use efficiency and lessen the need for excessive irrigation or leaching. Leaching management is also important: applying water strategically to flush soluble salts or excess salts from the root zone keeps soil conditions favorable for crops while avoiding unnecessary pollution of drainage waters.

In contrast, practices that rely on flood irrigation without soil management waste a lot of water and can increase runoff and nutrient losses; using sprinkler systems while ignoring soil salinity risks salt buildup and reduced efficiency; and applying fertilizers at high rates during rain events leads to nutrient runoff and groundwater contamination, undermining both efficiency and environmental protection.