Below each square meter of healthy soil there are about 15 t of living soil organisms. This makes soil the most densely populated “territory” on earth. It also means that about 1.5 kg of soil are home to as many living creatures as there are currently people on earth.
Each hectare of soil is:
- 2 t earthworms
- which create 9,000 km of tunnels
- a pore volume of 90 m3
- and a surface area equivalent to 7 football fields
Sources
Regenwurm: http://www.regenwurm.ch/de/leistungen/gangsystem.html
Bodenreise.ch: https://bodenreise.ch/wp-content/uploads/2014/08/brochure_1.pdf