Hands-on Activity Engineering a Hydroponic System to Feed a Class!

Learning Objectives

After this activity, students should be able to:

• Predict how human population growth will impact farming and food production for the next generation.
• Investigate and describe existing alternatives to traditional farming.
• Design and build a prototype that may solve the increased demand for food using limited land or space.
• Evaluate the design and iterate based on test results.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS: Next Generation Science Standards - Science

International Technology and Engineering Educators Association - Technology

State Standards

Materials List

Each group needs:

• Chromebook or laptop
• water (for testing hydroponic system)
• Brainstorming Worksheet and the Poster Rubric

Various recycled materials for students to use in their prototyping. Items may include:

• clean and dried plastic food containers (such as yogurt containers or milk jugs).

Various inexpensive materials for students to use in their prototyping. Items may include:

• colanders
• duct tape, masking tape, adhesives
• pipe cleaners
• plastic containers of all shapes and sizes
• tubing
• wooden sticks
• zip ties

For the whole class to share:

• timer (or alarm, watch, cell phone timer)

Worksheets and Attachments

Introduction/Motivation

Scientists and world leaders have identified 2050 as a key moment in history when the world’s population will be nearly 10 billion humans. How old will you be in 2050? What will your life be like?

It is predicted that we will need to grow 60-70% more food than we currently grow today to feed a population of 10 billion on the same amount of land or on less land. How do we accomplish that goal?

As a team, you will design a simple and practical hydroponic growing system for a small space, like a classroom, to grow multiple leafy green vegetables which have a smaller ecological footprint than traditional farming. Your team will build a prototype of the hydroponics system to present to the class for peer review. Once you have feedback, we will expand the designs to be used by the school population eating meals from the cafeteria.

Procedure

Background

We have all heard the word “sustainability” before, but what exactly is it?

Practicing sustainability means using resources in such a way that they will continue to be available in the future.  Examples of ecological sustainability include recycling, upcycling, consuming less, or relying on renewable energy to power our cars and heat or cool our homes. It is important to note that these examples all required a new technology to make it happen. For example, motors needed to be redesigned to create the electric car and a team of mechanical and electrical engineers were needed to design and test electric vehicles.

In this activity, students will be asked to think like an engineer and to collaborate to design a product that addresses food (leafy greens specifically) production and sustainability as the world population continues to increase and the land resources decrease.

Plants require three nutrients to complete photosynthesis – carbon dioxide, water, and light. This process is represented by the equation:  

CO₂ + H₂O + light = C₆H₁₂O₆ + O₂.

Soil is not required for plants to make sugar. Can we grow plants without soil? Yes, that is a hydroponic system. Hydroponic means the process of growing plants in sand, gravel, or liquid. Hydroponic farming s is a type of horticulture and a subset of hydroculture which involves growing plants, usually crops, without soil, by using water-based mineral nutrient solutions in aqueous solvents.

Before the Activity

• Gather materials
• Make one copy for each student of the Brainstorming Worksheet
• Make one copy for each group of the Poster Rubric

With the Students

Day 1: Pose the problem

1. Have students individually read the following article from the World Food Program USA: https://medium.com/@WFPUSA/how-do-you-feed-6-million-people-a-month-73ff5784a448
2. Have each student write down three approaches to solving the Syrian food crisis that are being used by the World Food Program.

Day 2: Research hydroponics and hydroponic systems/discuss constraints

1. Break students into groups and have them share out approaches to solving the Syrian food crisis.
2. Ask each group to contribute one “answer” to the class and the teacher should list these “answers” on the board for the entire class to view.
3. As a class, discuss the list. Ask the class: What are the limitations to the solutions? (Answers may include money, materials, water, available land.)
4. Bring the discussion home – how would we address a food crisis where we live. Ask students about their homes/apartments/local area – is there a yard or open space nearby? How large is the yard or open space? Challenge students to think about where they could grow a vegetable garden at their house or in their local area that would produce enough food to feed 50 neighbors. (This exercise can also be done using your school’s area. Where could enough food be grown at your school to feed the entire school and their families?) Note: Most students and/or school likely do not have a yard or open space large enough for this, so pivot to the concept of hydroponics.
5. Homework - Ask everyone to research and define hydroponics and create an image of a hydroponics system that can be presented to their group during the following class period.

Day 3: Group work and individual design

1. Break into groups and set a timer for 3 minutes for each person in the group to share their definition of hydroponics and the image of a hydroponics system they brought in. If working in groups of 4, person one will have 3 minutes to present. Re-set the timer for another 3 minutes so that person two can present and continue to re-set the timer until all students have had a chance to present to the group. No questions should be asked until all group members have presented their definitions and images.
2. Give teams time to ask questions within the group. Teacher should visit each group and ask them to create a shared definition of hydroponics and a list of “must-haves” that all the hydroponics images have in common.
3. Homework – Have each student think of three new designs for a hydroponics system.  Make sure students keep in mind the limitations of land availability (this can be thought of as limited space in our classroom), cost and materials.

Day 4: Sketching and Brainstorming

1. Break students into groups of 3-4 students.
2. Pass out the Brainstorming Worksheet; one to each student.
3. Give student groups 5 minutes for each student to sketch three new designs for a hydroponics system. (Note: Refer to the Example of student sketches if students need help with sketching, although this is optional; students should be able to roughly outline their ideas without a example.)
4. After 5 minutes, have students pass (clockwise) their sketches to the next person in their group. Note: each student in the group should get a paper passed to them.
5. Give student groups 5 minutes to look at the sketches from another person and have them do one of the following: add to the sketches, take something away from the sketches or create a new sketch.
6. After 5 minutes, pass the worksheets again, repeat having the students add, subtract, or edit the new sketches over 5 minutes.
7. Continue passing the worksheet until each student has their original sketch returned to them.
8. Give student 5-10 minutes to look at the modifications that their group members added and to ask questions about all the group designs.
9. As a group, have each student group decide which design should move forward to the prototyping stage   - which design best fits the needs of minimal space, minimal cost and easy access to materials.

 Days 5-8: Designing, Planning, and Prototyping

1. Have each group draw their hydroponics system design on a new (clean) piece of paper. They should label each material that will be used.
2. Teacher should meet with each group before they start building to ask questions like why did the group select this design? How does this design have an advantage over an existing hydroponics system? How many plants can be grown in this new design? Are there limitations to this design?
3. Once each group has teacher approval, each group should build one prototype using the recycled and/or Dollar Store materials outlined in their drawing.
4. Give students time to build their prototype.

Days 9-11: Testing and redesign

1. Have students take a video of their hydroponics system prototype to show how it should work. (optional)
2. Have each team decided what they will test their prototype for: testing may include waterproofing, weight, mobility of the system, etc.
3. Have students test their prototype based on their chosen criteria.
4. Encourage groups to take photos as they prototype and test.
5. Have students take video of their prototyping testing. (This can be included in the final video.)
6. Let students redesign their prototype to improve it based on the testing results.

Days 12-15: Create the Poster and Video

1. Groups use one Google Slide (24 inches x 36 inches) to create a scientific poster of this project. Use Google Slides so individual group members can all work on the same slide if the slide is shared.
2. Provide each student team the Poster Rubric so that each group knows what is expected in their scientific poster, section by section.
3. Teacher can also show an example of a completed scientific poster to help students before they start to create their own.
4. Have students put together a short video showing how their prototype works.

Vocabulary/Definitions

aqueous: Containing the properties of water or similar to water.

ecological footprint: The impact of a person on the environment, expressed as the amount of land required to sustain the use of natural resources.

horticulture: The practice of garden cultivation and management.

hydroculture: A type of hydroponics in which plants are grown in a medium that allows the distribution of water and nutrients through capillary action.

hydroponics: The process of growing plants in sand, gravel or water with added nutrients but without soil.

sustainability: Avoidance of the depletion of natural resources to maintain ecological balance.

Assessment

Pre-Activity Assessment

Investigate the food crisis in Syria and answer the question – How do you feed six million people per month?

Write down three approaches to solving the Syrian food crisis that are being used by the World Food Program  https://medium.com/@WFPUSA/how-do-you-feed-6-million-people-a-month-73ff5784a448

Activity Embedded (Formative) Assessment

Constantly monitor groups as they are brainstorming and prototyping to ensure that one to two students are not taking over the project.  Refer to the Example of student sketches if students need help with the sketching portion of the activity. Google drive can be used to store files and group work and while also being shared with the teacher. Students can use Google Slides to create the final poster – this allows all group members to work on the same document and the teacher can see which student contributed to the poster.

Post-Activity (Summative) Assessment

Create a scientific poster – one per group that will be graded by the teacher. See an Example of a completed poster for guidance and view the Poster Rubric for organization and grading. Teacher can adjust the total points.

Investigating Questions

• How do we farm plants without land?
• Generate a list of possible ideas on the board or give each group their own white board to brainstorm ideas.

Activity Extensions

Explore farming in 2050 further by expanding to include livestock. The hydroponics unit addresses plant growth but does not include how to maintain livestock with decreasing land availability. This unit can also explore the use of recycled materials and biodegradable materials to be used in the building of prototypes. 

Activity Scaling

For upper grades or advanced students, challenge students to include the molecules of photosynthesis (carbo dioxide, water, light, sugar, oxygen) and couple the project with cellular respiration – ask to design “landless” plant farms in cities where fresh oxygen is needed to balance poor air quality.

For lower grades, pre-pack materials to prototype in kits. This will limit materials, but it will also keep students focused on the build.

Additional Multimedia Support

Each group could submit a video of the hydroponics system over time. Can start with seeds and continue through and   plant growth.

Groups can access CAD software and use 3D printers to create parts for the prototypes if the school has access to this equipment.

Copyright

Contributors

Supporting Program

Acknowledgements

This curriculum as developed under the National Science Foundation Research Experience for Teachers on Quality of Life Technology from the University of Pittsburgh grant no. 1609566. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.