Teaching Hydroponics

Shelby Schaefers, Buchanan and Delaware County Ag in the Classroom Coordinator, and I attended a two day STEM teacher workshop hosted by Iowa Agriculture Literacy Foundation. We had the opportunity to tour many great STEM related facilities but my favorite was the FarmTek greenhouses.

FarmTek is a division of engineering services & products company founded in 1979. FarmTek offers farm supplies, chicken feeders, hay storage, barn fans, hog supplies, but the most unique is their line of greenhouses.

I emphasized in Horticulture and learned how to grow vegetables in water during my time at Iowa State University but I wish I would have learned about hydroponics at an earlier age. It is such a neat concept that holds a wide variety of benefits.

The actual meaning of hydroponics is "water works." The definition is the process of growing plants in a water/nutrient, rich solution without soil.

Many plant species can be grown hydroponically but the typical plants are exotic flowers, and greenhouse plants like lettuce, tomatoes, peppers, cucumbers, melons, and culinary herbs. I am sure you are looking at the pictures and thinking well this is cool but how can I teach it in my classroom? The Iowa Agriculture Literacy Foundation offers grants each year specific to agriculture education. If you can't get a hydroponic system in your classroom think about assigning it as a research project. Hydroponics can be taught in many core subjects.

So how do plants grow in water? Seeds are sown in a water absorbent medium and are transported to the greenhouse as seedlings. The plants are in a controlled environment and are carefully monitored for nutrient and light levels, temperature, and pests. Plants need 17 essential elements to grow.

Major macroelements include: nitrogen, phosphorous, potassium, calcium, magnesium, and sulfur.

In addition to teaching about what hydroponics is- experiment with nutrient levels, dependent and independent variables, light levels, temperature, water conservation, and natural resources.

Here are some sample interest approach questions:

1. What will happen if you take a nutrient away?

2. How does humidity play a role?

3. How many mediums are there to grow the plant in?

4. Does the plant grow normal size? Will it take the same amount of days to mature?

5. Will the plant absorb the same amount of nutrients?

School gardens are a popping up all over and raising the food to eat in the classroom or during lunch is a popular trend. A similar model can be done when teaching about hydroponics; grow basil and turn it into pesto, make salsa from tomatoes, or create a Cesar salad.

Extended ideas:

-Transition to talking about markets. How would we go about selling this product? What would the label be? Could we make a profit?

-Lead into other processes like aquaponics, combining conventional aquaculture with hydroponics in a symbiotic environment, and growing fodder for livestock. Fodder is dry hay or feed for livestock but the difference in conventional fodder and hydroponic fodder is the process and length. Hydroponic fodder grows in racks that are designed to produce forage using a 7-8 day cycle. One pound of barley seed can be turned into seven pounds of living forage.

Teaching about hydroponics can be a fun way to tie in Next Generation Science Standards. Use this as a real-world example to engage students.

Credits:

https://www.horizenhydroponics.com/files/education/Intro-to-Hydroponics.pdf