Not a lot of people realize that 95 % of our food comes directly or indirectly from soil. Not only are soils our most valuable ecosystem; they are also home to third of all living creatures on the planet. It is surprising then, that our knowledge of soil biology lags behind other science disciplines.
There is tremendous diversity of life within soils and one exceptional organism known as the ecosystem engineer. This creature shapes soil microbial life, how water moves through soils, the efficiency of nutrient cycling, helps plants to grow, and even influences the breeding success of birds. This creature is the humble earthworm, first recognized by Charles Darwin for its importance in soil ecosystems and functioning.
Earthworms are found all over the world and come in all colours and sizes, from the indigo blue worms with fried egg colour spots in Philippine forests; to the giant, metre long Gippsland worms in Australia that are detected by gurgling sounds coming from their large burrows; to the stripy tiger worms that most people will find in great numbers in, up the sides and under the lid of their compost bins. In fact, there are over 1000 species of earthworms found on our planet, and they are very adept at colonizing fields and paddocks where we grow almost all of our food.
It is one of the greatest joys of my job to talk to farmers about their earthworms. These creatures perform beneficial roles not known in nature. For example, earthworms improve the efficacy of surface liming to ameliorate acidity and they mobilize phosphorus fertilizer that has become chemically bound for crop uptake. Earthworms are well known as indicators of a healthy, well managed soil. However, we don’t know how earthworms are doing in farmland soils.
As part of my NERC soil security fellowship, I decided to ask farmers if they wanted to collaborate to co-create an earthworm monitoring method. The response was superb, the pilot study covered every region of England and the preprint of the results are in the top 5% of all results scored by altmetric. The method feedback and analysis led to the #30minworms test, freely available on the project page at www.wormscience.org. This year, over 3000 hectares have been surveyed and almost 20,000 earthworms counted and identified by farmers.
For the first time, we have an insight into soil management practices and earthworm populations. This has revealed some surprises for the farmer groups taking part, for example, within one catchment some people had exceptional earthworm populations where others found just 1 worm in the whole field! Monitoring is going to be an increasingly important part of realising soil health in practice. For World Soils Day, the humble earthworm certainly deserves to be at centre stage.
Dr Jackie Stroud, NERC fellow based at Rothamsted Research, UK.
If you would like to learn more about earthworm research or get involved please contact Dr Jackie Stroud via email: firstname.lastname@example.org