Hydroponics
description
Transcript of Hydroponics
Hydroponics
Phyllis Putnam
Jean Johnston
Jessica Garner
Introduction-- From Greek - Hydro = water and pronos = labor
-- First users of hydroponics
-- Earliest book, Sylva Sylarum: Or a Natural History of Francis Bacon, 1627
-- German scientists develop the first nutrient formula, 1929
-- World War II successful hydroponic operation
-- 1970s and 80s and on to Mars
AdvantagesAbility to grow vegetables year round
Grow plants in smaller spaces (apt, balcony)
Sterile Medium - No weeds, No soil-borne pests
Healthy Plants - All necessary growth elements readily available in solution
Plants mature faster (earlier crop)
Smaller root system (smaller spaces again) - Roots don’t have to spread out to reach food
Ability to automate system with a timer - Reduces time, Gardener can be gone for long periods of time
Eliminates need for vast farmland
Can raise crops in desert sands - Water is reused, Less water is used
Lettuce is cleaner (no soil on leaves)
No tillage
Plants often larger and healthier
DisadvantagesCost: Expensive to set up system (fixtures, water pumps, etc)
Nutrient solution must be kept at original volume - Water evaporates; add water, Solution can become toxic if too much nitrates (low light)
Use beneficial predators to control insects
Water quality can be a problem, poor plant growth - Excessive alkalinity or salt, Softened water, too much sodium
Roots need oxygen - Need a bubbler or continuous flow
Plants need to be supported (no soil to support)
Cost too high for most commercial growers (grow expensive crops)
Types of Hydroponic Systems
Aquaculture AggregateAeroponicsContinuous Flow
Aquaculture/AquaponicsEasiest set-up
Roots totally immersed in nutrient solution
Must: Support plant above solution, aerate solution and prevent light from reaching solution
Change solution every 1-2 weeks
Continuous Flow SystemTypically used in commercial hydroponics
Nutrient solution pumped or flowed by gravity to growing pipes
Bathes the roots then returns to holding tank
Solution aerates itself as it flows back
PVC pipe is commonly used.
AeroponicsRoots of the plant grow in a closed container
Misting system of nutrient solution
Near 100% humidity to prevent drying
A-Frame containers are most popular
Aggregate CultureUses some form of inert material (i.e. sand) to support plant roots
Pump and return solution using 1 of 2 methods
Flood and drain method
Trickle feed method