December 5 is the World Soil Day. This year’s theme – Keep soil alive, protect soil biodiversity – makes me very happy, as I have spent all my career studying biodiversity in soil microbes and their activities.
A recently published Finnish study indicated that an increased exposure to soil, i.e. children playing with soil material outside daycare centres, may prevent allergies by making children’s skin and gut microbes more diverse. These are incredible results that also point out how little we still know of soil biodiversity and of its impact on us and our environment.
The diverse community of living organisms maintains nutrient cycles in soil and builds vital networks between organisms, where everyone has their own purpose and place determined by evolution. For centuries, people have been changing this network by draining peatlands to fields and forests, and by shaping and fertilising land to gain the best possible tree growth or crop yields. For example, synthetic fertilisers make soil microbes unnecessary for crops, as crops no longer need them to release nutrients from organic matter. If the fertility of soil decreases, we will lose organic matter and nutrients. We already know that agricultural countries have lost a significant part of sequestered carbon during the past decades.
We can’t afford to lose biodiversity, as we do not yet fully understand its significance for entire ecosystems.
Soil can maintain biodiversity which protects the land and whose existence and importance can only be realised after it has been lost. We can’t afford to lose biodiversity, as we do not yet fully understand its significance for entire ecosystems. Soil biodiversity may also play an important part when global temperatures are rising. Many organisms contribute, directly or indirectly, to the amount of carbon sequestered in soil and to the amount of carbon released from soil into the atmosphere as greenhouse gases.
Working at Luke, I can proudly look in the mirror on the World Soil Day, as we are actively trying to solve soil mysteries that are important considering production and the environment. Currently, Luke has several ongoing projects, in which we researchers attempt to shed light on soil biodiversity and its impact on soil activities, such as carbon sequestration. The national BioValse project is a good example. It is based on samples collected from Finnish fields during a study spanning over decades, from which we are now for the first time determining biodiversity in microbes and other small soil organisms. Fields have their own cultivation and land-use history, and the aim is to combine knowledge of biodiversity with chemical and physical information collected from soil samples.
The final goal of the study is to draw a big picture of the most important factors that affect soil biodiversity on fields with differing land use histories and its ability to maintain healthy soil structures and activities. Perhaps this information finally helps us to take better care of our soil and use it while protecting the biodiversity and health of organisms.
PS. I also recommend the Food and Agriculture Organization’s (FAO) report “State of Knowledge on Soil Biodiversity: Status, Challenges, and Potentialities” to be published on the eve of the World Soil Day on 4 December.