Exam 12: Soils

Which are the least well-developed of all soil orders?

The time necessary for soil formation is about equal to that for soil degradation.

Organic material generally comprises less than 5% of the total soil volume.

Roughly one half of the volume of an "average" soil type is composed of ________.

Describe a soil-water budge for a Northern Hemisphere middle latitude climate with its greatest precipitation in the summer.

Based on the pH scale soils are neutral at ________.

The dynamic relationship between precipitation and evaporation in any given location is the ________.

Dead plant parts are known as ________ when they accumulate on the surface of the soil.

Spodosols are among the most fertile soils on the Earth.

A soil containing an A horizon atop partially altered parent material is said to be immature.

In semiarid climates there is a tendency for calcium carbonate to build up in a hardpan layer beneath the surface.

The boreal forest in subarctic locations is the typical setting for ________.

In the soil, the C horizon is unconsolidated parent material or regolith.

The highest rated soils for overall agricultural productivity are the ________.

Hardpan is a calcium carbonate concentration in the B horizon.

Distinctly alkaline diagnostic horizons, thin profiles, lack of organic material, and dominance of sandy materials are features most closely associated with which soil order?

Soil structure is usually determined by clumps called ________.

Oxisols are common in the Tropics and occur in Hawaii but are absent from the rest of the United States.

Regolith is the loose, inorganic material overlying unfragmented bedrock.

A major determinant of a soil's water holding capacity is its ________.