To understand how waste transformation farming works, we can do no better than to take a look at the work of Dr Paul Olivier. This disarmingly humble man – lives in Vietnam – and devotes his life to empowering the poor through waste transformation.
He’s developed a transformation model for biodegradable (organic) solid wastes.
Waste Transformation is a 4-step process: Wastes are identified…then they are categorised…and we add value to them…before putting them to their highest use.
4 Steps to Waste Transformation
- Value Adding
Waste is available from many sources – often just for the taking.
There are many different types of biodegradable waste. The following list is not exhaustive, but it will provide some insight in the scope of organic waste opportunities waiting to be exploited.
- Spent brewer’s grains
- Cardboard and paper
- Eggs shells
- Grain husks and hulls
- Plate scrapings
- Meat and fish scraps and offal
- Nut shells
- Plant residues
- Spoiled hay
- Stale bread and pastry goods
- Sawdust/wood shavings
- Urine – animal and human
- Manure – animal and human
- Windfall wood., twigs and leaves
- Coffee pulp
- Coffee grounds
- Weeds and grass
- Waste heat and expired CO2.
….and many others.
Of course, you don’t have to generate these wastes yourself. All you have to do is find them in your area…and then do the person who owns them a favour by taking care of their waste problem by taking them back to your place.
Is rice grown (rice hulls)? What about nuts (like almonds, macadamias, walnuts)?
Are there any shearing sheds in your area (the farmers will often allow the removal of sheep manure from under the sheds)…or is someone keeping horses (horse manure)?
Are your neighbours mowing grass that they might like to deposit in a heap at your fenceline?
Do tree loppers clear trees from around powerlines and then mulch the waste? Some morning tea or a light lunch may score you a truckload of mulched tree waste.
Is there windfall wood on the roadsides that you can harvest?
Do you live near food processing operations, restaurants/cafes, hotels or anywhere that has food wastes?
Once you identify prospective waste sources, think about the logistics of collecting and storing the waste.
What quantities of the waste are available? Is your requirement for this type of waste continuous, intermittent or regular? Do you have space to store the waste?
Do you have to pay for it? How much? What is the cost of recovery and transportation? Even if you do not place a financial cost on your time, do you have to use a vehicle to recover the waste…or are they being delivered to you…at a cost?
Can you ensure that the waste that you collect will not create a nuisance (like odours, flies, vermin) for your neighbours? Anxious neighbours are a clear and imminent threat for micro-farmers so you should not give them cause for concern.
To categorise available wastes:
Those wastes are divided into those which are putrescent…and those which are non-putrescent.
putrescent…. undergoing the process of decay; rotting
Further, split these categories into high grade or low grade.
And then rank the wastes in order of nutrient content.
Type 1 waste (e.g. fresh food and spent brewery grain) contains a lot of nutrients. Ideally this waste should be used for feed for higher animals. Lactic acid fermentation is the preferred way to transform Type 1 waste into feed. Another simple and effective way to ensure that food wastes are pathogen-free is to flash fry them.
Type 2 waste is food that is unfit for consumption by animals. Arguably the best example is livestock manure. Generally, there’s no better nor quicker way to transform this type of waste than through the combined action of larvae and worms.
Type 3 waste (e.g. leaves and coarse plant residues) is easily broken down by composting microbes into soil conditioners and amendments.
Type 4 waste (e.g. bamboo prunings, macadamia shells, wood shavings, twigs, rice hulls, etc) is the stuff that won’t quickly break down in the compost heap and is often carted to the tip – or just discarded. Type 4 waste, however, is ideal for the production of syngas and bio-char.
When we obtain:
- grain husks and hulls – or wood shavings or sawdust – and add animal urine to them to mesophilically compost them
- plant processing wastes and ferment them so that they become pig and poultry feed.
- fish wastes and mineralise them to become plant nutrients
- nut shells and burn them in a top loading updraft gasifier to get biochar and high-grade heat
- animal manure – or coffee pulp – and feed it to black soldier fly larvae to produce high quality animal protein
- food processing and aquaculture effluent and vigorously aerate it to produce plant nutrients
- kitchen wastes and flash fry them to become pig and poultry feed
…we are adding value to them.
Organic waste sources abound and the opportunities to add value to them are limited only by our imagination.
Another key WTF principle is that waste should always be put to its highest use.
High-grade putrescent waste (Type 1) should not be composted or fed to larvae and worms, unless it has spoiled to the point where it can no longer be preserved as feed for higher animals.
We only burn Type 4 wastes in a device that will give us biochar in addition to the high-grade. The effort involved making a top loading updraft gasifier (or the investment in buying one) is worthwhile in any situation where the waste is of uniform size…like nutshells, rice hulls and wood pellets.
Low-grade putrescent (Type 2) waste that can be fed to larvae and worms should not be composted. Larvae, worms and worm castings are far more valuable than compost.
That’s essentially how waste transformation farming works. It’s about identifying waste streams…adding value to it where necessary…and ensuring that we put all so-called ‘waste’ to its highest use…to achieve the greatest value from each waste type.
By treating waste in this way, we produce valuable farming inputs (feed, biochar, compost/fertilizer/plant nutrients at little to no cost.
The next article will look at the benefits of WTF.
If waste transformation farming interests you, and you’d like to talk about it with other like-minded people, feel free to take up membership of my Have More For Less forum.