Why are healthy soils important?
Your garden soil is at the root of everything (pun intended!) Healthy soil promotes:
aeration and drainage
Good aeration and drainage in your soil is vital for healthy roots (and healthy plants). We have probably all experienced the ill effects on our plants of waterlogged or very dry soils…. not good!
promotes root strength
Strong roots are critical to strong plants. These strong roots often grow deeper making plants more able to find water and nutrients they need during drier periods. Strong roots are obviously very important for root vegetables!
helps fight pests and diseases
Strong plants with strong roots are much more able to survive pests and diseases. Do you find yourself tempted to spray with artificial pesticides and insecticides? If so, take a step back and think about the cause of your disease and pest problems. Often they can be traced back to weak plants and (ultimately) a poor soil structure. Healthy, strong plants can tolerate common gardening problems such as lack of water, aphids, caterpillars, slugs/snails and mildew much more easily than plants that are already weakened from poor soils and lack of nutrients.
helps with water retention
Healthy soils with a good soil structure are able to hold and retain water more easily than poor, weak soils. This promotes healthy root and plant growth which, in turn, helps to maintain a good flow of water through the soil and protect the surface from leaching and flash flooding.
provides a slow release fertilizer
Microbes are a key part of any healthy soil. These microbes help to break down organic matter at a microscopic level and provide a continuous readily available source of nutrients for your plants. With a natural balance of microbes (and other biota), your soil will develop a natural balance of available nutrients.
What makes a healthy soil
Soils are made up of five major components. Most gardeners can identify four of these.
- Mineral matter: the inorganic elements of your soil; rocks, sand, gravel etc. This typically makes up around 40-60% of your soil.
- Organic matter (or humus): the decaying and waste remains of plants and animals that is the key source of nutrients in your soil.
- Air: approximately 40-60% of your soils volume can be space. This space will be filled with various ratios of air and water depending on the availability of water.
- Water: see above
There is also another very important element that is missing from the list above. Soil biota and microbes. Soil is a living system and needs the essential microbes, fungi, bacteria, grubs, and insects to support your growing garden.
What are soil biota?
As gardeners we often talk about the soil biota in three categories; primary decomposers (organisms which each the organic materials in the soil; such as microbes, fungi, bacteria, nemotodes, some types of mites, snails, slugs, earthworms, millipedes etc). Secondary decomposers (organisms that eat the primary decomposers; such as springtails, some types of mites, many beetles, nematodes, protozoa, flatworms) and, finally, tertiary decomposers (organisms that eat the secondary decomposers; such as centipedes, predatory mites, other beetles and some ants).
Without this network of life in your soil then your soil is simply dirt and will not help your garden thrive.
How healthy is my soil?
The first step to work out whether you have healthy soil is to look at your plants. Do you have an area of your garden where the plants always struggle, no matter how much attention and care you give them? Maybe you should be paying more attention to your soil. A healthy soil structure can revitalise even the sorriest looking areas of your garden.
Next, dig into your soil and inspect it. Healthy soil will be teeming with life; both that you can see and those too small for the naked eye. Dig a shovel depth down and keep an eye out for anything moving in your soil. You should see a few large healthy earthworms as well as smaller mites, and bugs throughout the soil depth. Remember, if healthy soil was just about the number of earthworms in your soil then there would be a thriving industry of worm breeders selling tubs of worms to add to your garden each year! Worms are often the easiest life to spot in your garden soil or compost pile. A healthy number of earthworms is an indication that there are the necessary conditions to support a network of biota in your soil.
How to improve the health of your soil
If you dig into your soil and realize that it is looking pretty dead, don’t despair! There are lots of things you can start doing now to revive your soil. Remember, the main reason that most soils look unhealthy is that they are lacking in the soil biota (most likely the microbes, fungi and bacteria).
Buy bagged compost
A common approach to improve the soil in your garden is to add shop-bought compost. Many bags of compost are sterilised before being sold to you. This means that all of the essential life in the compost has been removed. You may notice that some compost has had microbes and bacteria added afterwards. If you must buy bagged compost then make sure to get the ones with added microbes and bacteria.
Make homemade compost
Homemade compost from a healthy compost pile should have some of the life in it that your soil needs. However, you need to make sure that the compost is coming from a healthy, active pile that is teeming with the life that you want to inject into your garden. Many people have varying successes with compost piles. This can also be a slow way to get the life you need into your soil with compost piles typically needing at least a year of work to produce usable compost.
Bokashi composting is a great way to inject the microbes, bacteria and fungi into your soil. Within just 2-4 weeks you can have a supply of bokashi pre-compost teeming with healthy microbes to add to your soil (or compost pile). The bokashi compost tea is another great source of healthy microbes that you can add directly to your soil and containers. Bokashi composting is a method of fermenting food scraps using probiotics and microbes. The microbes in bokashi composting have been carefully selected to support life at all levels in your soil. The results will not disappoint you. Find out more about bokashi composting.
Add a soil amender
Alternatively, if you are too impatient to even wait 2-4 weeks for the bokashi composting then you can inject the essential microbes by adding our bokashi bran directly to your soil or compost pile. Dig a handful of the bran into your compost pile or directly to your soil. The microbes in bokashi bran are anaerobic and therefore should be mixed into your soil or compost pile to bury them and exclude oxygen. Find out more about using bokashi bran as a soil amender.