Soil Mineralisation Part 1: What Do We Need To Add To Our Soils And Why?
If you want to grow plants effectively, one of the most fundamental things you can do is provide them with soil which is appropriate for the species and which provides a rich and balanced amount of nutrients. The ideal of creating a permaculture system such as a food forest is that the soil will be balanced and nourished naturally by the diverse amount of species living there, with humans having only to input minimal effort by occasionally adding mulch or chopping plants to provide more organic material (see for example 1). But until you get to the point where you have a self-mineralising food forest, what is the best way of adding minerals to the soil? What do we need to be amending the soil with and how does this help? This article will explore some theories and methods of soil mineralisation and how they can be effective.
There has been a lot of research into how intensive agriculture, though it may at first provide the required nutrients to the crops grown, ultimately causes a loss of nutrients and minerals and degrades soil to the point where it is no longer viable to grow crops there, unless, of course, you increase the number of chemical amendments you put in (see for example 2, 3). Such short-term thinking is clearly unsustainable and doesn’t really make sense even for the chemical producers, since they are marketing their products as agricultural aids and if agriculture is no longer possible because all of the soil has been chemically and intensively degraded then they can no longer make a profit.
If you wish to grow crops in a place where there were previously such farming practices, or other damaging practices, going on, then you will have to pay attention to regaining some kind of balanced soil quality. There are many ways to do this, but first let’s have a brief look at what soil is composed of and what it needs to be healthy.
Soil is the stuff of stars…
About a year ago, and just 6 months before his death at the age of 64, permaculture biologist, lecturer and author Toby Hemenway published an intriguing trio of articles on his website on soil chemistry entitled ‘The Cosmos, The Earth, and Your Health – The Story of Soil’ (2, 4, 5). The series lives up to its grand title, as Hemenway, in looking at the origins of the chemicals which make up soil and indeed the rest of life on Earth, delved into history all the way back to the ‘Big Bang’. He pointed out that all of the main chemicals which make up soil and other things on Earth today originated in stars, so soil – and we – are in fact all “star-stuff” as he quoted numerous thinkers as saying. Though he left the question of how these elements and compounds went from being exploded around space by supernovae into forming the Earth as we know it today as a mystery he then went on to describe the functions each of the major soil chemicals play in generating healthy soil.
One important thing to note when it comes to knowing about the chemicals which healthy soil needs is that we do not know everything about how these chemicals interact (2). Soil scientists have done a lot to isolate and determine the functions of some particular elements essential to healthy soil, but this does not mean that you can simply follow a chemical formula and make soil which is beneficial to life. As Hemenway pointed out, the discovery of nitrogen, phosphorous and potassium as being the main nutrients which aid plant growth led to the development of an international industry in the synthetic production of these chemicals for use in the agricultural sector, thus creating a huge imbalance in soils all over the world, not to mention plant breeds which became unnecessarily chemically dependent (2). The point is that the isolation of chemicals, though it can lead to important scientific discoveries, ignores how soil works in real life – i.e. as a vast, interconnected web of relationships which cannot be reduced to the sum of its parts. This also applies to any process of isolation – it may be useful to determine some ways in which things work, but it cannot be a substitute for the creation of a holistic system because the world is holistic and trying to separate it into parts ignores this. For example, many health experts recommend ‘cultured foods’ as part of your daily diet (see for example 6), but also warn against buying commercially-produced ‘live’ yogurt as, even if the yogurt has had some of the requisite cultures (such as the lactobacillus bacteria) added to it, this ignores the huge ecosystem of bacterium present in naturally-fermented cultured foods so does not provide the same nutrients, even if chemically it would seem to have more or less the same ingredients (see for example 7).
So if you are creating compost, for example, it will be much healthier if you make it using organic matter which has the requisite chemicals present within it than it would be if you simply added the chemicals as isolated elements. For example, adding wood ash as a high potassium-content organic material rather than potassium as an isolated chemical. This is because the wood ash, since it has other chemical relationships present within it, can better interact and integrate with the other organic elements present.
How to be healthy
To continue with the human health analogy; if you happened to be very sick with multiple illnesses it would be possible to cure them by amending your health using holistic methods. However, it is much more energy-efficient to live a healthy lifestyle in the first place so that staying healthy is a matter of small changes to your diet or exercise routine (which I’m sure is the case with most readers anyway – may you all find an abundance of health and vitality!)
In exactly the same way, while it is possible to amend unhealthy soils which have been degraded by overuse of chemicals or over-intensified farming, it is far more energy-efficient to start with healthy soils in the first place (4). Of course, starting with perfectly-balanced healthy soils is an ideal which many readers may not have had the luxury of doing, and there is also the factor of restoration and regeneration to consider: since many soils are already degraded, it can be seen as a kind of duty of those who are willing and able to rebuild them to do so. That being said, whatever stage the soils you are working with are in, you may be able to ‘kickstart’ the process of healthy soil creation by adding some soil from a source which you know already has a healthy balance of nutrients. Nowadays this has become something of an industry wherein you can purchase high nutrient-dense ‘worm castings’ (8); however, it seems unnecessary to spend money and energy on importing such items if you have access to a forest anywhere close to you. When I studied my PDC with TreeYo (9) at Permaship (10) in Bulgaria they recommended adding a good few cups of forest soil to your compost as the ‘spice’; since the forest, as naturally-functioning ecosystem, already probably has a balanced network of micro-organisms, adding these to your compost will ensure that it can spark into life.
But what makes good soil anyway?
Once you have taken into account that although it is useful to some extent to know the exact chemicals needed to create healthy soil, it is also important to bear in mind the ‘invisible’ dimension of soil workers, and that regardless of the state of your soil you can ‘kickstart’ it by adding nutrient-rich ‘spice’, it still may be useful to be aware of the main chemical players and how they interact. This is what I will explore in the next part of the article, looking at what needs to be present in healthy soil and where you can find it, as well as examining the commercial sources of soil amendments and analysing the pros and cons of using them.
1. Eliades, A, 2011. ‘Why Food Forests?’ Permaculture News, 21/10/11.. https://permaculturenews.org/2011/10/21/why-food-forests/ – retrieved 23/7/17
2. Hemenway, T, 2016. ‘Who Does What in the Soil’ Toby Hemenway, 29/8/16. http://tobyhemenway.com/1404-who-does-what-in-the-soil/ – retrieved 23/7/17
3. Everything Connects, 2017. ‘Intensive Farming’. http://www.everythingconnects.org/intensive-farming.html – retrieved 23/7/17
4. Hemenway, T, 2016. ‘The Cosmos, The Earth and Your Health: The Story of Soil’. Toby Hemenway, 22/6/16. http://tobyhemenway.com/1363-cosmos-earth-stomach-story-soil/– retrieved 23/7/17
5. Hemenway, T, 2016. ‘A Big Bang for Big Soil’.Toby Hemenway,9/8/16. http://tobyhemenway.com/1388-big-bang-big-soil/ – retrieved 23/7/17
6. Dr. Mercola, 2017. ‘Fermented Foods: How to ‘Culture Your Way to Optimal Health’. http://articles.mercola.com/fermented-foods.aspx – retrieved 23/7/17
7. Dr. Mercola, 2017.’The Not So Secret Truth About Healthy Yogurt’. http://articles.mercola.com/sites/articles/archive/2015/05/20/healthy-yogurt.aspx – retrieved 23/7/17
8. Vermiculture, 2017. ‘What are Earthworm Castings?’ https://www.vermiculture.com/earthworm-castings – retrieved 23/7/17
9. TreeYo, 2017. ‘TreeYo’. https://treeyopermaculture.com/ – retrieved 23/7/17
10. Permaship, 2017. ‘Welcome to Permaship’. https://sites.google.com/site/permaship1/ – retrieved 23/7/17