Which Soil Do Plants Like Best? - Part 2, Collecting Data
Grade level(s):Elementary School (K-5), 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, 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, 4 types of soil (ex. gravel, sand, peat, potting soil), worksheets (see below) or science notebooks, seeds (ex. arabidopsis, parsley, catnip), 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
This part of the lesson will start with a brief whole class discussion. Students will then break into their groups to collect data and form group conclusions. The class will come back together to report data for the entire class and analyze the class data to form a class conclusion.
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.
In the second part of this lesson, students wil learn how to collect data about their plants by either ranking or measuring them. Students will use their data to form conclusions about the experiment. Students will also share their results and conclusions and will compare their group data to the class data. Finally, students will have a better understanding of the soil properties that support plant growth.
Modify the "Measuring Plants" datasheet to include the traits you want students to measure. Prepare a board or overhead data table to report class data.
Lesson Implementation / Outline
1) As a class, discuss the experiment students set up 3 weeks ago and the question it was designed to answer. Have students refer back to their "Observing and Making a Prediction" worksheet to remind themselves what their prediction was. Again have volunteers share their predictions.
2) Tell students that today, they will be collecting data from their experiment. Discuss what data is and what results are in general, then discuss the specific traits that students will be measuring. Model measuring each trait for younger students. Possible options for data to collect are day of first sprout (will have to be observed and collected throughout the intervening weeks), number of plants in a cup, number of total leaves, number of total side roots, stem height (longest, total, or average), root length (longest, total, or average), and leaf length (longest, total, or average). Younger students can compare among the soils by ranking plants by height or intensity of green color.
1) Distribute plants to groups as well as the "Measuring Plants" worksheet (modified if necessary for your students) and rulers and paper plates (for measuring roots) if necessary. If students are measuring roots, remind them to gently pull plants up so that they don't damage the root structure.
2) Once students have collected their data, ask each group to discuss amongst themselves their conclusions and record them.
1) Bring the class together to report results. Either on the board or on an overhead, use a data table to collect results from each group.
2) Discuss the data as a class and come to some conclusions about the data. What properties does "winning" soil have that are good for plant growth?
3) If your students measured multiple traits, do they all agree on which soil plants grow in best? Why or why not?
4) Does the data from all individual groups support the same conclusion(s)? Why or why not? Explain that by having each group do the same experiment, the class has more reliable data. Why is it important to do more than 1 trial of an experiment? After this discussion, have students think about new questions they could ask about plants and record them on their data sheets.
Extensions and Reflections
This part of the lesson is perfect for a math extension, such as making a group or whole class bar graph to represent the collected data. This lesson can also be extended by choosing one of the more testable new questions to have the class design their own experiment to test.
During our first implementation of these lessons, the plants did not grow really well - however, students were still able to collect data and make meaningful conclusions. Flexibility with the timing of the 2nd lesson and with the traits you ask your students to measure are important in case of poor plant growth.