the formation of soil Frameworks SCIENCE NS 1.6.1 Verify accuracy of observations. ESS 8.7.8 Identify the causes and effects of weather-related phenomena: thunderstorms, tornadoes, hurricanes, cyclones, typhoons, drought, acid precipitation. ESS 8.8.15 Investigate the formation of soil types. ESS 8.8.16 Identify components of soil as inorganic or organic through investigations. ESS 8.8.17 Identify the basic nutrients needed by plants that are present in the soils: nitrogen, phosphorus, potassium. Math G 8.7.1 Identify, draw, classify and compare geometric figures using models and real world examples. LANGUAGE ARTS OV 1.6.2 Use standard English in classroom discussion. OV 1.6.1 Develop vocabulary from content area texts and personal reading. OV 1.7.1 Use vocabulary from content area texts and personal reading. OV 1.8.1 Use vocabulary from content area texts and reading/literature. The students will learn: Objective #1 To design and measure a rectangular garden bed using the Magic Triangle. Objective #2 Describe the process of turning subsoil into topsoil. Objective #3 To define the roles of pioneer species in soil formation. Objective #4 To explain reverse soil formation and its causes. Objective #5 To appropriately use verbal speaking skills in class discussion with the teacher and Garden Program Specialist. Photo by Tim McCabe, USDA Natural Resources Conservation Service s Objectives
Page 2 Making Soil: Teachers Guide Even though subsoil itself is unsuited for gardening, it does provide essential nutrients and moisture storage. Overview Pioneer species play a crucial role in turning sediment into soil, initiating the process of plant succession and the formation of topsoil. Garden Activities : Optional: Measuring and outlining a garden bed s Loosening and amending subsoil s Recipes and Taste tests as time permits (refer to Delta Garden Study Recipe Book)
Making Soil: Teachers Guide Page 3 Tips for Teachers Pre-lesson preparation: 1. Review the Study Guide for Students pages to familiarize yourself with the extent of knowledge this lesson is designed to convey to students. 2. Review the Supporting Information for Teachers pages to familiarize yourself with additional information to teach as needed. This section is designed for reference purposes, not as lecture material read to the class. LESSON OUTLINE garden materials needed s 6 garden stakes (1 foot each) s Twine (at least 50 feet) s Measuring tape s Spades, shovels, garden forks s As available, fresh produce from garden in the classroom activities estimated duration actual duration s Offer the icebreaker 5 minutes in the garden back in the classroom : Optional: Explaining the mathematical principle of the Magic Triangle, outline a rectangular garden bed s Loosen and turn subsoil and amend with organic material. As students are working, explain how subsoil turns into topsoil s Pick and taste produce as available s Hand out Student Learning Workbooks, review and assign Take it Home Activity as homework 10 minutes 15 minutes (25 if optional activity is done) 5 minutes 5 minutes classroom materials needed s Student Learning Workbooks
Page 4 Making Soil: Teachers Guide Lesson PLAN I. Start in the classroom A. Icebreaker Tell students: The Dust Bowl has been called the worst natural disaster in recorded history. Today we will learn about the soil condition and farming practices that contributed to the Dust Bowl. : Another option is to show a clip of The Grapes of Wrath to start the lesson, or allow the students to watch this movie over a several day period. II. Take class to the garden : Optional: Instruct students to design a garden bed using the Magic Triangle (refer to Supporting Information for Teachers for additional information) s Describe how erosion, weathering and pioneer species turn subsoil into topsoil. s Instruct students to loosen, turn and amend subsoil, explaining that this activity is a man-made approach that speeds up the topsoil formation process. For detailed instructions, see the Garden Guide. s Define what factors disrupt the natural soil making process, including man-made disturbances. s Instruct students to pick and taste available vegetables. Explain that soil rich in nutrients yields better crops than a nutrient-poor environment. Meets Objective #1 Meets ObjectiveS #2 3 Meets Objective #2 Meets Objective #4 III. Take class back to classroom s Hand out the Student Learning Workbook as reference material and class assignment. Review take it home activities and encourage students to do them.
Making Soil: Teachers Guide Page 5 Supporting Information for Teachers BACKGROUND Nature requires thousands of years to turn subsoil into topsoil. Many areas lack sufficient topsoil and are therefore unsuited for gardening, particularly the growing of fruits, herbs and vegetables. To solve that problem, some gardeners build structures for raised beds and fill them with topsoil brought in from other locations. However, loosening the existing subsoil and turning it into topsoil by amending it offers two distinct advantages: 1. Subsoil contains small amounts of certain nutrients (micronutrients) that aren t always present in topsoil. 2. Subsoil can serve as a reservoir of water. Loosened subsoil that has been incorporated into topsoil increases the area s capacity to receive and store water, which is critical during times of little rainfall or drought. Students may learn about soil formation with these hands-on activities: 1. Building a Rectangular Garden Bed and Amending the Soil Materials needed s 6 garden stakes (1 foot each) s Twine (about 50 feet) s Measuring tape s Spades, shovels, garden forks, broadforks or deeper spades if available (essentially, these are big, extra-wide garden forks) s Organic material (sifted compost, shredded leaves, decomposed woodchips, etc.) Procedure Step 1. Outlining the Bed Before the lesson, decide where to build a new garden bed. An area not yet developed for gardening and void of large shrubs and trees is best. 1. Using twine and stakes, lay out a rectangular garden bed, 3 x 15. 2. To achieve accurate measurements and right angles, use the Magic Triangle, first conceived by the ancient Egyptians some 4,000 years ago. This is the formula: If one leg of a triangle is three units, the second leg is four units and the hypotenuse is five units, then the angle between the legs is a right angle. Therefore: 3. Attach twine to stake A and lay stake on the ground. Measure 3 feet to stake B. Tie twine to stake B, but don t cut, and drive stake B into ground. 4. From stake B, measure 4 feet of twine to stake C, attach and drive stake into ground. From stake C, measure 11 feet of twine, attach to stake D and pull twine taut so that it makes a straight line from B to C to D. Drive stake into ground and cut twine. 5. Measure 5 feet of twine and tie one end to stake C and the other end to stake A. Position stake A so that the twine makes a triangle ABC. Drive stake A into ground. 6. Measure 15 feet of twine and tie one end to stake A and the other end to stake E. Lay stake E on the ground. 7. Measure 3 feet of twine and tie one end to stake D and the other end to stake E. Position stake E so that the twine is taut to both stake D and stake A and drive into ground. You have a perfect rectangle. You can customize the measurements of the bed depending on the garden grounds and always build perfectly rectangular shaped beds as long as one leg is 3 units and the hypotenuse is 5 units. Step 2. Turning Subsoil into Topsoil 1. If necessary, remove sod, litter, debris and other materials.
Page 6 Making Soil: Teachers Guide 2. With shovels, spades, broadforks or garden forks as digging tools, loosen and turn over the soil. Stand on the perimeter, rather than in the bed to avoid compacting the soil. Thrust tools down into soil as deep as possible, then rock back and forth to loosen it. Remove large rocks, trash, concrete rubble, etc. 3. Add several wheelbarrow loads of organic material and incorporate into the loosened subsoil. Depending on the condition of the subsoil and the organic matter, the bed is ready for planting or needs more soil-building work. The Garden Program Specialist. will advise. VARIATION (If making a new bed isn t feasible): Instruct students to amend an existing, unplanted bed with organic matter. 2. Comparing Subsoil to Topsoil Materials needed s digging tools s a piece of tarp or plywood Procedure Instruct students to dig up a few shovels worth of subsoil from and an equal amount of topsoil from locations previously discussed with the Garden Program Specialist.. Place them in separate piles on the tarp or plywood. Instruct students to compare the two types. How do the colors differ? Dark colors usually indicate large amounts of organic materials. Shades of red or yellow usually indicate that subsoil material has been incorporated into the surface layer. How do the moisture levels compare? Subsoil usually serves as a moisture reservoir. How do the soils differ in compaction? Plants do not grow well in compacted soil because it lacks spaces for air and water to flow through. What kinds of living organisms do you find? You won t be able to see bacteria, fungi and nematodes, but you should discover earthworms and insects. Sources The ABCs of Ecology, An Educator s Guide to Learning Outside by Ecology Education, Inc., 2006 Ritter, Michael E. The Physical Environment: an Introduction to Physical Geography 2006 University of Wisconsin, http://www.uwsp.edu/geo/faculty/ritter/ geog101/textbook/title_page.html United States Department of Agriculture, Natural Resources Conservation Service http://soils.usda.gov/education/resources/ lessons/profile/ The Vegetable Gardener s Bible by Edward C. Smith, Storey Publishing, 2009 Wessels Living History Farm http://www.livinghistoryfarm.org/ farminginthe30s/water_02.html Wikipedia.org http://en.wikipedia.org/wiki/dust_bowl
the formation of soil study guide for students Garden and agricultural plants can only grow and thrive in topsoil or surface soil. This is the soil layer that contains organic matter, which is decomposed plant and animal matter. Top soil can vary from only a few inches deep on a rocky hillside to several feet deep in a grassland. It is missing altogether in some places, such as new housing developments, where it has been stripped and sold by the contractor, or in areas prone to flooding, where it has been carried away (eroded) by water. Underneath the topsoil is subsoil, it differs from topsoil in two significant ways: 1. It contains little to no organic material; 2. It has never been disturbed except for excavations for structures. But it has never been worked in preparation for planting, meaning it s never been tilled, dug up, turned over, or mixed with other components. Over long periods of time, nature turns subsoil into topsoil. As these pioneer species die, they decompose and add nutrients to the sediment. This mixture of inorganic sediment and organic matter, is now soil, although of fairly poor quality at this point. With soil, and not just sediment in place, the environment is now suited for more advanced plants, which move in and replace the original pioneer species. They, too, die and decompose, adding more nutrients to the soil, so yet other species can move in and continue the cycle. The process of one community of species replacing another over time is known as succession. Other living organisms, such as fungi, bacteria, single cell protozoa, insects and others, also settle in. They help break down plant material and later die and decay themselves, also turning to organic matter. The layer of topsoil gets thicker and thicker as plant and animal matter continues to grow and decompose. The process continues until a major disruption occurs, such as the advancement of a glacier, Continued next page Photo by Tim McCabe, USDA Natural Resources Conservation Service Soil formation starts with weathering, the process of rock being broken down into smaller pieces called sediment. Running water erodes the sediment and eventually deposits it in a stable place. Now some plants can establish so-called pioneer species. These are the first living organisms to take hold in areas with stable sediment. Typically, pioneer species are plants adapted to living in places with few nutrients in the soil. Lichens are common pioneer species because they can obtain most of their moisture needs from the atmosphere, rather than the soil.you find examples of pioneer species on tops of mountains and in the dunes at the beach.
Page 2 Making Soil: Study Guide rising sea levels or a massive flood. Or human intervention! Paving an area halts soil formation until the pavement is removed or broken up by plants. Next time you notice weeds sprouting in a cracked sidewalk, driveway or blacktop, consider it a step in soil formation. Unsustainable farming practices such as not using cover crops to hold soil in place or letting large herds of animals overgraze an area can even reverse soil development by removing nutrients and causing erosion. succession the coming of one person or thing after another in order, sequence, or in the course of events: many troubles in succession. pioneer species plants adapted to living in places with few nutrients in the soil. subsoil underneath the top soil, has never been worked in preparation of planting. topsoil the top layer of soil that contains organic matter. Remember the Dust Bowl? For several decades in the 19 th and 20 th centuries, many farmers in the United States practiced what we now call unsustainable farming techniques. They deeply plowed the soil, they grew the same or similar crops in the same location year after year instead of rotating them, they overplanted the fields instead of leaving them empty for a season and they failed to plant cover crops. In the 1930s, when a severe drought coupled with major storms hit the Plains (parts of Kansas, Nebraska, Texas, Oklahoma and Colorado), there were no natural anchors to keep the topsoil in place. It dried, turned to dust and blew away in large, dark clouds, reaching all the way to the Atlantic Ocean. This period lasted about 6 years (10 in some areas) and caused major ecological, agricultural and economic damage in central and southern parts of the Unites States, including Arkansas. The area affected became known as the Dust Bowl. The disaster made millions of acres useless for farming and forced hundreds of thousands of residents to leave their homes. You can read about it in novels by John Steinbeck, most famously The Grapes of Wrath and Of Mice and Men. Severely eroded farmland during the Dust Bowl. Photo by USDA NRCS
class assignment A ESS 8.8.15 Investigate the formation of soil types. 1. Twigs, dead insects, leaves, shredded paper and bits of plants are examples of what? a. Trash b. Organic matter c. Bedrock d. Subsoil 2. What is one major characteristic of pioneer species? a. They require lots of nutrients. b. They require few nutrients. c. They are so invasive no other plant species can grow in the ecosystem. d. They are extinct. Take it Home Take a hike in your local city or state park and pay attention to the different surfaces you walk on. These all present different stages in soil formation.
class assignment A answer key 1. Twigs, dead insects, leaves, shredded paper and bits of plants are examples of what? b. Organic matter 2. What is one major characteristic of pioneer species? b. They require few nutrients.
class assignment B ESS 8.8.15 Investigate the formation of soil types. 1. Twigs, dead insects, leaves, shredded paper and bits of plants are examples of what? a. Trash b. Organic matter c. Bedrock d. Subsoil 2. What is one major characteristic of pioneer species? a. They require lots of nutrients. b. They require few nutrients. c. They are so invasive no other plant species can grow in the ecosystem. d. They are extinct. 3. Describe the importance of pioneer species. Take it Home Take a hike in your local city or state park and pay attention to the different surfaces you walk on. These all present different stages in soil formation.
class assignment B answer key 1. Twigs, dead insects, leaves, shredded paper and bits of plants are examples of what? b. Organic matter 2. What is one major characteristic of pioneer species? b. They require few nutrients. 3. Describe the importance of pioneer species. As pioneer species die, they decompose and add nutrients to the top soil. These species are very well adapted to the environment they are growing in and can survive on fewer nutrients than typically are necessary.
class assignment C ESS 8.8.15 Investigate the formation of soil types. 1. Twigs, dead insects, leaves, shredded paper and bits of plants are examples of what? a. Trash b. Organic matter c. Bedrock d. Subsoil 2. What is one major characteristic of pioneer species? a. They require lots of nutrients. b. They require few nutrients. c. They are so invasive no other plant species can grow in the ecosystem. d. They are extinct. 3. Describe the importance of pioneer species. Take it Home Take a hike in your local city or state park and pay attention to the different surfaces you walk on. These all present different stages in soil formation.
class assignment C answer key 1. Twigs, dead insects, leaves, shredded paper and bits of plants are examples of what? b. Organic matter 2. What is one major characteristic of pioneer species? b. They require few nutrients. 3. Describe the importance of pioneer species. As pioneer species die, they decompose and add nutrients to the top soil. These species are very well adapted to the environment they are growing in and can survive on fewer nutrients than typically are necessary.