Soil and Water Conservation Flashcards

Which soil texture has the highest water-holding capacity per unit volume?

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.

The Universal Soil Loss Equation (USLE) factor 'K' represents:

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.

A farmer observes high nitrate concentrations in a nearby stream following heavy rain. The MOST likely source is:

Answer: Subsurface tile drain discharge

Subsurface tile drains rapidly transport dissolved nitrate from the soil profile to surface waters, especially after rainfall events.

Which tillage system typically results in the LEAST surface residue after planting?

Answer: Conventional tillage

Conventional tillage inverts the soil with a moldboard plow, burying most surface residue and leaving the surface bare.

Permanent vegetation established in a concentrated flow area to slow runoff and trap sediment is called a:

Answer: Grassed waterway

A grassed waterway is a shaped, vegetated channel designed to convey concentrated runoff safely and reduce erosion and sediment delivery.

Which soil organic matter fraction has the MOST immediate influence on nutrient cycling?

Answer: Labile (active) fraction

The labile or active fraction of soil organic matter decomposes rapidly, releasing nutrients and driving short-term biological activity.

When designing a terrace system, the vertical interval (VI) is primarily determined by:

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.