A Day at the Races. Students prepare soil flats using five different soil conservation techniques and then compare water flow and soil loss.

Transcription

1 THE LIVING EARTH OUTDOORS GRADES 5-6 FALL, WINTER, SPRING ACTIVITY A Day at the Races Students prepare soil flats using five different soil conservation techniques and then compare water flow and soil loss. To demonstrate soil erosion and ways to conserve soil. TEACHER BACKGROUND Throughout history, different means of soil conservation have been used. Terracing has been used to keep soil on hillsides by creating level platforms for farming that step down the hill. Terraces take a long time to build. Contour farming is a simpler practice, in which the planting takes place in rows across the hill rather than up and down the slope. However, the key to soil conservation is to mimic nature and keep the soil rooted in with plants. Five shoe boxes trimmed to 5 cm deep, V-notched on one end, and lined with plastic Five watering cans Five measuring cups Sod (enough to fill one shoe box) Soil Water Five blocks Three rulers Clock or watch Science journals CLASS DISCUSSION Why is soil important to plants? Have you ever seen soil washed away by rain or rivers? What do you think will happen to soil if it gets washed away year after year? Do you have ideas for saving soil and keeping it where it is? (List responses on the board.) Let s design a soil race and see who the real winners are. 1. Divide the class into five groups. 2. Distribute the materials. 3. Have each group fill a box with soil prepared in the following ways: Group 1: Fill the box with moist soil and pack it down tightly. Group 2: Fill the box with sod. Group 3: Fill box with moist soil and, using fingers, make packed furrows across the slope. (Furrows run the width of the box.) 108 THE GROWING CLASSROOM

2 A DAY AT THE RACES THE LIVING EARTH Group 4: Fill the box with moist soil and, using fingers, make furrows up and down the slope. (Furrows run the length of the box.) Group 5: Fill the box with soil and, using a ruler, make steps (terraces) across the slope. If other ideas were suggested during discussion, another group can be added to test the ideas. 4. Have each group use the blocks to line up their boxes on an incline and place measuring cups beneath the V-notches to catch the water that drains off. 5. Have one student from each group sprinkle a measured amount of water from about 12 inches (30 cm) above each box, pouring steadily for 5 seconds. 6. Have groups record in their journals how long water continues to flow out of the V-notch. 7. Let the water in the cups settle and have groups measure the sediment in each, recording the results in their journals. Discuss which box lost the most soil. Which lost the most water? Which methods were most effective in controlling erosion in the experiment? What other methods might help conserve the soil? DIGGING DEEPER Have students walk around school grounds and identify evidence of soil erosion. How can it be prevented? THE GROWING CLASSROOM 109

3 LET S WORK TOGETHER INDOORS, OUTDOORS GRADES 2-6 FALL, WINTER, SPRING ACTIVITY Group Juggle Children toss balls and learn one another s names. To learn everyone s name and build a sense of community. 5 different shaped, soft balls, each small enough to fit in one hand stopwatch or timer 1. Gather in a circle and have everyone put both hands up in front of themselves. 2. Explain the game: I m going to say someone s name, and then toss this ball to him/her. Then that person will catch the ball, say a new name, toss the ball to the new person, and then put his/ her hands down. We ll keep going until everyone has had the ball. 3. Practice. Once everyone has had the ball, have the final student toss it back to you. 4. Now have everyone point to the person they threw the ball to. With the other hand, have them point to the person who threw the ball to them. 5. Ask if they think they can do the same thing, in the same order, but faster. 6. Start the timer, then repeat. 7. Announce the time it took. 8. Ask for suggestions of how to make the process even faster. (Make eye contact with the person before you throw the ball, or make the circle smaller.) 9. Repeat, attempting to speed up. 10. Add more balls. Once one is going, start another one. Keep adding until you ve got 5 balls going at once, all in the same order. 11. Again, brainstorm ways to make it quicker, and time each round. What helped us speed up? How did we work together to achieve our goal? How might this type of teamwork help us out in the garden? After doing that, who thinks he/she remembers everyone s name? THE GROWING CLASSROOM _Lets_Work.indd 39 7/1/14 10:10 AM

4 LET S WORK TOGETHER OUTDOORS GRADES 4-6 FALL, WINTER, SPRING ACTIVITY Lighthouse This activity asks one student (Lighthouse) to verbally lead another blindfolded student (Boat) through a maze of people. To develop communication and cooperation skills. blindfold CLASS DISCUSSION What are some important parts of good communication? If we are having a class discussion and one of us wants to share some ideas, what will help us to communicate? Let s find out. 1. Ask for a student who feels that he or she can communicate clearly to be the lighthouse. 2. Ask for another student who considers himself or herself to be a good listener to be the boat. Blindfold this student. LIGHTHOUSE BOAT THE GROWING CLASSROOM _Lets_Work.indd 41 7/1/14 10:10 AM

5 LET S WORK TOGETHER LIGHTHOUSE 3. The remaining students will become obstacles in a bay. They can be bridges, logs, and so on. It is important that they are quiet and do not move during the activity. 4. Situate the lighthouse at one end of the playing area. 5. Place the boat at the other end. 6. The remaining students can take their places between the boat and the lighthouse as obstacles in the bay. 7. The task of the lighthouse is to verbally lead the blindfolded boat through the obstacles. The lighthouse should remain stationary. The lighthouse should give the boat explicit directions so that it will avoid the obstacles. It may help to have the boat keep a hand raised to assist in determining left from right. 8. The task is completed when the boat safely arrives at the lighthouse. If the boat hits an obstacle and sinks, choose another student to be blindfolded, rearrange the obstacles, and begin again. The obstacles should remain still and silent. How did it feel to be the boat? What did the boat have to do to stay afloat and reach the lighthouse? How did it feel to be the lighthouse? What did the lighthouse have to do to bring the boat in safely? What does concentration mean? What does communication mean? How did the obstacles help the lighthouse and boat communicate? 42 THE GROWING CLASSROOM _Lets_Work.indd 42 7/1/14 10:10 AM

6 ALL ABOUT PLANTS INDOORS GRADES 5-6 FALL, WINTER, SPRING PROJECT Photosynthesis Revealed Teacher'conducts'as'a'demonstration'a'simple'experiment'creating'a'visible'chemical'' reaction,'first'with'the'carbon'dioxide'humans'exhale'and'then'with'the'oxygen'released'' from'an'aquarium'plant.' To'demonstrate'how'plants'produce'oxygen'and'use'carbon'dioxide'in'the'course'of'photosynthesis.' TEACHER BACKGROUND Plants'have'the'unique'capacity'to'make'their'own'food.'This'process,'called'photosynthe> sis,'requires'carbon'dioxide,'sunlight,'and'water.'the'carbon'dioxide'is'taken'from'the'air,' and'from'the'chemical'reaction'of'photosynthesis'the'plant'gives'off'excess'oxygen.'animals' reverse'the'process,'taking'in'oxygen'and'giving'off'carbon'dioxide.'this'exchange'between' animals'and'plants'recycles'the'earth s'limited'air'supply.'most'scientists'are'concerned'about' the'increase'of'carbons'in'our'atmosphere'from'the'burning'of'petroleum.'an'increase'in' carbon'can'trap'more'heat'in'the'atmosphere'(the'greenhouse'effect).'according'to'the'us' Environmental'Protection'Agency,'this'is'leading'to'rising'global'temperatures,'which'have' been'accompanied'by'changes'in'weather'and'climate,'the'melting'of'glaciers,'and'a'rise'in'sea' levels.'plants'help'keep'the'carbon'ratio'in'balance'by'using'carbon'dioxide'in'photosynthesis.' The'chemical'equation'for'photosynthesis'is:' 6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2 Carbon'Dioxide + Water Sugar + Oxygen 'Observation'Sheet,'1'per'student,'page'416 'bromothymol'blue'(available'in'chemical'supply'catalogs) 'lab'coat,'apron,'or'smock '2'bottles'or'test'tubes'with'tight>fitting'stoppers'that'have'holes'for'straws'or'pipettes' '2'straws'or'pipettes'that'fit'in'stopper'holes' 'sprig'of'an'aquarium'plant'(elodea'or'hornwort)' PREPARATION Fill'a'bottle'half'full'with'bromothymol'blue.'Seal'with'a'stopper'that'has'a'straw'or'pipette' inserted'in'the'stopper'hole..'the'stopper'must'fit'tightly'in'the'bottle.'if'there'are'gaps' around'the'stopper'or'straw,'seal'them'with'tape.'note:'bromothymol'blue'can'stain'clothing,' so'wear'a'lab'coat,'apron,'or'smock. CLASS DISCUSSION Animals'inhale'oxygen'and'exhale'carbon'dioxide'as'part'of'their'respiration'systems.'Plants' use'the'carbon'dioxide'and'release'oxygen'into'the'air'during'photosynthesis.'we'can'demon> strate'this'exchange'by'using'a'chemical,'bromothymol'blue,'that'changes'color'when'carbon' dioxide'amounts'are'increased.'when'you'breathe'into'the'chemical,'the'carbon'dioxide'you' exhaled'changes'the'color'of'the'chemical'from'blue'to'yellow>green.' THE GROWING CLASSROOM 149

7 ALL ABOUT PLANTS PHOTOSYNTHESIS REVEALED 1.''Demonstrate'by'breathing'in'a'soft,'steady'rhythm'into'the'straw'of'one'of'the'rubber> stopped'bottles.'note:'it s'best'for'the'teacher'to'do'this'to'ensure'that'no'bromomythol' blue'is'inhaled. Wow! It s yellow-green! You must be putting carbon dioxide in there! LIFE LAB 2.''Breathe'into'the'bottles'until'the'blue'color'becomes'yellow>green.'Explain'that'the'' yellow>green'color'signifies'the'presence'of'carbon'dioxide.' 3.''Ask'students'to'hypothesize'how'some'of'the'carbon'dioxide'can'be'removed'from'the'' Bromothymol'blue'solution.'How'will'they'be'able'to'tell'if'this'has'happened?'(The color will return to blue.) 4.''Have'them'test'the'hypothesis'as'you'remove'the'stopper'and'place'a'sprig'of'elodea'in'one' of'the'bottles.'place'both'bottles'in'bright'sunlight'and'observe'changes'over'several'days.'if' students'develop'other'hypotheses,'follow'through'on'their'ideas.' 5.''Ask'students'to'report'the'results'of'the'experiment.'Discuss'the'importance'of'plants'in' removing'carbon'dioxide'from'the'atmosphere.' What'was'released'into'the'chemical'to'change'its'color?'How'was'carbon'dioxide'removed' from'the'chemical?'how'did'the'plant'use'the'carbon'dioxide?'what'is'an'important'exchange' that'takes'place'between'plants'and'animals?'why'are'plants'important'in'maintaining'the' carbon'dioxide'balance'in'our'atmosphere? 150 THE GROWING CLASSROOM

8 ALL ABOUT PLANTS INDOORS, OUTDOORS GRADES 2-6 FALL ACTIVITY Seed Ya Later Students explore seeds and learn about how they are adapted for travel. They then search around the garden or other outdoor areas for examples of seeds that travel in different ways. To understand how seeds adaptations aid them in traveling away from their parent plants; and to classify seeds based on their dispersal mechanisms, or the structures that allow them to travel. A variety of seeds that travel in different ways. Examples include: Soaring seeds: Ash, elm, linden, maple, dandelion, milkweed, goldenrod, thistle, columbine Velcro seeds: Any burr that gets stuck in your sock in a grassy field. (Note: A great way to collect these is to put a large old sock over your shoe, and take a walk through a meadow.) Edible seeds: Seeds inside of fruits and nuts Floating seeds: Palm, water lilies, coconuts Explosive Seeds: Seeds that spring away from their parent plants, like impatiens, sweet peas, lupines, California poppies, and pansies 1 large sheet of paper for each pair of students 1 bin full of water magnifying glasses for all students PREPARATION 1. Collect a variety of seeds, including at least one soaring, one Velcro, one edible, one floating, and one explosive variety, so that each pair will have 5-8 varieties. (Note: If a floating seed is difficult to find, a coconut from the grocery store or a photo of one will also work.) 2. Prepare an envelope with a variety of seeds for each pair of students, including at least one soaring, one Velcro, one edible, one floating, and one explosive seed. TEACHER BACKGROUND Seeds come in an incredible variety of shapes, sizes, and colors. Coconuts can be as heavy as 18 kilograms (40 pounds), and the seeds of snapdragons are almost like dust. Dandelion seeds float through the air, and walnuts may be carried away and buried by squirrels. For all of their differences, seeds have this in common: They all have adaptations that allow them to disperse and reestablish, ensuring the plant s survival. During this activity, students will be classifying seeds that have been gathered from the kitchen and from plants in your area. If you collect seeds from natural areas for this lesson, please collect only a small fraction of the available seed from each species so that there are enough for the plant to continue to reproduce. CLASS DISCUSSION Together with a partner, make a list of all of the ways you can think of that humans travel. Make the list as long as you can! What are some of the ways humans travel? Have students share their answers. Ask for them to share means of travel they don t think any other groups might have thought of, like dog sleds or hot-air balloons. Now we re going to talk about how seeds travel. A seed has a baby plant inside it, and for that baby plant to grow, it needs to land in a place where it will receive water and nutrients from the soil, and where it won t have too much competition from other plants for these basic 128 THE GROWING CLASSROOM _All_About_Plants.indd 128 7/1/14 10:11 AM

9 SEED YA LATER ALL ABOUT PLANTS resources. Since a parent plant can drop thousands of seeds at a time, many seeds will need to end up at some distance from their parent plant to survive. But seeds can t walk! So how do you suppose they are able to travel away from their parent plant? Seeds travel in a variety of ways. Some soar on the wind. Has anyone every blown a dandelion flower and watched the seeds fly away? (demonstrate). Some float on water (float an example on water). Some have little hooks that allow them to stick to the fur of animals that are passing by. These seeds fall off much later in faraway places. Has anyone ever had a seed stuck to their sock? (show an example). Did you know that Velcro was, in fact, invented in 1941 by a Swiss engineer named George de Mestral, who was inspired by the seeds stuck in his dog s fur after a hunting trip? He looked carefully at the hook-and-loop design of the seeds and fur, and mimicked this natural model to make Velcro! Still other seeds travel by being stored or eaten by a bird or other animal, and then being deposited somewhere else. Has anyone ever seen a squirrel bury a nut somewhere? Or has anyone seen a bird eat a berry and then deposit it (or poop it out) in another location? Did you realize that that bird might have been planting a berry bush? Still other plants disperse their seeds by ejecting them forcefully so that they fall well away from their parent plant. When a sweet pea pod dries in the sun, for example, it opens up in a tight spiral, pushing the seeds away. Note: You can show students a very engaging 3-minute video of seeds dispersing at: or by searching YouTube for David Attenborough Seeds. Today each of you will get an envelope full of seeds. With a partner, you ll look carefully at the seeds and then classify them based on how you think they travel. 1. Get students into teams of two. 2. Have each pair of students fold a large piece of paper in half, and then into thirds, creating six sections. Have them write the following words, one in each section: Soaring, Velcro, Edible, Floating, Explosive, and Unknown. 3. Hand each pair of students an envelope of seeds. Have them look at the seeds carefully and put each one in the box in the section of their paper where they think it belongs. They can throw the seeds in the air to see if they fly; stick them to their socks; try to float them on the water in the bin, and do further investigations. But they should not taste any of the seeds! Remind them that any given seed might travel in more than one way. 4. Ask pairs to share how they think each seed travels, and what evidence they used. Discuss as a whole class. 5. Take a walk around the garden and other outdoor environments and collect seeds. Look carefully at each one to guess how it might travel. What kinds of structures help seeds travel? Which seeds do you think are able to travel the farthest? Why? How do you think habitat impacts seed adaptations? (In areas with a lot of water, more plants make floating seeds; in areas with high winds, more plants have seeds that can soar on the wind). DIGGING DEEPER Have student pairs design their own seeds with various adaptations that would help them travel, and share with the class. THE GROWING CLASSROOM _All_About_Plants.indd 129 7/1/14 10:11 AM

10 WE ARE ALL SCIENTISTS OUTDOORS GRADES 3-6 FALL, SPRING ACTIVITY Six of One, Half Dozen of the Other Groups of students use multiple senses to find and classify contrasting objects in the natural environment. To use the senses to identify and classify objects in the garden laboratory. One egg carton per group of three PREPARATION On the bottom of each egg carton write two words. One should be a likely quality of a garden object, such as wet. The other should be its opposite ( dry ). Use words that will encourage students to use their senses, such as dark/light, rough/ smooth, dull/colorful, scented/ unscented, scratchy/ soft, etc. Label each carton with different opposites. To discourage unsupervised tasting, avoid opposites that refer to taste. CLASS DISCUSSION What senses can we use to explore opposites in the garden? In this activity you will be searching for objects that have a specific quality, and those that have the opposite quality. What are some examples of opposites? 1. Divide the class into groups of three. Tell the class that each group will get a special collecting container in which to collect 12 items. They shouldn t let any other group see the secret information on the bottom of the carton. 66 THE GROWING CLASSROOM

11 SIX OF ONE, HALF DOZEN OF THE OTHER WE ARE ALL SCIENTISTS 2. Distribute the cartons and demonstrate to each group how the opposites should be placed, with six of each category in a long row. On the bottom of the carton are secret words that tell what category of objects to collect. Every group will be collecting different opposites. 3. Remind students to handle everything gently and to take only small specimens. Allow enough time for students to explore the site and gather the items. 4. When groups are finished, have them exchange cartons and try to determine the opposite categories that the other group collected without looking on the bottom of the carton. 5. Discuss strategies that groups used for identifying the other group s classification. What things that you collected felt the scratchiest, looked the most colorful, had the strongest scent, etc.? (Include an answer from each group about the best example in each category.) How did you find objects for each category? THE GROWING CLASSROOM 67

12 THE LIVING EARTH OUTDOORS GRADES 2-5 FALL, SPRING ACTIVITY Space Travelers Students work in small groups as space travelers trying to decipher the composition of soil. To explore the composition of various soils. TEACHER BACKGROUND Soil is something all of us take for granted. However, it is one of the necessary life-sustaining ingredients of our planet. And soil is exciting! It varies dramatically within a small area. When students explore the surface soil (topsoil) they will discover many living things, including roots, earthworms, and insects. In addition, the topsoil contains humus (the highnutrient component of the soil that is formed by decayed organic matter) and rock particles. As students dig deeper, the soil composition changes. Soil formation is a very slow process. Each inch (2.5 cm) of topsoil requires more than 100 years to form, by the processes of weathering and decomposition. Weathering, caused by rain, wind, freezing and thawing, glaciers, and plants, breaks down rocks into tiny particles the inorganic part of the soil. Bacteria, fungi, and other living things slowly decompose nutrients, such as leaves and twigs, recycling them into humus the organic matter in soil. Soil is alive: More than 100 billion microorganisms live in a pound (0.45 kg) of soil. Two trowels per team of three One hand lens per team Tweezers Newspaper Science journals CLASS DISCUSSION Ask students to close their eyes. Read the following in your most alien voice: Imagine that we are scientists from the planet Zog, journeying to planet Earth on the Star Ship Zogma. We have been chosen to make an important journey. The people of Zog are growing tired of raiding other planets for food, and want to find out how to grow our own food. Our astronomers have detected a faraway planet called Earth, which appears to be covered in green plants. Our computers have analyzed the reason for this and it appears to be a combination of sun, water, air, and a brownish-gray substance called soil. On Zog we have plenty of sun, water, and air, but no soil covering the rocky ground. It is difficult for us to believe that all their food comes from this substance. Our mission as scientists is to find this material called soil, dissect it, and record each and every ingredient for our computer. This will allow us to learn the secret of this material so we can make soil back on planet Zog. Upon landing we will break into groups of three scientists, with two soil dissectors and a recorder in each team. Each team will use the specially designed tools that our engineers have created just for this purpose. THE GROWING CLASSROOM 81

13 THE LIVING EARTH SPACE TRAVELERS Remember: It is crucial to the success of our mission that each and every substance found in the soil be recorded. Good luck to all of you. Long Live Planet Zog! 1. Divide students into groups of three and give each team a trowel, some newspaper, and a hand lens. Have them explore soil in different areas of the garden and schoolyard by digging up a trowelful and placing it on the newspaper. Have two students in each group dissect the soil, identifying each substance found. Have the third student in each group record the soil ingredients in his or her journal. 2. Upon completion of the task, ask teams to compare and contrast the soils they investigated. Ask them to report for the class the ingredients of their soil. Have the groups discuss the ingredients they found: crushed rocks, crumpled leaves, twigs, bugs, sand, and so on. Many groups will list among their ingredients dirt or brown stuff. Challenge them to figure out what the brown stuff is. The simplest answer: It s just smaller pieces of all the other ingredients. 3. Assign some of the listed ingredients to each team and ask them to return with a small quantity of each ingredient. 4. Upon their return, challenge teams to use the raw ingredients to manufacture soil by scraping rocks together, breaking twigs apart, and so on. When the frustration level of the students is reached, ask them whether or not soil can be made by hand. Why not? Explain that each inch (2.5 cm) of topsoil requires more than 100 years to form, by the processes of weathering and decomposition. Our hands and tools cannot equal the power of weathering and decomposers! Also, soil is alive, with more than 100 billion microorganisms living in a pound (0.45 kg) of soil, in addition to the roots, insects, worms, and other living things we can see in the soil. There is no recipe that could duplicate this substance so full of life and so necessary for life! Will the super computer on planet Zog be able to manufacture soil? How is soil important to Earthlings lives? Could Earthlings make more soil if we lose what we have to erosion or pollution? Is soil alive? How? Do all materials in soil decompose at the same rate? What do earthworms do for the soil? 82 THE GROWING CLASSROOM