24/08/2026
Under the microscope, alongside the bacteria and fungi, we count protozoa — tiny single-celled grazers: flagellates, amoebae, ciliates. They eat bacteria.
This is one of the most simple, natural ways your soil feeds a crop.
Bacteria are rich in nitrogen — they lock it up in their cells. When protozoa graze on them, they take the carbon they need and release the surplus nitrogen as ammonium, straight into the root zone, in a form plants can take up. Soil scientists call it a "microbial loop" and research attributes a real share of the nitrogen a plant takes up to this grazing.
It's why a soil that looks "fed" on a chemical diet can still underperform: if the biology that unlocks and cycles nutrients isn't there, the nutrients struggle to reach the plant. This is why we don't just measure bacteria and fungi: the predators that prey on them are a crucial part of the engine too.
When we see protozoa numbers crash, it often points to compaction, hard tillage or inputs that have knocked the system back.
If your nitrogen is being recycled by life you can't see, how would you know it's still working?
👉Source: https://nph.onlinelibrary.wiley.com/doi/10.1111/j.1469-8137.2004.01066.x