Soils to supply essential nutrients

Colin Austin 1 Nov 2015 © Creative commons this document may be reproduced but the source should be acknowledged. Information may be used for private use but commercial use requires a license.

Health starts in the soil?

How diet affects health is a hot topic - but the chain starts in the soil, this Newsletter goes to the start of the chain by looking at how to create soil which will make us healthy.

In previous articles I have talked about metabolic syndrome (fat around the vital organs) and how it leads to diseases such as diabetes, heart attacks and strokes. There are immense personal costs - diabetes is the most common cause of amputations and blindness and is the single largest drain on our health costs.

People get fed up with doom and gloom – they want solutions – the answer lies in the soil.

The modern food distribution system

Look at old photographs or film from thirty years ago and people were generally slim. But walk around any shopping centre today and look at the people, some are at the extremes, either obese or emaciated but the majority are carrying excess fat around their stomachs.

In such a short period of time this cannot be genetic but simply the food we are eating. Let us be realistic - the supermarket system with the factory farming and processed food chain provides us with convenient and abundant supply of cheap food.

One reason they taste so good is they are full of sugars, fats and salt which unfortunately make us feel hungrier - in essence they are addictive so we eat more than we need.

Simply recommending a change in diet simply does not work. We need food that people actually want to eat.

lina Fig 1 There is a world of difference between food we should eat and food we want to eat. This is at the root of why we get fat, we just love processed food high in sugars, fats and salt - they taste so good.

Our Daughter Lina is an excellent cook and is working with me to develop recipes which are both healthy and tasty.

wrap Fig 2 One of Lina’s most successful dishes is this simple vegetable wrap. You can delude yourself you are eating tasty junk food but in reality it is full of nutrient rich vegetables. Dieticians seem to forget that we are real people that just love to eat.

I (or more accurately Lina) will talk about how to prepare food which is both healthy and we actually want to eat in future Newsletters.

Even Lina cannot prepare food which will make us healthy if the basic nutrients are not there in the first place.

The easiest way is to grow your own and urban agriculture is increasing rapidly in our cities allowing even people who live in apartments to benefit from healthy food - again that is a topic for further Newsletters.

I and many others have talked about fat around the vital organs add infinitum but where are the solutions? This newsletter focuses on a key aspect – soils and minerals.

Soils and minerals

Let’s start with a key point. Any good book on horticulture will describe in detail the fertilisers needed to grow healthy plants. But that can be missing the point, the aim is to grow plants which will make us healthy and this is a far more complex issue.

We need a whole range of minerals that the plants simply does not need - for example selenium which is used to the reproduction of our DNA. If there is no selenium our DNA does no reproduce accurately and most likely we will get cancer and die.

We need other mineral in much larger quantities than plants - for example the sex minerals iron and zinc. We won’t die from lack of zinc or iron but without the sex minerals life will not be as much fun and our species would become extinct.

Diet and Health is discussed in detail in ‘How to grow (or buy) healthy vegetables’  in the June 2015 newsletter

Widely reported deficits in our modern diet

The table below shows the minerals that plants need to grow well, the primary and secondary elements and the elements that we as humans needs to be healthy. Some minerals such as iron and zinc are needed by plants but in small quantities. We need these in large amounts.

Others like selenium and iodine are not needed by plants at all but are essential for our health. Over the years of continuous farming these trace elements have become denuded from the soil. Modern intensive farming aided by chemical fertilizers is highly productive but exhaust the soil of biology and minerals.

Bio-essential trace elements are critical to human life. These include iron, cobalt, selenium, copper, zinc, molybdenum, vanadium and cadmium. The elements are linked into the chemical structure of the cells and become a natural nutrient for survival. Cobalt is a central atom in the structure of vitamin B12, whereas zinc is essential for growth, magnesium guards against heart disease, Type 2 diabetes, prostate cancer and osteoporosis.

Elements needed by plants  
Elements available from the air or water carbon, oxygen, hydrogen
Primary elements from the soil N, P, K
Secondary elements Ca ,Mg, S
Trace elements Mn, Fe, B, Zn, Cu, Mo, Cl, Co
Widely reported dietary deficits  
Elements needed by plants but we may need higher doses Ca, Mg, Zn, Fe ,Cu
Essential extra elements needed for health Selenium, Iodine, Vanadium, Chromium
Vitamins humans are generally short of Omega 3, B12, B6, E, K

food chain Fig 3 When we talk about us needing minerals we never mean the basic element, we need the elements as part of complex chemicals. These are produced in a chain starting from soil biology reacting with minerals in the soil to make them available to the plants - then the plant converting them into further chemical which are available to us (or more realistically the bacteria in our guts) - these are converted into hormones which are sent to our brain - which in turn converts them into yet more hormones which control our body.

Roots 101

Roots absorb nutrients and water but they also need to breathe taking up oxygen and expelling gasses like ethylene which acts as a growth inhibitor.

Plants have developed roots with different functions. In some plants this is totally obvious; there are the fine fibrous surface roots and a deep tap root.

roots Fig 4 Fibrous and tap roots. Fibrous roots need to be able to breath taking in oxygen and expelling stale gases - they need an open soil so they can breathe. Tap roots are tough and seem able to handle being immersed in water. The fine surface or fibrous roots have evolved to survive in an open soil where they can absorb oxygen and expel the toxic gasses. By contrast tap roots have evolved to bore down deep into even the hardest soil (where they may be very little air) and extract moisture and nutrients.

Many weeds have highly developed tap roots which is why they are so tough. Many of our food plants have predominantly fibrous roots which makes them more delicate. In nature there is a natural synergy between deep tap rooted and surface rooted plants which grow comfortably together.

Minerals and biology

Minerals are readily available - for example from volcanic rock or marine products.

However soil biology is living, it needs looking after just like a farmer looks after his cows and that means feeding them.

Soil biology gets its food from two sources – plant exudates and compost.

Plants exude simple sugars as energy and more complex chemicals to facilitate the growth of certain beneficial biology.

Farmers have known for at least a hundred years (maybe longer but that’s as far back as I could find) that growing sunflower is highly beneficial for later crops like wheat. We now know that this is because sunflowers attract mycorrhizal fungi.

The second source of food is from composting. I don’t mean conventional hot composting but in-soil cold composting which is the natural process.

I appreciate there are many compost enthusiast out there who promote the nutritional benefit of compost. The real benefit of compostable material is that it provides energy for the soil biology. There will certainly be macro nutrients in compost but if the micro-nutrients are not in the original material they will never be in the final compost. The micro-nutrient must be added.

A quick zap to China


In China there is a particular mountain valley where people live to a ripe old age – well into their nineties and hundreds. The statistics are one thing but better to go and see the real situation for yourself. The Chinese are a nocturnal race and love street music and dance. There you can see old ladies dancing away in the night after a day’s work in the fields.

This has attracted serious medical research which has identified a high level of selenium in the soil and water and Selenium is known to be essential for the reproduction of DNA.

Scientific proof would require long term trials with a control group from the same population but with a different diet. This has happened by accident with the migration of younger people to the cities. It seems their diet is a major factor in providing such energy into their elder years.

I drink a lot of tea and it just so happens that this region is a major tea producer. This tea is difficult to buy and costs some three times normal teas. But I still try and buy it whenever I can. I have no proof that it will keep me active for longer in my later years so I have to take a cost benefit judgment.

It costs about a $1 a week for me to buy this special tea, life is always a question of risks and judgment and for me there is no hesitation - I never see it advertised or promoted - it just seems to sell by word of mouth - but I will buy it whenever I can.


The aim is simple – we need to add the minerals which are essential for us to the soil and we need to foster the soil biology which will release these minerals to the plants and be the first leg in the mineral chain.

My experiments with wicking bed soils (but this applies equally to all soils) have led to the development of two products.

I am generating two separate soil layers

- an upper layer with a fine texture aimed primarily at seed germination and containing minerals plus additives to increase void content and to make the soil hydrophilic to aid wicking
- a lower layer aimed primarily to supply the soil biology

WickiMix-M M standing for Minerals contains the essential minerals plus additives which provide a high void space and make the soil hydrophilic.

WickiMix-R R standing for Root or Rhizosphere is a root mass from living plants which contain a broad spectrum of soil biology.

I am now splitting my wicking beds into two layers, in this Newsletter I want to focus on soils and in later Newsletters I will talk about the physical construction of the beds but for now let me give an example how these soils are used in a simple wicking bed.

A simple modified wicking bed

In most of my experiments I have used either an existing wicking bed or a simple tote box which forms the main container – sitting on top is a conventional seed tray with an open mesh base.

If I my bed is outside where I am not worried about smells I fill the main container with
organic waste (waste food or weeds). When sufficient material has been collected I cover with WickiMix-R to provide the soil biology and partially fill with water.

box half full Fig 5 In a garden where smells would not be a problem food waste and weeds can be collected until the base container is nearly full then WickiMix-R is used to cover the surface. The seed tray is then placed on top and filled with WickiMix-M making sure that soil falls through the mesh to give a continuous link to the soil below

wickimix minerals Fig 6 I developed WickiMix-R (for Rhizosphere or Roots) for the main container. It has a highly fibrous texture taken from the root zones of selected plants and has a diverse soil biology

I then put a seed tray onto the base and fill with WickiMix-N making sure the soil goes through the mesh make sure there is no air gaps then seed in the normal way. I have been top watering with a fine spray until the root system has developed.

seed tray Fig 7 All that is needed is a traditional seed tray with an open mesh base. These can be purchased very cheaply, often second hand from nurseries. They simply sit on the base container soil.

WickiMix Rhizosphere Fig 8 The seed tray is filled with a soil which is both hydrophilic e.g. it attracts water which aids wicking and has a high void space and the essential minerals. I developed WickiMix-M (for Minerals) for this purpose. It has an average particle size of 0.2 to 0.5mm which makes it suitable for seed germination.

I am anxious to have a system which can be used in apartments; I believe urban agriculture is going to become very important as a way of proving fresh healthy food for city dwellers. Obviously there must be no smells.

compost bin Fig 9 Smells must be avoided in apartments when collecting waste food. The waste can be collected on a daily basis in a conventional rubbish bin. When needed the waste is covered with a layer of WickiMix-R.
WickiMix-R Fig 10 WickiMix-R is fibrous which make an effective barrier and is full of biology including worms which help to quickly decompose the waste

waste bin full Fig 11 When the rubbish bin is full the compost soil mix is transferred to the wicking bed and more WickiMix-R is added, and the tray placed on top and filled with WickiMix-M and seeded When the soil level drops I replenish the bed by lifting out the tray and adding extra compost and WickiMix.

It is beneficial use a smaller tray and leave an area around the outside; this can be planted with perennial herbs with large roots which provide a permanent home for the biology.

Converting conventional Wicking Beds

converting conventional wicking bed Fig 12 I have many conventional beds which I have converted by simply raising the water level and placing the trays on top.

King of mulches

While the WickiMix’s was developed for wicking beds with two separate layers I use them extensively as a mulch on both my older wicking beds and on conventional garden beds providing both nutrients and soil biology. Probably overkill but certainly the must be the king of mulches. I apply at about 5Kg per square meter.

If you want to talk to me about this just email me or skype colinaustin1000.


Use a top layer of soil which is open to allow ingress of air, hydrophilic and has a high mineral content. WickiMix-M

Use a lower layer which is mixture of compost and soil biology. WickiMix-R

If possible use a mesh as a dividing layer so the top layer can be lifted to replenish the nutrients. If not possible use WickiMix as a mulch.

How WickiMix is made

I appreciate that people may not want to make their own WickiMix so I am setting up to supply this but I thought readers may be interested in how I make them.

I live on an eco-village near Bundaberg in Queensland. The total area is over two hundred hectares about half of which is natural bush which has never been tilled or worked and is pretty close to a pristine environment.

This is a very dry area – to far North for the winter rains and far enough South to dodge most of the normal summer tropical deluges. But we do have an excellent system of lakes which provide water throughout the year and provide habitat for a wide range of birds and animals which visit my block bringing with them the biology from the native bush.

I am a compost nut so everything that is vaguely organic, from food waste to door to door salesmen gets composted. (That’s a fib we are to remote to get door to door salespeople).

I am not particularly squeamish but even I have some concerns about what goes into my composting system, I also throw in a lot of woody material which takes for ever to decompose. So I have developed a two stage composting process.

I have made a waste pile with a horse shoe ring of plants around the outside. (My wife, Xiulan does not approve of my waste pile so I have to make sure it is hidden from the house.)

I grow a range of plants such as Comfrey, Queensland Arrow root, Senna Alata, Bananas etc. which have powerful root systems and big broad leaves. These pick up nutrients from the slowly decomposing waste pile and filter out any unwanted contaminants to give me a supply of green leaves which I can use for my second stage composting. I refer to these as mining plants as they put down deep roots to extract minerals from the soil and form luxuriant foliage.

I have plenty of space so do not have to worry about tying up the land area.

I appreciate most people prefer hot composting, I generally prefer cold in-ground composting because I see compost as a way of feeding the soil biology rather than a direct source of nutrients.

Fortunately Kookaburra Park Worm Farms are a close neighbour so I have an abundant supply of vermicast or worm casting and not too far away is an old volcanic rim which can supply volcanic rock dust.

I have experimented with all sorts of wicking beds from the small wicking baskets which holds about 10 litres, through tote boxes (about 60 litres) and larger permanent wicking beds of about five square metre in shade houses, open wicking beds to sponge beds which are much larger.

I have experimented with various commercial products which are supposed to provide biology but have not been that impressed with the results. Soil biology has been around for billions of years and I have read that some ecologist believe that mycorrhizal fungi played a key role in enabling plants to move out of from the sea to the land.

I have therefore studied the natural process of how soil biology is formed and have tried to imitate this. Plants have a synergistic relationship with biology; while most plants exude sugars to feed biology and mycorrhizal fungi - some plants exude complex chemicals which attract beneficial fungi.

I have selected areas of my land which have not been disturbed and I know are biologically active. I convert these to sponge beds by covering the undisturbed soil with a layer of my second stage compost (e.g. from the leaves of my mining plants).

I then cover this with a layer of vermicast and then plant my mother plants which will attract the biology and fungi. I have tried to make this a balanced eco-system which is self-controlling. Some plants attract fungi, others control nematodes others help control insects etc.

I practise minimum till so I avoid damaging the eco-system. When I need some WickiMix I take samples from small areas and mix so I get a good sample of soil and do minimum damage to the biology.

WickiMix-R is mainly from the lower root zone while I make the WickiMix-M from the upper layers and blend in the essential minerals.

At this moment I am producing far more than I need for my own use so am offering this for sale. Basically I am testing the response and if there were a significant demand I would look to expanding the production.

So if you are interested please contact me at