- Samples of soils from in and around the garden
- Tools for digging
Soil Investigation
Summary:
In this lesson, students deepen their understanding of the relationship between soil and crop health by conducting a hands-on soil investigation. They start by collecting soil samples from multiple areas in the garden, and then conduct a “jar test” in which they identify and describe the soil types in their garden. This “jar test” takes a day for results to be meaningful. During this time, students learn more about how soil type impacts plant growth. This lesson forms the foundation for considering the environmental conditions that support different types of crop growth for the next lesson, Crop Planning.
Materials & Prep:
- Water for soil test
- Two clear jars (ideally a mason jar) per group
- Gardening gloves (optional)
- Gardening books (optional)
Download Lesson Plan
Vocabulary:
- Soil: the upper layer of earth in which plants grow; a complex living system made up of dead and decomposing organic material (like leaves and animals), rocks, minerals, oxygen, water, decomposers (like microorganisms, insects, and fungi), and the roots of living plants.
- Soil type: a way of classifying soil based on its characteristics (especially its texture).
- Control variable: an element in an experiment that remains unaffected or unchanged by other variables. A control variable gives you a reference to compare your other results to.
Teaching Notes:
- The “READ” sections of this lesson plan can be used as talking points or a script to introduce activities. Please note, these sections simply provide brief introductions to the topics. We recommend using your experiences to add more information and context to the topics being covered.
- If teaching asynchronously or assigning the lesson plan as homework, for the sections that instruct students to READ, consider recording you reading the sections aloud and sending the recording to students. This adaptation offers a helpful strategy for differentiating learning that supports all students, especially English Language Learners.
- The “THINK” and “DISCUSS” sections of the activities provide some great prompts for informal conversations. Consider asking your students these questions as they are gardening. You could also create a “question board” with the different questions and have students informally choose different questions to answer while they garden.
- The “DO” section of this activity involves a “jar test” that measures the comparative densities of different materials in the soil. Samples need at least 12 hours for the investigation to work because different soil particles settle at different rates. Students will collect samples on the first day of the lesson, and record their observations on the second day. You may want to fill a sample jar with soil one day ahead in order to give students an illustration for how the investigation will work.
- Optional—as an added activity you could create a public space where students can share the things they notice during each of the rotations. This could take the form of a board with chart paper or markers where students can write down their answers to the questions labeled, “NOTICE.” This extra activity supports students to glean observations from their classmates and learn from one another.
- For more information on the practices of organic farming, see the Center for Agroecology and Sustainable Food Systems curriculum on Organic Farming and Gardening Skills.
- At some point during this lesson, have students return to the garden bed in which they are conducting the plant start investigation (Lesson 3). They should record their observations about the plants and soil on the Plant Start Investigation.
