Soil Science & Amendments Flashcards
7 cards from real CFB practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Soil Science & Amendments flashcards as text
Which soil test is used to determine the lime requirement for a sports field?
Answer: Buffer pH test (e.g., SMP buffer test)
A buffer pH test measures the soil's resistance to pH change and is used to calculate the exact lime rate needed to reach the target pH efficiently.
In the USGA construction method, what is the primary function of the gravel layer placed beneath the sand root zone?
Answer: To create a perched water table that improves moisture retention in the sand above
The gravel layer creates a textural discontinuity that suspends water in the overlying sand root zone (a perched water table), improving moisture and nutrient retention while still allowing excess drainage.
In soil science, 'permeability' refers to:
Answer: The ease with which water or air moves through the soil
Soil permeability describes how readily fluids and gases flow through the pore network, which directly governs drainage performance of a sports field.
Gypsum (calcium sulfate) is most commonly applied to sports field soils to:
Answer: Improve clay structure by supplying calcium without significantly changing pH
Gypsum provides calcium that displaces sodium and helps aggregate clay particles, improving structure, drainage, and aeration without altering soil pH.
What is the primary agronomic benefit of a regular topdressing program on a natural grass sports field?
Answer: Gradual modification of the root zone profile and smoothing of the surface
Topdressing applies thin, repeated layers of sand or soil mix that dilute thatch, smooth surface irregularities, and gradually improve root zone drainage and firmness.
Which factor most significantly affects the load-bearing capacity of a natural grass sports field on any given day?
Answer: Soil moisture content at the time of use
Saturated or near-saturated soils have greatly reduced shear strength, dramatically lowering the field's ability to bear loads and resist surface disruption.
What does soil moisture tension (matric potential) measure?
Answer: The force with which soil particles hold water, affecting plant water availability
Soil moisture tension measures the suction or negative pressure with which soil holds water; higher tension means water is bound more tightly and harder for plant roots to extract.