Amazon Jungle Lesson 3 Of 3 – The Soil Food Web
In the first two posts I covered how important it is to balance the mineralization in the soil in order to be able to grow the kinds of plants we want to grow, and then how to increase organic matter in soil the way nature does it.
Now I want to get into the third part of this soil health triangle, the soil food web.
This refers to the life in the soil, especially the bacteria, fungi and other microorganisms, and the insects and other small animals.
The plants are part of this too since they have a tremendous impact on the soil.
If you had x-ray, microscopic vision and could see what’s going on in the soil food web in this forest, you would see that many of these trees and plants are connected to each other through a network of fungi called mycorrhizal fungi.
Even if you don’t have x-ray vision, you can sometimes find the mushrooms, which are the fruits of these fungi.
The fungi bring water and nutrients directly into to the plants roots. They also protect plants from root-feeding predators. They do this in exchange for carbohydrates and other food sources which the plants give them in return.
Even further, plants can exchange food and other substances and probably even knowledge with each other through this fungal network.
There are also microscopic bacteria and protists in the soil food web performing similar functions. And indeed, insects and other small animals contribute, too.
All of these organisms are very much interdependent, each having specific jobs to do.
They may have roles such as feeding and protecting plants, fixing nitrogen from the atmosphere, decomposing organic matter, improving soil structure, cleaning up toxins, and a list of ongoing tasks similar to what any human community needs taken care of.
In the forest, the conditions are pretty good for these organisms, which is why they are generally abundant.
In our gardens, maybe not so much.
Our soil has taken more of a beating over the years from construction work, tilling, compaction, monocultures, maybe even chemical fertilizers and pesticides that destroy soil structure and the soil food web. Even organic fertilizers can cause major issues if used improperly, which may be more common that not.
So in our gardens, we may need to do something to reintroduce the biological diversity to the soil.
We’ve already discussed compost, and that is one of the best ways to do it, provided you can make or buy good quality, nice-smelling, aerobic compost.
Most people know that compost provides nutrition and organic matter, but just as important is that it provides a huge, diverse array of microorganisms – and if it’s good compost, it’s good microorganisms.
But we often don’t have enough good compost around, and while it would be prudent to find or make at least a little because it really is the best option, there are a few other options that can help tremendously regardless of whether or not you use compost.
I started off this post talking about mycorrhizal fungi in the soil food web. There are ways to propagate them yourself from healthy tree roots which already have them, but by far the most time-efficient method is to buy it as an inoculant and use just a pinch every time you plant or seed.
You can also culture your own lactic acid bacteria, which is a useful thing to do, but in my opinion much better is to spend the $15-$30 to buy a product called effective microorganisms (EM) or another similar brand, to supply a small group of very important fermenting microbes to the garden.
And then for maximum diversity, although you need a little more knowledge and experience to do it right, is to brew your own compost tea to extract and then multiply the tens of thousands of species of beneficial microbes from quality compost.
An added benefit of the EM and compost tea is you can also apply them to plant leaves where they will feed and protect plants above ground.
I should mention there are many other inoculants making their way onto the market in the last 20 years, a few of which I’ve tried but most not. Here I’ve mentioned the most important.
So compost, mycorrhizal fungi, EM and compost tea are some of the best ways to improve the health of your soil food web with a diversity of beneficial microorganisms.
Of course we also need to stop most of the tilling, compacting and chemical use if we want them to stay around. And we also need to provide them with a healthy habitat.
That means watering the whole soil and mulch, not just the plants. It means ensuring the soil has sufficient humus and mulch and plants, even during the fallow season. It means balancing out the minerals in the soil in order to give the microbes the tools they need to create good soil.
In the Academy, I cover the soil food web and all of these inoculants in more detail, including how to activate your own EM so that is costs less than $2 per liter, how to use it to make a special kind of compost called bokashi, how to brew your own compost tea, and even how to culture your own microbes.
I hope you’ve enjoyed these three lessons. It’s been a real treat to put them together for you here in the jungle.
Phil, do we harm the soil web by pulling out plants roots-and-all? What’s a good way to clean up the garden at the end of the growing season? I enjoy your work very much!
Ideally, we’d leave those plants there over winter to break down and continue to feed the soil food web, but since that can be rather unattractive, what I often do is move those plants to the compost and seed a cover crop instead.