Part 4h. Methods of increasing food production and improving sustainability

4h. Growing plants in glasshouses

Doc Brown's Biology exam study revision notes

There are various sections to work through,

after 1 they can be read and studied in any order.

Sub-index of notes on increasing food production

Index of notes on ALL aspects of food production

re-edit 11/05/2023

4(h) Growing plants in glasshouses  (see also section (i) on hydroponics)

principles of operating a greenhouse in horticulture sunlight heater carbon dioxide source artificial lighting water supply humidifier

The growing conditions in a green can be rigorously controlled for maximum growth.

glasshouse of Mulgrave Estate Gardens, North YorkshireA greenhouse used is to artificially create the best environment for growing plants and increase photosynthesis efficiency.

Ventilation - need to keep the air fresh and ensure the carbon dioxide level doesn't fall below that in the air outside. You can artificially increase CO2 available to plants to increase rate of photosynthesis.

Glass (or transparent plastic) panels - allows the transmission of visible light for photosynthesis and infrared radiation to be absorbed and raise the temperature.

Plants need a constant supply of water, the soil or compost may get to dry for optimum plant growth and the higher temperatures in a greenhouse increase the rate of transpiration.

An electric heater can raise the temperature on colder days, preferably from renewable source.

Artificial lighting enables photosynthesis to be continuous 24/7 and independent of the weather, BUT you need periods of darkness (use a timer) to allow the plant to transport and store glucose as starch.

Growing crops in greenhouses can significantly increase the crop yield for a given area.

Large scale greenhouses and hydroponics units are good methods of 'factory farming' plants and biological methods of pest control are quite successful.

See also Photosynthesis, importance explained, limiting factors affecting rate

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