World Soil Day (WSD), 5 December is the United Nations Observance that celebrates healthy soils for a food-secure future. This years' campaign "Keep soil alive, Protect soil biodiversity" urges us to focus our attention on the workers belowground - from tiny bacteria to agile millipedes and slimy earthworms - all of which contribute to processes that are indispensable to life on Earth.
These days biodiversity loss is a worry – and soil is also affected. Soil is home to more than 1/4 of our planet's biodiversity. Yet, we only know 1% of this universe. There are more living creatures in a single teaspoon of healthy soil than there are people on Earth. Soil organisms are responsible for many critical ecosystem processes, on which humans depend: from supporting plant growth, to storing carbon and being a vast reservoir for pharmaceuticals. But soil biodiversity is under pressure! Unsustainable soil management affects life belowground.
Key messages 
•    Soil is a living resource, home to more than one quarter (25%) of our planet’s biodiversity.
•    Up to 90% of living organisms live or spent part of their lifecycle in soils, yet we know only 1% of this hidden universe.
•    Soil organisms work 365/24/7 in a coordinated effort to sustain life on Earth.
•    Soil biodiversity is an essential component of soil health. Healthy soils produces more nutritious and safer food. 95% of our food comes from soils.
•    Soils organisms help soils store carbon and reduce GHG emissions.
•    Soil biodiversity contributes to the remediation of soil pollution by breaking down contaminants.
•    Soils are vast, vital pharmacies. Did you know that almost all of the antibiotics that we take to help us fight infections were made using soil micro-organisms?
Fun facts
•    In just 3 inches of soil, there are 13 quadrillion living organisms, weighing 100 million tonnes. 
•    One hectare of soil contains the weight equivalent of two cows of bacteria. 
•    There are more organisms in one gram of healthy soils than there are people on Earth. 
•    An earthworm can digest its own weight in soil every 24 hours. 50% of the planet soil passes through the gut of earthworms each year.
•    Soil organisms process 25,000 kg of organic matter in a surface area equivalent to a soccer field, which is the weight of 25 cars.  
 Source: FAO