Chapter 10- Soil

HORT 201 Exam #3

False

Saline soils are beneficial for most crop plants.

False

Climate has little impact on the rate of soil formation.

True

Silt particles are smaller than sand but larger than clay.

True

Macropores allow for better air and water movement than micropores.

True

Soil horizons develop through processes such as weathering, leaching, and organic matter accumulation.

True

Silty soils hold more moisture than sandy soils.

True

A soil with equal amounts of sand, silt, and clay is classified as sandy loam.

False

Clay soils tend to have better drainage than sandy soils

True

Soil texture is determined by the proportion of sand, silt, and clay.

False

Clay soils tend to have a low CEC and poor water retention.

True

Soils with high cation exchange capacity (CEC) hold fewer nutrients.

True

Micropores are smaller than 0.000079 inches (0.008 mm) and hold water tightly.

False

Parent material refers to the organic matter content in the topsoil layer.

True

Sandy soils are typically well-drained but have low nutrient-holding capacity.

True

Soil structure refers to the arrangement of soil particles into aggregates

True

Soil organic matter improves water retention and nutrient cycling.

True

Soil pH affects nutrient availability for plants.

True

Soil formation is primarily influenced by five factors: parent material, climate, organisms, topography, and time.

True

Soil bulk density is higher in compacted soils.

True

Soil erosion is mainly caused by wind and water movement.

True

Alkaline soils (pH > 7.5) may limit the availability of iron and phosphorus.

True

The USDA Soil Taxonomy classifies soils into 12 major orders.

False

Soils with high porosity tend to have poor drainage.

False

Sand particles are smaller than clay particles.