The Exchange
Sunlight, stored as sugar, traded for nutrients.
Long before there were plants, bacteria were already capturing sunlight and locking it into carbon chains — the basic definition of "organic". Photosynthesis, in a plant, is the same trick refined: turning light into sugar, and holding that energy in a form the plant can move around and spend.
A plant doesn't keep all of that sugar to itself. A large share moves down into the root system, and a further share of that is released straight into the soil as root exudates — a mix of sugars, proteins and carbohydrates whose exact ratio shifts depending on what the plant needs right now. More sugar recruits bacteria. More of the complex, protein-rich compounds recruit fungi.
It isn't waste. Bacteria and fungi can't travel to find food, but they can multiply extremely fast wherever food turns up — a single bacterium can divide roughly every 20 minutes. By feeding a steady stream of exudates at the root, a plant recruits its own workforce exactly where it needs one, and adjusts the order as the season goes on.
"The soil food web doesn't start with fertiliser. It starts with a plant paying for help."
Deep roots
~4 billion years
How long photosynthetic bacteria have been building soil carbon — long before plants, or algae, existed.
Not a one-off
Continuous, all season
Exudates flow constantly while roots are active. A bare, unplanted bed is a bed with nothing feeding its biology.
Demand-led
The recipe changes
The mix of sugars, proteins and carbohydrates a plant releases shifts to recruit whichever organisms it currently needs.
Put It Into Practice
Feed The Soil
No-dig beds, compost tea, leaf mould and organic liquid feeds — the practical techniques that put this biology to work in your own garden.
Explore Garden Techniques →