The information paradox
The world is changing at an incredible rate. Climate change, the virus and the polarisation of the political system are immense problems. New technologies like artificial intelligence may seem beneficial, but whatever the benefits, they increase inequality between the haves and have-nots.
Innovators like me ask how we can develop technologies to help mitigate these problems. Often, that is the easy bit. A bigger problem is how to make that technology widely available with clear, relevant documentation.
It’s not enough to invent better systems—we have to make them simple enough for everyday people to use and maintain.
It is tempting to focus on the new developments, but at times an overview is needed to keep things in perspective. This is such a time, so I start with an overview.
The birth of Wicking beds
It is approaching thirty years since I was invited to go to Ethiopia to see if there was anything I could do to help feed people during one of those terrible droughts.
I could see the two main issues were lack of water and lack of nutrients. Nutrients were the easy bit. Weeds may be a pain, but they are incredibly effective at extracting the last bit of nutrients from the soil and can then be used as fertiliser.
Water was a bigger problem, but I had travelled extensively in the Australian deserts and seen a natural phenomenon: water being collected in clay basins, flowing to the lowest point then wicking up to feed luxuriant vegetation in the middle of a dry desert.
That was the birth of what I named Wicking beds—dig a trench, line it with a waterproof layer (clay or plastic film), load the base with weeds, then backfill with soil.
There was no question of the weeds going putrid by soaking in stagnant water—this was in the middle of a severe drought.
Publicity vs technology
On my return to Australia I wrote about this and the idea caught on. But some bright spark decided they could “improve” on this by replacing the weeds with stones and adding a cloth layer to prevent the soil and roots entering the water zone.
This actually works fine as a self-watering bed, but it does little to improve nutrients or soil biology.
We live in an era where publicity often beats good science. Stone-filled “wicking beds” became popular not because they were biologically superior, but because they were well-promoted.
We live in an era where skills in publicity are often more important than being technically correct, so wicking beds with stones caught the public imagination.
Sponge beds
I had yet another idea: the sponge bed. This was even simpler than a wicking bed. Take off the topsoil and level the ground. Fill with any organic material that is available, then replace the topsoil.
This gives three layers: the underlying earth, a layer of soft, spongy material with very high water-holding capacity, and a layer of regular soil on top.
Plants could be germinated in the top layer, then put down their roots into the moist, nutrient-rich layer below.
There was no attempt to contain the water. These systems relied on surface tension in the sponge layer to hold water in place.
Have no doubt—this was a great system, but it just did not catch people’s imagination and it went the way of many other good innovations: just a dot in the history books.
The bugs arrive
We seem to have suddenly “discovered” microbes. Bugs (or more politely, microbes) arrived well before any other living creature. They were the first, and they made all other life forms possible by making soil and nutrients available so plants could grow.
For a long time humans thought bugs were bad and had to be killed off. Then, in a flash of inspiration, we realised there were good bugs and bad bugs—and that our very lives depended on the good bugs.
We spent time and money trying to work out how to kill the bad bugs without killing the good ones, with limited success. Then we discovered another truth: if we manage the conditions in favour of the good bugs, they simply outbreed the bad bugs.
Gbiota beds are not about killing microbes, but about creating conditions where the good microbes win the breeding race.
That is what Gbiota beds are all about: creating the conditions where the good bugs outcompete and outbreed the bad bugs—a concept nature worked out a few million years ago. But we got there in the end.
Flood and drain
Plants need nutrients, water and air. We can achieve this with flood and drain. The basic principle has been known for years.
Lower a container into water and it will expel the stale air.
Let the water drain out and it sucks fresh air into the soil. This cycle of flood and drain means the soil is actually breathing, expelling stale air and taking in fresh air.
Making it work in practice
Of course, we cannot just raise and lower a complete paddock. Instead we use a pump to flood the base of the bed, purge the air, and then let the water drain away to suck in fresh air.
This works well, but a snag appeared.
KISS – Keep It Simple, Stupid
I have been writing articles about breeding beneficial microbes in Gbiota beds and people tell me it all sounds too complicated. So I have been experimenting to find the simplest possible way.
To explain this, I introduce a few made-up characters—George and Mary. The crux is for George to grow Wickimix, the soil that goes into Gbiota Wicking boxes. He is willing to make and sell Wickimix to extend his retirement funds, and he is also happy to help Mary by giving advice and encouragement on what to grow in the various seasons.
Randy bugs
Microbes breed incredibly fast—it is classic exponential growth. Breeding is not the problem; the real problem is that bad bugs grow equally fast. So the name of the game is to create conditions where the good bugs outbreed the bad bugs.
That is the key to the Gbiota system, and moisture level is the critical factor.
Most readers know the basic principle of Gbiota beds: flood from underneath for a short period to expel stale air, then drain to suck in fresh air.
And the rains came
I had a wake-up experience with all the heavy rains and flooding we have been experiencing in my neck of the woods. This is a global phenomenon we have to learn to live with.
Yes, I am one of those “nutters” who thinks that climate change is real and that the biggest threat will be to our food supply. That’s why I write all this.
It is not just climate change. We have been destroying our topsoil by using toxic chemicals which kill off the natural living microbes that create soil in the first place.
I am now a great-grandad and I want the generations that follow to have a decent life.
Experiments with Gbiota beds
My latest experiments started when my garden was flooded. There are two main types of flood:
- Fast water coming from upstream, washing over everything in its path
- Back-flooding from downstream, when water cannot escape and rises more slowly
My original beds were in-ground beds at the same level as the parent soil. They suffered from fast-flowing water washing over the top. The first big change was to fully raised beds.
At first I used conventional raised beds in rows, but I realised it could be made much simpler.
Basically, take whatever ground you have and lay Ag pipes (the common corrugated pipes with holes you buy at any hardware store). These are used as both drainage and irrigation pipes.
Previously I made my beds with a plastic liner to avoid wasting water as it soaked into the ground. But I live on a duplex soil with a layer of heavy clay under silt, so I experimented with no liner. It may use a bit more water, but not that much.
On sandy soils this won’t work well, but we can copy the canal builders of old and import a layer of clay.
In the past I was fanatical about making the entire bed totally level. Now I just make sure the pipes themselves are level so they can run along a contour line.
Making the raised bed
My first experiment was a conventional raised bed with a filler-cum-drain pipe.
Then I realised there was a better way. Rather than multiple narrow beds with furrows, I now make one wide bed with multiple drainage pipes.
In simple terms:
- Take any piece of ground—if it’s sandy, add a layer of clay.
- Lay a series of Ag pipes along the contour line.
- On my block, I use about 1.5 m spacing between pipes.
Filling and drainage pipe
The ends of the pipes need to be raised: the inlet above the bed surface for filling, and the outlet at least one pipe diameter higher, to create pressure so water flows into the surrounding soil.
The pipe is raised by pushing some soil underneath it. That soil must be porous so that after flooding, the water can slowly drain away.
This “leaky dam” allows a short-term flood and then a drain—partial flood and drain.
Organic waste
Next, cover the whole bed with organic waste.
We need lots of organic waste. It sounds simple and sustainable, but getting clean organic waste is more difficult than it seems. A huge percentage of food grown is wasted and dumped into landfill to make methane.
Setting up large-scale systems to recycle organic waste is something humans need to learn to do. The Gbiota team can’t fix that alone—it needs government action—but we can at least demonstrate how to use it well in soil building.
I have found grass clippings are one of the easiest waste sources to access.
High-temperature composters rightly focus on precise carbon-to-nitrogen ratios. But our stomachs don’t run at 60°C, and we are trying to breed the microbes that will end up in our gut. With in-ground systems, lower temperatures and longer timeframes work fine.
There are many soil creatures that help break down organic material—worms, soldier fly larvae and countless small organisms. Much of the composting happens inside the gut of these animals, not just in the soil itself.
Books say you should avoid citrus, onions and so on in compost. In my in-ground systems, something always appears to eat everything. Come back after a few months, dig down, and you’ll find beautiful soil and no trace of orange peel or onion.
Nitrogen
If there is not enough nitrogen, woody material in organic waste never seems to decompose. Adding extra nitrogen in soil-based composting doesn’t seem to cause problems.
I therefore make sure to add plenty of nitrogen. For me, that’s free-range chicken manure—again, it depends on availability and quality.
Manures, especially chicken manure, can be quite acidic, so I add Dolomite. It helps buffer acidity and adds calcium and magnesium.
Human manure
I used to live on an eco village and used human manure to grow plants in special beds not used for food. I then used those plants as compost material, so I was not using human manure directly—and I am still alive.
Minerals
After organic waste and manure, we need minerals. Typically we are short of magnesium and zinc.
Basalt (a volcanic rock) is rich in magnesium plus a broad spectrum of trace minerals, including iron. Volcanic rock dusts usually supply most trace elements, perhaps except zinc.
My local supplier sells “cracker dust” for driveways. As far as I know, it is essentially basalt. I can buy it by the tonne for a fraction of the cost of small “garden” bags.
I also buy 20 kg bags of calibrated rock dust (Biomin) to ensure the trace element balance, including some zinc.
I notice that adding minerals markedly improves the structure of the final soil (Wickimix).
Zinc
At the home gardener level, blood and bone fertiliser contains plenty of zinc. On a global scale, zinc supply is a bigger issue—along with the elephant in the room: phosphorus.
As most of our waste ends up in the sea, it may be time to buy shares in a seaweed company.
Ratios
It is difficult to give precise numbers when dealing with variable organic waste. What matters is the final result, but here is a typical mix, using organic waste as the reference:
- 1,000 kg organic waste (largely green material)
- 500 kg chicken manure
- 100 kg basalt (cracker dust)
- 10 kg premium rock dust (Biomin)
- 10 kg organic fertiliser containing zinc
Soil creatures
Now we need the creatures of the soil—from viruses and bacteria to worms, soldier fly larvae, geckos, lizards and birds. They may seem like a nuisance, but they play critical roles in the ecosystem.
You will notice I’ve left out cane toads. I’m not sure what role they play in a balanced eco system, but if you want some, you are welcome to visit my place and take as many as you like.
In an open garden bed, most creatures will arrive naturally once conditions are right.
There are two possible exceptions:
- Heavily cultivated soil may lack essential microbes—this can be fixed by adding small amounts of soil from natural bush.
- Compost worms may need to be introduced, even if you already have some earthworms.
Once worms are present and well-fed, they will multiply quickly.
It’s the plants that feed the microbes that make the soil
This is my Gbiota bed for making Wickimix. It looks a total mess, doesn’t it? If you read anything about gut biology, you’ll see the word diversity over and over. The wider the range of microbe species, the better.
Each plant attracts different species of soil microbes, so I plant a whole range of species. I also use the bed for seed collection.
So yes, it’s a bit of a jungle, but that’s what you need in your gut.
Just say to yourself one hundred times: I need diversity.
If you were a few million years old (which is nearly as old as me), you would have observed the first creation of soil. It may have started with microbes breaking down rocks, but that was incredibly slow because there was no external energy source.
As soon as a bit of soil formed, plants began to grow. They captured energy from the sun and used it to create simple and complex chemicals, particularly sugars, which they exude from their roots to attract specific microbe species.
For example, sunflowers are particularly good at attracting mycorrhizal fungi. You can’t see the fungi themselves, but you can see the soil turning white from the network of hyphae.
I did buy mycorrhizal fungi powder once, but now I just plant sunflowers.
I don’t know exactly which microbes each plant attracts, so I use a mix of about 26 different plant species to get a good balance of microbes in the soil.
Magical water and air
Plants and most living creatures need a specific combination of air and water. Some plants like rice and watercress can survive and flourish when submerged, while others like cacti rot easily if waterlogged.
The great challenge is to get the optimum ratio of water and oxygen. Even liquid water contains dissolved oxygen—fish rely on it just as we rely on air.
A good understanding of how water moves through soil is essential, so I recommend my short article on water.
Water has a particular attraction to most soils and is at the heart of growing anything. Wicking beds are one way of exploiting this.
Types of wicking beds
There are three main types of wicking beds:
- Twin-container beds – One container holds the soil and plants, and another below holds water. Wicks transfer water upward. All space in the lower container can be used for water storage. These are efficient and have few issues with stagnant water if well-managed.
- Stone-based beds with a cloth barrier – The lower layer holds water among stones and is covered by cloth to keep soil out. These rely mostly on evaporation and condensation rather than true wicking. They work as self-watering systems but don’t do much for soil biology.
- Sponge beds – These have a lower layer of organic material with very high water-holding capacity. There is no cloth barrier; roots are encouraged to enter the sponge layer to take up water before it can go putrid.
In terms of water storage, sponge beds sit between twin-container systems and rock-based systems. But they have a major advantage: they create a zone with an ideal mix of air and water for breeding beneficial microbes.
These microbes are drawn into plants and become part of what we eat—natural pre- and probiotics.
Sponge-style Gbiota beds are, in effect, microbial nurseries that grow the gut-friendly organisms we need for long-term health.
Where are we up to?
To summarise the process:
- Remove and temporarily store the topsoil (or bring in new topsoil).
- Lay irrigation/drainage pipes along the contour line.
- Create a 300 mm layer of the best organic material you can access.
- Replace the topsoil and plant a diverse range of species.
Then:
- Make a sump, fit a pump with a manifold to each pipe.
- Fill the sump with water and let the float switch run the pump until water returns to the sump.
This works well, but some people don’t want pumps or don’t have electricity.
Nature’s solar pump
I use solar pumps and they work well, but there is another solar pump—plants.
A large tree has a pumping capacity comparable to a high-powered fire pump. So why not use plants as pumps?
At the end of the leaky dam, plant water-hungry species. I like spinach—it is tough and keeps growing year-round—but tomatoes and many other plants also work (just not cacti).
To irrigate, push a hose with running water into either end of the Ag pipe (past the leaky dam if at that end) and leave it until water flows out. Then move on to the next pipe.
It is simple and effective, but not automated like an electric pump. As they say—horses for courses.
Maintenance
The prime purpose of the Gbiota bed is to make Wickimix (see the stories about George and Mary in the Gbiota news section).
The key point about microbes is that they breed like crazy but die quickly. So think “keep it fresh”.
Work the bed in sections: dig out Wickimix to put into Mary’s Gbiota box while it is fresh, and bury available organic waste (she may even bring you some).
This way the Wickimix is always renewed.
When you re-seed, surface watering is needed until roots reach the moist zone. The surface of a wicking bed should be dry to reduce evaporation losses, so early surface watering is essential for germination.
With a flood-and-drain system, some irrigation control is still needed—such as switching off during heavy rain. With a manual system you must regularly check moisture. Flash moisture meters are available, but I use a cheap auger—I can see and feel the moisture distribution.
Gbiota boxes
This is a simple, effective system for making Wickimix, and it works really well.
Wouldn’t it be nice to have a similarly simple system for wicking boxes? I’ve been experimenting with that too. It is a bit more challenging, as Mary has no time for fiddling around growing things, but I hope to share that story in my next post.
I will also introduce you to Sue, who has only a small garden but is fanatical about recycling and wants to reuse all her waste herself in a wicking box.
