This week on Ocean FM soil scientist, Dr. Aga Piwowarczyc, spoke about life in our soils and how important healthy soils are for climate mitigation, biodiversity and human health.
Did you know?
- There are more living organisms in eight teaspoon of soil than all the people living on earth
- One teaspoon of soil contains about one billion bacterial cells
- Soils absorb one third of all carbon dioxide produced by humans
- Worms and insects shred and chew organic material into smaller bits that bacteria and fungi can easily access
- Garden earthworms burrow and create pathways in soil that fill with air and water – these help plant roots to grow
- Worms do not actually eat the plants and food scraps we feed them – they survive on the bacteria and fungus (or micro biome) while breaking the material into smaller pieces
Why is this important?
- Soil is full of life such as bacteria, fungus, protozoa and nematodes – as a result, our soils can hold carbon deeply in the earth so that it will not be released
- Soil absorbs one tonne of carbon per hectare per year but use of chemical fertilisers, herbicides and slurry all damage this life in the soil and therefore its ability to store carbon
- 60% of European soil is of poor quality and only 30 of good status. Soils currently absorb one third of man-made carbon dioxide, if we improve soil health this could be doubled
- Plant roots and microbes need to access to varying amounts of nutrients, air and water for optimum growth – the availability of these is regulated by microbes in the soil. Having all of these working well allows better production of food with reduced need for fertilisers
- Soil compaction and disturbance such as excessive tillage can eliminate these important microenvironments. This makes it hard for plant roots to penetrate the soil, absorb water and nutrients, and interact with beneficial microbes
What can we do?
- Incorporate organic material such as mulch, manure or homemade compost into your soil to help provide lots of nutrients and increase air, water and nutrients for the fauna and microbes living there. This will also help minimize weeds, and reduce plant stress by moderating soil temperatures
- Sow green manures (such as clover or mustard leaves) to protect bare ground or exposed soil when it is not being used for planting – these bring nutrients to the surface and improve the structure of the soil – which stops it from being washed away by rain
- Try not to use chemical fertilisers, herbicides or pesticides as these chemicals harm the micro-organisms living in the soil and run off into nearby water bodies causing further damage to wildlife
- Rotate your vegetables. While most microbes are beneficial to plants, disease-causing microbes may overwinter in soil and plant litter. These pathogens prefer to infest and feed on certain plants. Planting the same crop in the same soil year after year can increase diseases
For More Information
How to Embrace Greener Gardening
Living Soil, healthy garden
Getting started with Composting
Talamh Beo – the Soil Food Web