Soil Study Guide

Vocabulary:

1. Soil: a naturally occurring mixture of minerals, dead plant and animal bits, water, and air that form the surface of the land

2. Weathering: breaking down of rock by wind, water, and living things

3. Erosion: loosening and movement of soil by wind, water, ice and landslides

4. Natural resource: something found in nature that people can use; soil, water,

Forests, wildlife, rocks, etc.

5. Nutrient: something that provides nourishment for an organism to live (it can be food or chemicals)

6. Magma: melted rock inside the mantle and crust layers of the Earth

7. Lava: melted rock that overflows from volcanoes; magma becomes lava when it reaches the surface of the Earth.

8. Conservation: wise use and protection of our natural resources

9. Igneous rocks: rocks formed by cooling magma or lava; pumice, obsidian, granite

10. Sedimentary rocks: the most common type on Earth, formed in layers at river

Mouths and under the sea; limestone, sandstone, shale, coal

11. Metamorphic rocks: rocks that have been changed by heat and pressure; marble,

Slate

Concepts:

1. Soil is formed by rocks that break up through the weathering process and become mixed with organic material such as bits of decaying plants and animals. Some soils are better for growing plants than others. Humus or loam is best because it absorbs water well, is loosely packed so that air to enter it, and contains nutrients plants need. Clay has small particles that pack together so tightly that water and air have a hard time getting into it. So do the roots of plants. Sand lacks organic material needed as nutrients for plants.

2. Earthworms are good for soil. They mix up the layers as they eat their way through it. They deposit “castings” which contain nutrients needed for plant growth. Their tunnels allow rain and air to enter the soil more readily. Plant roots find it easier to grow in earthworm burrows.

3. Good soil must be protected. Bare areas should be planted to guard against erosion. Farmers’ crops should be rotated so that nutrients aren’t depleted from the soil.

4. Be familiar with the diagram showing the layers of the Earth from the inner core to the outer core, to the mantle to the crust.