February 12, 2015
February 12, 2015
Soil types differ in how they hold water. Soil that is mostly humus absorbs water like a sponge with only a little runoff, and this water is then available to the plants. Sandy soil does not stick together when wet and does not absorb water very well. soil Clay absorbs water but can have a lot of runoff. The water is hard for plants to use because wet clay soil holds water so well that it is difficult for plants to get the water from the soil. Soil types are different in color and texture. Color refers to the way the soil looks and texture means the way it feels. The color shows the presence of certain minerals of substances. For example, red soil contains a lot of iron and black soil contains a lot of humus. Dark soil is warmed a lot by the sun, but -colored light soil reflects more sunlight and is warmed less. Texture describes the size of the particles that make up soil. A coarse soil is made up of large grains which feel rough. A soil fine is made of dust and other powdery substances and feels smooth. It may also feel sticky when wet.
Properties on Soil Humus- Sand- Clay-
Explain how weathering and erosion contribute to the formation of soils. Weathering breaks down rock into smaller pieces and erosion carries the smaller rock particles away. Soil Formation The link in the planner is not working. BrainPOP: Soils
Discussion: How is soil formed? Soil is formed from different layers of living and non-living material and is a mixture of weathered rock particles and organic matter- the remains of plants and animals. Where on Earth is soil? Soil forms a relatively thin layer that covers most of Earth's land surface; only the polar regions or some deserts are without it. How does soil change over time? Soil is an ever-changing system because a variety of plants and animals live in soil and weather continually adds to its composition. As organic matter decays, nutrients are added to the soil, improving its ability to sustain life. What are the layers of soil? A layer of humus, consisting of dead and rotting leaves, lies on the surface. Subsoil, between the topsoil and a layer of partly weathered rock, has less organic matter. Only deep-rooted plants such as trees reach the subsoil. A hard layer of solid bedrock lies below all the other layers.
Soil Layers Create a neatly labeled diagram of the layers of the soil in your notebook.
What Do You Know About Soil? What are some foods that are grown in soil? (fruits and vegetables) How does the soil provide us things we need and use? Give two examples. (Answers will vary but can include: Plants that we eat grow in soils. Animals that we eat and get materials from eat plants that grow in soils.) Which layer of the soil contains the most humus? What helps weather the rocks in the subsoil layer? (temperature changes and plant roots) (topsoil) What are the three layers of soil and of what are they made? (topsoil-rotting humus and bits of rock; subsoil-mostly small rocks; bedrock-large pieces of rocks) How does water freezing in a crack in a rock help break the rock apart? (The water freezes and expands. As it expands, it forces rock farther apart, widening the crack and after a while it breaks the rock apart.) What two processes work together to form soil? (Weathering and erosion form soil.) Explain the differences in weathering and erosion. (Weathering is the breaking apart of rock and erosion is moving the rock pieces to a different place.) How is the weathered rock relocated? (Wind and water can move rock particles.)
February 12, 2015 Day 2 Think about what might happen to these fields during wind storms or very heavy rains. Think about what farmers would need to do to protect the soil from eroding. Farm Fields
Investigation A Investigation B Design an experiment to see how well different types of soil hold water. Design an experiment to see how to prevent a field from eroding. Soil Types and Water Drainage Soil Convservation identify the question state your hypothesis plan the procedure identify and list materials needed conduct the experiment record results and conclusions