Image Credit: Neo-farms
Farmers in colder regions use greenhouses to try and extend the growing season of their crops. They work on the principle of convection which enhances the growing environment of plants. However, building these structures and heating them during winter are highly expensive.
Underground greenhouses are comparatively more effective and inexpensive than these glass structures.
Underground Greenhouse System
Underground greenhouse techniques were first developed two decades ago and deployed in the cold regions of South America. This method uses natural resources to provide a stable, warm and productive environment, even during winter.
Underground greenhouses make use of heat stored at a depth of several meters under the earth’s surface during winter. The temperature variation beneath the earth’s surface is considerably lower and therefore, the environment around underground greenhouses will have large thermal mass.
The Benson Agriculture and Food Institute at Brigham Young University first investigated this approach in detail, and constructed an experimental design in Bolivia at a cost of US$250-300.
Building an Underground Greenhouse System
Underground greenhouses are suitable for different climatic and geographical conditions. It is essentially a rectangular hole constructed at a depth of 6 to 8” beneath the ground and covered by a plastic sheet. A thick wall of compressed earth behind the structure and a lower front wall provide the required angle for placing the plastic sheet roof. The roof creates an insulating airspace which allows the sunlight to penetrate the structure. The structure also collects and stores daylight.
As the ground is cooler in summer and warmer in winter, the design creates an ideal environment for efficient growth of plants.
Benefits of Underground Greenhouse System
Underground greenhouse systems ensure natural insulation which favors rapid growth of horticultural crops under extreme cold conditions.
They can be built in a variety of sizes depending on the commercial needs and are ecologically smart, inexpensive and viable.
Unlike conventional growing methods that are influenced by varying climatic conditions, underground greenhouse systems have proven to be more useful and profitable.
In today’s world, there is an increasing demand for natural and organic food materials. At the same time, the area available for cultivating organic crops is decreasing constantly.
Crop growers are in need of sustainable growing techniques that are environment-friendly, affordable, and yield higher quality products. Underground greenhouses are the ideal solution that satisfies all these conditions and also ensure better crop yield.