Corn is a major US crop that is grown on 91.6 million acres of farmland, primarily in the Upper Midwest. Current agricultural methods used in this region depend heavily on the use of natural and synthetic fertilizers which can cost upwards of $230/acre to boost corn crop yields. Despite efficient application methods, many nutrients from these fertilizers enter the surrounding water system through runoff. This process leads to nutrient accumulation in nearby lakes and streams which then concentrates in rivers like the Mississippi, and is deposited in the Gulf of Mexico and other estuaries.
Therefore we have identified farm fields as our focus area and aim to provide clean water leaving the fields as a primary outcome of our design. Drainage tiling is implemented in many of these fields to reduce the rate of surface run-off but nonetheless contributes to the eutrophication process by draining nutrient-rich water from the fields into surrounding water bodies.
To solve this issue, our team looked to the earthworm, villi in the small intestine, wetlands, and the soil/biotic cycle for inspiration. These organisms and natural processes were chosen for their filtration, sequestration, and symbiotic abilities.
Using the above biomimetic strategies, our team has developed The Living Filtration System (LFS), a closed-loop drainage system. LFS uses soil micro-organisms to retain nutrients in the soil so that they can be absorbed by plants rather than leaving fields as runoff. Doing so will greatly reduce nutrient input into surrounding water bodies, and eliminate one cause of eutrophication. The requirements we placed on the design were that it required minimal/no maintenance after installing; it must serve as a catalyst for changing current farming techniques; and it must have the potential to be widely adopted at a variety of different scales and phases.