Earthgarden as an ecological habitat design
Earthgarden was designed as a habitat model toward sustainability. It had the following ecological features.
1. An edible organic garden
The garden was created to simulate natural ecosystems. Though small, it was full of biodiversity and was amazingly productive: a survey of garden plants conducted in May, 2012 by an expert identified 232 edible and medicinal plant species during a one-year period. Vegetables, fruit trees, herbs, wild plants, mushrooms and aquatics were all included on the list. The organic garden was widely recognized as a small intensive model of a permaculture home garden.
2. Water recycling systems and rain water tanks
The waste water was treated by microbes, then used for gardening. A bio-geo-filter (BGF, or a Living Machine) was also installed. To make the water recycling process successful, biodegradable soap without synthetic suds was used. Rain water was harvested in small rain water tanks.
3. Ecological construction materials for the house
Lumber from local forests, bees wax, fermented persimmon extract and other paints without pollutants were used inside, keeping the level of so-called ʻsick-houseʼ chemicals low.
4. Passive solar design for energy saving
The eves were set at an angle which blocked the summer sun while allowing the winter sunshine to come in. A solar collector on the roof heated water for showers and baths.
5. A wood-fired stove
A wood-fired stove was installed on the first floor. The stove chimney went up to the rooftop warming the two rooms on the second floor. Another stove using pellets from local forests was used in the office. The ashes collected once cooled from the two stoves were used in the garden.
6. Nutrient cycling
All the kitchen scraps went into compost bins and worm bins for use in the vegetable garden. The pet rabbitʼs manure helped fertilize the flower beds and trees.
7. Harvesting solar energy (Solar panels)
Solar panels were installed by Kyoto Green Fund, a non-profit organization promoting energy saving and the use of solar energy.
8. Methane digester tank (biogas system)
In a small anaerobic tank connected to the family toilet, humanure was turned into a clean liquid fertilizer for use in the garden. A small amount of biogas was also harvested for cooking.