CGM Assessment & Monitoring Methods 3 — Questions and Answers
Question 1: Which irrigation audit metric expresses how uniformly water is distributed across a zone?
- Distribution Uniformity (DU) (Correct answer)
- Precipitation rate (PR)
- Runtime efficiency (RE)
- Hydraulic conductivity (Ksat)
Correct answer: Distribution Uniformity (DU)
Distribution Uniformity (DU) measures how evenly water is applied across an irrigated area, calculated from catch-can data.
Question 2: What does a refractometer measure in the context of plant health monitoring?
- Brix (sugar/soluble solids concentration) in plant sap, indicating plant vigor (Correct answer)
- Soil salinity in parts per million
- Chlorophyll content in leaf tissue
- Water potential in xylem
Correct answer: Brix (sugar/soluble solids concentration) in plant sap, indicating plant vigor
A refractometer measures Brix, the concentration of dissolved sugars in plant sap, which correlates with overall plant health and nutritional status.
Question 3: When assessing pavement conditions adjacent to tree roots, which tool provides a non-destructive subsurface view?
- Ground-penetrating radar (GPR) (Correct answer)
- Resistograph drill
- Increment borer
- Shovel probe
Correct answer: Ground-penetrating radar (GPR)
Ground-penetrating radar sends electromagnetic pulses into the ground and maps subsurface features, including root intrusion, without excavation.
Question 4: A grounds manager suspects thatch buildup is reducing fertilizer uptake. What is the CORRECT assessment method?
- Remove a 3-inch plug with a cup cutter and measure the thatch layer thickness with a ruler (Correct answer)
- Conduct a soil pH test
- Perform a percolation test
- Use a chlorophyll meter on leaf blades
Correct answer: Remove a 3-inch plug with a cup cutter and measure the thatch layer thickness with a ruler
Cutting a core plug and physically measuring the thatch layer between the green vegetation and the mineral soil is the standard thatch assessment method.
Question 5: Which statistical concept is MOST important when designing a monitoring grid for soil nutrient sampling on a large property?
- Representative sampling to capture spatial variability across management zones (Correct answer)
- Using the largest possible sample size for every test
- Sampling only from the center of each zone
- Collecting samples only after rainfall events
Correct answer: Representative sampling to capture spatial variability across management zones
Representative sampling from multiple points within each management zone captures the actual spatial variability in soil nutrients, producing actionable data.
Question 6: In turf disease monitoring, what is the significance of recording 'disease progress curves'?
- They show the rate of disease spread over time, helping predict outbreak peaks and time fungicide applications (Correct answer)
- They document the cost of chemical treatments
- They identify the pathogen species causing the disease
- They measure soil temperature at infection depth
Correct answer: They show the rate of disease spread over time, helping predict outbreak peaks and time fungicide applications
Disease progress curves plot disease severity versus time, revealing infection rates that guide the timing of preventive or curative fungicide programs.
Question 7: Which factor does an arborist assess using the 'TRAQ' (Tree Risk Assessment Qualification) methodology that a standard visual inspection might miss?
- Internal decay detected by advanced diagnostic tools such as a Resistograph or sonic tomograph (Correct answer)
- Surface bark texture
- Leaf color during growing season
- Branch angle at major scaffolds
Correct answer: Internal decay detected by advanced diagnostic tools such as a Resistograph or sonic tomograph
TRAQ-trained arborists use tools like the Resistograph or Picus sonic tomograph to detect internal decay not visible from the exterior.
CGM Assessment & Monitoring Methods 3
Which irrigation audit metric expresses how uniformly water is distributed across a zone?