Landscape Design Soil Science and Site Analysis 2 — Questions and Answers
Question 1: What does 'N-P-K' stand for on a fertilizer label?
- Nitrogen-Potassium-Kale
- Nitrogen-Phosphorus-Potassium (Correct answer)
- Nitrate-Phosphate-Kelp
- Nutrient-pH-Kelp
Correct answer: Nitrogen-Phosphorus-Potassium
N-P-K represents the three primary macronutrients — nitrogen, phosphorus, and potassium — listed as percentages by weight.
Question 2: What soil condition does a low pH (below 5.5) most commonly cause in landscape plants?
- Nitrogen toxicity
- Nutrient deficiencies due to reduced availability of key elements (Correct answer)
- Excessive drainage
- Root burn
Correct answer: Nutrient deficiencies due to reduced availability of key elements
At pH below 5.5, phosphorus, calcium, and magnesium become less available, causing nutrient deficiencies even when present in the soil.
Question 3: What is the purpose of organic matter (compost) in landscape soil preparation?
- To raise soil pH only
- To improve soil structure, water retention, drainage, and nutrient availability (Correct answer)
- To kill existing weeds
- To reduce soil volume
Correct answer: To improve soil structure, water retention, drainage, and nutrient availability
Organic matter improves both drainage in clay soils and water retention in sandy soils while feeding soil microorganisms.
Question 4: Which site analysis factor must be determined before locating any underground irrigation or electrical lines?
- Soil pH
- Underground utility locations via 811 (Call Before You Dig) (Correct answer)
- Plant hardiness zone
- Prevailing wind direction
Correct answer: Underground utility locations via 811 (Call Before You Dig)
Calling 811 is legally required before digging in most US states to locate buried utility lines and prevent damage.
Question 5: What is 'solar aspect' and why does it matter in landscape site analysis?
- The brand of solar panels installed
- The direction a slope faces, determining sun exposure intensity and duration (Correct answer)
- The reflectivity of hardscape materials
- Average daily sunlight hours recorded at a weather station
Correct answer: The direction a slope faces, determining sun exposure intensity and duration
A south-facing slope receives more intense sun and heat, while north-facing slopes stay cooler and moister, influencing plant selection.
Question 6: What does 'bioavailability' mean in the context of soil nutrients for landscape plants?
- The total amount of a nutrient in the soil
- The portion of a soil nutrient that plants can actually absorb and use (Correct answer)
- The rate at which fertilizer dissolves in water
- The depth at which nutrients are stored
Correct answer: The portion of a soil nutrient that plants can actually absorb and use
Bioavailability depends on soil pH, moisture, and microbial activity — a nutrient present in soil may still be unavailable to plants.
Landscape Design Soil Science and Site Analysis 2
What does 'N-P-K' stand for on a fertilizer label?