Exam 15: Global Soils

The downward transport of fine particles carrying them out of the upper soil layers is:

Cultivation that involves clearing land, growing crops, and moving on a few years later to newly cleared land when the fertility has decreased is called:

When more than half of the parent material is volcanic ash, the soil is a(n):

Ions of hydrogen and aluminum help to make the soil more fertile.

The process that affected the ancient Sumerian civilization was:

Many areas of the earth's land surface lack soil.

The youngest of the soils is the inceptisols.

Water is held to soil particles against the pull of gravity by:

Colloids are considered clay-sized soil fragments.

A soil with a pH of 7 is considered neutral.

Fine textured soils have a lower storage capacity than coarse textured soils.

The soil that is strongly acidic and low in plant nutrients and humus, with a pale gray to white E horizon is the:

The highest level of the Soil Classification System of the United States Soil Conservation Service is the soil orders.

Red soils are usually high in:

Arid climates tend to have soils with high acidity.

_____________ are mature soils characterized by a clay-rich B horizon produced by illuviation.

The water storage level below which is insufficient for plants is the:

Soil orders are grouped by:

The soil layer rich in both mineral and organic matter is the:

Decomposing organic matter that remains recognizable is the soil layer called: