Soil Science and Plant Water Requirements Flashcards
7 cards from real CIT 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 and Plant Water Requirements flashcards as text
Which soil characteristic most directly controls the rate of water infiltration?
Answer: Soil texture and structure
Soil texture (particle size) and structure (arrangement of particles into aggregates) determine pore size and connectivity, which directly govern infiltration rate.
Soil compaction reduces water infiltration primarily because it:
Answer: Crushes aggregates and reduces pore space between particles
Compaction collapses soil aggregates and reduces the volume and connectivity of pore spaces, leaving fewer pathways for water to infiltrate.
To prevent runoff on low-infiltration clay soil, an irrigation technician should program the controller to use:
Answer: A cycle-and-soak strategy
Cycle-and-soak applies water in multiple short cycles with rest intervals, allowing slow-draining clay soil to absorb water between cycles before runoff occurs.
Organic matter improves soil water retention primarily by:
Answer: Binding soil particles into aggregates and increasing water-holding pore space
Organic matter improves soil structure by cementing particles into aggregates, creating more stable pore space and significantly increasing plant-available water holding capacity.
Which pairing correctly matches a soil texture with its approximate plant available water (PAW) per foot of depth?
Answer: Sandy soil — approximately 0.5 to 1.0 inches PAW per foot
Sandy soils hold approximately 0.5 to 1.0 inches of plant available water per foot because their large pores drain quickly, leaving relatively little tightly held water.
The primary purpose of performing a ring infiltrometer test before designing an irrigation system is to:
Answer: Establish the maximum application rate to match when selecting sprinkler heads
Infiltration test results define the maximum precipitation rate soil can absorb without runoff, directly guiding the selection of sprinkler nozzles with compatible application rates.
High soil salinity harms turfgrass primarily because:
Answer: Dissolved salts draw water out of plant roots through osmosis, causing drought-like stress
High salinity creates an osmotic potential outside the roots that reverses normal water uptake, causing water to move out of roots rather than in, producing physiological drought stress.