Exam 12: Soils

Of the following, which covers the least area on Earth's surface?

The lowest level of the Soil Taxonomy soil classification system is the ________.

If you lived in Texas or California and your house foundation crumbled because the soil swelled when it was wet and cracked when it was dry, chances are that the soil would be a(n) ________.

For all soil orders, the surface layer is the ________.

Scientists recognize 175 gradations of soil color.

Permafrost and minimal profile development are most closely associated with which soil order?

Which of the following horizons is found furthest from the surface of the soil?

Because of its comprehensiveness, the Soil Taxonomy presents great difficulty for small scale maps.

The pedogenic regime typified by silica removal and iron-aluminum concentration near the surface is ________.

Name a soil order that is not prominent in the United States as a whole and explain why that is.

An immature order of soils with faint characteristics, not yet prominent enough to produce diagnostic horizons is a(n) ________.

In cool climates, areas of poor drainage have pedogenic regimes of gleization.

The soil classification system currently in use in the United States is called the ________.

Gravitational water is ________.

The term "clay" is a reference to ________.

There are approximately one hundred major soil orders recognized by the U.S. Soil Taxonomy.

Earthworms ________.

In thinking about soils, why have various human activities greatly altered world soils?

The soils characterized by plentiful partly decayed plant material are ________.

In the United States, the ________ states are most closely associated with gleization.