Tuesday, January 10, 2017

Aquaponics, What's all that about then?



 Thanks to Milkwood for the pic



Seed catalogues are a welcome browse for the New Year. You can get online ones but there’s something more satisfying turning the glossy pages of your favourite seed companies. I do order online though after flicking through the pages and try to get the packets by at least march for planting in April.

Klaus Laitenberger from Milkwood farm always says that the most common garden activity is sowing seeds too early in the year. He and I think it’s far better to wait until the farmer warms his bottom on the soil (or so I’ve been told, I’d opt for a thermometer in the soil).  With the exception of a few vegetables the majority should only be sown/planted from April or May onwards.  Sowing too early often means poor or no germination (each crop has an optimal germination temperature), poor growth and more pests and diseases.

There are exceptions for early planted crops such as early potatoes (planted in mid-March), onion and shallot sets (planted from mid-March onwards), garlic (February to March at the latest), broad beans (February to early April) and Jerusalem artichokes (planted March).

Planting now
Try sowing the seeds of aubergine, beans, cabbage, carrots, cauliflower, kale, leeks, onions if you really feel the urge to start early as these are pretty hardy.

If you fancy starting some flower seeds then choose for a wide range but remember again to keep them protected. Choose from: Achillea Antirrhinum Begonia- both seeds and tubers, cactus, cineraria, coleus, cyclamen, delphinium, geranium, lobelia, lupin, sweet peas, verbena and a host of other annual and perennial plants.

No Soil gardens
If the thought of tidying up the garden and getting mud through the house for spring is a daunting prospect, how about relaxing, staying clean and growing with just water?

Aquaponics
Aquaponics is the up and coming way to grow vegetables and other plants in environments that are too harsh for regular growing. Aquaponics is essentially the combination of Aquaculture and Hydroponics and can be as small as a fishtank or as large as a farm. 

Definition:
Aquaculture, also known as aquafarming, is the farming of fish, crustaceans, molluscs, aquatic plants, algae, and other aquatic organisms. 

Hydroponics is a subset of hydroculture, which is the growing of plants in a soil less medium, or an aquatic based environment. Hydroponic growing uses mineral nutrient solutions to feed the plants in water, without soil.

Both aquaculture and hydroponics have some down sides, hydroponics requires expensive nutrients to feed the plants, and also requires periodic flushing of the systems which can lead to waste disposal issues. Re-circulating aquaculture needs to have excess nutrients removed from the system; normally this means that a percentage of the water is removed, generally on a daily basis.
This nutrient rich water then needs to be disposed of and replaced with clean fresh water.
While re-circulating aquaculture and hydroponics are both very efficient methods of producing fish and vegetables, when these two techniques are connected, these negative aspects are turned into positives. 

How it works
It needs a container for the fish and one for the plans with a circulation pump. The plants extract the water and nutrients they need to grow from the water, cleaning the water for the fish. There are bacteria that live on the surface of the clay ball growbed media that holds the plant roots in place. These bacteria convert ammonia wastes from the fish into nitrates that can be used by the plants. The conversion of ammonia into nitrates is often termed “the nitrogen cycle”. The fish water can be filtered through a worm bin.

Sensitive ecosystem – The system relies on the relationship between the fish, bacteria, worms and plants to maintain healthy ecosystems for each of the species. Water is only added to replace losses from absorption into the organisms, transpiration by the plants and evaporation from the tanks. As a result the system is very water-efficient compared to conventional vegetable production and ideal for areas with little available water.

Local initiative
There is a system in place at the Playtrail in Pennyburn, Derry.  It’s a partnership between students from The Playtrail and Ardnashee School and College and the Nerve Centre’s FabLab. It’s funded by Comic Relief and almost 100 young people are involved in the region’s first social enterprise aquaponic digital farm.  The idea has gone from the initial concept, design to build and maintenance and is still being developed. Some lucky members are going on a fact finding mission to a larger set up in Bristol to find out more about the idea and how to improve the system.

Using state of the art digital fabrication equipment from the Nerve Centre’s FabLab, students are receiving hands-on training and experience in a range of digital design and making techniques, allowing them to design, build and operate an aquaponic farm for themselves. The initial system at the playtrail is already in place and supplying fresh herbs and salad plants to a cafe in the city.

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