Water Use in Agriculture

A Self-Guided Homeschool Lesson:

Recommended Age Range: 10–18
Subject Areas: Science, Environmental Studies, Health, Nutrition Life Skills
Estimated Time: 3–5 flexible sessions, ~30–60 minutes each

 Learning Goals:

• Understand what sustainable agriculture means and why it’s important.
• Understand that water is part of sustainable agriculture.
  Explore microgreens as a tool to understand water use.
  Think critically about our food system and how it can be more sustainable.
  

 What You’ll Need:

• 1. Broccoli microgreen seeds
• 2. 5×5 microgreen tray, with cover and bottom tray
• 3. Weight for tray (a can of beans, rock, etc.)
• 4. Growing medium (soil disc)
• 5. MIcrogreen 101 directions
• 6. Notebook or science journal
• 7. Internet access

 Lesson 1: What Is Sustainable Agriculture?

Explore:

• Research the term “sustainable agriculture.” Find at least 3 sources. Write your own definition in your journal.
  • Start here: https://cias.wisc.edu/curriculum-new/module-i/module-i-section-a-what-makes-agriculture-sustainable/
    
• Watch one or more of these videos or read an article you found in your research.:
  
  • National Geographic: What Is Sustainable Agriculture? (for older students) https://www.nationalgeographic.com/environment/article/sustainable-agriculture . (From Farm to TableFrom humankind’s first farmers to the present-day battle over GMOs, photographer Jim Richardson takes us on a 5,000-year journey documenting how agriculture has transformed our planet and how we must continue to transform in order to feed Earth’s ever-increasing population.)
  • Search: Kids Explain Sustainable Farming  on YouTube (for younger and older students)
    
  • OR find a book or article on the topic

Think About:

• 1. Why does the way we grow food matter?
  2. What problems can unsustainable farming cause?
• 3. What does water have to do with sustainable farming?
  4. What might a sustainable farm look like?
  

 Lesson 2: Are Microgreens sustainable?

Microgreens are generally considered more sustainable than traditional crops due to their fast growth, low resource requirements, and zero need for pesticides and fertilizers. Let’s experiment to see if that is true.

Learning Goal:

• Are microgreens considered part of sustainable agriculture?
  

Background:

• The average teenager or adult needs 6 servings of vegetables daily to meet minimum phyto nutrient needs.
• A serving is:
  • ½ cup of cooked vegetables (like broccoli, cooked carrots, etc.) OR
  • 1 cup of raw vegetables OR
  • 2 cups of dark green leafy, raw greens OR
  • 1 cup of vegetable juice
• Microgreens contain many more nutrients per ounce (up to 40X) than full grown vegetables. That means you need to eat much smaller servings to get the same important nutrients. A serving of microgreens is:
  • 1 small handful, or ¼ cup loose microgreens.

In your microgreen kit, you have 5×5 planting trays. We will use these trays for our experiment.

Hands-On Experiment: Plant one tray of broccoli microgreens

You will need:

1. 1 planting tray
2. 1 cover tray
3. 1 water tray
4. ½-1  teaspoon of broccoli seed
5. 1 soil disc
6. Spray bottle with exactly ¼  cup fresh water.
7. Science journal

Directions:

Prepare your tray to plant by placing it on a water tray. 

Rehydrate one coir disc in ½ cup water. Record this amount of water in your science journal. Put the moist soil in the planting tray.

Sprinkle the broccoli seed evenly over the soil.

Spray the seed lightly with about 5 squirts of water from your spray bottle. Measure the remaining water in the bottle.

Cover the tray with the second tray, and put a weight in the tray.

Leave for 3 days before uncovering. Then, place the sprouted tray in a bright area to grow for 10 days. Water with ¼ cup water after removing the cover tray and weight. Record the amount in your journal.

Water your microgreens as needed.  Place the water in the bottom water tray, not over the top of the plants! Record the amount of water you use each time. Don’t water so much that there is standing water in the tray. See Microgreen 101 for more watering and growing information. 

Track The Growth:

• In your notebook, draw your microgreens or take pictures each day.
  
• Record when they sprout, when the cotyledons appear, and if they’re ready to harvest in 10 days.

From planting the seed to harvesting a head of fresh broccoli takes between 60-90 days from transplanting. Each plant in the garden or field requires an average of 2 gallons of water per week. If we average the growing time of broccoli to 75 days, that is 10.7 weeks. Math Question: how many gallons of water are required to grow one head of broccoli? (*1)

Record the question and answer in your science journal.

At harvest, a medium head of broccoli will give about 3 cups of chopped, fresh florets. Each cup of fresh broccoli will give about ½ cup of cooked broccoli. Math Question: How many servings are in an average (medium) size head of broccoli? (*2)

Record the question and answer in your science journal.

Optional:  purchase a head of broccoli and cut it up. How many cups of fresh broccoli were in the head of broccoli? The peeled stems are also edible, so you can add the measurement of the peeled stems if you are willing to eat them!). You may use these measurements instead of the average 3 cups per head.

 Lesson 3: Harvest and Record

• At 10 days of growth, your broccoli microgreens are ready to harvest.
• With a sharp pair of scissors, carefully harvest the microgreens right above the soil.
• Measure your microgreens. Without pressing the greens down, fill a 2 cup measuring glass with your harvest. Shake the measuring glass to settle the greens. Measure and record the amount of microgreens harvested from your tray.
• Each ¼ cup of microgreens equals one serving of vegetables
• • How many servings were you able to grow in your tray of microgreens? How does this compare with the full grown broccoli?
  • Return to your journal and determine the amount of water you used to produce your microgreens. How much water was needed to produce each serving of microgreens?
  • How does this compare to the amount of water used to produce each serving of full-grown broccoli?
  • Record your findings in your journal
    

 Lesson 4: Reflection

There are many issues in Sustainable Agriculture. In this lesson, you have learned about one important part of sustainable agriculture- water.

Many farmers are working to be better stewards of our water resources. Farmers can conserve water through various methods, including implementing efficient irrigation systems like drip irrigation, managing when they irrigate, growing drought-tolerant crops (GMO), and employing practices like cover cropping, mulch, conservation tillage, and utilizing soil moisture sensors. These changes have to be done carefully to assure that is both cost effective and practical as well as sustainable. Farming is an impressive challenge when we need to both increase production to feed a growing population, and care for the environment to make long-term farming possible and practical.

Ask Yourself:

1. What have you learned about sustainable agriculture?
2. What have you discovered about water in agriculture?
3. Why might it be difficult to grow mature broccoli with less water?
4. Do you consider growing broccoli microgreens as sustainable agriculture? Why or why not?
5. How is growing microgreens in your home different from large-scale farming?
6. Do you think it would be practical to grow broccoli microgreens large-scale? Why or why not?
7. Does growing your own food help the environment? Why or why not?

• Talk About the Following With Someone:
• What are some ways the U.S. food system could be more sustainable?
  
• How could more people grow food at home, even those in cities without yards?
  

 Additional Projects:

• Create a presentation or poster about what you have learned..
  
• Make a chart comparing water use, space, and time between microgreens and traditional crops.
  
• Use your microgreens! Add them to a sandwich, salad, smoothie, taco, pizza, or in another creative way.
  
• Interview a local farmer or visit a farmers market to ask about sustainable practices.
• Introduce microgreens to another family and tell them what you have learned.
  

 Related Subjects and Standards

Science:

• MS-LS1-1: Structure and function in plants
  
• MS-ESS3-3: Human impact on the environment
  

Life Skills & Health:

• Nutrition, gardening, food systems
  

ELA / Writing:

• Reflective journaling, informational writing
  

🌟 Final Thought

You don’t need a big garden to make a big difference.
Growing microgreens at home is a tiny action with a powerful message:
Anyone can help create a more sustainable food system.

Additional Resources

1. : http://www.myamericanfarm.org/ Quick learning games pre-K to 5th grade
2. https://web.archive.org/web/20060828210433if_/http://susdev.agecon.vt.edu/worksheets/Sustainable%20Agriculture%20Worksheets.pdf  Pesticides and alternative practices. 3 page PDF
3. https://cias.wisc.edu/curriculum-new/module-i/   Introduction to Sustainable Agriculture- University of Wisconson- Center for Integrated Agricultural Systems
4. https://foodwise.org/articles/10-ways-farmers-are-saving-water/ ways that farmers work to save water.

(*1) Do the math- 2 gallons x 10.7 weeks = ?

(*2) 3 cups of fresh broccoli / .5 cup per serving = how many servings?

(*3) each quarter cup = one serving