High tunnels are plastic-covered, passively ventilated and heated structures where crops are grown directly in soil. They have become important tools for Iowa specialty crop producers to increase production of quality crops, extend the season, and increase profitability. The environment in a high tunnel, without rainfall, limited space, and potential climate control requires a unique set of crop management skills. High tunnel production is primarily dominated by tomatoes. Interest among growers focuses on year-round production in high tunnels. A cohesive and focused approach is needed to tackle issues that arise due to continuous production under these structures. One emerging issue is the intensive use of fertilizers to manage crop nutrient demand and the lack of crop rotation within high tunnels. This could lead to problems such as high salt build up, resurgence of soil-borne and foliar diseases, poor soil structure, lack of microbial diversity, and reduced crop yields.
Iowa State University
Nair, Ajay; Carpenter, Brandon H.; Tillman, Jennifer L.; and Jokela, Dana L., "Integrating Cover Crops in High Tunnel Crop Production" (2014). Iowa State Research Farm Progress Reports. 2009.