CH Irrigation and Water Management 2 — Questions and Answers
Question 1: Irrigation run times should generally be split into shorter 'cycle and soak' cycles for slopes and clay soils to:
- Increase water penetration speed
- Allow water to infiltrate before runoff occurs (Correct answer)
- Reduce pump wear
- Prevent head pop-up failures
Correct answer: Allow water to infiltrate before runoff occurs
Cycle-and-soak scheduling runs short irrigation cycles with rest intervals, allowing slow-draining soils or slopes time to absorb water between applications and eliminating runoff.
Question 2: Which factor most directly affects irrigation precipitation rate (how fast water is applied)?
- Pipe material
- Nozzle flow rate and spacing (Correct answer)
- Controller brand
- Soil organic matter content
Correct answer: Nozzle flow rate and spacing
Precipitation rate (inches per hour) is calculated from nozzle flow rate and spacing; mismatched nozzles on the same zone create highly uneven application.
Question 3: A smart irrigation controller adjusts run times automatically based on:
- Manual input from the homeowner daily
- Local weather data such as temperature, wind, and ET (Correct answer)
- The age of the irrigation system
- Number of plants in each zone
Correct answer: Local weather data such as temperature, wind, and ET
Smart (weather-based or ET) controllers use local climate data to calculate actual plant water needs and adjust schedules daily without manual changes.
Question 4: Over-irrigation of landscape plants most commonly leads to which root problem?
- Nutrient toxicity
- Anaerobic conditions promoting root rot pathogens (Correct answer)
- Salt burn
- Excessive root hair growth
Correct answer: Anaerobic conditions promoting root rot pathogens
Waterlogged soils become oxygen-depleted (anaerobic), promoting Phytophthora, Pythium, and other water mold pathogens that cause root rot.
Question 5: What is the primary advantage of using reclaimed (recycled) water for landscape irrigation in the US?
- Higher pathogen load benefits soil biology
- Conservation of potable drinking water supplies (Correct answer)
- Eliminates need for fertilization
- Provides higher water pressure
Correct answer: Conservation of potable drinking water supplies
Reclaimed water is treated wastewater that would otherwise be discharged; using it for irrigation reduces demand on potable water supplies and can supplement plant nutrients.
Question 6: Hydraulic zoning in irrigation design groups plants together based on:
- Plant color and texture
- Similar water requirements (hydrozones) (Correct answer)
- Root depth only
- Bloom season
Correct answer: Similar water requirements (hydrozones)
Hydrozoning groups plants with similar water needs on the same irrigation zone so water can be applied efficiently without over- or under-irrigating any plant.
CH Irrigation and Water Management 2
Irrigation run times should generally be split into shorter 'cycle and soak' cycles for slopes and clay soils to: