At first sight, soil might look like a lifeless material where not much action happens. But nothing could be further from the truth! By learning how to make living soil in your garden or farm, you’ll be arming yourself with some of the most basic knowledge needed to grow healthy food.
Soil is one of our most important resources as gardeners, farmers, and humans alike. And healthy soil, is full of life.
Despite our knowledge and awareness of the importance of soil life, it is still being taken for granted in many parts of the world.
In this article, you’ll discover what is meant by living soil and what you can do to make it. You’ll also learn the importance of soil life and how it directly contributes to the health of your crops, allowing them to thrive.
What is Living Soil?
Living soil refers to the different life forms in the soil which, together, form part of the soil ecosystem, where energy and nutrients are cycled through the bodies and poop of different organisms.
It’s the interaction of these life forms which support the health of our plants, and in-turn, us. Without this life, soil would simply be dirt!
There are thousands of different life forms found in soil, such as bacteria, fungi, protozoa, nematodes, micro-arthropods, and earthworms (just to name a few).
Depending on the soil environment, how often it’s disturbed and what you have growing there, soil could be either bacterial or fungal dominated.
Your annual vegetable garden, for example, would typically be bacterial dominated, while a forest would be more fungal dominated.
In just one teaspoon of healthy soil there can be around one billion microorganisms, all working together, providing different services to each other and their environment.
It can be hard to imagine at times how life so small can be so critical to our garden and our health.
The Soil Food Web
The soil food web is a way in which we can describe how energy and nutrients cycle through different life forms, where the primary producers (plants) are eaten by the primary consumers (bacteria and fungi), secondary consumers eat the primary consumers, third level consumers eat the second level consumers (and so on and so forth). Visit the NRCS’s website for further details
Organisms basically predate on each other, pooping nutrients back out, while cycling the energy and providing services which support their ecosystem and the cycles of life within it.
In a sense, it’s similar (but different) to a basic food chain, where you have the predator at the top of the chain and those which the predator eats below it, and what they eat sit below them, etc.
However in the case of the soil food web, there are a number of different pathways in which nutrients can be cycled through predation and interaction of different organisms, not just one simple path, but from side to side (so to speak), forming the notion of a web.
You might ask yourself why you should care about this to begin with. Well I think if you’re serious about wanting to learn how to make living soil to support your crops, you’ll probably want to know what kind of life forms there are, and how this life interact with each other to move energy and nutrients around.
Plus it makes great conversation at family reunions when you have nothing else to talk about!
Why is Soil Life Important?
So why is it so important to make living soil? Well that part’s easy, but complicated!
At the very core of it, it’s the life in the soil which:
- Help feed your plants by making nutrients available through the decomposition of organic matter, and eating each other (nutrient cycling)
- Keep plants healthy by protecting them from the “bad” life forms such as certain pathogens
- Feed other life forms, which in turn feed other life forms, which in turn.. (you get the idea)
- Form symbiotic relationships with your plants/plant roots (for example, plants feed the microorganisms in exchange for nutrients)
- Lock-up carbon in the soil, keeping it from entering the atmosphere as carbon dioxide (a greenhouse gas)
- Break down organic matter, creating humus and therefore a healthy crumb structure in the soil, which improves oxygen and moisture holding capabilities (perfect for plant roots)
An important benefit of soil life is the humus content which it creates and thrives in. The decomposition of organic matter by microorganisms adds humus to your soil, which has a number of benefits including moisture retention, disease prevention, prevents nutrients from leaching out of your soil, among so many other benefits.
Different species in the soil play different roles and provide services to the plants and their roots, or to other life forms which ultimately benefit your plants.
For example, a particular type of bacteria, called Rhizobium, form small nodules (which are actually colonies) on the roots of legumes such as peas, beans and clovers. These guys take nitrogen from the atmosphere and “fix” (i.e. places) it in the soil.
The plant can then make use of this nitrogen to grow. However, nothing is free in life. So, the Rhizobium, in return for their services, expect a payment of sugars which the plant makes via photosynthesis, sending it to its roots for the bacteria to feed on.
Another type of species with a specific role is fungi. Fungi are known to be the teeth of the forest, which break down carbon-rich organic matter such as wood and ligneous material.
Certain types of fungi, called mycorrhizal fungi, form relationships with plants and trees by colonising their roots. The fungi form extensive underground networks (which can be kilometers/miles long!) which take nutrients to the plant roots in exchange for sugars produced by the plant.
So knowing all of this, imagine for a moment that you had no life in your soil. How would these services and benefits be achieved? Not in a natural way, that’s for sure.
Feeding the Life in the Soil
Now to the fun part of actually doing something to feed and encourage the wonderful life in your soil.
Have you ever heard the term “feed your soil, not your plants”? This refers to feeding the life in your soil, which in-turn feeds your plants. Because, if you have a healthy soil ecosystem allowing life forms to thrive, you will naturally be feeding your plants, and would not require extra fertilization.
There are a number of ways in which you can feed the life in your soil. However the basic idea is always the same.
You need to add a good amount of organic matter to your soil.
Whether this be by mulching or composting, you need to consistently be adding (or rather, returning) organic matter to your soil.
From a permaculture perspective, you need to get into the mindset of returning all of your surplus energy and nutrients, or waste, back into your soil, closing the waste loop.
This could be achieved in a number of ways, but the following are some of the most common:
1. Composting
Composting is the process of taking organic matter in the form of food scraps, crop residues, prunings, leaves, grass clippings, weeds, etc., and forming a pile (or not), allowing for the microbial life to decompose it.
It requires a mixture of carbon-rich and nitrogen-rich materials, moisture and oxygen, which together provide the ideal environment for bacteria to decompose the organic matter.
Whether you’re physically creating a hot or cold compost pile, or just allowing organic matter to compost right where it’s dropped, what you’re doing is facilitating an environment for the microscopic life to setup camp and start cycling nutrients.
Once the organic material is composted, you would then add the compost to your garden to not only give your plants some of the nutrients they need, but also inoculate the soil with life.
Bokashi composting (which is actually an anaerobic fermentation process) is a way to process certain types of food which you normally wouldn’t put into a compost pile, such as dairy and meat.
The fermented product would then be dug into the ground or added to your compost pile, again adding and feeding life.
Vermicompsting (a.k.a. worm composting), although considered a form of composting, is covered in the manure section below.
2. Mulching
Adding a good, thick layer of mulch has a range of benefits. However, when it comes to making living soil, it’s the organic matter from the mulch which feeds the microorganisms and starts the soil food web process.
All of the nutrients and energy contained within the mulch is cycled and made available to your plants by the microorganisms. Life is encouraged to thrive by the addition of the organic matter.
Aim for a mixture of carbon-rich materials such as leaves, and a nitrogen-rich material such as grass clippings or lucerne (alfalfa).
Mulches rich in carbon can help buffer the pH in your soil, reducing the risk of your plants up-taking heavy metals, for example.
Mulches rich in nitrogen are great for restoring nitrogen after a heavy feeding crop such as corn or broccoli. If your soil already has a good level of nitrogen though, be mindful of what you intend on planting there next, and ensure it’s something that can do with extra nitrogen.
3. Manuring
Manure is full of microbial activity and is a great soil amendment and conditioner. Adding a little to your soil will go a long way.
Whether it be by grazing animals on your land, free ranging your own chickens, or by adding bagged manure, the life in manure can be extremely busy.
Worm castings (or worm poop) is an excellent way to add nutrients to your soil, as well as inoculate it with life. Similar to the manure of other animals, a little goes a long way.
Another form of manure which is full of microbes is humanure (that’s right, human manure!). Normally the product of composting toilets, when composted thoroughly and allowed to sit for a year or more, it can be an excellent addition for your fruit trees.
You never want to overdo it with manures though, as you could be polluting your soil. Remember that it’s a soil additive, so common sense will be your best friend here, as will watching how your plants respond.
4. Cover cropping
I think it’s worth mentioning how maintaining a cover crop can also help to build soil and encourage the life within it.
Cover crops are basically plants which are sown to help maintain a constant ground cover, improve soil fertility, erosion control, water retention, etc.
There are a range species which you could select from to form part of a cover crop. However, ideally you would have a mixture of different species performing different functions (such as fixing nitrogen), and encouraging diversity.
One key benefit of cover cropping is that the plants are photosynthesizing and producing sugars for the microorganisms life in the soil. This helps to remove carbon from the atmosphere and store it in the soil, to the benefit of your garden and the environment.
Keeping the Right Mindset
Although you should try to use a mixture of the above methods, whichever method you choose, try to keep the mindset of returning all of your waste back into your garden, in one form or another.
You could do this by either returning your surplus harvest scraps back to your soil and letting the microorganisms take care of the rest, composting them, feeding them to your worms or other animals, etc.
When you see weeds in your garden, don’t fret, but rather get excited! (just not too excited). Gather them and follow one of the first three steps above to cycle those nutrients via the soil life. Check out this article on how to make a powerful weed tea fertilizer.
You can’t go wrong! Just stick to it and in no time your soil will be teaming with life.
Not only will you be building top soil and structure, but you’ll be encouraging a thriving living soil.
Things to Avoid
There are a few things which you’d want to avoid doing to your soil so that you don’t disturb the precious life which lives in it.
After all, it wouldn’t make much sense if you spent time building and making living soil only to kill the life in it due to poor practices.
One of these practices I’m referring to is tilling.
Why isn’t tilling a good practice? Because it not only disturbs the soil and therefore the life in it (which can affect the structure of the soil), but it also exposes the life to sunlight, which kills many of the microorganisms which were once happily protected by their surroundings.
By tilling you’ll also be releasing carbon dioxide into the atmosphere which was once stored as carbon in your soil, supporting the life in it. So instead, look at doing something like no-dig gardening.
Below are some other things you’ll want to avoid doing to your soil to ensure the life within it isn’t impacted:
- Avoid tilling (did I already mention that?)
- Don’t disturb the soil (similar to tilling, but here we try to avoid ripping roots out where possible and other mechanical or chemical disturbances)
- Don’t leave soil uncovered (soil needs a “skin”, be it mulch or vegetation)
- No chemicals. Period. (that means no insecticides, pesticides, herbicides, fungicides, chemical fertilizers, etc., etc.)
- If possible, avoid using chlorinated water (this kind of falls under point 2 above)
- Avoid burning
- Rotate plantings to allow for sections of your soil (or garden beds) to rest, balance out the nutrient up-take and break disease cycles
- Avoid compaction
Conclusion
Remember the bottom line when it comes to making living soil – keep adding organic matter and minimize soil disturbance. It’s that easy.
Ultimately, after processing all of your waste, it should all be returned to your soil to support and feed the life in it, increasing the humus content.
So look after the life in your soil, and it will look after you!
