AquaTerraPonik® - StadtFarm in Berlin

The current agricultural situation:

The increasing demand for food has led to a rapid expansion of the agricultural sector in the 20th century - with the corresponding use of fertilizers and pesticides as well as herbicides. The consequences are:

• deforestation,
• degradation of soils (while we need to produce MORE!),
• heavy pollution of water,
• high CO2 emissions etc.

That's why we need products that are produced close to the consumer - preferably like in our city - and without pesticides, hormones, antibiotics, or artificial fertilizers. In StadtFarm, they use at least:

• 90% less water,
• 80% less land and
• 85% fewer CO2-equivalent emissions than conventional produce.

So, everyone can help to protect our planet and still eat healthy and delicious food.

AquaTerraPonik® process:

The productivity of AquaTerraPonik® is 10 times higher than that of conventional farming. Neither hormones nor antibiotics are used in this system, nor are pesticides or herbicides. There are three main filters for the water:

1. Mechanical filter: Fish are fed, and their droppings must be removed to keep the water clean. To achieve this, we first pump the water from the fish to a mechanical filter where suspended solids settle.
2. Earthworm filter: The solids go into the earthworm filter so that they are decomposed. The water flowing through thus contains the enzymes from the earthworm guts, which as a natural antibiotic keep the entire system healthy.
3. Biofilter: The rest of the water goes into the biofilter, where bacteria convert the ammonium first into nitrite and then nitrate.

Then it flows to the plants, which pull out the nutrients they need. The water flows back to the fish, nothing is exchanged, this only replenishes what evaporates and is used up by growth.

The fish:

The African catfish (Claris gariepinus) originates from North African waters. The natural habitats are lakes, rivers, marshes, and floodplains. It can grow up to 170 cm and 60 kg. The catfish takes in oxygen not only through the gills but also through the labyrinth organ (similar to lungs). It can thus breathe air for several days; it only needs to keep its skin moist.

Why does Stadtfarm have this fish?

• Animal welfare: High stocking densities possible without stress
• Ecology: WWF and Greenpeace approved
• Economy: Fast growth (slaughtering after 6 months),
• Gastronomy: Catfish is super tasty, totally versatile, and therefore very good to market.

StadtFarm's goal with the versatile Catfish is to replace the consumption of other animal proteins as well because our meat consumption is one of the biggest climate killers.

Plants:

Every year, 30 tons of seasonal vegetables like lettuce, herbs, tomatoes, and cucumbers, as well as exotic tropical fruits such as bananas, papaya, taro, avocado, citrus, Ceylon spinach and passion fruit are produced there.

In the subtropical climate, different varieties of tomatoes, cucumbers, peppers, chilli, and eggplant grow in the summer, and in the temperate climate, again 8 different varieties of lettuce and up to 20 different herbs.  Since this year, StadtFarm has also grown more than two dozen edible flowers.

Positive impacts:

StadtFarm's interdisciplinary, innovative approach can contribute to the development and implementation of alternative models of water use and food production.

• High potential to green and sustainably use for the unused land in urban areas.
• Local cultivation facilitates, direct exchange between producer and consumer.

Furthermore, production in urban areas brings a variety of ecological advantages:

• Food can be consumed fresh.
• Late, timely harvesting increases nutritional values.
• Short transportation distances reduce the use of fossil fuels.
• Complex refrigeration mechanisms are unnecessary.
• High CO2 levels in cities and higher temperatures promote plant growth.
• Urban green spaces inhibit urban heat and condition the air.

Owners of StadtFarm

Anne-Kathrin Kuhlemann and Markus Haastert started StadtFarm in 2017 and operate sustainable agriculture here. They are the founders of the ZERAP Germany e.V which I volunteer through ESC. They have been entrepreneurs in Berlin for ten years, but always with a strong connection to agriculture and rural areas. Markus accompanies communities and medium-sized companies in developing sustainable, innovative business models. Anne-Kathrin and her team operate aquaterraponic farm StadtFarm in Berlin.

Source: https://www.stadtfarm.de/