Plant and Soil Science

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Plant and Soil Science

• Introduction to Hydroponics

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What is hydroponics?

• The word hydroponics is derived from the Greek
  words hydro and ponos
• It is the science of growing plants in an inert
  medium
• Nutrients come from a nutrient solution

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Commercial use of hydroponics

• It has been used in the industry for over 45 years

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Crops

• Almost any herbaceous plant
• lettuce, tomatoes, peppers, cucumbers, and herbs
• The crops that are grown are usually specially
  bred for hydroponics

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Advantages of hydroponics

• It can be used regardless of soil type
• Fresh produce can be grown all year round
• Crop yields are higher with hydroponics compared
  to conventional methods
• Higher quality product can be produced
• Soil borne insect and disease problems are
  greatly reduced

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Advantages of hydroponics

• Since there is no soil, there is no need to
  cultivate or weed the crops
• Less pesticides are used because the crops are so
  healthy
• All plants receive the correct nutrients at the
  right time
• Hydroponics allows for greater efficiency of
  water and fertilizers

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Disadvantages of hydroponics

• High start up cost
• Operators need to be skilled
• The system must be sanitary and kept clean
  because disease can affect all plants if it gets
  into the solution

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Hydroponic methods

• Water culture
• Aggregate culture

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Water culture

• Nutrient film technique (NFT)
• Aeroponics

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Nutrient Film Technique (NFT)

• Plants are grown with their roots in a trough
  that water runs through continuously
• Water level is very shallow to allow adequate air
  exchange
• Troughs can be up to 100 feet long and are sloped
  about two or three degrees to allow the water to
  flow

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NFTNutrient Film Technique
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Aeroponics

• The roots of the plant are suspended in a chamber
  where the roots are misted constantly.
• The chamber creates an environment in which there
  is 100 percent humidity

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Aeroponics
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Aggregate culture

• Gravel culture
• Sand culture
• Sawdust culture
• Other cultures
• Common rockwool culture

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Hydroponics
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Gravel culture

• There are beds that are filled with gravel
• Plants are placed in the gravel
• The plants are irrigated through sub-irrigation.
• The number of irritations depends on temperature
  and size of plants.

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Sand culture

• There are beds that are filled with sand
• The beds can be on benches or on the floor
• Plants are placed in the sand
• The plants are watered through drip irrigation
  that brings water and nutrients

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Sand culture
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Sawdust culture

• Similar to sand culture
• Sawdust from Douglas fir and western hemlock give
  the best growing results
• Medium sized particles are the best size to use

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Rockwool culture

• Rockwool is one of the most widely used mediums.
  Almost all the plants that are used in the other
  aggregate cultures were started in a rockwool
  cube
• Rockwool can be reused for three or four years
• Drip irrigation is usually used with it

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Rockwool