Every year on June 27, we celebrate World Microbiome Day — a special occasion to recognize and give visibility to the millions of microorganisms living in the soil beneath our feet.

At the heart of that soil lie it microbiome: complex communities of bacteria, fungi, viruses, and other tiny organisms that support our crops, our food security, and the balance of the planet — not only through their presence but also through the ecological functions they perform and the interactions they establish with plants, minerals, and organic matter.

The soil microbiome is not simply a collection of microorganisms. It is an ecosystem in itself: a living, dynamic community constantly interacting with its environment, influencing the health of the soil, the plants, and ultimately the entire agricultural system. Understanding and protecting these microbiomes is key to a regenerative, resilient, and truly sustainable agriculture.

 

What role do the microorganisms within the soil microbiome play?

Often invisible to the naked eye, soil microorganisms—through their diverse functions and interactions—are powerful allies for transforming agriculture. They improve soil fertility, reduce dependency on chemical inputs, and help mitigate the effects of climate change. Some of their most important functions include:

• Organic matter decomposition

Microorganisms break down plant and animal residues into humus — a stable form of organic matter that improves soil structure, enhances water and nutrient retention, and provides a fertile base for crops.

• Nitrogen fixation

Bacteria such as Rhizobium or Azotobacter convert atmospheric nitrogen into forms accessible to plants. This natural process reduces the need for chemical fertilizers and supports more sustainable plant growth.

• Protection against pathogens

Beneficial microorganisms compete with soilborne pathogens by producing natural antibiotics, forming protective biofilms, or triggering plant defense mechanisms. This creates a protective microbiome that reinforces plant health.

• Improved soil fertility

A microbiologically active soil is more fertile, better structured, and has a greater capacity to retain nutrients—leading to higher productivity, better crop quality, and reduced soil degradation.

• Resilience to climate challenges

Healthy soils, teeming with microbial life, store carbon, retain water, and increase resilience to drought and extreme weather events. Conserving and restoring soil microbiomes boosts agricultural productivity and contributes

to climate change mitigation.

The incorporation of beneficial microorganisms into agriculture marks a paradigm shift — from a model that has degraded soils to one that centers on their preservation. The top few centimeters of Earth’s crust host a quarter of the planet’s biodiversity, highlighting the crucial importance of protecting it.

 

How do we support the soil microbiome?

There are many practices that can help regenerate the soil microbiome — from the use of biostimulants and beneficial microorganisms to sustainable crop management, reduced tillage, and more balanced fertilization strategies. All of these aim to:

• Stimulate the soil’s natural biological activity. 
• Promote a balanced, healthy rhizosphere. 
• Foster plant–microorganism symbiosis. 
• Reduce dependence on synthetic inputs.