FOR IMMEDIATE RELEASE
November 17, 2009
Kevin Coburn, Director of Communications
Windham Foundation Grant Helps GMC Study New Agricultural Methods
POULTNEY, VT - While greenhouses lengthen the production season for vegetable farms, heating these structures with gas-fired or electric air burners is expensive and energy intensive. Research at Green Mountain College, funded by a $15,000 grant from Vermont's Windham Foundation, will explore new ways to sustainably grow vegetables by integrating a solar- powered hot water system in "high tunnel" greenhouses. The three-year study may reveal inexpensive ways to produce higher yields while consuming less energy.
"The existing research on season extension tends to focus on structural designs and crop production methods, but our knowledge about the economics of heating greenhouses with renewable energy resources is lacking," explains Prof. Philip Ackerman-Leist, director of the College's Farm & Food Project. "This study tests the hypothesis that in-ground solar heating of soils will provide a cost-effective way of extending the growing season."
GMC researchers will experiment with thermal root-zone heating, a process that warms the soil at the roots of plants through a system of underground hot water radiant tubing. The system will generate heat from solar thermal collectors.
The radiant tubing will be installed in two new "high-tunnel" greenhouses, plastic-covered structures that provide a level of temperature control somewhere between open field conditions and heated greenhouses. High tunnels cost very little to build and are large enough to walk in comfortably and to grow tall, trellised crops like tomatoes.
One half of each greenhouse will be planted using raised beds, while the other half will be planted using typical in-ground cultivation methods. One greenhouse will be heated solely by available sunlight. The other will be equipped with the solar thermal system and radiant tubing.
By comparing vegetable yields over a three year period, GMC researchers hope to gather useful information for farmers about season extension while providing a hands-on introduction to farm research and ecological design principles to GMC students.
Much of the construction will also be done by GMC faculty and students. Ackerman-Leist's Seasons Extension class and Prof. Lucas Brown's Design and Build class are working collaboratively on the siting, design, and construction the new high tunnels and solar thermal system. This combination of expertise in agriculture and ecological design is preparing students from both disciplines to integrate their own knowledge while working on a College research project.
The College farm has long been utilized as an educational venue for new farmers, schools, colleges, community recreation programs, and nonprofit groups. "By integrating renewable energy systems into a working model of sustainable agriculture, the GMC Farm & Food Project is able to effectively demonstrate the interdependence of agriculture and energy," said Ackerman-Leist.
Headquartered in Grafton, Vermont, Windham Foundation's mission is to promote Vermont's rural communities through its philanthropic and educational programs and its subsidiaries whose operations contribute to these endeavors.