CCA Soil and Water Conservation 2 — Questions and Answers
Question 1: Which soil texture has the highest water-holding capacity per unit volume?
- Sandy loam
- Silt loam
- Clay loam (Correct answer)
- Loamy sand
Correct answer: Clay loam
Clay loam holds the most water per unit volume due to its high proportion of fine clay particles with large surface area.
Question 2: The Universal Soil Loss Equation (USLE) factor 'K' represents:
- Rainfall erosivity
- Soil erodibility (Correct answer)
- Slope length and steepness
- Cover management
Correct answer: Soil erodibility
The K factor in USLE represents soil erodibility, reflecting how susceptible a soil is to detachment and transport by rainfall and runoff.
Question 3: A farmer observes high nitrate concentrations in a nearby stream following heavy rain. The MOST likely source is:
- Atmospheric deposition
- Subsurface tile drain discharge (Correct answer)
- Stream bank erosion
- Groundwater seepage
Correct answer: Subsurface tile drain discharge
Subsurface tile drains rapidly transport dissolved nitrate from the soil profile to surface waters, especially after rainfall events.
Question 4: Which tillage system typically results in the LEAST surface residue after planting?
- No-till
- Strip-till
- Conventional tillage (Correct answer)
- Ridge-till
Correct answer: Conventional tillage
Conventional tillage inverts the soil with a moldboard plow, burying most surface residue and leaving the surface bare.
Question 5: Permanent vegetation established in a concentrated flow area to slow runoff and trap sediment is called a:
- Grassed waterway (Correct answer)
- Riparian buffer
- Field windbreak
- Filter strip
Correct answer: Grassed waterway
A grassed waterway is a shaped, vegetated channel designed to convey concentrated runoff safely and reduce erosion and sediment delivery.
Question 6: Which soil organic matter fraction has the MOST immediate influence on nutrient cycling?
- Humin
- Humic acid
- Labile (active) fraction (Correct answer)
- Fulvic acid
Correct answer: Labile (active) fraction
The labile or active fraction of soil organic matter decomposes rapidly, releasing nutrients and driving short-term biological activity.
Question 7: When designing a terrace system, the vertical interval (VI) is primarily determined by:
- Soil type and rainfall intensity (Correct answer)
- Crop rotation and tillage
- Field width and aspect ratio
- Drainage area and outlet capacity
Correct answer: Soil type and rainfall intensity
Vertical interval for terraces is determined using formulas that incorporate soil erodibility and rainfall intensity to set safe spacing.
CCA Soil and Water Conservation 2
Which soil texture has the highest water-holding capacity per unit volume?