Soil Science and Site Analysis Flashcards

What are the three primary soil texture classes in the USDA soil texture triangle?

Answer: Sand, silt, and clay

The USDA soil texture triangle categorizes soils based on proportions of sand, silt, and clay particles.

What does a soil percolation test measure in landscape site analysis?

Answer: The rate at which water drains through the soil

A percolation test determines drainage rate by measuring how quickly water infiltrates, guiding decisions about drainage improvements.

Which soil amendment is commonly added to heavy clay soil to improve drainage and aeration?

Answer: Coarse sand or grit, along with organic matter

Coarse sand improves drainage by increasing pore space, while organic matter improves overall soil structure in clay.

What is the purpose of a 'topographic survey' in landscape design site analysis?

Answer: To map existing grade elevations and slopes across the site

A topographic survey establishes existing elevation contours that inform grading, drainage, and design decisions.

What does a 'soil compaction test' using a penetrometer measure?

Answer: The resistance of soil to penetration, indicating compaction level

A penetrometer measures pounds per square inch (psi) of soil resistance, indicating how compacted a soil is.

Which landscape condition is indicated by a high water table near the soil surface?

Answer: Poor drainage and risk of root suffocation for non-wetland plants

A high water table saturates the soil root zone, depriving roots of oxygen and causing root rot in non-adapted plants.