Everything your plants eat was once something else's lunch. Tap a creature to meet the workforce.
Simplified on purpose. A teaspoon of healthy soil holds thousands of species. This is the cast, not the census — the major groups, doing their real jobs, in roughly the right order.
🍽️ Trace a nutrient: how dead stuff becomes plant food
Roots leak sugar. A living plant pumps up to a third of its sugars out through its roots as exudates — free lunch, on purpose, to feed microbes.
Bacteria feast. Bacteria eat the exudates (and dead leaves) and lock nitrogen inside their own bodies. The nitrogen is there, but plants can't use it yet.
Protozoa hunt bacteria. A flagellate or amoeba eats a bacterium and gets more nitrogen than it needs — so it excretes the excess as ammonium, right next to the root.
The plant eats. Ammonium is plant-available nitrogen. No bag, no factory — just lunch, twice removed.
Worm castings shortcut this whole chain: the worm already ran the food through a microbe-rich gut, so castings arrive with biology and plant-available nutrients in one package.
Science note: trophic levels here follow the standard soil food web model (bacteria and fungi eaten by protozoa and nematodes, which are eaten by larger predators, with earthworms as ecosystem engineers). Species counts and exact diets vary by soil; nothing here is a lab guarantee — it's how the system works.