Study Guide 2009 - Soils

Science Study Guide: Soils Test is: ________________ Students may want to review the following pages in their science books: C14-C15, C58-C65, C68-C74. Objectives covered in this unit.  describe soil and compare different types of soil (texture, color, and other physical properties – i.e. smell, water absorption;  explain how soil forms  compare different types of soil: loam, sand, silt, and clay  explain the importance of soil  compare weathering and erosion (water, wind)  identify ways humans change the earth’s surface  explain how the intensity of rain affects soil erosion  identify men and women of all ages, backgrounds, and ethnic groups that engaged in a variety of scientific and technological work;  label the layers of the earth: crust, mantle, core  sketch and label a soil profile: topsoil, subsoil, bedrock  explain how earthquakes and other natural events can change land quickly

You will need to know the following information: 1) Be able to label the layers of the Earth and a soil profile. 1. crust 2. mantle 3. outer core 4. inner core

topsoil subsoil

bedrock

2) Compare weathering and erosion.  Weathering is the breaking down of rock into soil. Soil is formed mainly by rocks weathering or breaking apart into smaller pieces. Wind, water, and temperature change (freezing) are all causes of weathering  Erosion is the movement of soil by water and wind. When it

rains hard or when the wind blows hard, a lot of soil may erode. Plants help prevent soil erosion by holding soil in place with their roots. Farmers use strip cropping and contour plowing to conserve soil. 3) Different kinds of soils include loam, sand, and clay.  Loam is the best type of soil for growing plants. Loam is a kind of soil with clay and sand.  Sandy soil drains water quickly and is usually dry.  Clay soil tends to hold the water. 4) The tiny bits of rock in soil are made of minerals. 5) Humus is a material that was once living or was formed by living things. Humus adds nutrients to the soil. Soil is an important natural resource because it has nutrients that all living things need. 6) Soil is made up of many different materials including small rocks, sand, silt, and clay. 7) Plants grow better in thick soil than in thin soil. 8) Identify ways humans change the earth’s surface. (See p. C63) 9) Explain how earthquakes, tornados, and other natural events can change land quickly. (See pages C68-C74)