Now, the basic principle on which the Green Houses work is, "allowing natural sunlight to plants and containment/ moderation of the heat, the sunlight carries along" and this purpose is achieved by constructing them with transparent material, which in most of the cases is either plastic or glass. The temperature inside it can be controlled by creating small ventilators or through installation of air conditioner and heaters. Green houses can be very effective in areas of extreme weather. Very hot regions like deserts are often unsuitable for growing crops. Similarly very cold regions like Siberia are also unsuitable for natural growth of vegetation. Hence, certain food necessities are met this way.
Speaking of the "Green House Design", there are no strict limitations regarding size, shape and material of the proposed structure. Instead, the flexibility allows one to prepare a custom green house keeping in view one's own limitations, i.e. available land/ resources and targeted quantity of plantation. For commercial purposes, These houses are built with glass structure, which are more dependable/ secure and are built in the shape of large barracks. In advanced countries; they are monitored electronically for better growth and maximum yield. Netherlands, for instance holds the record for largest number of green houses in a country exceeding 9000 of them. For domestic purposes, plastic is more preferable being cheap and easily installable.
With the advancement in agriculture industry, improvements in green house technology can also be seen. Historically, the green houses were initially built to save the crops from unexpected rain and hailstorms. Initial Designs were not transparent, instead were either made of hard fabric or metal sheets, however with the scientific development, it evolved into a profitable business. Today's "Green house Design" encompasses following salient features:
• It should at least be covering 50 meters of plain area.
• It should at least be 10 meters in length, 5 meters in width and 3 meters in height.
• Foundation depth of the structure should be 0.5 meters, however the deeper the better principle can be applied in this case.
• Door of the green houses should be 1 ½ meters in height and 0.6 meters in width, whereas ventilating window should be 2 x 3 feet and should be installed at the opposing wall of the door wall.
• It should be constructed preferably in open areas, where sunlight is available for most part of the day.
• In areas, where there is a risk of intrusion of wild birds or animals, the green house can also be protected with a firm layer of metal grill.
To summarize the discussion, following points need to be remembered while dealing with the phenomenon under question.
• What is GH: A structure, built to provide artificial environment for plants to grow under unfavorable outer conditions. They are built to increase vegetation and grow unseasonal plants and fruits.
• What are the key benefits:
o Off-season crops regardless of type can be grown
o Higher yield can be achieved through provision of most suitable environment
o Requires less use of chemical fertilization and water irrigation, thus minimizing cost of yield.