Nurturing soil vitality is one of the best things you can do as a gardener. Plants thrive in soil that is teeming with life. The aliveness of soil really matters. To create superb soil you need to do these two things:
Feed soil life.
Protect soil life and structure.
I was just speaking about this today at the Brisbane International Garden Show. (If you live in the Brisbane region, it's on until Sunday 9 Oct). I get super excited when I'm talking about this because it's the basis of everything really. There is this whole world of incredible diversity under our feet which we pass by every day, usually without noticing - yet plants and animals (including us) rely on it so completely.
A single teaspoon (1 gram) of rich garden soil can hold up to one billion bacteria, several yards of fungal filaments, several thousand protozoa, and scores of nematodes. (see definitions at the end of this post)
As you know healthy soil = healthy plants = nourishing food = good health. Plants in sterile soil perform poorly. Unhealthy plants are more prone to pest and disease problems, just as unhealthy food leaves us more prone to disease and malnourishment.
So what are superb soils?
They feel crumbly and moist.
They smell earthy.
Their structure is open allowing movement of air, water and nutrients to plant roots.
This is exactly what we need to be doing. I wanted to add some extra information here about why.
Did you know most plants have root extenders .....?!
Plants in real soil - superb alive soils - are supported by the web of life in the soil, in particular, fungus. Did you know that 90% of plants rely on fungus to access most of the nutrients and moisture they need - the fungal filaments are like root extensions. They go finer, further and deeper than roots could ever go. So plants and fungus live in symbiosis - a mutually supportive relationship - and plants in this relationship are stronger and more resilient.
Why gardening in the ground is so important...
This plant-fungus relationship is why I recommend, wherever possible, to grow food in the ground and work to improve the aliveness of soils. (Understandably this not as easily achieved in balcony gardens and areas of soil contamination). The importance of connecting with soil life also explains why raised garden beds that are disconnected from actual soil can limit the vitality of your garden soils and plants.
How to create soil aliveness?
The base of the soil food web is organic matter. More organic matter = more soil life. The two main things that support beneficial bacterial and fungal growth in the soil are: organic matter and protection from the elements, this also supports the flourishing of the entire soil food web.
What damages good soil?
tillage damages the fungi - it severs the fungal threads
fungicides and pesticides kill the good fungus, bacterias and bugs
lack of organic matter - no food for soil life
no soil protection - over-exposure to sun, rain and wind kills soil life
5 Simple Strategies to Feed and Protect Soils
Here are some natural and simple ways to feed soil life, protect soil structure and tend the soil:
1. Activate your soil with compost.
I have a range of compost systems on the go, but I really love the simplicity and portability of the movable compost bins. I take them to an area that need a real boost, compost there for a while, attracting a zone of soil aliveness, then moving the bin on to another spot, but leaving the compost there to spread out, mulch over and make a new garden. There are also a number of herbs you can add into a compost to activate it. Read about these here: http://our-permaculture-life.blogspot.com.au/2016/01/improve-your-soil-with-herbs.html
Movable compost bin and worm tower - creating soil life hot spots.
3. Add organic matter, compost and leafy greens to garden beds - in a no-till way.
Making no-dig gardens feeds and protects soils and creates a great environment for your soil life to thrive. This helps so much to support a thriving vegetable garden. By using the no-dig garden method rather than digging it into the soil protects the soil structure. Visit my previous post to see how to make a no-dig garden: http://our-permaculture-life.blogspot.com.au/2016/01/morags-simple-successful-no-dig-garden.html
4. Plant deep rooted plants
I plant comfrey around the edge of the garden and beside the compost. The thick penetrating roots accumulate nutrients from deep in the soil and bring them to the surface. You can then use comfrey leaves as an excellent compost activator, to make a potent homemade comfrey fertiliser (http://our-permaculture-life.blogspot.com.au/2016/07/film-3-how-to-make-comfrey-tea-with.html), to add organic matter and nutrients into the soil layer while making a no-dig garden, or just to chop and drop. Also fruit trees with comfrey nearby seem to do better.
Comfrey
5. Regularly chop and drop organic matter.
I am often wandering around the garden, chopping back surplus growth and tossing it around trees and garden beds to feed and protect soil life. It's amazing how quickly it breaks down and gets taken into the soil. Because having enough organic matter is so vital, I actually grow plants especially for this purpose such as the comfrey, Queensland arrowroot, lemongrass and pigeon pea - but many other plants can be used too, such as the abundant mulberry or pumpkin leaves.
Old pumpkin vines as chop and drop mulch.
In and around the veggie garden I mostly use mulch - a seedfree grass hay that is easy to work with around the little plants.
Thick layers of mulch get drawn rapidly into our soils.
I also recommend using cover crops (living mulch) to cover bare soils, open soils, add organic matter and renew areas.
DEFINITIONS:
Bacteria - single celled organisms that are the most abundant microbes in the soil.
Fungal filaments - the fine white threads called mycelium you can see in healthy soil. We need this mycorrhizal fungi (symbiotic relationship between the plant and fungus) - 90% of plants rely on it. It increases plant strength, increases water uptake, absorbs minerals & nutrients and in addition stores 1/3 of soil carbon.
(Interestingly, mycorrhizal fungi does not form relationships with the Cruciferae family (eg mustard, broccoli), Chenopodiaceae (eg spinach, beets) and Proteaceae (banksia, macadamia). Fungal numbers drop in the soil with these plants, same as when the soil is left bare and exposed.)
Protozoa - single cell organisms that eat bacterias and release nitrogen to plants.
Nematodes - microscopic wormlike creatures, that are the most numerous multi-celled things on Earth and an essential part of healthy soil ecosystems. They are found in every conceivable habitat from the deepest ocean to the highest mountain. They feed on bacteria, fungi, algae, small invertebrates and other nematodes. Gardeners immediately think of root knot nematodes, and cringe in fear when they hear their name mentioned. Having root knot nematodes are an indicator that your soil ecology is out of balance - adding more organic matter, compost and moisture can usually help regain the balance, as well as planting a crop of brassicas that are more resistant to the root knot nematodes - particularly the mustard varieties.
