The 212 acre Wagbo homestead is being developed into a model of a sustainable family farm. We have a 2 acre organic (not yet certified) produce garden currently being turned into a CSA, we work with draft horses in our fields and forest, and we plant about 5 acres of corn for our livestock which includes a little bit of everything, 4 horses, 6 jersey cows, 4 sheep, 2 goats, 4 pigs, and countless ducks, chickens and rabbits. The land is approximately ¾ wooded, with 20 acres of pasture, ½ acre apple/pear orchard (newly planted), a 2000 tap maple syrup system and a small apiary (6 hives). A woodlot management plan is in place, with a WoodMizer sawmill for lumber production on site. There is also a gravel pit, many natural springs, and an abundance of wildlife. Our goal is what we call “whole farm resource stewardship”. We want to find “waste” that is being created on the farm and utilize it as a resource. This greenhouse system was on big step in doing that.
PROJECT DESCRIIPTION AND RESULTS
The Permaculture Greenhouse System is based on the idea that excess heat generated by chickens in a coup could be utilized as a supplemental heat source for a greenhouse. Enhanced exchange of oxygen from the plants and carbon dioxide from the chickens is also a benefit, as is chicken manure for compost for use in the greenhouse.
Based upon the 1998 season, we have found the Permaculture Greenhouse System to be successful. We believe that this system represents a good base model that is worthy of duplication and fine tuning.
The problems we identified were:
– Increasing marketability at a new CSA in a northern (zone 4) climate by extending the growing season
– Developing a cost effective method of integrating available resources into an energy efficient solution (using chicken heat to support a greenhouse), and
– Expansion of educational opportunities for existing Youth-At-Risk Apprenticeships students, consumer outreach, and training workshops.
Our objectives have been met. Interest in our CSA has been very positive. We are pilot testing with twelve families this year (98 growing season). The greenhouse has allowed us to grow an adequate number of starter plants and to hold them protected until after the frost period. We also maintained back up starters as “insurance” to better guarantee produce to our subscribers in the event of late freezes. We did have a late freeze, June 3-6 and lost many tomato and pepper plants. Our greenhouse was a tremendous help in recovering from that loss.
Our records indicate that the supplemental heat provided by the chickens increased the temperature by 8 degrees on average, prior to installing any solar collection devices or installing insulating window covers to hold heat in at night. Subsequent to installation of these devices, inside temperatures averaged 19 degrees above overnight outside temperatures, average inside temperatures overnight was 53.8 degrees and controlled inside temperature for daytime was 86.6 degrees. Open windows for ventilation was the main “control” for daytime inside temps, which were reaching 108 degrees. Insulating window covers were a crucial element in maintaining the heat overnight. These were built using 2”x3’x3’ Styrofoam boards framed with ¼ inch wood for stability. They were painted white with latex paint and covered with muslin fabric. Two more layers of paint sealed the bats. Two bats were joined together with more muslin which was simply painted to each bat to make a cloth “hinge”. They were attached to the ceiling above the windows and fit snugly in the window frames. They could then be folded up to the ceiling accordion style and held up out of the way with bungee cords. Plans for the greenhouse and more specific details of the actual building are available to interested farmers.
The following data is based on the winter and spring of 1998.
Note: climatic conditions were much milder than what is considered to be normal.
Data related to building progress & temperature:
– January & February 1998: building enclosed, chickens (approx. 40) housed in coup, no passive solar heat collectors, no insulating window covers, no circulating vents between chickens and greenhouse.
Overnight low temperatures averaged -1 degrees outside, dropped to 32 degrees in greenhouse, 40 degrees in chicken coup. Chickens produced 8 degrees of additional heat. Chicken coup averaged 5.1 degrees above greenhouse temperatures overnight. Daytime record high was 108 degrees in the greenhouse, and dropped to 38 degrees a loss of 70 degrees.
– March & April 1998: sixteen 15 gallon plastic barrels painted black and filled with water were placed in direct sun to collect solar heat for slow dispersal overnight, insulating window covers were built and installed to hold heat in overnight, and circulating vents (two 6”x16”) between the greenhouse and chicken coup were added 18” above floor with no forced circulation. Additional plans call for heat from the ceiling of the chicken coup to be fan forced through a pipe and directly under the planting beds (to be added before winter ’99).
Windows had to be opened during the daytime to control overheating seedlings, as temperatures ranged in the 90’s and above in the greenhouse. The average “controlled” daytime temperature was 86.6 degrees. Weather conditions were as follows: 25% of this period was cloudy with snow or rain, 20% partly cloudy and 55% sunny. The extreme overnight low in the greenhouse was 47 degrees, with the average at 53.8 degrees. The greenhouse maintained a 19 degree margin over outside overnight low temperatures.
No outside resources were utilized to maintain adequate temperatures in the greenhouse; therefore no costs were incurred in supporting its functioning. More will be known after a number of years of using this system, but currently it is providing a very cost effective, energy efficient way to meet our needs.
This project has been extremely helpful for our operation. Purchasing starter plants is extremely expensive compared to starting seeds in the greenhouse. We are counting on our new CSA program to provide significant income and much of its success will be determined by successfully raising plants earlier than normal so that we have a jump on the growing season. We found this year that we could have left our tomato and pepper plants in the greenhouse even longer to completely avoid the late frost dates and avoid the risk of loss. We will be preparing to transplant our hot weather plants into larger containers next spring instead of putting them out too soon. They system is also very worthwhile because these growing season benefits do not require the additional expense of supplemental heat sources. Because of our sawmill and timber, we had the resources to supply our own lumber. This detain may make the cost of construction higher then is reasonable for a farm without such resources.
In relation to education and outreach, several groups of students toured the farm with particular interest in the permaculture greenhouse system. One charter school is considering they style of system for their agriculture program. We held a greenhouse discussion potluck with six families in the area who have or are building greenhouses, and swapped information about ideas. This lead to building our insulating window covers as a community project with 3 other families and on going dialogue and cooperative efforts with our farms. We had 3 days per week with youth-at-risk apprenticeship students directly involved in the final construction of the greenhouse, record keeping during the winter, seed planting and care, seedling transplanting and gardening. They also participated in the other aspects of the farm. School groups continue to tour our farm and we use the greenhouse as a central focus of our teaching about sustainable practices.