Training agricultural professionals and extension educators manage crop environment and soil quality in high tunnel vegetable production

Project Overview

Project Type: Professional Development Program
Funds awarded in 2016: $69,924.00
Projected End Date: 12/31/2019
Grant Recipient: Iowa State University
Region: North Central
State: Iowa
Project Coordinator:
Dr. Ajay Nair
Department of Horticulture, Iowa State University


  • Vegetables: cucurbits, eggplant, peppers, radishes (culinary), tomatoes


  • Crop Production: cover crops, cropping systems, crop rotation, fertigation, grafting, high tunnels or hoop houses, irrigation, nutrient management, shade cloth, varieties and cultivars
  • Education and Training: demonstration, display, extension, farmer to farmer, focus group, mentoring, networking, on-farm/ranch research, participatory research, workshop
  • Pest Management: allelopathy, biofumigation, biological control, biorational pesticides, botanical pesticides, chemical control, integrated pest management, mulches - general, mulching - plastic, weed ecology
  • Soil Management: green manures, soil analysis, soil quality/health
  • Sustainable Communities: local and regional food systems

    Proposal abstract:

    High tunnels have become an important tool in Iowa’s specialty crop production. High tunnels are simple, plastic-covered, greenhouse-like structures that are passively ventilated and crops are grown in it directly in the soil. In Iowa, NRCS has supported the construction of over 350 new high tunnels in Iowa since 2010. The environment without rainfall, limited space, and potential climate control in a high tunnel requires unique set of crop management skills.

    One of the major issues identified by growers and grower organizations such as Practical Farmers of Iowa (PFI) and Iowa Fruit and Vegetable Growers Association (IFVGA) was sustaining, and in some cases re-building, soil quality inside high tunnels. Growers understand how important it is to manage soils well as it directly affects nutrient cycling, crop growth, health, development, and yields. Soil quality is degraded with intensive tillage and fertilization, monoculture, and removal of crop residues, which leads to poor soil structure, soil compaction, reduced water infiltration, and reduced soil biology. Growers need strategies to manage soil fertility, crop pests and diseases, soil quality, and soil organic matter under high tunnel production. One such strategy/practice is the use of cover crops. High tunnel is a high priced real estate when it comes to vegetable production so selection and planting of cover crops inside high tunnels need to be carefully designed without compromising grower profitability. Currently high tunnel growers search out information and rely on their own time consuming investigations to understand principles and practices of cover cropping. Without understanding these principles it is difficult for growers to choose, grow, and manage specific cover crops suitable for their high tunnels. They need to identify the appropriate cover crop species, its growth characteristics and pattern, when and how to seed, when and how to terminate, and potential challenges associated with them. High tunnel vegetable growers need extension specialists and agricultural educators with knowledge and expertise on a number of topics such as cultivar selection, crop rotation, succession cropping, cover crops, temperature management, soils, summer shading, fertility and pest management in high tunnels.

    Project objectives from proposal:

    Extension specialists and educators need continuing education to provide growers relevant information on topics such as cultivar selection, crop rotation, succession cropping, cover crops, temperature management, soils, summer shading, fertility and pest management in high tunnels. Extension personnel and agricultural professionals who are trained about high tunnel crop production, its advantages, and any potential challenges are more likely to assist growers interested in growing inside high tunnels.  The overall objective of this project is to provide professional development and educational forum on basic and advanced aspects of vegetable production in high tunnels. The intended audiences for the project include extension personnel from Iowa State University, Iowa State University Research & Demonstration Farm superintendents, county extension personnel, government agency staff, leaders of grower organizations, and staff from Natural Resource Conservation Service. Core objectives of the project are to:

    • Highlight the importance of crop, environment, and soil management for vegetable production in high tunnels
    • Provide a platform to share resources, knowledge, and expertise in the area of high tunnel vegetable production
    • Promote hands-on learning opportunities to better understand crop production in high tunnels
    • Connect agricultural educators to professionals in the area of sustainable vegetable production
    • Develop brief and concise extension bulletins and fact sheets that can be interpreted and used by extension staff, agricultural professionals, and the end client (fruit and vegetable growers)
    • As a long term strategy, facilitate integration of cover crops into high tunnel vegetable production systems to improve soil quality and health
    • Educate local agencies, organizations, extension staff, and growers about efficient crop production, crop rotation, integrated pest management, fertility and soil management approaches inside high tunnels.
    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.