Urban Food Production

Overview

Urban food production is one of the best strategies for reducing Greenhouse Gas (GHG) emissions and to learn about sustainable practises.
When supplies of cheap fossil fuels (oil, coal, gas) were cut off from Cuba during the Special Period (1990-2000) the population reverted to organic and permaculture farming practises both in cities and in rural areas. Collectively they were able to reduce per capita GHG emissions to 4 tonnes per person per year.
They did this by composting organic waste material, planting nitrogen fixing cover crops, and using more human labour inputs to help manage local food production. Organic, regenerative and permaculture food production techniques were widely practised as presented in the documentary film The Power of Community: How Cuba Survived Peak Oil

You don't become an expert gardener overnight. It takes years of practise.
To get a head start it worth joining a Community Garden or attending a course such as the CERES Complete Urban Farming Course presented by Justin Calverley which runs for 14 weeks (weekly sessions). There is also a book that accompanies the course titled The Urban Farmer.
There are also other good on-line resources to draw inspiration from:
- My Smart Garden and especially the Resources section that has instructional videos from local experts.
- My Green Garden by Maria Ciavarella has a focus on Italian food production and preservation practises.
- Deep Green Permaculture is an excellent resource prepared by Angelo Eliades and showcases a Permaculture urban food forest in Melbourne, Victoria, Australia.
- Huw Richards - Permaculture Inspired Kitchen Gardening on YouTube which presents short, easy to follow gardening videos for beginners.

There are two big issues that need to be addressed with urban farming, but are rarely discussed.
- Water loss as stormwater (roof rainwater) and water loss to sewage (toilet flusing, showers, sinks)
- Nutrient loss mainly to sewage (nutrients in our urine and poo).

It requires a large amount of water to grow food.
Foodprint Melbourne project has found that it takes over 475 litres of water per person per day to grow our food Food Print Melbourne, Dr. Rachel Carey, University of Melbourne. This number would be lower if Melburnians ate less meat, dairy and processed foods, which in general require larger water inputs in comparison to more vegetarian based diets.
Growing food locally at home, using roof water and large rainwater tanks (10,000-20,000 litres storage), grey water diversion to the garden, taking shorter showers (2 minutes) and using dry composting toilets leads to an overall reduction of total water usage ANU Press Troubled Waters: Confronting the Water Crisis in Australia’s Cities
Ideally we should prioritise water use at home to grow food and plants. Minimal water should be used in the home for other household requirements (e.g. 2 minute showers, dry-composting toilet, cooking and drinking).
The United Nations recognises our basic right to clean water and estimate that daily water requirement should be 50 to 100 litres per person per day UN The Right to Water
Melbournian's currently use 155 litres per person per day and most of this water is sent to the sewer.

Nutrients are naturally contained within soils and can be made available to plants through:
- composting of food and other organic material
- weathering of rock to release minerals
- fixing of nitrogen by nitrogen fixing plants and associated bacteria
- addition of other inputs such as crushed rocks, seaweed and shells
However, in a typical household most food nutrients are lost because they are flushed into the sewer.
To recycle these nutrients back to the garden requires a waterless composting toilet. As a first step urine can be recovered in a pee bucket, diluted with water (1 in 10) and used as a liquid nitrogen fertiliser on the garden.
The correct processing of humanure is detailed in The Humanure Handbook by Joel Jenkins. This book is also available for free as a pdf on The Internet Archive.
The Victorian EPA also presents a list of approved Waterless Composting Toilets].
Humanure can be safely used under fruit, nut trees and in non-food producing garden beds (but not for most Australian natives because they prefer soils low in nitrogen).
Food waste can be safely composted and used in vegetable food growing beds.