Lesson Synopsis: Students will explore soil by conducting tests on texture, capacity to retain water and ability to support life. TEKS:
4.11 The student knows that the natural world includes Earth materials and objects in the sky.
4.11 A Test properties of soils, including texture, capacity to retain water, and ability to support life.
Process TEKS: 4.1 The student conducts field and laboratory investigations, following home and school safety procedures and
environmentally appropriate and ethical practices.
4.1 A Demonstrate safe practices during field and laboratory investigations.
4.2 B Make wise choices in the use and conservation of resources and the disposal or recycling of materials.
4.2 The student uses scientific inquiry methods during field and laboratory investigations.
4.1 A Plan and implement descriptive investigations including asking well-defined questions, formulating testable hypotheses, and selecting and using equipment and technology.
4.2 B Collect information by observing and measuring.
4.2 C Analyze and interpret information to construct reasonable explanations from direct and indirect evidence.
4.2 D Communicate valid conclusions.
4.2 E Construct simple graphs, tables, maps, and charts to organize, examine, and evaluate information.
4.3 The student uses critical thinking and scientific problem solving to make informed decisions.
4.3 B Draw inferences based on information related to promotional materials for products and services.
4.3 C Represent the natural world using models and identify their limitations.
4.3 E Connect Grade 4 Science Concepts with the history of science and contributions of scientists
4.4 The student knows how to use a variety of tools and methods to conduct science inquiry.
4.4 A Collect and analyze information using tools including calculators, safety goggles, microscopes, cameras, sound recorders, computers, hand lenses, rulers, thermometers, meter sticks, timing devices, balances, and compasses.
4.4 B Demonstrate that repeated investigations may increase the reliability of results.
GETTING READY FOR INSTRUCTION
Performance Indicator(s): Students will demonstrate an understanding of soils by completing a lab report that supports their inquiry into soil
tests. (4.11A) ELPS: 1E, 2E, 2I, 3D, 3J, 4E, 5B
KEY Understandings and Guiding Questions: Soils have properties.
— What makes sediments (sand, silt, clay) different from each other? — Which soils retain the most water? — Which soil do plants grow best in? — Is there a relationship between water retention and plant growth?
Materials: sand gravel silt clay potting soil sealable bottles water funnels (optional) cotton balls ring stands (optional) graduated cylinder large bus trays to hold
types of sediments and water (6)
bean seeds two-liter bottles or sealable
clear bottles, vials, or what ever teacher chooses
soil mixture samples from around the school
plastic spoons spray bottles of water large cups for planting
beans mixture of gravel, sand,
silt, and clay to use as a potting mixture for bean plant’s cup #5
centimeter ruler colored toothpicks golf balls marbles ammunition from pellet
guns wax beads clear drinking cup timer
nail beakers red food coloring pitcher crayons label from potting soil bag hand lens, microscope, or
hand-held microscope permanent marker sponge baggies paper plates sieves
Appropriate materials may be substituted as needed to incorporate district resources and availability.
Resources: http://www.farmland.org/news/audiovideo/default.asp is the website where “The Apple as Planet Earth” can be
found. http://gale.cengage.com/free_resources/bhm/bio/carver_g.htm is a resource website for George Washington
Carver.
Advance Preparation: 1. Make copies of the following handouts:
The Apple as Planet Earth Instruction Teacher Only (1 per teacher) Sorting Sediment (1 per group) Sorting Sediment KEY (1 per teacher) Texture Recording Sheet (1 per student or group) Texture Recording Sheet KEY (1 per teacher) Growth Monitoring Instructions Teacher Only (1 per teacher) Water Flow Demo Teacher Only (1 per teacher) Water Flow Test (1 per student) Student Evaluation Lab Write-Up (1 per student or group) Rubric for Student Evaluation Lab Write-Up (1 per student or group)
2. Collect samples of sand, silt, clay, and potting soil. Sediment samples can also be ordered from science suppliers.
3. Prepare baggies of spheres (one baggie per group) for the Explain Water Flow test or have an example of each type of sphere for demonstration handy.
4. Make a mixture of gravel, sand, silt, and clay for the Engage Bean Plant – Support Life Test. Use 1 cup gravel and 2 cups of each of the following: sand, silt, and clay. Then mix them very well. Place the mixture in a tray or baggies for easy distribution.
5. Go to http://www.farmland.org/default.asp to explore the American Farmland Trust website before class. This will help you navigate the website during the Engage portion of the lesson.
6. Place gravel, sand, silt, clay, and potting soil into five separate bus trays or tubs. Label them appropriately. 7. Save the bag from the potting soils for the advertisement exercise. 8. Mix the soil mixture samples of gravel, sand, silt, and clay in baggies for the Explain activity. Soil samples may be
collected from the immediate area outside, but make sure you have a mixture of gravel, sand, silt, and clay in your sample.
9. Find a place outside where the soil samples can be returned to the environment to model conservation.
Background Information: Sediments are sorted by their size and are created by mechanical and chemical weathering. Boulders are very large sediments. In the classroom, we generally deal with gravel, sand, silt, and then clay. Sediments are an important part of soil. The formation of soil is one of the most important processes on Earth. Primary succession is the process where soil is formed gradually over time by weathering and erosion from rock. Over time, rocks are broken down little by little, creating a layer of soil. This layer thickens with time. When the soil starts to thicken, it is able to sustain life. You would be amazed at how little soil is needed for some plants to grow! Some areas of the country are noted for their sandy soil or loamy soil. Agronomists classify soil by the percent of each type of sediment present in a soil sample. Soil is a mixture of sediments, humus, air, and water. Soil makes up about one-fourth of the Earth. Humus is a unique property of soil. It contains valuable nutrients needed for plants to grow. Some areas of the country have very fertile soil – like swampy areas, which have lots of humus. Deserts have very little humus. Spaces between sediments are filled with either air or water. Air contains oxygen, which is needed for organisms to grow. Water is also an important factor in plant growth.
GETTING READY FOR INSTRUCTION SUPPLEMENTAL PLANNING DOCUMENT Instructors are encouraged to supplement, and substitute resources, materials, and activities to differentiate instruction to address the needs of learners. The Exemplar Lessons are one approach to teaching and reaching the Performance Indicators and Specificity in the Instructional Focus Document for this unit. A Microsoft Word template for this planning document is located at www.cscope.us/sup_plan_temp.doc. If a supplement is created electronically, users are encouraged to upload the document to their Lesson Plans as a Lesson Plan Resource in your district Curriculum Developer site for future reference.
INSTRUCTIONAL PROCEDURES
Instructional Procedures Notes for Teacher
ENGAGE Suggested time: Day 1
1. Ask: What is soil? (Soil is needed for plants to grow. Soil is formed from
the weathering of rock. Soil takes time to form.) How much of the Earth is covered in usable soil? (Answers will
vary.) After the web-based video clip, Ask: Why is farming important? (Farms are where most of our food is
produced. Production of food helps sustain our population and keeps us from being dependent on other countries – as we are for our oil, which comes from fossil fuels.)
What type of food is grown around here? (Answers will vary. Every region in Texas has some production of food, even if only in family gardens.)
What is topsoil? (Students learned in the last lesson that topsoil is the upper portion of the soil where plants grow.)
If one-fourth of the Earth is land, why can’t we grow plants on all of that land? (Most of the land is unsuitable for farming; also the land
Use the American Farmland Trust website to show a video called “The Apple as Planet Earth”: http://www.farmland.org/news/audiovideo/default.asp Handout: The Apple as Planet Earth Instructions Teacher Only
Instructional Procedures Notes for Teacher that is left is becoming crowded with people and suffering the consequences of overcrowding. Pollution is also a factor.)
2. Notebook: Write about the importance of farming and how humans are
affecting the job that farmers have to do. 3. Say: Let’s set up some crops just like farmers do and then watch
them grow. 4. Support Life Test: This test should be begun on Day 1 because the beans
need as much time to grow as possible. Monitor the plants daily. During the Explain portion of this lesson, the Support Life Test will be revisited to determine which sediment or mixture of sediments works best to support life (beans).
5. Crop Planting Instructions:
Have students place a type of soil in each of their pots (cups). Fill the cups 3/4 full of the chosen sediment.
Each group should have five cups. One for each of their sediments: Gravel, Sand, Silt, Clay, and a Mixture of all four.
Before putting the sediment into the cups, be sure each group labels their pots with the type of soil used.
Plant 6 bean seeds to a pot.
6. Tell the students to hypothesize which soil will support plants best. Have them write down their hypotheses in their notebooks.
7. Water each pot with the same amount of water, as
determined by the teacher.
Science Notebook: Write about the importance of farming and how humans are affecting the job that farmers have to do.
MATERIALS: large drinking cups types of sediment (for the soil, one
cup 3/4 full of gravel, one cup 3/4 full of sand, one cup 3/4 full of silt, one cup 3/4 full of clay, and one cup 3/4 full of a mixture of all four, based on the recipe in Advanced Preparation section)
beans water ruler Bean Note: Bean seeds need to be planted just below the surface. Don’t plant the seeds too deep. Plant all seeds at the same level. You may not be able to get all six beans into your pots (cups) based on the size of the container. Adjust the number as needed. Just make sure that you plant more than one seed in each pot. Water Note: Because the cups can be of varying sizes, it is impossible to dictate how much water to add. Add enough water to make the soil moist but not overly wet. Over watering can cause your seeds to mold.
Science Notebook: Monitor growth daily in your notebooks
EXPLORE Suggested time: Day 21. Monitor bean seed growth using handout: Growth Monitoring
Instructional Procedures Notes for Teacher 2. Explain that soils are made of combinations of sediments, living matter,
decaying matter, air, and water. Besides the living things (roots, Earthworms, bugs, bacteria) that can be found in soil, soil has three main sediments – sand, silt, and clay. Soil also has larger particles called gravel. In-between the sediments, decaying life forms, and living things in the soil, are spaces full of air and water. Ask: Does anyone know the difference between sediments of sand,
silt, and clay? (Accept all answers.) How can we tell the difference between these sediments? (By
looking at sediments and performing tests.)
3. Tell the students that today they are going to explore properties of gravel, sand, silt, clay, and potting soil. Ask: What are properties? (Properties are characteristics that describe
matter.) What do you already know about gravel, sand, silt, or clay?
(Answers will vary, but students may have experience with beaches, pottery, etc.)
Have you ever helped someone plant flowers in pots or containers? (Answers will vary.)
4. Say: Many times we use potting soil from the store as the soil for
plants. Let’s look at the label for potting soil. Ask: What does the label say makes up or composes potting soil?
(Answers will vary based on your local potting soil.) Why do you think people spend money to use potting soil when
the backyard is full of dirt? (Potting soil is a special mixture that has nutrients in it that help plants grow healthy and strong.)
What kind of nutrients are added to potting soil? (Answers will vary.)
Where does the “organic” (living or once-living) material come from in potting soil and soil? (Animals are alive and are in the soil. Animals also die, and when they die they become a part of the soil. Potting soil also can have lots of manure in it. Manure is full of nutrients that help plants grow (nitrogen, for example). The organic material in soil is called humus.)
How do manufacturers place air in their soils? (Some nurseries will use a shovel to move the soil around in the potting soil. This allows air to flow. Before putting in a garden, you till the soil. To till means to dig down and turn over. This helps break up the soil and bring air into the soil mixture.)
5. Tell the students that they are going to investigate different sediments.
MATERIALS: label from potting soil bag paper plates sand, silt, and clay samples from
trays of sand, silt, and clay microscopes, hand lens, or hand-
held microscopes plastic spoons spray bottle of water Set up sediment trays: Place gravel, sand, silt, clay, and potting soil in five trays or containers. Make sure you label each container clearly. Keep the potting soil bag for a look at the advertisement label. Handout: Sorting Sediments GRAVEL CANNOT BE PLACED ON A SLIDE BECAUSE IT IS TOO LARGE. USE A HAND LENS. They can be observed under a stereoscope.
Instructional Procedures Notes for Teacher 6. Give the following oral instructions:
Divide a paper plate into five sections. Label each section with the following labels: Gravel, Sand, Silt, Clay, and Potting Soil.
Pick up samples of gravel, sand, silt, and clay on a paper plate. Observe the sample of sediment with a hand lens, microscope, or
hand-held microscope. NOTE: Gravel may be too large to be viewed under a microscope. Use a hand lens.
7. Have students record their observations on the handout: Sorting
Sediments. 8. After students have observed the sediments under a microscope or hand
lens, ask: What do we know about soil? (Answers will vary. Soil is made of
sediments. Sediments can be very different.) What is soil made of? (Soil is made of sediments and organic – living
or once-living – matter called humus.) After looking at the soil samples, do the samples look like each
other? (No, the sediments looked different.) What makes each of these soils different from the other?
(Answers will vary. Sediments differ in size and texture.)
9. Say: Now that we understand some basic differences between sediments, let’s see how they react to water. Record your results on the handout: Texture Recording Sheet.
10. Water Test:
Take a tablespoon of sand and put it in your palm. Mist it with a spray bottle four times. Now squeeze it into a ball. What happens? Write on your recording sheet whether or not sand will
stay in a ball. Do this with the other four samples. 11. Rolling Test:
We are going to perform one more test on the silt and clay samples since they are the two that kept their ball shape.
Take the silt sample. Try rolling it between your palms into a long strand. Add some water if your sample is too dry or more silt if it is too wet. Do the same with the clay sample. Which one were you able to roll into a strand? Which one fell apart?
Record your observations on your recording sheet.
Microscope Note: If you decide to look at the sediments under a microscope, paper slides are easy and cheap to make. Just take a piece of heavy paper (cardstock or manila folder) and cut it into slide-size rectangles. Punch a hole in the center of the slide with a single-hole punch. Take clear tape and place it over the hole. On the side of the slide with the exposed sticky tape surface, place a few grains of sediment. These slides are easy to make and stand up to children! Sand and gravel will not stay in a uniform ball very well. Handout: Texture Recording Sheet
MATERIALS: 2-liter bottles with lids soil samples (can be brought in
baggies; samples should include a mixture of gravel, sand, silt, and clay)
funnel
This activity can be changed to use any type of sealable container you want.
Instructional Procedures Notes for Teacher 12. Ask:
What is in our soil?
13. Have students collect soil from around the school. Have students collect different types of soil – from under trees, by sidewalks, near the flagpole, from the playground. Place the collected soil in baggies and label where they came from with a permanent marker.
14. Have the students fill a 2-liter bottle 2/3 full with water. (Container is
teacher’s choice.) 15. Tell them to use the funnel to add the sand until the water level is about 3–
4 inches from the top. 16. Tell them to shake the bottle vigorously for 1 minute. 17. Have the students set their bottles in a place where it will be undisturbed
until the next day. 18. Tell the students to take out their notebooks and write down some of the
observations they noticed about the samples. Also tell them to note any questions that they have that will guide us in our examination of these soil samples.
Vials would work well. As long as the container is clear and tall, it will work well.
EXPLAIN Suggested time: Days 3 & 41. Have the students look at their soil bottles from yesterday. Tell them to
observe the layers in the bottle. Ask: Do the bottles all look the same? (Answers will vary.) What different types of sediment do you see? (Accept all answers
that indicate the number of layers – hopefully four.) What is your soil mainly made of? (Answers will vary.)
2. Say: Today we are going to conduct several tests on our soil
samples: gravel, sand, silt, and clay. 3. Explain that scientists use sieves to sort sediments in soils. Sieves are
containers that have screens of different sizes. Ask:
How do you think a sieve would work? (Sieves work because the screens only allow sediments of a certain size to pass through each layer.)
How does water work like a sieve? (In water, sediments layer just like through the sieve. The mass of each sediment affects its rate of settling. Heavier [usually, larger] sediments fall and settle faster.)
Are the soils around the school all the same? (Answers will vary.) How do you think soil from different areas of the country would
appear? The same or different and why? (Soil from other areas will look different. Every area has its own unique soil composition – just like fingerprints. Soils are one of the types of evidence taken at crime scenes. Soils tell us where a person has been.
4. Monitor bean seed growth using handout: Growth Monitoring
Instructions Teacher Only.
MATERIALS: Handout: Growth Monitoring
Instructions Teacher Only sieves Gravel will definitely sink straight to the bottom. After that, sand particles will settle. Silt will settle after sand but before clay.
Showing a sieve will increase the student’s understanding of how it works. A middle school or high school in your district may have a sieve you can borrow.
Instructional Procedures Notes for Teacher 5. Say:
So now we have learned several things about sediments in soil – they have different sizes and textures. Ask: Why is it important that several of us test the samples? Repeated
tests help support our findings. We also can see from our growing bean plants that different sediments affect plant growth. What do we add to the soil/bean system that helps it grow?
(water) Does the amount of water make a difference? (Yes, we had to add
the same amount of water to each cup for our test to be fair.) Did the water behave the same way in each cup? (No, the water did
not behave the same.) Why do you think water behaved differently? (Answers will vary.) Do you think the size of the sediment affects how water flows?
(Answers will very.)
6. Lead the students to a discussion that involves the spaces between each sediment particle.
7. Introduce this activity by showing a saturated sponge.
Ask: What is this object? (a sponge) What do you know about a sponge? (Answers will vary, but lead
student to say sponges have holes.) What do the spaces in the sponge hold? (Answers will vary, but
lead the students to say air. Some students may recognize that the sponge is wet.)
That is correct; the spaces in the sponge can hold water, but what else can they hold? Squeeze sponge and allow water to exit the spaces. (water)
How is a sponge like a model of a layer of sediment – sand, silt, or clay? (Layers of sediment also have spaces that can be filled with air and water.)
Why is air and water important in the soil? (Air and water help to sustain the life that lives in the soil)
While a sponge can model a layer of sediment, what are the limitations of this model? (A layer of sediment is actually separate particles, while the sponge is interconnected.)
8. Show the students a demonstration with golf balls, marbles, yellow beads,
and wax beads. Put out an example of each sphere on the demonstration table or give each group a baggie with each type of sphere contained inside. Ask: How are these pieces of matter alike? (They are all spheres or
round in shape, they are all solids.) How are these pieces of matter different? (They are different colors.
They are different sizes. They have different textures.) How are these solid spheres like sediments? (Sediments have
different sizes and textures but are roughly round in shape.) Who can order these solid spheres from largest to smallest? (Call
on a volunteer. Golf balls, marbles, yellow beads, wax beads.) Remembering our experiences with the Sorting Sediment Activity,
which one of these solid spheres would be the best model to
MATERIALS: sponge water
MATERIALS: golf balls marbles yellow beads wax paraffin beads clear cups nail tub (use a bus tray) to collect water red food coloring water pitcher to hold colored water timer beakers or other large collection
containers graduated cylinder crayons The purpose of this activity is to give students support in how to set up a fair test using the scientific method and write a lab report. Because the evaluation of this lesson is to have the student write a report on the soil test independently of direct teacher support, this example of how to write a report is
9. If students find this difficult, go back to the handout: Sorting Sediments,
where the students ordered their sediments from largest to smallest. Ask: How do you think water will flow through the golf balls? The
marbles? The yellow beads? The wax beads? (Accept all answers.) How can I test to see how water flows through the different solid
sphere? (Accept all answers.)
10. As students respond with suggestions, write them on the board or on an overhead projector. Lead students to the Water Flow demonstration on Handout: Water Flow Demo Teacher Only or a demonstration of your choice.
very important.
ELABORATE Suggested time: Days 5 and 61. Say: Yesterday, we spent time learning how to write a lab report just
like a scientist. Today I want to introduce you to a scientist who worked with agriculture (farming).
2. Give the students the following information:
George Washing Carver was a black scientist who devoted his life to scientific research connected with farmers in the southern regions of the United States.
He worked to find ways to turn the farming of peanuts, sweet potatoes,
and soybeans into productive moneymaking crops. This allowed the South to move away from the farming of cotton, which was a crop largely grown with the help of slaves.
George Washington Carver was born a slave in 1864. His life had
many exciting events. George and his mother were actually abducted from his master’s plantation when he was just an infant. While his mother never returned, George’s plantation owner ransomed him and got him back. His ransom? A racehorse.
While working as a farmhand, George worked and completed a high
school diploma. He was then admitted as the first black student into Simpson College – now Iowa State University in Indianola, Iowa. He worked as the school’s janitor as he attended college. He obtained a degree in agricultural science in 1894. He continued his education at Simpson College until he earned a master’s degree. After getting his master’s degree, George became the first black faculty member of Simpson College. From janitor to college faculty! Now that was an accomplishment. George became famous for being born a slave and breaking down all barriers and ending up a faculty member of an important college.
While word of his work spread, he was eventually asked to return to
the South. George was asked to join the faculty at Tuskegee Institute in Alabama. His life had come full circle. He was returning to the South, but he was returning in a far different way than he had left.
George Washing Carver created 300 products from peanuts. Peanuts
There are many websites devoted to the work of George Washington Carver. One of the websites has been sited in the Resources section of this lesson. Reading a nonfiction book about George Washington Carver would be a valuable supplemental activity.
Instructional Procedures Notes for Teacher are still grown in the South today. Peanuts are grown and sold in United States and all over the world. The South is no longer dependent solely on cotton to be “king.”
George Washing Carver devoted much of his life to doing scientific
research. Yesterday, we set up a scientific test involving water flow and spheres.
Ask: What did the sphere represent? (the different-sized particles we
have been studying about in this lesson – gravel, sand, silt, and clay) 3. Tell the students that yesterday’s lesson was designed to help them
understand the importance of using your group to come up with ideas for what to test, and how important it is to implement that test correctly.
4. Tell students that today they will work with their groups to design an
experiment to determine which type of soil (gravel, sand, silt, clay, potting soil, or a mixture of your choice) holds water best.
5. Tell students to discuss as a group and then decide the purpose of their
experiment. Say: I have already given you the general idea. Your group needs to write down the purpose in your own words. When you have decided on your purpose, call me over and I will listen to your proposal and decide whether your purpose or testing question is approved.
6. Once every group’s purpose has been approved allow the students to
continue to set up their tests. Approval from the teacher has to be obtained before any experiments are actually set up or begun.
7. Students may bring items from home for the test. Items brought into the
classroom must meet with the teacher’s approval. Most of the materials needed for the test need to come from inside the classroom or school (with permission). Encourage students to conduct their test more than once to validate their data and conclusions.
8. After the tests are complete, have students dispose of their soil mixture in
an area around school where erosion has been at work. This will help conserve the school environment.
9. Have students record the steps of their experiment in a lab write-up in their
notebooks or on the handout: Student Evaluation Lab Write Up.
Students have been learning about the scientific method since 2nd grade. Grouping your students for success is very important. English Language Learners need to be placed in groups that will give them support in this process. Encourage the groups to stay focused on the object of soil tests and water retention. Teacher must approve the experimental design before actual set up or testing can begin. Handout: Student Evaluation Lab Write up Handout: Rubric for Student Evaluation for Lab Write Up Give students a copy of the rubric before they begin their evaluation project!
EVALUATE Suggested time: Days 7 and 81. After students have finished writing up their experiments, they must
present their results to the class. After all presentations are made, students must individually answer a set of questions regarding their tests on soil on the handout: Evaluation Lab Write-Up Reflections.
MATERIALS:
Handout: Evaluation Lab Write-Up Reflections
Presentations should include everyone to the level of their abilities. An English Language Learner Level 1 may only be able to contribute by drawing graphics. While an advanced English Language
Instructional Procedures Notes for Teacher Learner should be able to share in the oral presentation. A special needs child may present a visual they created that reflects what they learned about soils in addition to the presentation about the lab write up. Using the handout: Evaluation Lab Write-Up Reflections, allow students to bring all the information they have learned about soils together in creating a potting soil of their own.
Sorting Sediments KEY Materials: Sediment samples Paper plates Pencil or markers Hand lens, microscope or hand-held microscope Optional: manila folders, tape, and one-hole punch Spray bottles Water
Divide a paper plate into five sections. Label each section with the following labels: Gravel, Sand, Silt, Clay, and Potting Soil.
Pick up samples of gravel, sand, silt, and clay on a paper plate. Observe the sample of sediments with a hand lens, microscope, or hand-held microscope.
In the space provided, draw your observations of the sediment samples. Gravel Sand Silt Observations will vary.
Clay Potting Soil
1. Do the samples look the same or different? While all have some general characteristics that are
the same, they vary in size and appearance. 2. List the sediments (gravel, clay silt, and, sand only) from largest to smallest: Gravel, Sand, Silt,
Clay 3. How does the potting soil compare to the pure gravel, sand, silt, and clay samples? Potting soil
is a mixture (many difference sizes and textures) and is (usually) darker due to the humus or organic matter it contains.
Sorting Sediments Materials: Sediment samples Paper plates Pencil or markers Hand lens, microscope, or hand-held microscope Optional: manila folders, tape, and one-hole punch Spray bottles Water
Divide a paper plate into five sections. Label each section with the following labels: Gravel, Sand, Silt, Clay, and Potting Soil.
Pick up samples of gravel, sand, silt, and clay on a paper plate. Observe the sample of sediments with a hand lens, microscope, or hand-held microscope.
In the space provided, draw your observations of the sediment samples. Gravel Sand Silt
Clay Potting Soil
4. Do the samples look the same or different? ____________________________________ 5. List the sediments (gravel, sand, silt, and clay only) from largest to smallest:
_______________________________________________________________________ 6. How does the potting soil compare to the pure gravel, sand, silt, and clay samples?
Growth Monitoring Instructions Teacher Only Remember the bean seeds we planted on the first day of our soil unit? Let’s look at the hypotheses you wrote as to why you thought we were planting these seeds.
Allow students time to share their hypotheses. We have discovered much about the different types of soil. By watching our plants germinate and grow, we are going to discover which soil is best for growing our bean plants.
Let’s add our charts to our notebook. Notice on one of the charts it asks you to write down the number of seeds germinated in each type of soil.
Germination happens when a seed first starts to sprout or show itself through the soil. Let’s write down the number of seeds we see germinating in each type of soil. We will stick a toothpick by the ones that have germinated so we won’t count them again. Once we count one, we will start to measure its growth.
Day 1 for Monitoring Growth: Allow students time to see and record seed germination on their charts. Record the date for the first seed to germinate as “Day 1.” Everyday, check the germination and growth of the plants. Use the centimeter rulers to measure growth. You may want to choose the healthiest plant out of each pot to monitor its growth. Keep a red toothpick by it to distinguish it from the others. After the seed germination project is finished: Ask:
What can you conclude about our bean growing investigation? Let’s write a conclusion statement about what we have observed.
Which soil did the beans grow best in? Why do you think they grew better in one type of soil than in the others?
Materials: Clear drinking cups (at least four, the bigger the better) Golf balls Marbles Yellow beads Wax beads (paraffin beads found in the craft or cooking sections of department stores or craft retail centers) Water Red food coloring Nail Timer Container for colored water (large pitcher) Graduated cylinder Container larger than clear drinking cup – like a beaker (Avoid glass beakers for safety issues with breaking. If
you choose to use glass, take appropriate safety action – WEAR GOGGLES.) Container like a bus pan or tub (to catch water that is still flowing out of clear cups at the end of the test) Crayons Ring Stands (optional)
NOTE: The spheres used in this lab (golf balls, marbles, yellow beads, and wax beads) can be changed to suit what you have on hand; the only thing you need to consider is that you must have four different sizes. If you had different textures, that would be an added bonus. The spheres originally chosen do not differ greatly in texture. Only the golf ball and wax beads differ due to dimpling and the nature of wax. Having more textures present would make this model even stronger.
ADVANCE PREPARATION:
1. With the nail, poke holes in the bottoms of four clear cups. The number of holes in the base of the each cup needs to be the same.
2. Fill each cup to the same level with the different spheres. 3. Collect water in the container of your choice (pitcher) and color it red with food coloring. 4. Pour 50 milliliters of red water into four different cups or be prepared to re-measure 50 milliliters of red liquid with
each trial. 5. Place the cups with spheres into a larger clear container (beaker).
Once initial preparation is complete, all you have left to do is make a prediction and then complete the test. Challenges: How are you going to hold the drinking cup above the beaker? If you have ring stands, you can set up the experiment easily. Place the cup in the ring stand positioned over the beaker. If you do not have ring stands, use students! One student can hold the cup over the beaker and another student can pour the colored water. Allow another student to use the timer to time the water flow test. Things to keep constant:
Size of the clear cups Amount of “sediment” –(must be to a “fill” line that is at the same position on each cup) Amount of red water (50 milliliters) Time for water to flow (15 seconds) Size and number of holes in sphere cups
Now that you have the test set up, have decided on a ring stand strategy, and know what you have to keep constant, you are ready to organize the test in written form. To lead the students to understand exactly what we are measuring, ask:
Which type of sphere will allow water to pass through the fastest and why? (Answers will vary.) How much water do you think will flow through the golf balls into the beaker in 15 seconds? (Answers will
vary, but students need to write their predictions in their notebooks.) To help lead the students to being able to set up their own tests, model writing the experiment elements (purpose, hypothesis, materials, procedure, results, and conclusions) on the board or an overhead projector and then have the students record their own information in their notebooks or journals. Handout: Water Flow Test can be used to help students record this information.
What are we testing? What experiment are we conducting? (What type of sphere allows the most water to flow in 15 seconds?) Scientists call this the purpose or question. Write the purpose on the board and have the students write the purpose in their notebooks.
What is your prediction? (Answers will vary.) Scientists call this the hypothesis. Scientists base their hypotheses on research and past experiences. A hypothesis is often referred to as an educated guess. Record your hypothesis in your notebook.
How are you going to set up your test? What materials are you going to need? (Answers should reflect a list similar to the list above.) Scientists call this the list of materials. Make a list of the materials in your notebooks.
What steps are you going to follow to conduct your test? Let’s make a list of steps and record them in our notebook. Would it make sense to number our list? (Yes, because these are steps that we want students to perform in a specific order.)
1. Have a student volunteer hold the clear cup filled with golf balls over the catch beaker. 2. Have another student work the timer. This test will last 15 seconds. 3. Another student needs to be in charge of pouring the red water at the timer’s signal. 4. Upon the timer’s start signal, have the student in charge of the red water pour all of the water into the clear golf ball
cup. BE CAREFUL NOT TO SPLASH THE WATER. 5. When time reaches 15 seconds, have the timer call time and stop the test by removing the catch beaker from
under the golf ball cup or vice versa. Have a pan nearby to catch excess drainage after the 15 seconds is up. 6. Measure the amount of water that flowed into the catch beaker. 7. Repeat test to confirm results. 8. Repeat steps 1–7 with each type of sphere. What information will you need to collect and how will you organize it? (Amount of water in catch beaker.
Organize information in a table, graph results.) This is called the results. Results can be represented in many ways. Let’s use a chart. After charting our data, scientists like to graph results. I think graphing will be a great way to represent our results.
At the end of the data collecting, what do you need to do? (Answer the beginning question with the evidence you learned from the experiment.) Scientists call this portion of the experiment the conclusion. After all our data is collected, analyzed, and graphed, we will form a conclusion and write down whether our original prediction answered the original purpose or question.
Once you have gone over the elements in the experimental design, conduct the test, gather the data, organize the data, graph the data, and draw conclusions with the students. **Because every test is different, there is no KEY to this lab. Expected results are that water flow in 15 seconds will be greatest in the sphere or spheres that have the most space between particles – golf balls.
Rubric Student Evaluation for Lab Write-Up Description 5 pts. 3 pts. 1 pt. Purpose Purpose was clearly stated
and approved. Purpose tested water retention in soils.
Purpose was stated and approved. Purpose tested water retention in soils.
Purpose was completed but required help from an outside source to test the correct property of soils.
Hypothesis Hypothesis was stated clearly with reflections on why the students believed the prediction to be accurate.
Hypothesis was stated. Weak hypothesis was stated.
Materials – Your teacher has many materials, but you need to approach her about what you need and play an active role in getting it for you group!
Materials list was complete. Materials were collected by students and returned to their original places, clean and in original condition.
Material list was complete but teacher had to collect materials. Students did not make a 100% effort to gather materials from the classroom or home by themselves. Materials were returned clean and in their original condition.
Materials had to be supported by the teacher. Students did not make their best effort to compile the needed materials. Materials may have been returned not in their original, clean condition.
Procedure Procedure is written in numbered order or the steps are easy to follow. Directions are clear. Test is repeated to improve the results.
Procedure is written and clear.
Procedure is present but required support to become actually testable.
Results Results were represented in tables and graphs. Graphs were appropriate for the results and in color. Results were easy to read.
Results were represented. Either tables or graphs were used to represent the results but not both. Representation of the results was incomplete.
Results were incomplete and did not show all the information learned from the experiment.
Conclusions Conclusion represented the results of the experiment. Conclusion included a statement that reflected whether the original hypothesis was correct or incorrect.
Conclusions represent the results.
Conclusions poorly represented the results of the experiment.
Oral Report Each member of the group represented correct information from their lab to the best of their abilities. Students showed a visual representation of their work.
Not every group member contributed, or each group member represented information but the representation was not equal to the abilities of the students. The presentation looked like one or two students did the whole presentation. A visual may have been used.
Not every member of the group contributed to the presentation. No visual was used.
2. What type of soil allowed bean seeds to grow the best?
3. Why do people pay extra money for potting soil when their backyards are full of dirt?
4. Compare the texture of the sediments found in soil.
5. How does the ability to retain water and texture relate to a soil’s ability to support life?
6. Based on all you have learned, create a recipe for your own potting soil. It must contain the amounts of sand, silt, and clay you feel are most appropriate for healthy growing plants. Make sure you don’t forget about air, matter from living and once-living organisms, and water. After you have recorded your recipe for potting soil, create an advertisement that represents your product.
