CGM CGM Irrigation & Water Management 1 — Questions and Answers
Question 1: What is the primary advantage of a smart irrigation controller over a traditional timer-based controller?
- It costs less to install
- It automatically adjusts watering schedules based on weather and soil data to avoid overwatering (Correct answer)
- It can only water at night
- It eliminates the need for backflow preventers
Correct answer: It automatically adjusts watering schedules based on weather and soil data to avoid overwatering
Smart controllers use real-time weather and sensor data to irrigate only when needed, significantly reducing water waste compared to fixed schedules.
Question 2: Which irrigation system type delivers water directly to the root zone of plants, minimizing evaporation losses?
- Pop-up spray heads
- Rotary sprinklers
- Drip/micro-irrigation (Correct answer)
- Impact sprinklers
Correct answer: Drip/micro-irrigation
Drip irrigation delivers water at low flow rates directly to the soil near plant roots, reducing evaporation and surface runoff.
Question 3: What does evapotranspiration (ET) measure in the context of turfgrass irrigation?
- The rate of water absorption by soil
- The combined water loss from soil evaporation and plant transpiration (Correct answer)
- The speed of water movement through irrigation pipes
- The amount of rainfall captured in reservoirs
Correct answer: The combined water loss from soil evaporation and plant transpiration
ET quantifies the total water consumed by a landscape through soil evaporation and plant transpiration, forming the basis of efficient irrigation scheduling.
Question 4: A backflow preventer on an irrigation system is required primarily to:
- Increase water pressure
- Prevent contaminated irrigation water from flowing back into the potable water supply (Correct answer)
- Filter sediment from sprinkler heads
- Reduce water hammer in the main line
Correct answer: Prevent contaminated irrigation water from flowing back into the potable water supply
Backflow preventers protect public drinking water from contamination by stopping reverse flow of irrigation water, which may contain fertilizers or pesticides.
Question 5: What is the term for the percentage of water applied by an irrigation system that is actually used by the plant, expressed as a percent?
- Precipitation rate
- Distribution uniformity
- Irrigation efficiency (Correct answer)
- Hydraulic conductivity
Correct answer: Irrigation efficiency
Irrigation efficiency measures how effectively applied water is used by plants versus lost to runoff, evaporation, or deep percolation.
Question 6: Which factor most directly determines the correct spacing between sprinkler heads in a residential or commercial irrigation design?
- The color of the sprinkler body
- The sprinkler's radius of throw and the head-to-head coverage principle (Correct answer)
- The brand of the irrigation controller
- The time of day watering will occur
Correct answer: The sprinkler's radius of throw and the head-to-head coverage principle
Head-to-head coverage—spacing sprinklers so each head reaches the adjacent head—ensures uniform water distribution across the entire zone.
CGM CGM Irrigation & Water Management 1
What is the primary advantage of a smart irrigation controller over a traditional timer-based controller?