Final Project-Freshwater Farms

https://prezi.com/view/m06n9ZIwAS733YNIUA5f/

Freshwater Farms

Background: In the past 40 years the world has lost a third of its arable land due to erosion or pollution. Using lakes as a surface to produce crops, aquatic plants, eliminates the need for soil. Additionally, about 70 percent of all the world’s freshwater withdrawals go towards irrigation uses.

Growing plants on the surface of lakes and ponds (freshwater) allows us to use water already in place and use it to produce food.

Explanation: My system consists of a floating “net pot” disc with a net underneath holding gravel and clay. The discs are tied together and set up to a dock on a lake or pond.

Strategy: The system I have created is considered an “aquaponics” system. Aquaponics is the combination of aquaculture (raising fish) and hydroponics (the
soil-less growing of plants) that grows fish and plants together in one integrated system. The fish waste provides an organic food source for the plants, and the plants naturally filter the water for the fish.

Credits: Inspiration for this project comes from growing up on a lake and having gardens at my home. We used to take the lake water to water our plants, and I always thought what if we took it one step further and just put the plants in the water? Initially I thought it couldn’t be done, but certain crops don’t actually need soil, just nutrients, which can be found in lake water.

Budget: $10 disks
$10 netting
$5 foam for flotation
$25 plants
$10 clay balls
$10 rope to tie to dock or to
rock anchor
= $70 total estimated cost

Note: I made all the visuals above myself in Illustrator.

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Much like the chinampas of the Aztecs, which were small, artificial islands created on freshwater lakes, my idea is to have a trench dug into lake sides to hold discs for plants such as watercress, cranberries, reeds, and sedges. There would be some kind of loose soil and rocks in the bottom of the trench to hold the surrounding soil in place, plus a woven barrier to hold the up the integrity of the soil, otherwise the barrier soil would be eroded. This would also allow the roots of the plants a foundation for growth. I would include some kind of buffer plants around the trench to not allow run-off to get into the trench water. This would also solve another problem, the disks being impacted by strong current and waves in the lake.

I made a prototype of my floating disc as seen below. The plastic disc I used (a paper plate holder) has small foam noodles attached around the circumference to keep it afloat. I made the fake watercress out of green fabric and wire with string attached at the end of each strand to act as roots. There is a net holding in the roots and possible rocks and soil bits(not shown).

Floating in water:

Top views

Side view

Bottom view