Permaculture adventures in Sector39

A classic sub-urban permaculture garden, by Claire Gregory

This post is a collection of thoughts on food production opportunities using permaculture design thinking.

With declining oil reserves and the high dependence of agriculture on fossil fuel derived inputs its seems highly likely that food production is going to have to change significantly. One of the key challenges will be that of producing protein. The need to reduce climate changing gasses emissions is a further challenge to food production and methane and NO2 and significant damaging outputs of current practices. So first up is this amazing aquaculutre system, which is an excellent example of a closed loop system that makes best use of the biproducts of the fish to input into the cultuvation of plantmatter, which both cleans and oxygenates the water whilst growing food stuffs for the fish.

I have not given much thought to tilapia production here in the UK as water temp is a critical factor, and not suited to Welsh climate, however, this has sparked my interest and this is a subject i would like to explore further.

There is a series of videos on the same farm here..

Here are some notes on the geographical range of outside Tilapia production and the implications for indoor growing.

The geographical range for culturing tilapia in outdoor tanks is dependent on water temperature. The preferred temperature range for optimum tilapia growth is 82° to 86°F. Growth diminishes significantly at temperatures below 68°F and death will occur below 50°F. At temperatures below 54°F, tilapia lose their resistance to disease and are subject to infections by bacteria, fungi and parasites.

So that is 30 deg C down to 10 degrees, meaning to grow them successfully in Wales we would have to heat the water. this is the case in the example in the video above, so it might be interesting to consider our options if we wanted to produce tilapia here in Wales. I wonder if this wold be possible with a mix of solar thermal with a biomass back-up?

Common Bream

I am also interested in the bream, it is a bottom feeding lake fish, that eats insect larvaie, worms, and snails as well as pond weed and daphnia. I am thinking that they might be ideal for a cool aquaculture system that we might be able to reproduce in Wales without needing estra heat input. They can self feed happily, and respond to extra feeding apparently.

Biochar
Another key line of thinking and area that requires research is that of biochar. It is the chance to use NO2 free fertilizers that build water retention in the soil and develop the microbial content as well, which in turns holds nutrients in place and can make them available to plants.

There is growing interest in this potential, here is a recent USDA article on the subject. What is immeditely apparent is that much research is required, and that biochar from different sources, prepare in different ways, and added to different soil types all brings about results. Further more… biochars can be innoculated with different nutrients before being introduced to the soil, preventing nitrogen robbery and kickstarting the positive effect the biochar can bring about in the soil. In his brilliant book, Biochar solution, Albert Bates likens it to a coral reef. If it is not the reef itself that provides the fertility to the environment, but it creates a matrix that life can fix onto. In terms of edge and the famed permaculture edge effect, it vastly expands the edge within the soil providing micro cavities that can be occupied by beneficial organisms, all feeding off each other, storing water and making nutirents avialble to the plants. In fact Biochr Slution is misnamed as a book, in that it is much more about a wider relationship with and undrstanding of soil. Biochar merely being a component of that, or a factor in our relationship with soil..

From: http://www.biochar.org.uk/

What is biochar?

Biochar is a carbon-rich product, created by the slow burning of plant material with little or no oxygen. Biochar is organic, increases crop yields [3, 4, 5], improves fertilizer efficacy, breaks down pesticides, suppresses methane and nitrous oxide (two aggressive greenhouse gases) [6, 7] and sequesters carbon [8]. On a large scale, it is proposed as a method for reversing the carbon dioxide (CO2) build-up in the atmosphere, thus mitigating climate change.

Get involved in the Big Biochar experiment Set up a 1m sq test plot and receive a fre bag of biochar to test it out.

Smoke free back yard biochar burner

Here is an excellent radio interview with Bill Mollison (45 mins)

And here is Richard Heinberg relaxing in his back garden and explainging wny the end of growth will afford more opportunities for happiness.