Soil Biosolarization: Sustainable Weed Killer

Contributor
RESOURCE GK-12 Program, College of Engineering, University of California Davis eGFI Jesús D. Fernández Bayo
Type Category
Instructional Materials
Types
Activity , Experiment/Lab Activity , Instructor Guide/Manual
Note
This resource, vetted by NSTA curators, is provided to teachers along with suggested modifications to make it more in line with the vision of the NGSS. While not considered to be “fully aligned,” the resources and expert recommendations provide teachers with concrete examples and expert guidance using the EQuIP rubric to adapted existing resources. Read more here.

Reviews

Description

Students will be acting as agricultural engineers as they conduct a scientific experiment to test the effectiveness of a sustainable pest-control technique called soil biosolarization that uses organic waste (oatmeal, flour or cornstarch) rather than toxic compounds (pesticides) to help eliminate weeds. Students will examine their experimental results to see how well the soil biosolarization worked.  It is suggested that this activity follow an introductory lesson on soil solarization.  A Daily Dose of Sun Keeps the Pests Away: How Soil Solarization Works

Intended Audience

Educator
Educational Level
  • Grade 6
  • Grade 5
Language
English
Access Restrictions

Free access - The right to view and/or download material without financial, registration, or excessive advertising barriers.

Performance Expectations

3-5-ETS1-2 Generate and compare multiple possible solutions to a problem based on how well each is likely to meet the criteria and constraints of the problem.

Clarification Statement: none

Assessment Boundary: none

This resource appears to be designed to build towards this performance expectation, though the resource developer has not explicitly stated so.

Comments about Including the Performance Expectation
To best align to this performance expectation it is suggested for teachers to clearly state the criteria and constraints of the problem before the students begin the activity. As suggested in the Activity Scaling section each group could add a different amount of organic waste to the soil in the treatment pots which would provide multiple solutions that could be compared. It is also suggested to encourage students to generate ideas for further investigations (variables could include type of soil amendment, duration of solarization, etc., as well as ratio of organic matter). This will provide students more opportunities to design/conduct experiments to make sense of the phenomena. At the completion of the activity, after the students have analyzed their data and decided which experiment eliminated the most weeds, they can brainstorm another possible solution to the problem of eliminating weeds.

5-LS2-1 Develop a model to describe the movement of matter among plants, animals, decomposers, and the environment.

Clarification Statement: Emphasis is on the idea that matter that is not food (air, water, decomposed materials in soil) is changed by plants into matter that is food. Examples of systems could include organisms, ecosystems, and the Earth.

Assessment Boundary: Assessment does not include molecular explanations.

This resource appears to be designed to build towards this performance expectation, though the resource developer has not explicitly stated so.

Comments about Including the Performance Expectation
Students will be testing the effect of adding organic waste into 3 of the plant pots. Was there an odor from the pot? Which pots had an odor? What happened to the oatmeal? How did the temperature compare from the pots with the organic material to the control pots? Did the sun get through the plastic wrap? How do you know? What effect did the sun have on the soil? Odors can be minimized if the windows are open for good ventilation. It is suggested to introduce 'wafting' to the students if they have not had prior experience with this practice. The teacher should model how to safely smell the pots before the students engage in this activity. Another suggestion to align to this performance expectation is to have the teacher talk about how matter is moving in this system and what their model would look like on a farm or in a garden. Creation of waste products from microbes is evidence that matter is moving as the students can smell microbes 'eating' up the organic matter. Another example of the movement of matter is the heat created if the soil in the experimental set-up is warmer. Other evidence of matter moving that results in the plants growing is the intake of carbon dioxide from the air and the absorption of water from the soil.

Science and Engineering Practices

This resource appears to be designed to build towards this science and engineering practice, though the resource developer has not explicitly stated so.

Comments about Including the Science and Engineering Practice
Groups will have 3 plant pots filled with only soil that will be the control treatment and 3 experimental treatment pots that are filled with soil and the organic waste. All 6 plant pots will be covered with a clear plastic as they are set in the sun. They will be collecting data from each of the six pots throughout the activity. Students will be recording observations and measuring the temperature of the soil. To best align to this practice, it is suggested that when students have analyzed their data and decided which experiment eliminated the most weeds, they are encouraged to perform another trial to see if they have similar results. It is suggested that the students explicitly as asked to discuss the importance of a control in this experiment. It is also suggested that this activity be performed under lights if the trial period happens to be cloudy.

Disciplinary Core Ideas

This resource appears to be designed to build towards this disciplinary core idea, though the resource developer has not explicitly stated so.

Comments about Including the Disciplinary Core Idea
It is suggested that students have some exposure to solarization prior to this activity on biosolarization. This could be as simple as a reading or discussion of images of it in farm fields. Administering the Pre-Activity quiz will engage the students as well as inform the teacher of the student's prior knowledge on organic waste, pesticides, the use of compost and any experience with the effects of covering soil with transparent plastic. It is suggested that students are asked to write down evidence that a gas was created by microbes.

This resource is explicitly designed to build towards this disciplinary core idea.

Comments about Including the Disciplinary Core Idea
The addition of the oatmeal into the soil helps to slightly increase the temperature during the process as the microbes decompose the organic matter. Did you smell something from the plant pots? What did it smell like? What do you think this was?

Crosscutting Concepts

This resource appears to be designed to build towards this crosscutting concept, though the resource developer has not explicitly stated so.

Comments about Including the Crosscutting Concept
To best align to this crosscutting concept, students should be reflecting on what they observed from their models. How did the soil interact with the organic material? What flows in and out of the soil system? How do you know what is coming out? Were there less weeds in the soil with the organic material? What caused this to happen? Students are encouraged to discuss how these potted plants act as a model for a farm or garden system.

Resource Quality

  • Alignment to the Dimensions of the NGSS: The practices, disciplinary core ideas and crosscutting concepts work together to support students as they make sense of phenomena and design a solution to the problem of eliminating weeds from the soil. It is suggested to make the crosscutting concept more explicit for the students as suggested in the tips.

  • Instructional Supports: This lesson engages students in an authentic and meaningful activity that reflects the practice of science and engineering in a real world scenario of a phenomena that effects crops. Students engage in multiple practices that work together with disciplinary core ideas and crosscutting concepts to support student learning. Activity scaling and troubleshooting tips are included with this lesson as well as a 25 minute video/lecture that is suggested for the teacher's viewing purposes. It is suggested in the Activity Scaling section that students should be given specified amounts of organic wast and soil. Math calculation and percentages are above the 5th grade math level so it is suggested to do these calculations as a class or convert to fractions as that would be 5th grade appropriate. As mentioned in the tips it is also important to introduce the students to the concept of 'wafting' and practicing safe science. Activity handout includes data table for recording results and scaffolding in the form of explanations to go along with directions.

  • Monitoring Student Progress: Formative assessments of three-dimensional learning is embedded throughout the lesson. A pre and post activity assessment is included to provide students opportunities to demonstrate their understanding of the disciplinary core ideas and crosscutting concepts. Feedback to the pre- and post-assessment is encouraged to help students make sense of the phenomena as they reflect on the investigations they perform with the soil. Students should be encouraged to use evidence when talking about his activity as a model of a system which they could use to make recommendations for farmers and/or gardeners.

  • Quality of Technological Interactivity: There is a 25 minute audio/visual lecture on bio solarization included with this lesson.