General materials: Post hole digger Meter stick 0.5m x 0.5m wooden frames or plotted with stakes and string Bulb planter (soil corer)

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1 Eco-Explorers! Title: Splendid Soil Topic: Soil Measurement and Graphing Pinckney 3 rd Grade Benchmarks: Science 3.1, 3.6, 3.9, 3.11; Math 3.7, 3.14; Social Studies 3.4 Key Questions: 1. How is the soil and detritus different in a temperate forest system different from a tropical rainforest system? 2. How is soil created? How are the detritus layers turned into soil? 3. What are the differences in the nutrient cycle of a temperate forest and a rainforest? Why is there a difference? Objectives: 1. Students will measure the detritus and topsoil depth in a temperate forest. 2. Students will clear, sort, categorize and illustrate the detritus sample. 3. Students will sample several soil cores and sort, categorize, and illustrate the soil contents (seeds, invertebrates, roots, leaves, etc.). 4. Students will graph results. 5. Students will generate questions and draw conclusions from their collected data and compare their temperate data to data collected in a tropical rain forest. Key Words: Decomposition Detritus Fauna Flora Nutrient cycle ph Temperate Topsoil Materials: General materials: Post hole digger Meter stick 0.5m x 0.5m wooden frames or plotted with stakes and string Bulb planter (soil corer) Each group of 4 students need: Small hand shovel Ruler with centimeters Large container to sort soil samples Large plastic bag to sort detritus Record sheets Getting Ready: 1. Dig a post hole up to 1.25m deep with a hand post hole digger in your forest test site. Collect a sample of soil every 20-25cm and place in a labeled ziploc bag. Eco-Explorers! Splendid Soil Page 1 of 7

2 2. Designate 0.5m x 0.5m quadrants (1 per 4-5 students) in your forest site. Sample sites can be designated with stakes and string or wooden frames. Procedure: PART 1: Whole group activity 1. In the classroom, explain what topsoil is. Hypothesize about topsoil depth in your forest and what the depth is in the rainforest. 2. Take the group to your sample site with their materials. 3. Observe the post hole and associated pre-collected soil samples. Determining any changes in the soil and at what depth the changes occur. Can you observe where the topsoil ends? The topsoil in most places in Michigan is up to 2-4 meters deep, therefore you may not see any changes from the surface to the bottom of your hole. 4. What is the composition of the soil at different levels? Is it all the same? What color is it? What texture is it? Is it rocky? Gravely? Sandy? Clay? PART 2: Small group activities A. Detritus Layer 1. Using the data sheet, describe the visual ground cover in side your sample square. E.g. thick brown oak leaves, wet/damp/dry, small flowering plants poking through, rocky, sandy, thin leaf cover, acorns, etc. 2. Gently clear three small area of detritus away to the soil level. Insert your ruler and record the depth of the detritus layer. Record the depth for all three sites. B. Categorizing Detritus 1. Spread out your plastic bag next to your sample site. Begin to remove all of your detritus layer and sort into similar piles. Count and record how many different kinds of leaves are found in this layer. What kind of leaves are they? Are there seeds? Sticks? Stems? Other? How many of each kind? Illustrate some of your samples from each of your categories. C. Soil Samples 1. Use the bulb planter to remove three samples of soil from your site. 2. Clear off your plastic bag. Spread out the soil into three different piles on your plastic bag. 3. Count and record how many different things you find in the samples. Were there insects? Worms? Roots? Leaves? Seeds? Other? Illustrate some of your samples from each of your categories. PART 3: Using the Data 1. Hold a discussion about the top soil depth and soil characteristics. Make a comparison about Michigan soil to the soil of the rain forest. Look at the website to see the results of the soil depth and qualities from the rain forest. 2. Chart the data from the detritus and the soil samples. 2. What does the soil and detritus tell you about the plants and animals in the forest? 3. How do you think this compares to the soil and detritus from a rain forest? Is the same or different? How? Look on the website to look at the real data from the rainforest. Is it what you thought it would be like? 4. What is the relationship of detritus and soil? What are the factors that influence the detritus and change it into soil? Temperature, moisture, other organisms? Bacteria, insects, worms, centipedes, isopods and other invertebrates all influence soil creation from detritus. Dead animals, feathers, fecal material and other animal byproducts all are part of the detritus as well! Eco-Explorers! Splendid Soil Page 2 of 7

3 Background Information: Temperate Deep topsoil up to 5m deep! Rich soil often rich loam Deep detritus layer Slow rate of decomposition Slow nutrient cycle Rain Forest Very shallow topsoil cm oxisol is the main type of soil -bright red clay/loam, nutrient poor, acidic High rate of decomposition Thin detritus layer Fast nutrient cycle Turnover of organic materials is much faster in a rain forest than in a temperate forest. Almost all the biomass in a rainforest is up in the trees vs. in a temperate forest a lot of it is on the ground because it takes so long to decompose. In a rainforest, when a leaf falls it decomposes right away and is sucked back up into living organisms. Temperature, fauna and moisture are all involved in the rate of the cycle. Extension Activities DECOMPOSITION AT TOP SPEED Students can create their own rain forest floor in a freezer bag and watch it decompose. Give each student a quart-sized plastic freezer bag. They should label their bag with their name and date. Have each student collect two handfuls of detritus. Have them break up the leaves etc. into small pieces and then put the pieces into the bag. Each student should add a tablespoon of water and a 1/2 teaspoon of blood meal (available at hardware stores). The students then put their bags in a sunny window. After a couple of days, students will notice the rapid decomposition of the plant material and the growth of bacteria. Have students record the changes in their samples colors, new growths, etc. GROW YOUR SOIL SAMPLE Students can observe their soil more closely and find out what seeds it holds that they couldn t see. Each small group brings in a 20cm x 20cm square of soil and plants it in a pot. They set their pots in a sunny window and water them twice a week. Students watch their soil samples and record new growth. MUDSHAKES Students learn about soil layers by creating mudshakes. Each student brings in one 500ml clear plastic bottle and a soil sample (1-3 cups) in a small plastic bag. The teacher arranges the soil samples on a large table. Students go through, cafeteria style, and pick a little of this soil and a little of that. They fill their bottles about half full of soil. The teacher should try to make sure that each child gets a variety of soils: sandy, loamy, rocky, clay. That will guarantee that their mudshake shows clear layers. Students fill their bottles to 3/4 full with water and put the lids on tightly. Students shake their bottles and then observe them as the layers settle. Students draw their bottles with the layers. Students write about why they think some layers are at the bottom and some are on the top. Students come back to their drawings and hypotheses the next day when they observe their mudshakes again. MEASURE THE PH OF SOIL Eco-Explorers! Splendid Soil Page 3 of 7

4 Using ph paper or a ph meter determine the acidity of your soil samples. Discuss how acidity affects plants as well as abiotic factors such as acid raid from pollution which influences soil acidity and plant growth. Eco-Explorers! Splendid Soil Page 4 of 7

5 DATA SHEET: TOP SOIL MEASUREMENT Predictions: 1. How deep do you think the top soil is in Michigan? 2. How deep do you think the top soil is in the rain forest? 3. Why do you think they are different or the same? Measurements and Observations: What does the soil look like at each level? 25cm 50cm 75cm 100cm 125cm 150cm Eco-Explorers! Splendid Soil Page 5 of 7

6 DATA SHEET: DETRITUS & SOIL 1. Look at your square. What do you see? 2. Clear three small holes so you can see the dirt. Measure how deep the detritus is above the dirt. A. Hole 1 measurement B. Hole 2 measurement C. Hole 3 measurement 3. Spread out your plastic bag. Sort all the detritus in your square onto your bag. Put all the leaves together, all the seeds together, all the sticks together etc. Set rocks aside. Count and record the data below. Number of leaves: Number of sticks: Number of roots: Numbers of seeds: Number of insects: Number of worms: Number of pine needles: Other: Draw below 3 or 4 things you found in your detritus sample. Eco-Explorers! Splendid Soil Page 6 of 7

7 4. Clear off your plastic bag. 5. Use the bulb planter to pull up three soil samples from your square Spread the soil out in three piles on your plastic bag. Count and record the things you find in your soil below. Number of leaves: Number of sticks: Number of roots: Number of seeds: Number of insects: Number of worms: Number of pine needles: Other: Draw below 3 or 4 things you found in your soil sample. Eco-Explorers! Splendid Soil Page 7 of 7