Leopold Center for Sustainable Agriculture

Completed Competitive Grant

Feasibility of unheated large gutter-connect greenhouses for winter organic vegetable production in Iowa

Project ID: E2009-24

Abstract

The researcher compared air and soil temperature dynamics, as well as growth and yield of crops in small hoop and large greenhouses, and evaluated the effects on temperature and crop performance of different row covers and row cover management.

Key Question: Is it practical to grow vegetables in the winter in an unheated one-acre greenhouse in Iowa and what type of row cover will provide the best protection for the crops?

Findings: Produce can be grown quite well through the winter in the large unheated greenhouse. Growth was slightly greater in the small unheated greenhouse than in the large greenhouse for some crops. Poly row covers provide more cold protection than fabric row covers, and in some cases crop quality and yield are better if the covers are off during the day and on at night. If covers are not removed during the day, fabric covers are better.

Lead investigator: Steve McLaskey, Maharishi University of Management

Year of grant completion: 2011

This competitive grant project was part of the Leopold Center's Ecology Initiative.

Topics: Fruit and vegetables, Organic production practices and comparisons