Which Soil Do Plants Like Best? - Part 1, Planting
Grade level(s):Kindergarten, Grade 1, Grade 2, Grade 3, Grade 4, Grade 5
Topic:Plant and soil science
Scientists use discrete steps to conduct an experiment and together they are called the scientific method.
Plants need certain things to grow and some soils support the needs of plants better than others.
gravel, sand, peat, potting soil, observe, stem, leaves, roots, scientific method, question, prediction/hypothesis, experiment, observation, results, trait, data, conclusion
What you need:
planters or paper/plastic cups with holes punched in the bottom, masking tape, foil trays, paper plates, rulers, plastic wrap, 2-4 types of soil (number depends on grade level, would use fewer soils with lower grades, ex. gravel, sand, peat, potting soil), worksheets (see attachments below) or science notebooks, seeds (ex. arabidopsis, Wisconsin Fast Plants, radish, catnip - please see links below for sources of seeds), spray bottle, small paper/plastic cups (no holes)
OPTIONAL: small sealed container with water for suspending very small seeds, plastic dropper for dispensing very small seeds, grow lamp with fluorescent bulb
The lesson will start with a whole class discussion, during which students will also have to confer with a partner before addressing the class. After the initial discussion, students will be working in groups of 4 to plant.
Each part of the lesson will take approximately 45 minutes to 1 hour. The second part when students are collecting data may take longer depending on how complicated data collection and analysis is.
Students will explore how plants grow while using the scientific method to conduct an experiment.
Students should be somewhat familiar with what plants need to grow. If students are measuring their data, they should be familiar with how to use a ruler.
Students will learn about different soils and their properties through observation. Students will set up an experiment to answer a specific question and will hypothesize about the experiment. Students will also learn about what plants need to grow.
Most plants need a few key properties from soil in order to grow well in it. The soil needs to contain nutrients (organic matter such as compost), to retain some water but also drain well, and to provide air to the roots (aeration). Some soils meet these needs better than others.
Scientists use an organized thought process called the scientific method to probe the world around them. It breaks down into 6 steps:
1) Ask a question - what do you want to find out by doing your experiment?
2) Do background research - what can you find out about your question that will help you design your experiment? Frequently, background research will also help refine your question.
3) Make a hypothesis - based on the background research you have done, what do you think the outcome of your experiment will be?
4) Test your hypothesis by doing an experiment - what procedure will you use to answer your question and test your hypothesis? What type of data will you collect?
5) Analyze data and draw a conclusion - does your data support your hypothesis? What does your data tell you about your original question?
6) Report results - share your data and conclusions with your peers. Are your results surprising? Does your data bring up new questions?
If you are using cups, each group of students will need 4 cups with holes punched in the bottom. If you are using very small seeds, such as arabidopsis, they will need to be suspended in water by shaking in a sealed container. For the initial observation, prepare 2 cups of each type of soil in the cups with no holes in the bottom. For the activity, prepare a tray with 4 cups (with holes), a length of masking tape, a marker, and copies of "Setting Up Your Experiment" for each group of 4 students. Also make copies of the "Observing and Predicting" worksheet.
Lesson Implementation / Outline
1) As a whole class, ask students "Who likes watermelon?" "Where do they come from?" (Looking for "seeds.") "What do seeds need to grow into plants?" (Looking for "light, air, water, and soil.")
2) Introduce the four different soils and ask students how they might observe them. Emphasize look, touch, smell, ect. (but not taste!). Pass cups of the soils around for students to observe and discuss with a partner (think-pair-share). As a class, discuss some of their observations. Ask students if they think plants will grow well in each soil. Guide the class toward the question "Which soil will grow plants the best?"
3) Tell the class they are going to do an experiment to answer that question. Ask students if they know what an experiment is and discuss (we asked if they had seen MythBusters, which was a good reference point for them).
4) Tell students that before scientists do an experiment, they make a prediction or a hypothesis based on what they already know and have observed. Ask students to discuss a prediction with their partners, then ask for hands of those that want to share their predictions with the class (think-pair-share). Ask students why they think a particular soil will grow plants the best. For younger students, take a class tally of their predictions instead of having them complete the "Observing and Making a Prediction" worksheet.
5) Explain that the students will work in groups of 4 for this experiment and that each group will need a labeler, a cup filler, a planter, and a waterer. Model how the experiment will be set up using the cups of soil (which should have gone completely around by now). Talk about making the experiment fair by using the same amount of soil, the same number of seeds, and the same amount of water in each cup.
1) Students return to their desks. Before passing out materials, have students fill out the "Observing and Making a Prediction" worksheet - alternatively, they can write down their observations and hypothesis in a science notebook free form, or for younger students, the class tally taken during the introduction can substitute. Have a set of cups with the 4 soils available at the front in case they need to remind themselves of an observation.
2) Remind students that they need to decide on their roles within each group. When all students in a group have made predictions, collect their worksheets and give them a tray, 4 cups with holes in the bottom, masking tape, a marker, and the "Setting Up Your Experiment" worksheet. As you attend different groups, the students that are waiting can use the time to draw their experimental setup. The drawing can also be done free form in a science notebook. For younger students, you can have them paste pre-drawn cups onto their set-up diagrams.
3) Ask the labler to label the cups with the group name/number and the type of soil. Once the labeler is done, bring the soils around to the group and have the cup filler use an extra cup or scope to fill each soil cup to approximately the same level with the appropriate soil. Have the planter indent the soil in the center a little bit, drop 5 seeds in each cup, and lightly cover them with soil. Once the seeds are planted, have the waterer mist each soil with the spray bottle twice and place the cups in the foil tray. Place the foil trays in a sunny window or underneath the grow light. Have students finish their experimental setup drawings.
1) As a whole class discussion, ask students to remind you what question they are testing. What is a prediction/hypothesis? What is an experiment? How do you make sure an experiment is fair?
2) Following the planting lesson, you can have students take turns in their groups watering the plants as they grow. Students can also observe the plants daily or a few times a week to see when the first plant sprouts. It will take at least 3 weeks before the plants are big enough to collect data (see part2!).
Extensions and Reflections
Students can graph different data they have collected. For example students can graph the height of their plants. Students can also graph the length of the leaves and the height of the stem and then present it to the class.
Students can compare and contrast two different kinds of plants. Students can also write a paragraph describing one of their plants, using adjectives to describe how the plant looks like? How does the plant feel?
This lesson can be taught in a wide range of elementary grades. Young students will need more scaffolding of the scientific method and opportunities to discuss or draw if they don't have writing skills yet. Also, the lesson can be simplified for younger students to 2 soils, or even to a single soil, with the question changed from "Which soil do plants like best?" to "What happens to a seed when it is planted?" Students can draw their hypothesis by drawing what they think the seed will look like after a week.
For older students, there can be a rich discuss not just about what plants need in general, but what they need specifically from soil. Older students can write free form about their observations of the soils and can keep a science notebook of observations and diagrams as the plants grow.