Teachers: With this close-up look, students learn that soil is more than dirt! The students explore outside where they will play a game focusing on soil types. In the classroom they will perform an experiment testing different types of soil, soil porosity, and water-holding capacity. Data collection, measurement, observation, and scientific predictions are reinforced. Also available is an activity where students determine soil texture through the feel method and explore soil and erosion as they walk the grounds at the Arboretum. There may be the possibility of pulling a soil plug out of the ground to see the different horizons, depends on the weather and time available at Blandy. Your students may have the opportunity to separate soil particles by size using soil sieves or tour the terracing area that illustrates this farming method. Updated Dec-11
Teachers Notes: The following terms and concepts will be addressed in the Scoop on Soils program. While it is not necessary for your students to have a working knowledge of the terms, it may be useful to introduce the concepts prior to your trip. Organic matter: living or dead plants or animals Inorganic matter: minerals (non-living) substance such as sand or rocks. Topsoil, subsoil and bedrock: the three basic layers of soil in the horizon. Erosion: wearing down or washing away of soil by wind, water or ice. Weathering: physical and chemical changes produced in rocks and soils by the forces of nature Soil conservation and renewal: natural and human efforts to preserve soil resources Scientific method: includes observation, measurements, experiment, constant, variable, hypothesis, and conclusion Pre trip activity: Included with this letter is a pre-program activity to get you and your students thinking about soil. There also is a post-program activity to help you wrap up your soils program. It is advisable that you engage your students with these worksheets so that they may walk away from our program with a complete understanding of soil. If you have any questions please do not hesitate to contact us prior to your scheduled program. The Education Staff at the State Arboretum of Virginia Updated Dec-11
Pre Program activity 200 milliliters of water. 1. If, in the picture above, the arrow is pointing at 200 milliliters of water, then what measurement does each line represent? 2. If you pour 200 mls of water into an open-ended tube with soil in it and only 150 mls drip out through the bottom, what is the water holding capacity of the soil (how much water is retained in the soil)? 150 ml. 3. Circle which of the following tools will help you determine how fast water percolated through the soil? a. calculator b. stop watch c. ruler d. soil probe 4. Match the colored dot with the soil description by connecting the two with a line. a. When iron is present in the soil it gives it a reddish brown color. b. Very dark or black soils are high in organic matter, often found in the A horizon or top soil. c. Dull grey soils indicate a poorly drained or waterlogged soil. d. Well drained or aerated soils are yellowish in color.
Directions: There are three boxes below with different size dots. Place the point of your pencil on the left hand side of the page and as quickly as you can draw a line to the right hand side of the page without crossing through any dots. Through which box of dots were you able to make your line the quickest? The slowest? Sand Silt clay Reflect on the activity that you just completed, what do you think the lesson is?
Post Program Activity Use the provided graphs to plot the results from the soil science experiment conducted at Blandy Farm. 100 Bar graph of soil water holding capacity Amount of water in soil in milliliters 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 Gravel Coarse Sand Fine Sand
Bar graph of wetting front time Seconds 300 285 270 255 240 225 210 195 180 165 150 135 120 105 90 75 60 45 30 15 0 Gravel Coarse Sand Fine Sand
1. Compare your results from the graphs with other teams. Are there similarities? What? Why? Are there differences? What? Why? What are some possible reasons for the difference? 2. Which soil type has the greatest water-holding capacity? 3. Which soil type has the least water-holding capacity? 4. Which soil type has the fastest wetting front time? 5. Which soil type has the slowest wetting front time? 6. Why does the water move differently depending on the soil type?