Soil Management Flashcards

What is the primary reason to avoid placing mulch directly against a tree's trunk ('volcano mulching')?

Answer: It promotes bark decay, disease, and adventitious rooting at the stem

Mulch piled against bark creates a moist, dark environment that accelerates fungal rot, pest colonization, and girdling root formation.

Which soil amendment is most appropriate for improving drainage in a heavy clay soil?

Answer: Incorporating coarse sand and organic matter

Coarse sand combined with organic matter increases macroporosity and improves drainage in compacted clay soils.

Which of the following best describes the role of earthworms in soil health for trees?

Answer: They create biopores that improve aeration, drainage, and nutrient cycling

Earthworm burrows improve soil structure, and their castings enrich the soil with plant-available nutrients.

When interpreting a soil test, 'base saturation' refers to:

Answer: The percentage of CEC occupied by calcium, magnesium, potassium, and sodium

Base saturation is the percentage of the CEC filled by basic cations (Ca²⁺, Mg²⁺, K⁺, Na⁺) rather than hydrogen or aluminum.

A newly planted tree in heavy clay shows wilting despite wet soil. The most likely cause is:

Answer: Anaerobic root conditions preventing water uptake

Waterlogged clay deprives roots of oxygen, impairing cellular respiration and the energy-dependent process of water absorption.

Which of the following is a sign of excessive soil nitrogen in landscape trees?

Answer: Excessive succulent vegetative growth with reduced hardiness

Excess nitrogen drives lush, soft growth that is more vulnerable to frost, drought, and pest attack.

The soil textural triangle is used to classify soil texture based on percentages of:

Answer: Sand, silt, and clay

The USDA soil textural triangle classifies soils by plotting the relative percentages of sand, silt, and clay particles.