Despite what you might think, the most important part of our soil could be the space between the soil particles. About half of the total mass of soil is made of up interconnecting cavities or holes. These holes fill with both air and water. The amount of air and water in these spaces varies by season and location, but averages about 50% each.
- Allow mineral nutrients dissolved in water to reach the roots of plants
- Support the structure of the plant
- Allow water to pass through so the plant can take it up through the roots without sitting in water and rotting
- Hold oxygen that sustains the bacteria and fungi so they can break down organic matter, making nutrients available to the plants
To give plants the best chance in your garden, here are three simple steps you can take to avoid over-compacting and protect those spaces between the soil particles:
- Avoid trampling on wet soil and be careful about driving vehicles or heavy machinery across it, especially if the soil is clay. If you are a hard landscaper, be mindful that your repeated footfall or machinery could harm the health of soil when you work in wet weather.
- Make sure you have plenty of organic matter. This helps to create larger soil particles so the spaces between them become larger too. Adding a regular layer of mulch or good quality compost will also insulate and provide much needed nutrients.
- Manage the PH. If you are working with sandy acid soil, adding a small amount of clay can act like a glue and stick the particles together, as well as providing better conditions for bacteria and worms to do their job.