When we talk about biodiversity, we often picture tropical forests or coral reefs. But one of the most diverse ecosystems is right beneath our feet. Soil is full of life, from tiny bacteria to earthworms, and this underground world plays a crucial role in keeping our environment healthy and our farming systems productive.The SOB4ES (Integrating SOil Biodiversity into Ecosystem Services) project is working to make this life in the soil more visible and better understood. The goal? To find better ways of measuring soil biodiversity so that farmers, land managers, and policymakers can make more informed decisions. That way, we can continue to enjoy ecosystem services, which are the benefits that healthy natural systems provide for humans, such as clean water, food, and timber.

Why Soil Biodiversity Is So Important

Soil may seem lifeless, but it’s home to an incredible variety of organisms that keep it rich and healthy. These include bacteria, fungi,arthropods, and worms, all working together to:

• Break down organic matter and recycle nutrients;
• Improve plant growth with fewerchemical fertilisers;
• Reduce crop pests and diseases naturally;
• Store carbon and support climate regulation;
• Help water soak into the soil, hold it and prevent erosion.

In short, when soil life is thriving, the land is more productive, more resilient, and better for human wellbeing. Without this diversity of life, soils can’t function properly. They become less fertile, less able to hold water, and more vulnerable to erosion and extreme weather events. Caring for soil biodiversity isn’t just beneficial for nature—it’s vital for farming, the climate, and for the future of our food systems.

Why We Need to Monitor Soil Life

Despite its importance, soil biodiversity is under growing pressure. Erosion, pollution, and unsustainable land use and management practices are damaging the life below ground. And because we can’t see most of these organisms, we often don’t realise there’s a problem until it’s too late.

This is why regular monitoring is so important. By looking at the biological side of soil—alongside its physical and chemical properties—we get a fuller picture of how healthy it really is. And if we can spot changes early, we have a better chance of protecting the soil before it suffers serious damage. 

Reflecting this growing awareness, the European Union has adopted a Soil Strategy and launched the EU Mission A Soil Deal for Europe under Horizon Europe. The mission aims to establish 100 Living Labs and Lighthouses to drive the transition towards healthy soils by 2030.

What the SOB4ES Project Is Doing

As part of the EU Soil Mission, the SOB4ES project explores how soil biodiversity changes over time, across different landscapes, and under various land uses. The project’s primary goals are to:

• Identify which soil organisms live in which types of land;
• Study how land use intensity affects the balance of soil life;
• Develop cost-effective, easy-to-use tools for measuring soil biodiversity and its links to ecosystem services;
• Share knowledge with land managers, citizens, policymakers, and others.

A key aim is to ensure that monitoring soil life is not only scientifically robust but also affordable and practical to apply at large scale, so that farmers, land managers, and local authorities can integrate biodiversity checks into routine soil assessments without heavy costs or complex equipment.

Ultimately, the ambition is to build capacity across Europe to protect and promote soil biodiversity through more innovative, more efficient policies and land management practices that deliver maximum benefits for both nature and people.

How To Assess Soil Biodiversity

Because the organisms in soil come in all shapes and sizes, SOB4ES researchers use a mix of tools to study them.

• For microbes like bacteria and fungi, DNA sequencing helps identify what’s in the soil and in what amounts;
• For bigger creatures like arthropods and earthworms, fieldwork involves collecting soil samples and counting what’s found using hand-sorting or traps, followed by morphological identification.

To understand how soil biodiversity changes over time, across landscapes, and under different land uses, SOB4ES researchers collect samples from a range of ecosystems, including grasslands, croplands, wetlands, and forests. At each site, samples are taken from multiple locations to account for the fact that soil life is not evenly distributed across the area.

What’s Next?

A significant strength of the SOB4ES project is its commitment to translating scientific knowledge into practice. Through open workshops, Policy Briefs, and diverse communication activities, the project aims to equip land managers, policymakers, and industry players with the tools to manage soils in a more biologically informed way.

One example is the mini-public held in Dublin in May 2025—the first in a series planned across Europe—which brought together citizens to discuss soil biodiversity and its relevance for land use, food, and climate. These events are designed to spark dialogue between science and society ensuring that soil health becomes part of the wider public debate.

Soil life may be hidden, but its impact on our food, environment, and future is clear. And with better tools and knowledge, we can do a much better job of looking after it.

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This article is based on the practice abstract “Why and how to assess soil biodiversity,” published by the SOB4ES team. You can download it from the project website. Also, this material is part of a series of guest blog posts, as part of our collaboration with the host, the BIOservicES project, under the Mission Soil.