Sustainable designers 4: Nils Ferber + Charlotte Dieckmann (Design for Food 2)

Continuing with the "Design for Food" posts, today we will comment the  Parasite Farm. It is a design developed by Nils Ferber and Charlotte Dieckmann in a seminar called “Agriculture and the City” held by Harald Gründl.

The Parasite Farm  is not as massive as the Window Farm project if you may, but includes something essential to my point of view: The intention of closing the nutrient cycle around what we eat. This system does not only allow you to grow your own edible plants in your apartment, it also lets you produce your own nutrient rich soil, using your food scrapings.

The system consists of two main elements: A vermi-composter and illuminated plant boxes that fit into any bookcase. Why illuminated bookcase boxes instead of window sills? They said:
"Of course you could just put them on your balcony or window sills. That would probably work even better than artificial illumination. But we tried to develop a concept that works independently from outdoor space and sunlight. We wanted to show that composting food scraps and growing vegetables is possible even within your apartment or flat."

 Picture from Alexander Giesemann

The most interesting component is the vermi-composter. It hangs from your kitchen table, and has a sliding cutting board as a lid. It houses some tiger worms and other micro-organisms that feed off your organic waste, producing nutrient rich soil to feed your plants with. The container separates the soil from the liquid fertilizer (consisting mainly of water held in the vegetables), which you can later mix into the water you give the plants. The composter also includes a small fly trap to avoid small fruit flies invading your kitchen.

 Image from Charlotte Dieckmann

This part of the project is what raises the most questions:
First of all: Does it smell horrible?
Apparently not. They say that it smells like humid forest soil, that when your standing with it in the kitchen people hardly notice the smell. It is clearly not comparable to decomposing organic waste.
 
Then other use related questions we asked: Do you have to buy worms for it every now and then? Or, do you have to get rid of excessive worms, maybe?

"No, you normally start with about 500-1000 worms but if these worms will find good conditions in your vermicompost-container the population will slowly grow and adapt to the amount of nutrients that is available. And just like in nature the population will stabilize after a while on a level that is compatible with its environment."

Has this prototype been used by someone for some prolonged time period?

If so: What is the ratio between the compost you produce, compared to what is needed by the plants? What is the ratio between the liquid fertilizer produced and what the plants need?
"I am testing the system in everyday life at the moment but too little time has passed to make final statements yet. But normally you would start with more or less filled plant boxes and add fertilizer and humus soil from time to time until you eventually have to remove excessive soil or add more plant boxes. But the ratios depend very much on how intensive you use the vermicompost, what kind of plants you grow and what kind of food scraps you put in..."

This is one product I would love to see available in the market. Maybe not because it will be able to process all our organic waste (I don't think people will grow that many plants in their flats) but because it helps us recall the importance of closing cycles in an organic way. After all, you are what you eat, no?