On-farm High Tunnel Project

Eldon Everhart, Field Specialist-Horticulture, Southwest Area

Problem Statement: 

Some farmers are interested in investigating the profitability of growing crops in high tunnel on their farms.  High tunnels are unheated, plastic-covered, structures used to grow high value crops for an extended number of months out of the year.  Fresh market produce grown and sold out-of-season has a higher profit margin.

Programmatic Response: 

During the spring and summer of 2007, two farmers participated in an on-farm high tunnel project supported in part by a grant from the College of Agriculture and Life Science.  This ISU/PFI On-Farm Research project provided an on-farm apprenticeship for Milton Amos and Robert Amos of rural Griswold, Iowa.  The farmers received hands-on training in the use of high tunnel technologies at the ISU Armstrong Research and Demonstration Farm and in high tunnels on their own farm near Lewis, Iowa.


The farmers learned how to manage and market high-value horticulture crops that they grow in two high commercial high tunnels that they built on their farm.  They also developed a better understanding of the feasibility, sustainability, and profitability of high tunnel technology.  They were involved in all aspects of the project including cultural practices such as irrigation, fertilization, pest control, and harvest.  They also sold the produce, collected data, kept records, and wrote reports.  On August 28, thirty people toured the farm and the farmers presented information about the high tunnel project.  During the summer, several other smaller groups visited the farm and viewed the high tunnels.  On August 13, 2007, the farmers and Field Specialist Eldon Everhart presented the results of the project to about 50 participants at a field day hosted on the farm.  Participants rated the usefulness of the field day high to very high.

Tomatoes grown in the high tunnels on the farm generally produced a higher yield and a lower percentage of culls than field-grown tomatoes.  For example, 150 tomato plants were grown in one 1,050 square foot high tunnel on the farm.  The average yield was about 17 pounds of fruit per plant with a total yield of about 2,500 pounds.  Early season tomatoes were sold at a retail price of $2.40 per pound.  At an average retail price of $2.20 per pound, one small 14 by 75 foot high tunnel produced a gross annual income of $5,500 or $5.24 per square foot.  The farmers is adding three more high tunnels for the 2008 growing season for a total of 6,438 square feet.  This enterprise is expected to generate $34,000 in a gross annual income.


130  Horticulture: Commercial and Consumer

Page last updated: April 11, 2008
Page maintained by Linda Schultz, lschultz@iastate.edu