Irrigation and Water Management Flashcards

Which irrigation system delivers water directly to the root zone with the greatest water-use efficiency?

Answer: Drip/micro-irrigation

Drip irrigation applies water slowly at or below the soil surface directly to the root zone, minimizing evaporation and runoff compared to overhead methods.

Evapotranspiration (ET) represents the combined water loss from:

Answer: Soil evaporation and plant transpiration

ET combines evaporation from soil surfaces and transpiration from plant leaves, and is used to calculate irrigation replacement needs.

A distribution uniformity (DU) test for a sprinkler system measures:

Answer: How evenly water is applied across the irrigated area

DU compares catch-can volumes across the irrigated zone to determine how uniformly water is distributed; low DU indicates dry spots requiring over-irrigation elsewhere.

Which condition is an early visible sign of plant water stress (drought stress)?

Answer: Leaf curl or wilting in the morning

Temporary wilting or leaf rolling/curling during morning hours (before midday heat) indicates significant water deficit and is an early stress indicator in many species.

Irrigation scheduling based on soil moisture sensors is preferred over calendar-based scheduling because it:

Answer: Applies water only when plants actually need it, reducing overwatering

Soil moisture sensors measure actual water content in the root zone, allowing irrigation to trigger only when plants need water rather than on a fixed schedule regardless of conditions.

Backflow prevention devices on irrigation systems are required in the US primarily to:

Answer: Prevent contaminated irrigation water from entering the potable water supply

Backflow preventers protect public drinking water supplies from being contaminated by chemicals, fertilizers, or pathogens that may enter the irrigation system.