As some of you may know, I grew up in a small collection of towns on the south-western corner of the beautiful island portion of Newfoundland and Labrador, on Canada’s east coast. We are frigid 405,720 km2 (156,649 sq.mi) boulder sticking out of the Atlantic Ocean, and I couldn’t be happier. With a population density of just over 1.3 persons per square kilometer (0.9 per square mile), and 17,542 km (10,900 mi) of coastline. Our winters are long and bitterly cold, our summers are brief and often uncomfortably hot (for me). Farming is scarce, though we are 100% self-sufficient for beef and milk, but little else. 25% of the world’s crab comes from our waters and 30% of the world’s shrimp. A VAST majority of the island is unspoiled wilderness, with a nearly half of our island residing on our eastern most point, the Avalon Peninsula. There is simply not enough arible soil and growing season for us to be a thriving agricultural economy, without help. Not without Greenhouses.
My home patch of the island, is St. David’s, and sharing a fence with that area is St. Fintan’s, an area in which I own 14 hectares (~35 acres) of land. For many years I fought to do something with it, while on a vapourous budget, Etherial really, and never got any where with it. I managed to summon a team of volunteers over the year to help me clear patches and even had the beginnings of a cabin built about 70m (~200′) in from the asphalt road before the wedding and my illustrious move 534km (400mi) north. It’s a crime that I never got to do more with the property, but I did get a sign installed, which will soon be taken down and put in my shop as a keepsake (Special thanks to one of my volunteers, Dave, for the photo op next to my sign). But just because I did not get done all that I dreamt of doing doesn’t mean that a solid decade’s research into sustainable agriculture and off-grid living won’t be put to a waste! While at Grenfell Campus of Memorial University of Newfoundland, my alma mater, I was working with a PhD adviser on a project of his, with hopes of completing th eplans and building a model of the greenhouse design on my own land in St. Fintan’s. It never worked out that way. I’ve done the research, though, and intend on putting it to good use. I’d like to share some of that research with you today.
Now. In case you missed my passive solar thermal article that I wrote earlier this morning, this is where my work ended up. You can clearly see a photograph of my garage workshop, a facsimile rendering in Google Sketchup, and the third image is one in which I indicate my desire to rework the roof section to accommodate better solar gain for my rooftop hydronic thermal collection system. We good? Great. This new roof slope will allow me to extend the original roof down over the space BEHIND the lumber storage extension and make it much easier to build a seamless transition from the asphalt shingles and hydronic plumbing for heat collection into the transparent glazing necessary to run the greenhouse. This last image in the series is the rendering of the transparent glazing (roof) over the space that will become the greenhouse space. I will require some post-holes drilled and cardboard sonotubes with concrete piles to act as load-bearing supports for my work in this space. The access to the greenhouse space is not set in stone, so to speak, but must be accessable only from inside the building. This will avoid dangerous air-leakage and loss of humidity/heat. This space will have insulated walls that extend to the ground, and I’m considering excavating some earth away below the structure below the frost barrier, to avoid that conduction of frozen earth through the structure, but that may just be overkill.
The building itself will be either 8′ by 16′ long, or 8′ by 32′ long. That depends on what I’m going to do with the firewood wood shed behind the garage. This will take place YEARS into the future, so I’m not terribly concerned about the small details yet. I can plan for both cases and see what rolls.
Inside this building I will run two very different experiments over a number of years. Fortunately, neither of them are very labour intensive to run/record once the proverbial ball gets rolling. The image seen in the rear of the greenhouse has been colloqually labelled The “Tater Tower”, though really any root vegetable would probably work. That’s up to the experiment to determine!
There are eight units back there, seen more clearly in the second image. These towers are approximately 8′ (~2.5m) tall and 2′ (600mm) on a side. They are built in 2′ (600mm) lifts, and I’ll explain why in a moment. The space below the tower is meant for storage of a specially balanced feed mixture and a small collection container for the drain-out. The openings will each be covered by a door that will open to allow access to the soil behind it.
The principle is very simple. In the first 2′ (600mm) lift, we plant a whole, sprouted potato. Let the greenery grow up to the top of the unit and place on the second tower level and add soil until the plant half-buried. Wait for the plant to grow, and keep adding soil until you reach the top of the current level. Let the plant grow again, add an identical level, add soil, wait. Rinse repeat. The flowering buds and leaves have a chance to turn into a potato beneath the soil (There is conflicting evidence to this effect, but this is one of the purposes of the research) Once the stack of towers is at the full height, let the plant grow to it’s own comfort height. By that point, the sprouts at the base of the tower should be prepared for harvesting. Open the door, scoop out the soil and the spuds, and close the door. Climb to the top of the tower and push the whole soil column down. Add soil, allow the plant to grow. Harvest potatoes weekly or bi-weekly, depending on various growing conditions. Each time fresh soil is added from compost, NOT Recycled directly. ‘Spent’ soil can be added to existing compost mixture for revitalization. This method takes advantage of potato’s perennial properties, instead of it’s annual properties that are employed when they are dug up. Some records indicate that single potato plants, harvested regularly all year round, have survived for generations in this way. Experimentation will determine if other tubers, like carrots, turnips, rutabagas, parsnips, radishes, and similar will behave in the same way. The towers serve the same functionality as “raised bed gardening” and are thus more easily regulated for soil contamination, pest infestation and polluted groundwater infiltration.
The second experiment is much more exciting (at least, to me). This is a much more intensive project, requiring a much more delicate balance of dynamic parts. It is a “closed-loop integrated aquaponics with bacteria microfilter bioreactor”. 😀 The biology and chemistry involved can get hella complicated, but it is basically thus: A (~50gal, or ~200l) tank of water at the bottom of the system which contains fish that are comfortable in pond water, like talipia. These fish will be fed (more on their source of food in a moment) and their waste into the water provides a resource. That water is then pumped, unfiltered, into tanks at the top of the racks, which contain a specially cultured bacteria that feed on ammonia-nitrates and their “waste product” is a combination of Potassium, Nitrogen and Phosphorous. This can eventually balance and work out to a perfect blend of nutrients needed for selected plants in the system. The second rack (first rack of plants, below the top rack of bacteria filters) will consume more of one type of nutrient in the fertilizer, the next level will have different demands, and the third the final demands. The lowest levels of plant trays will require the least amount of nutrients, like non-flowering herbs and grasses.
Each plant is suspended not in soil but in a fine gravel substrate like aquarium stone. The roots will intertwine around the stone and provide a stable foundation upon which the nutrient-rich water will rain down from level to level continuously. This flow can be adjusted using a pump and a dial. This third-party diagram may more clearly indicate the method I am describing. Please remember that we are separating the bacteria culture found in plant soil into a separate filter, to more easily control soil health without damaging plant roots.
This technology is not new, nor do I hold any specific claim to any part of it. The information is often largely open-sourced and free for the revitalizing process of experimentation and testing, augmentation and re-testing. It’s all the best of science that is sometimes lost in the High School science labs.
One of the ways in which we add a layer of complexity and self-sufficiency to the system is by allowing a secondary system of insect harvesting. We feed the remains of fish to insects, like black soldier flies, crickets, grasshoppers, silk worms, meal worms, etc, in order to sustain the larva, and feed the plant cuttings (as well as grass clippings from lawns) to the mature creepy-crawlies. The insects take care of a great deal of the waste from the system, and they feed the fish.
All of the final-stage waste from this closed-loop system is contributed to a specially balanced “hot compost” which is capable of boiling water. This system involves a type of biodigestion that generates an exothermic reaction that can easily heat the greenhouse without aid all year round. The installation of specially balanced 5000k (Daylight frequency) fluorescent lighting tubes above the plants to supplement daylight hours will contribute to our drastically shorter days this far north.
This system, taken together, is it’s own ecosystem and can provide enough food for two to three families. It is modular, adaptable, and will be the subject of my agricultural research while not in the workshop this winter. I am also enlisting the help of my wife and of teenage volunteers from the local area to help me do my research in the summer while I am away. This work is a PhD thesis waiting to happen. A scholastic journal entry with my name somewhere in the heading. That, and it will feed myself and my family healthy, clean, readily available food all year round in a region where groceries are sometimes prohibitively expensive.