We have moved again - now at St Kilda. You can contact us on 0411 105 365. We are in the process of setting up hydroponic and aquaculture displays.

Monday 0930 to 1730
Friday 0930 to 1730
Saturday 0930 to 1230

We are available for consultation and site visits at these times- other times by appointment by email (robin@soladome.com.au)

After 35 years at 44 Chapel Street it was time for a change to a web based operation and to offer guidance based on many years of practical experience.

 

 

What is Polyculture?

The word has been created from two words – poly meaning many and culture meaning a crop of experimental bacteria or the like. The general understanding of polyculture is the growing of more than one crop within the same cultivation system.

The word has been created from two words – poly meaning many and culture meaning a crop of experimental bacteria or the like. The general understanding of polyculture is the growing of more than one crop within the same cultivation system.

In hydroponics a polyculture system might have aquatic animals living in the reservoir that is used to fertilize the plant crop being grown. In aquaculture a polyculture system might have some plants growing in the animal culture water so that the plants take up some or all of the aquatic animal waste products.

A well-designed polyculture system is likely to have similarities to a permaculture system – the elements within the system are in balance.

A very sophisticated polyculture system would have different animal and plant species in the various levels of the water column, crustaceans on and in the bottom substrate, a bottom dwelling fish species under a mid level fish species with aquatic plants and surface dwelling fish species on and near the water surface and then some terrestrial plants being irrigated with part of the culture water before the water is returned to the culture system.

Simple polyculture systems can be made by using a water reservoir, putting some washed quartzite gravel in the base, filling with water and establishing some crustaceans like yabbies and native fish, Aquatic plants can be grown on foam floats on the surface and a small pump can be used to pump the water from the reservoir through a series of plastic gutters that contain plants and then returning to the reservoir.

Matching the requirements of the animals and plants in the system to their relative sizes and quantities is the key to keeping the whole system in balance. A good balance results when the outputs from one animal or plant are utilized by another in the system and waste products from the cultivation are fully utilised in the system.

Our experience has shown that in our system 15 to 25 grams of high-energy fish pellets (40% protein) fed to four yabbies and 50 Murray River Rainbow fish (4 cms long) per day in a 400 litre tank supplies enough food to sustain the fish and yabbies. The organic waste products from the fish and yabbies are acted upon by heterotrophic bacteria to produce ammonium ions. A small biofilter in the system allows autotrophic bacteria to oxidise the ammonium to nitrite and nitrate ions. The 24 plants in 10 cm pots that are part of the system remove the ammonium, nitrite and nitrate ions and use these through the process of photosynthesis to grow. The only power used is a small submersible water pump of 18 watts to pump the polyculture water up to the plastic troughs that contain the plants in pots and to the biofilter.