Healthy soil is a commonly used term, but what do we actually mean? Generally, we see healthy soil as soil growing strong, pest and disease resistant plants and nutrient-dense food, even when weather conditions are not ideal. Because functioning soil ecosystems are needed to get these outcomes, healthy soil is essentially soil with a functioning ecosystem.
Soils with functioning ecosystems are the most complex, profound and self-organising living systems on earth.
They are dark brown from the plant and animal waste materials eaten and broken down into minute particles by soil invertebrates and microbes. These diverse communities of soil organisms combine this organic matter with the sand, silt and clay minerals to form soil particles of various shapes and sizes that scientists call aggregates.
Soil Aggregates (© Wendy Seabrook)
One tablespoon of healthy soil usually contains kilometres of mycorrhizal and other fungal threads and 6 – 7 billion soil organisms, including bacteria, nematodes, protozoa, and arthropods.
Above-ground, plants are the base of the food chain. Below ground, our soil ecosystems source their nutrients and energy from:
- Organic waste materials (leaf litter, roots, wood, faeces, dead animals, etc.),
- Secretions of sugars, proteins and the other organic compounds plants release from their roots (root exudates), and
- Nutrients from rainwater, dust and mineral particles in the soil.
Why is Healthy Soil Important
Unhealthy soil won’t produce wholesome food, even if we feed our soil with nutrient supplements!
Whereas, soils containing biodiverse communities of soil organisms and provided with sufficient food supplies, use their billions of years of on-the-job training to:
- Maintain soil infrastructure
- Break down organic waste materials
- Produce acids and enzymes which release nutrients locked up in the sand, silt and clay particles in the soil 
- Recycle the nutrients from the organic materials and mineral particles and make them available for our plants to reuse
- Control soil pathogens and soil-derived plant pests and diseases through complex predator-prey relationships  
- Form beneficial symbiotic associations with plant roots 
Our plants get comfortable accommodation and a nutritious diet!
Find out how to Build Healthy Soil
Recommended articles –
- How to Build Healthy Soil – Eco-logically
- How to Reduce Fertiliser Costs
Or alternatively, develop practical solutions suitable for your climate and other growing conditions with these resources for your farm, or
for your garden.
References – What is Healthy Soil?
 Wendy Seabrook, 2021, What is Regenerative Farming and Gardening? Publ Learning from Nature
 Elaine Ingham, 2016, Roots of your Profit, Oxford Real Farming Conference 2016
Thakur M.P., Geisen S., 2019, Trophic regulations of the soil microbiome. Trends Microbiol. 27:771–780. DOI: 10.1016/j.tim.2019.04.008
 FAO 2008. An international technical workshop Investing in sustainable crop intensification. The case for improving soil health. Integrated Crop Management Vol.6-2008. FAO, Rome: 22-24 July 2008