Data collected from 1400 households across numerous local authorities has indicated that food waste makes up 30% by weight of average household waste. This equates to 2.84 kg per week or 148kg per annum.
This was made up of 54% avoidable, 12% potentially avoidable and 34% non-avoidable food waste .Based on the audit, the average household spent $10.83 weekly on food that is wasted unnecessarily [$563] annually. On a national basis this equates to $872 million per annum.
(ref NZ Food Waste Audit Report 2015).
If we take the potentially avoidable and non-avoidable food waste and view this as a household resource rather than a waste product by composting it, householders can make a difference by reducing amounts of organic waste going to landfill.
A simple and easy method to compost the household potentially and non-avoidable food waste is to utilize a method called Bokashi.
Bokashi is a process of fermenting organic waste instead of decomposing it. It is a very sustainable practice for diverting food waste that is efficient and cost effective without causing environmental problems. Organic waste is essentially pickled using a suite of beneficial microbes. These microbes are all safe and are sourced from within the local environment. Many are used in common everyday food processing, such as yeast and lactic acid bacteria..
In the process, organic waste is fermented in airtight an environment where very few microbes can survive. Some greenhouse gas- producing microbes cannot function or survive under these conditions and virtually all disease causing organisms are destroyed and incapable of survival.
This fermentation process is very efficient taking only about 7 days to convert raw organic waste into a completely fermented end product, that can then be placed in the soil where it is rapidly converted into a nutrient rich organic soil useful in sustaining microbial diversity in soils .This process is generally around 4 weeks in New Zealand. This process has been used in farming throughout the world and has proven to increase crop yields effectively without or minimal supplemental fertilizers.
Added directly into the soil fermented food-waste does not require a fixed ratio of carbon to nitrogen, nor require the addition of any additional feedstock. Soil can be made available for planting in a very short time with seedlings being able to be planted within 10 days of adding the fermented material to the soil.
These factors make the system ideal for the homeowner where it can successfully used in the home garden to enhance the garden soil and reduce purchase of chemical fertilizers and pesticides and return healthy food back to the table .
Mary Tingey from ‘A Place of Learning’ in Christchurch, and who runs organic gardening courses says ‘clients of mine used mainly bokashi for soil fertility and were blown away by how the plants grew. I still think for city dwellers Bokashi is the quickest best way to create soil fertility.’
Food waste contains many of the nutrients required for plant growth and when fermented and added to the soil add these plus millions of beneficial microorganisms and their metabolites which in turn enhance the soil health and in time leads to a disease resistant soil.