Exam 3: Soil Classification

The name of a subgroup indicates the order, suborder, and great group of which it is a member.

A soil pedon is ____.

Which soil moisture regime has the highest soil moisture levels?

Andisols are found mostly near recently active volcanoes.

A polypedon or individual soil is a group of closely related pedons that conceptually approximates what in the United States is called a soil series.

An aquic soil moisture regime connotes a higher degree of soil moisture saturation than an ustic one.

In soils of which great group would you most likely find wide surface cracks during periods of dry weather?

Which of the following diagnostic horizons would likely not restrict root growth in soils?

Which of the following subsurface diagnostic horizons would you expect to find in a highly weathered soil of the humid tropics?

The broadest category of classification in Soil Taxonomy specifies 12 soil orders, 11 of which are for mineral soils.

In which soil orders would recent alluvium most likely be a common parent material?

The categories of Soil Taxonomy can be listed from the broadest (first) and most specific (last) as: order, suborder, great group, subgroup, series, family.

Russian scientists were the first to develop the concept of soils as natural bodies.

Which of the following soil temperature regimes would provide the warmest and least variable soil temperatures?

Epipedons are diagnostic subsoil horizons that are one of the primary means of classifying soils in the United States.

Organic matter distribution in the profile is a significant criterion for differentiating epipedons.

Investigating the soils of northern Canada on summer, you dig a soil pit easily though fairly uniform peat material until, at 75 cm deep, your shovel hits a layer that is frozen solid. Into which type of soil are you most likely digging?

Oxisols are more highly weathered than are the soils of any other order.

Histosols generally have higher organic matter contents than Mollisols.

Soils in the Oxisols order are deeply weathered and have deep subsurface horizons of silicon oxide.