Chapter 1 Soil Science

Soil supplies anchorage, water, oxygen, and nutrients to plants.

• True

• False

The Dust Bowl of the 1930s was caused by drought, soil misuse, and wind erosion.

• True

• False

Soil exchanges temperature, oxygen, water, and carbon, which are factors needed by living things.

• True

• False

The continental crust, the rocky solid surface of the earth, is generally about ____ miles thick

• 50

• 75

• 100

• 125

Oxygen, carbon, and ____ are gases exchanged in soil.

• Helium

• Lithium

• Nitrogen

• Calcium

Soil is a medium for plant growth because it provides water, oxygen, nutrients, and ____.

• aeration

• carbon

• organisms

• anchorage

Of the nutrients needed by most plants, ____ come from soil.

• 3

• 20

• 14

• 17

Only about (a)   percent of the earth’s surface is suitable for agriculture.

Water reaches roots either by water flowing toward the root or the root growing into ____ soil.

• dense

• water-logged

• aerated

• moist

Hardpans, water-logged soil, and ____ prevent roots from growing deeply.

• micropores

• bedrock

• minerals

• mulch