A high tunnel (pictured above) is a structure used for growing plants. High tunnels increase the quality and yield of fruits and vegetables grown in a relatively small area by controlling some environmental conditions that impact plant growth and production.
Similar to a green house, a high tunnel uses one or two layers of plastic to protect the plants from rain, wind and cold while still providing adequate sunlight for plant growth. Plastic sidewall curtains can be raised or lowered based on temperature, humidity and wind speed. (See image below). This allows for ventilation and temperature control in the high tunnel.
Unlike a greenhouse, plants are grown directly in the ground in a high tunnel. (See image below). Typically, high tunnels use the sun as the only source of heat, while greenhouses have heaters powered by electricity and other fuel.
The environmental protection a high tunnel provides can add 4-6 weeks to the growing season of fruits and vegetables by offering protection from frost. A high tunnel also protects delicate crops from wind and rain damage, making it possible to grow high value specialty crops that are often damaged in the field.
The comparison site (pictured above) is used to demonstrate the differences between high tunnel crop yields and quality compared to normal outdoor growing conditions. Research and demonstration plots measure these differences by planting the same crop, managed in the same manner, so that the only variable is the environmental control provided by the high tunnel. Results from these research plots provide data that will help farmers make decisions about production techniques for fruits and vegetables on their farm. The goal of this research is to improve the quality, yield and profitability of North Carolina farms while minimizing the environmental impact and improving sustainability of agricultural practices.
