Controlled Environment
Agriculture Systems
Commercial Structures
Today's commercial greenhouses are constructed of galvanized steel, extruded aluminum, fibreglass,
polycarbonate, acrylic, polyethylene and glass. The percentage of each, comprising a typical structure,
varies by type of design.
Loosely categorized, the following basic shapes and styles are prevalent:
l freestanding grade to grade hoop houses (quonset) clad in
polyethylene, double polyethylene, corrugated fibreglass sheet, or
plastic composite structured panels
l linked or gutter-connected straight-wall hoop houses clad in
polyethylene, double polyethylene and so on as above
l linked or gutter-connected straight-wall hoop houses clad in
curved automotive glass
l linked or gutter-connected straight-wall peaked houses clad in flat
tempered glass. This style of range breaks down into three further subcategories:
- single peak gutter-to-gutter
- double peak with floating gutter
- triple peak with two floating gutters
All of the above styles or designs of greenhouses are popular, the grower selecting which he will build
based on crop to be grown, usage pattern, seasonal pattern, as well as economic considerations.
l Nutrient control insures that the plants get the minerals they need at the right pH and temperature.
l Faster growth then soil grown plants.
l No weeds. The medium is mostly inert and unless it is out doors, there is no way for weed seeds
to get into the growing medium.
file:///D|/new/pages/general_hydroponics.htm (3 of 6) [2/8/2004 8:55:24 PM]
General Hydroponics
l No guess work about what nutrients are going to the plant.
l Easy to correct for plant deficiencies.
l No backbreaking soil conditioning.
l The water has all the nutrients that is required by the plants. The roots don't have to grow bigger
looking for food. The growth of the plant goes mostly to the upper plant.
l Plants can be spaced closer together then in soil. Spacing is dependent only on the space needed
to supply adequate light to the plant.
l Garden can be at a good working height.
l Up to twenty times the amount of plants can be grown in the same space in hydroponics then in
soil.
l No soil to harbor bugs.
l Healthy plants have better taste.
l Healthy plants resist insect infestations. Less insecticide is needed.
l Educational for children of all ages learning about plant growth.
l Faster growth so that more then one crop can be raised in a season.
l Can be made portable so that you can move it from classroom to classroom or take it with you
when you move.
l Ground is left undisturbed on rented property.
l Condensed growing methods make better use of greenhouse space.
l Consumes 1/10 the water that field crops do.
l Conversation piece.
l Good past time for those that likes to tinker.
l It's something the Jones' don't have. :-)
Some disadvantages to growing plants in hydroponics are;
l Higher cost to get started then soil culture.
l System failure could result in a lost crop if not caught right away. Some systems can go days
before damage occurs.
Agriculture Systems
Commercial Structures
Today's commercial greenhouses are constructed of galvanized steel, extruded aluminum, fibreglass,
polycarbonate, acrylic, polyethylene and glass. The percentage of each, comprising a typical structure,
varies by type of design.
Loosely categorized, the following basic shapes and styles are prevalent:
l freestanding grade to grade hoop houses (quonset) clad in
polyethylene, double polyethylene, corrugated fibreglass sheet, or
plastic composite structured panels
l linked or gutter-connected straight-wall hoop houses clad in
polyethylene, double polyethylene and so on as above
l linked or gutter-connected straight-wall hoop houses clad in
curved automotive glass
l linked or gutter-connected straight-wall peaked houses clad in flat
tempered glass. This style of range breaks down into three further subcategories:
- single peak gutter-to-gutter
- double peak with floating gutter
- triple peak with two floating gutters
All of the above styles or designs of greenhouses are popular, the grower selecting which he will build
based on crop to be grown, usage pattern, seasonal pattern, as well as economic considerations.
l Nutrient control insures that the plants get the minerals they need at the right pH and temperature.
l Faster growth then soil grown plants.
l No weeds. The medium is mostly inert and unless it is out doors, there is no way for weed seeds
to get into the growing medium.
file:///D|/new/pages/general_hydroponics.htm (3 of 6) [2/8/2004 8:55:24 PM]
General Hydroponics
l No guess work about what nutrients are going to the plant.
l Easy to correct for plant deficiencies.
l No backbreaking soil conditioning.
l The water has all the nutrients that is required by the plants. The roots don't have to grow bigger
looking for food. The growth of the plant goes mostly to the upper plant.
l Plants can be spaced closer together then in soil. Spacing is dependent only on the space needed
to supply adequate light to the plant.
l Garden can be at a good working height.
l Up to twenty times the amount of plants can be grown in the same space in hydroponics then in
soil.
l No soil to harbor bugs.
l Healthy plants have better taste.
l Healthy plants resist insect infestations. Less insecticide is needed.
l Educational for children of all ages learning about plant growth.
l Faster growth so that more then one crop can be raised in a season.
l Can be made portable so that you can move it from classroom to classroom or take it with you
when you move.
l Ground is left undisturbed on rented property.
l Condensed growing methods make better use of greenhouse space.
l Consumes 1/10 the water that field crops do.
l Conversation piece.
l Good past time for those that likes to tinker.
l It's something the Jones' don't have. :-)
Some disadvantages to growing plants in hydroponics are;
l Higher cost to get started then soil culture.
l System failure could result in a lost crop if not caught right away. Some systems can go days
before damage occurs.