Hooked on Hydroponics In the Classroom Hope & John Chybion June 2011
WIIFM “What’s in it for me?”
• If the next 80 minutes go as planned, you will leave this room convinced that you’ll never again plant a seed or root a plant in soil! • You’ll learn what Hydroponics is, where it came from, what shapes it comes in, and where it’s going.
• You’ll also build your own, fully functional hydroponic garden to further stimulate your newfound desire to incorporate soil-less gardening into your classroom!
WHAT IS HYDROPONICS? • “Hydroponics is a method of growing plants using mineral nutrient solutions in water, without soil. Plants may be grown with their roots in the solution only, or in an inert medium such as perlite, gravel, rock wool, or coconut fiber.”
WHAT DOES THAT MEAN? • It means, Hydroponics is all about growing plants without putting them in the dirt. • The idea is, soil-or dirt presents a variable that is, at best, difficult to control. By eliminating that “dirty variable” we can provide our plants with optimum growing conditions and high volume production.
What CAN we control?
Quantity of light
Duration of light
Amount of water
pH level of nutrient solution
Bugs and soilborne diseases
Discussion – While light, temperature, water and pests are vital variables in all plant growth, each of these components could be the topic of its own workshop. – So-o-o, Back to the topic!
What’s in a word? “Hydro,” means water “Ponos,” means labor “Hydroponics,” means working water. You need to know this, because eventually, someone is going to ask you!
Hydroponics is a “blanket term” to describe any one of a number of methods used to grow plants without organic soil.
History of Hydroponics
Can you name the Seven Wonders of the World?
History of Hydroponics • • • • • •
Great Pyramid of Giza Statue of Zeus at Olympia Temple of Artemis at Ephesus Mausoleum of Maussollos at Halicamassus Colossus of Rhodes Lighthouse of Alexandria
The Hanging Gardens of Babylon •King Nebuchadnezzar II ordered the gardens built to appease his homesick wife, who pined for the tall trees and fragrant flowers of her homeland, Medina (now western Saudi Arabia) •Babylon-a city state near Al Hillah-about 60 miles south of Baghdad, near the Euphrates river.
•100’ x 100’ x 75’ tall •Built in tiers to resemble a theatre •Ascending terraces carried the weight •Vaults were heavily waterproofed with reeds, tar, brick and lead •Top planted with large trees •Water was lifted to the top with Archimedes’ screw
Mexico’s floating gardens
Chinampas • 1100 AD • Sent sewage into canals • Bacteria in the mud actively composted the sewage, organically neutralizing it and converting sewage into nutrient-rich fertilizer
17th Century – Jean Baptista van Helmont’s willow tree experiment
Conclusion: Plants don't consume soil
19th Century • Sachs and Knop – “The Fathers of Waterculture” – Discovered that nitrogen, phosphorus and potassium (NPK) are the building blocks of plant growth – Developed nutrient formulas aka-fertilizer
20th Century • 1920 Dennis Hoaglund creates a “nutrient formula,” and names it for himself. – Hoaglund’s Solution still abundantly used.
• 1920’s-30’s Dr. William F. Gericke creates the term “Hydroponics”
1930’s Pan American Airlines established a hydroponics garden on Wake Island-a refueling stop for the first transPacific flights-to grow vegetables for passengers and crew.
U. S. Army • In 1952, the peak of it’s demand, the Army’s hydroponic division grew Eight Million pounds of fresh produce. • All produce consumed during the Korean War was produced hydroponically – Ascention Island – Guyana – Iwo Jima
1960’s • Drip irrigation – Delivers nutrients to roots drop by drop – Gro-rocks (expanded clay) as growth medium
1960’s & 1970’s • Rock Wool – Spun heated rock fiber
1960’s & 1970’s continued • Nutrient film technique (NFT) – “film” of nutrient & oxygen-rich water passes over roots, is collected and re-circulated.
1980’s Hydroponics, “heads,” and the Internet – Regan administration’s get tough on drugs policy – Exponential growth of worldwide Internet-only business – Perceived anonymity of Internet commerce – A certain “….Times” magazine offering “howto” articles on hydroponic growing
Trigger a huge surge in hydroponics by the home gardener
1990’s to present • Growth of Aeroponics • Nutrient solution constantly sprayed onto roots stimulates vigorous growth
I’m going to Disneyworld!
ADVANTAGES OF HYDROPONICS • No soil needed • Water can be reused • High degree of control over nutrition levels means lower nutrient costs • No nutrient pollution released into the environment • Stable, high yields • High degree of control over pests and diseases
DISADVANTAGES of hydroponics • Presence of fertilizer and high humidity can create a favorable environment for salmonella growth – A rare occurrence for the home or school gardener
• Inadvertent over watering may produce conditions favorable to damp-off such as Verticillium wilt because of high moisture levels. – Avoided through good water management, discarding or sterilizing contaminated growth medium.
• Static Solution Culture – Plants are grown in containers of nutrient solution (Mason Jars, buckets, tubs, tanks) – Cut a hole in the lid of the container and put the plant in! – Aerate with an aquarium pump
Continuous-flow solution culture • • •
Nutrient solution constantly flows past the roots One large tank can feed thousands of plants, thus automation is easier NFT (nutrient film technique) is an example of con-flow.
Aeroponics • Roots are continuously (or frequently) saturated with a mist or aerosol of nutrient solution
Passive subirrigation • AKA semi-hydroponics – Plants grown in a medium which causes capillary action to draw nutrient solution up to the roots
Another look at passive subirrigation
Ebb and Flow irrigation • Similar to Nutrient Film Technique, except the water stops once in a while! • A GREAT use for that stream table that sits in the closet but for two days a year!
Run to Waste • Using a timer, water and nutrients are pumped from above, flows from one container to the next, and any excess is lost.
Deep Water Culture • Roots are suspended in nutrient-rich, oxygenated water. – Air pump and porous stones provide and hold oxygen saturated nutrient solution
Bubbleponics • Think, “Deep Water Culture,” but you’re circulating the nutrient solution to the roots. – Airstone oxygenates the solution, while a pump circulates the nutrients to the young roots via tubes. – Stimulates rapid growth in young plants.
GROWTH MEDIA • It’s the stuff we use instead of “dirt.” – Different media are appropriate for different growing techniques.
Expanded Clay • Clay is formed into round pellets and fired in kilns. This causes the clay to expand and become porous, much like popcorn popping. • Light weight, does not compact with use. • Can be easily cleaned and sterilized for reuse.
Rock Wool • Most widely used medium in hydroponics – Rock, basalt or “slag,” that is spun into bundles of single-filament fibers, then bonded into a medium capable of capillary action
Coco Coir, or Coco Peat • Leftover material from the outside of a coconut. – 100% natural growth medium – Perfect air/water ratio makes it easy to use
Perlite • Volcanic rock that has been superheated into lightweight expanded glass pebbles
Vermiculite • A superheated mineral – Holds lots of water – Natural “wicking” property helps young roots – Mix with Coco Coir, or some other growing medium.
Sand • Cheap, easily available • Heavy and dense, poor water retention, and must be sterilized between uses
Gravel • Aquarium gravel, any small gravel • Must be washed first • Inexpensive, provides good drainage, but HEAVY
Polystyrene packing peanuts • Inexpensive, readily available with excellent drainage • VERY light-indoor or closed system use only • Possible health risk. Plants may absorb styrene and pass it to consumers.
Wood Fiber • Produced from steam friction of wood • Very efficient organic substrate • Long lasting
Nutrient solutions • Hydroponics nutrients are dissolved in water and are mostly in inorganic and ionic form. – Ionic calcium Ca2+, Magnesium Mg2+, and Potassium K+
• Numerous recipes for solutions are available, using potassium nitrate, calcium nitrate, potassium phosphate and magnesium sulfate
Do it yourself nutrient blending • Hydrocal • HydroBuddy • Both are freeware, neither are designed for the “casual,” grower, but for individuals with the desire to “dig deep” into nutrient blending, they provide precise formulas with great flexibility. • I wouldn’t suggest either for elementary or middle school classroom use http://www.soft112.com/hydroponic-nutrient-formula-calculator-p192459.html
Complete Hydroponics Systems • Examples of commonly available systems. Contains everything you need except plants and water.
Verti-Gro • One-stop shopping, educators discount, wealth of knowledge. • www.vertigro.com
Hydro-stacker • One-stop shopping, deep knowledge base, patented system • www.hydrostacker.com
On a personal note… • Following are a few slides from our personal experience with hydroponics. • Florida Agriculture in the Classroom grant facilitated this journey • Over 1000 students have learned about hydroponics through the Endeavour Urban Agriculture program.
THANK YOU! Now, it’s time for Make ‘n’ Take!