Tunnel farming has been around in South Africa for almost 4 decades. It stems from the original idea in the 19th century that crops could be grown using hydroponics as opposed to growing in the soil. In the 70’s it was found that vegetables could be successfully grown without soil by using nutrient based solutions. Furthermore, great success was achieved by covering the the plants with a plastic-clad semi-circular structure, dubbed a “tunnel”.
Tunnels may also be called hoop houses, high hoops, high tunnels or polytunnels. Tunnels are sometimes confused with greenhouses. The key difference is that tunnels are not heated and provide less climate control and are less expensive. In South Africa, heating is not as critical as other climates such as in European countries. This immediately gives tunnel farming in South Africa a competitive advantage over establishment costs.
There are many advantages to using this hydroponic method of cultivating plants. The plants are grown in plastic tunnels in a growth medium other than natural soil. The plants get a constant flow of nutrients as they are dissolved in the irrigated water system thus creating large and high quality crops.
Plants are grown in black plastic bags which assists in eliminating soil borne diseases. The bags can be filled with various types of mediums however the most cost effective method is untreated pine sawdust mixed with shavings.
When seedlings reach about 10cm they are planted in the bags. Most vegetables/ fruit such as tomatoes cucumbers and green peppers are trained to climb up a string which is attached to the plant bag and overhead wires. The string is continuously wound around the main stem of the plant. To create optimal growing capacity.
Advantages of hydroponic tunnel farming.
- High quality product
- No soil is needed
- Plants get a constant supply of nutrients through an automatic irrigation system
- Able to produce larger yields of vegetables on a small area of land
- Soil borne diseases are reduced or eliminated
Tunnel farming has become very popular over the years, with most vegetable farmers opting for this method.