Wednesday, June 27, 2018

It's Water-Wise Wednesdays with Frannie the Fish! {Irrigation: Aquaculture and Hydroponics}

This is the fourth part in Frannie's exploration of irrigation. Check out the previous post here!

Like Frannie mentioned in the last blog, there are two types of urban agriculture that are very unique: aquaculture and hydroponics. Both of these processes are almost solely water-based and require the farmers to be creative in the way they save water and money.

Aquaculture is usually defined as the raising fresh and salt water fish but it can include other kinds of water creatures and plants. It produces healthy, high-quality fish that can either be used to stock lakes for people who like to fish or sold directly to markets for consumption.

Fish can be raised in wide open waters or in smaller tanks depending on space availability and the species of fish. Fish-farming has a long history and has played a culturally important role for those who do it. For over 4,000 years, the Chinese have bred and raised a meaty carp and the Japanese have farmed koi that can often sell for thousands of dollars.

Hydroponics is a system that, instead of growing plants in the soil, grows them in a “nutrient solution” or water jam-packed with plant food. Plants “eat” and “drink” through a recirculating system.

At home, you can model this by planting a small plant in a 2 liter bottle with a string connecting the nutrient solution in the bottom to the plant bed.  In an urban farm, however, highly technical systems can grow many rows of crops that are layered on top of one another so that a very small area can have a high crop density.

If an environment allows, a hydroponic farm can benefit greatly from an aquaculture farm.  In an earlier blog post, Frannie demonstrated that old fish water can actually help grow beautiful gardens. Aquaponics does that on a much larger scale, repurposing the nutrient-rich water from the fishery tanks to feed the plants in the hydroponic system. The plants and micro-organisms clean the water that is then returned to the fish tank. This provides a mutually beneficial environment for both the fish and the plants, and results in two crops (the fish and the plants).

In urban environments farmers have to be creative in the way they use space and water, but ultimately they can be very productive. Share with us some of your creative ways to use water and space and check out past blogs to learn more about irrigation!

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