The [Grow] Network is pleased to publish Colin Austin’s 10 part series, How to Grow (or Buy) Healthy Food. This article is Chapter 6 of 10. You can read the other chapters here:
• Chapter 1 – Diet and Health, a Personal Experience
• Chapter 2 – Statistics and the Diet Controversy
• Chapter 3 – Eat Right, Not Less
• Chapter 4 – Finding a Diet by Self-Experimentation
• Chapter 5 – Essential Nutrients for Good Health
• Chapter 6 – The What and Where of Minerals
• Chapter 7 – The Rhizosphere
• Chapter 8 – Transferring Nutrients and Biology to Growing Beds
• Chapter 9 – From Garden to Kitchen
• Chapter 10 – Community Action
Chapter 6 – The What and Where of Minerals
I have talked about how science and technology need to work to solve complex practical problems – the methodology – which may not turn many practical growers on. Now it is time to leave the debating chamber and put on our boots and get out into the block and get muddy and messy. The fun bit!
What’s to Come in Chapter 6
This chapter is pretty straight forward. I simply look at what minerals we need and where to get them. So, let’s get to it.
How to Grow Healthy Vegetables
Just over a year ago I gave a talk at Wuhan University in which I discussed the details about the nutrients our bodies need. This is available at my website, here: http://www.waterright.com.au/Newsletter_8_May_2014.pdf. I don’t want to duplicate, so I am basically going to pick up from that talk.
Among the key points were that we have a good understanding of the needs of plants and so we can grow plants that are healthy in and of themselves. However we humans need a much wider range of minerals and nutrients in our own diets. We need to consume foods that contain all of them in order to be healthy.
These charts, reproduced from that talk, show the nutrients that are required by plants, along with commonly reported nutrient deficiencies in humans:
Elements Required by Plants
| Elements Available from Air or Water | Carbon, Oxygen, Hydrogen |
| Primary Elements from the Soil | Nitrogen, Phosphorous, Potassium |
| Secondary Elements from the Soil | Calcium, Magnesium, Sulfur |
| Trace Elements from the Soil | Manganese, Iron, Boron, Zinc, Copper, Molybdenum, Chlorine, Cobalt |
Widely Reported Human Dietary Deficits
| Elements Available from Plants | Calcium, Magnesium, Zinc, Iron, Copper |
| Other Essential Elements | Selenium, Iodine, Vanadium, Chromium |
| Vitamins | Omega 3, B12, B6, E, K |
The farmer has little incentive to add the minerals which we humans need but the plants do not. However, these nutrients are vital to our health.
Selenium is used by our cells for the reproduction of our DNA and there is a view in the medical profession that lack of selenium in our diet is an issue tied to cancer, which is caused by rogue cells not reproducing correctly. And lack of iodine is well-recognized as a cause of loss of brain function.
It is well known that fertile women need extra iron, and there is a lesser-known fertility nutrient. Male semen contains a high proportion of zinc, apparently enough to drain the body of its normal intake. So the message is clear for men – either give up sex or get some more zinc in your diet. This may just be the most motivating part of this entire series.
Requirements for specific nutrients are well covered in the Wuhan talk I referenced above, so I won’t duplicate them here.
The Long Chain from Soil to Stomach
Eating healthy food is not something we can look at as one step. In fact, there are at least four links in the chain that extends from the soil to the stomach that we need to examine.
The four steps in the healthy food chain are:
Minerals – First we must get the minerals into the soil. This is easy – there are several sources.
Soil Biology – Secondly we need soil biology to release the nutrients to the plants. Soil biology could be a study for several lifetimes but you don’t need to know everything – the basic rules can be as simple as ‘stop killing them with chemicals and churning up the soil.’ Just let the soil biology carry on. Creating healthy soil biology may be a bit slow, and you can use different things to kick start the process. I will describe the way I “farm” soil biology.
Growing Plants – Thirdly there is how to grow our plants – I find that most of my readers are keen gardeners and already have a high level of knowledge so this is not a gardening manual. Different varieties of plants provide us with their own set of phytonutrients and minerals so I am a great believer in consuming a wide variety of plants. In fact, I call my diet a varietarian diet. Every plant has its own particular requirements or horticultural protocol. I find this vast amount of information mind boggling and have long since given up trying to absorb this mass of information. As I’ve said before, it is important to study how the diet affects us as individuals by self-experimentation. I will make a few comments on my experiments with making a largely vegetarian diet tasty – but as I am probably near the world’s worst cook, this may be your chance to gloat.
Community – I just don’t think it practical for each person to grow every single plant that is needed to give the variety for a really healthy diet. I know I have tried self-sufficiency – yes it is possible, but a diet of pumpkins day after day is boring and not particularly healthy. So later I want to talk about how to have a community where plants can be bought and sold. There is more to this than meets the eye.
Getting the Minerals in the Soil
If it is not in the soil, then it can’t be in the plant. This is so basic I feel embarrassed by saying it, but I read so many articles where the author describes the minerals in a particular plant without thinking about how they got there – I feel I have to make this obvious but important point. Even if you grow common plants which have no recognized benefit for delivering minerals – if they are grown in nutrient rich soil, they will also probably be rich in nutrients.
There is no little sentry in the root system saying to a particular mineral, “Sorry, we don’t need you – away you go.” No one seems to have a kind word for the nutrient value of the humble lettuce, but if you grow them in nutritious soil they can have decent nutrient content.
I go very carefully with the big three – nitrogen, phosphorous and potassium (N, P, K). Particularly nitrogen. They may make the plants grow fast but slower growth does not worry me – I want to give them time to develop the phytonutrients which are essential for health. I am adding a lot of green compost to the soil which takes up a lot of nitrogen – so I watch this carefully.
I use manure and blood and bone as my primary sources of nutrients.
While plants need a certain amount of the secondary minerals such as calcium, magnesium, etc. – we humans need these in larger quantities than plants. I use significant quantities of gypsum and dolomite, which are available everywhere.
However, I really focus on the trace elements that we need but that plants have no need for, or only use in small quantities – minerals like magnesium, zinc, chromium, selenium, and iodine. In many commercial farms these have been exhausted from the soil, but they really are essential for our health.
Sources of Secondary and Micro Nutrients
There are several sources. Volcanic rock dust often contains a broad spectrum of trace elements. It is not necessary to have your own private volcano, it is quite expensive putting a hole down to the earth’s mantle and the neighbors may object anyway. Instead I use quarry dust which can be bought dirt (or dust) cheap from a local quarry. But you may need to find out what actually is in the dust by having it tested.
You don’t have to worry about sustainability issues with trace elements. The Himalayan Mountains are volcanic and are quite big. I have seen them – they are seriously big. These alone could keep humanity going for the next million years or so. Alternatively, you can buy trace elements packs fully tested but often at exorbitant prices.
Another source is probably right under your feet. The top soil may be denuded but there could well be an adequate supply deep in the ground. Don’t worry, I am not going to suggest that you build a mine – there are plenty of deep-rooted plants that will bring the trace elements to the surface for you.
Marine Sources
Other excellent sources of trace minerals are sea-based products, such as seaweed, processed fish remains, etc. I have some concerns about heavy metals in these products, so I am careful about purchasing them. Fortunately, Australian waters are pretty clean.
Life on an Eco-Village
Let me tell you the system I use, which obviously will not suit most people, but works brilliantly if you live on an eco-village or on acreage where you have to dispose of your own waste.
I have all this nutrient-rich waste water, what I could euphemistically call rainbow water. It is really grey, black and green, but missing blue, so it is not really rainbow water. I score pretty low on the squeamish scale, but even I balk at the thought of putting this nutrient-rich – but yukky – water straight onto my lettuce plants. So I use a two stage approach – the first is really yukky – just using any and every bit of organic yuk I can find. (I told you I was mean).
I divert all the rainbow water into a depression. I then grow a whole bunch of plants in this depression; I select plants which have thick soft leaves which will make excellent compost, and deep roots so they go right down into the subsoil.
I use plants like Senna alata which is a legume, Queensland arrow roots which has fantastic leaves, comfrey, and even bananas. And, if I am honest, any weeds which decide they might like to take a holiday in this nutrient-rich plant paradise. I can then use these soft squelchy leaves to provide the food to farm the biology. More on my yukky biozone later.
Coming Up in the Next Chapter
We will look at what some people (well, at least me) think is the most important part of the nutrient chain – the root zone. We’ll talk about why it’s the most important, and why it’s the most neglected.
• Chapter 1 – Diet and Health, a Personal Experience
• Chapter 2 – Statistics and the Diet Controversy
• Chapter 3 – Eat Right, Not Less
• Chapter 4 – Finding a Diet by Self-Experimentation
• Chapter 5 – Essential Nutrients for Good Health
• Chapter 6 – The What and Where of Minerals
• Chapter 7 – The Rhizosphere
• Chapter 8 – Transferring Nutrients and Biology to Growing Beds
• Chapter 9 – From Garden to Kitchen
• Chapter 10 – Community Action
© 28 July 2015 Colin Austin – 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.
