Pick up a handful of healthy soil.

At first glance, it may not look extraordinary. It is brown. It crumbles between your fingers. You may see a tiny root, an insect, or perhaps an earthworm.

But hidden inside that handful is one of the most astonishing communities of life on Earth.

There are bacteria and archaea, fungi weaving microscopic threads between soil particles, single-celled organisms hunting microbes, tiny roundworms called nematodes, mites and springtails breaking apart dead material, and plant roots releasing chemicals into the world around them.

In 2023, scientists reviewing global biodiversity data estimated that soil is home to about 59% of Earth’s species, with an uncertainty of about 15 percentage points.¹

If that estimate is approximately correct, more than half of the species on our planet live in soil for at least part of their lives.

The ground beneath our feet isn’t simply dirt.

It is an ecosystem.

And nearly everything happening above ground depends, in one way or another, on what happens below it.

SOIL IS ALIVE

Soil is much more than crushed rock.

It contains mineral particles formed as rocks weather over time, along with water, air, organic matter and an enormous community of living organisms.

These organisms are not merely passengers living in the soil. They help create many of the properties that allow soil to function.

Bacteria, fungi and other organisms decompose dead material and recycle nutrients. Fungal threads and substances produced by microorganisms can help bind soil particles together. Earthworms and other animals dig tunnels, move organic material and alter the spaces through which air and water travel.

Together, these organisms form an extraordinarily complicated network known as the soil food web.²

Plants capture energy from sunlight. Some of the carbon they capture eventually enters the soil through roots, dead leaves and other plant material. Bacteria and fungi consume organic compounds. Protozoa and nematodes feed on microbes. Tiny arthropods shred dead material. Predators eat other organisms. Earthworms mix and transform organic matter.

And when organisms die, their bodies become resources for other life.

Nothing is wasted for long.

A leaf falling from a tree can be broken apart, digested and transformed until atoms that were once part of that leaf become part of the soil, a microorganism, another plant—and perhaps eventually another animal.

The soil beneath a forest, prairie or garden is therefore not a graveyard of dead material.

It is one of nature’s great recycling systems.

A UNIVERSE AROUND EVERY ROOT

Now imagine shrinking yourself until a plant root towers over you like the trunk of an enormous tree.

The world surrounding that root would be anything but empty.

One of the busiest regions in soil is the narrow zone influenced by living roots, called the rhizosphere.

Plants do not simply sit silently in the ground and wait for nutrients to bump into them. Their roots release an astonishing mixture of compounds into the surrounding soil. These substances are commonly called root exudates.

Some contain carbon compounds that microorganisms can use as food.

This helps create a hotspot of biological activity around the root. The microorganisms living there can, in turn, influence plant nutrition, growth and health.³

The USDA describes the rhizosphere as the most active part of the soil ecosystem, where readily available food from living roots supports intense microbial activity and nutrient and water cycling.⁴

What looks to us like a simple root buried in dirt is actually surrounded by a microscopic community.

Chemicals are exchanged. Microbes multiply. Nutrients change form. Predators hunt. Fungi grow.

And much of it is happening within millimeters of an ordinary-looking root.

THE FUNGAL PARTNERS BENEATH OUR FEET

Among the most remarkable organisms in this underground world are mycorrhizal fungi.

The word “mycorrhiza” refers to a close relationship between a fungus and a plant root.

Plants use photosynthesis to capture energy from sunlight and build carbon-rich compounds. Mycorrhizal fungi can receive some of this carbon from their plant partners.

What does the plant get in return?

The fungus grows incredibly thin threads called hyphae through the surrounding soil. These threads can reach into spaces beyond the root itself and help the plant acquire resources, including nutrients such as phosphorus.

The scale can be astonishing.

Peer-reviewed research describes soils containing tens to hundreds of metres of fungal hyphae in a single gram of soil.⁵

Think about that for a moment.

A pinch of earth can contain microscopic fungal threads that, if placed end to end, could stretch farther than a football field.

And those threads are not simply lying there. They can form pathways through which nutrients are transported.

It is an ancient biological partnership.

The plant captures energy above ground.

The fungus explores the soil below it.

Each possesses something the other can use.

Mycorrhizal fungi can also influence soil structure and the stability of soil aggregates, although the size of these effects depends on the plants, fungi, soil and environment involved.

What appears above ground to be a plant standing alone may therefore be intimately connected below ground with an enormous hidden fungal world.

THE TINY ARCHITECTS OF EARTH

Healthy soil is not simply a pile of loose particles.

Look closely at good garden or forest soil and you may notice that it forms little crumbs and clumps.

These are called soil aggregates.

An aggregate is a collection of smaller soil particles held together by physical, chemical and biological forces. Plant roots, fungal threads, organic matter and compounds produced by microorganisms can all help build and stabilize them.⁶

The spaces between aggregates are just as important as the aggregates themselves.

These pores create pathways for water and air. They provide habitat for organisms and room for roots to grow.

When rain falls on well-structured soil, some of that water can travel into these spaces rather than immediately flowing across the surface.

Even an earthworm can help reshape this underground architecture.

As earthworms burrow, feed and produce casts, they move organic material and alter soil structure, nutrient cycling and the pathways through which water and air can move.

A single worm may seem insignificant.

But a living soil is built from countless small actions happening at the same time.

Roots grow through pores. Fungi extend between particles. Microorganisms consume and transform organic material. Animals tunnel and feed. Water moves through changing pathways.

Out of all these tiny interactions emerges something much larger:

soil capable of supporting an ecosystem.

THE THIN LAYER THAT SUPPORTS CIVILIZATION

Soil performs jobs so fundamental that most of us rarely stop to think about them.

It anchors plants.

It stores and transmits water.

It stores, transforms and cycles nutrients.

It provides habitat for an enormous variety of organisms.

Its minerals and microorganisms can filter, hold or transform some substances moving through the environment.

And soils store enormous amounts of carbon, making them an important part of Earth’s carbon cycle.

For humans, there is an even more obvious connection.

Food.

Wheat, rice, corn, potatoes, fruit and vegetables all depend on land-based systems. Animals raised for meat and dairy often depend on plants grown in soil. Forests producing wood and other materials depend upon it as well.

Human health is influenced by many things, so it would be too simple to say that healthy soil automatically creates healthy people.

But our civilization depends heavily upon something remarkably easy to overlook:

a relatively thin, living layer covering parts of our planet.

WHAT HAPPENS WHEN WE BREAK THE SYSTEM?

Humans can damage this living system.

But it is important to be precise about how.

Agriculture itself is not the enemy. Humans have grown food in many different ways for thousands of years, and different soils, climates and crops require different approaches.

The problem occurs when land is repeatedly disturbed in ways that damage important soil properties faster than they can recover.

One example is excessive tillage.

Plowing and other forms of tillage can be useful agricultural tools. But frequent or intensive tillage can break apart soil structure, disturb organisms, contribute to losses of organic matter under some conditions and leave soil more vulnerable to erosion.⁷

Bare soil creates another problem.

Imagine a heavy raindrop striking a forest floor protected by leaves and plants.

Now imagine that same drop striking bare, exposed earth.

Vegetation and plant residues can soften the impact of rain and slow water moving across the surface. Without that protection, soil particles can be detached and carried away.

Wind can do the same thing to dry, exposed ground.

Grain by grain, a landscape can begin to lose the very soil upon which its productivity depends.

WHEN THE SKY TURNED TO DUST

History gives us a frightening example of what can happen when vulnerable soil, damaging land use and extreme weather collide.

During the 1930s, severe drought struck the Great Plains of North America. Crop failures left enormous areas of soil exposed, and powerful winds began lifting dry topsoil into the atmosphere.

The result became known as the Dust Bowl.

On May 11, 1934, one enormous dust storm carried fine soil particles eastward across the United States, over Washington, D.C., and far out over the Atlantic Ocean.⁸

More severe storms followed.

Imagine standing in a city more than a thousand kilometers from the Great Plains and watching soil from distant farms darken the sky above you.

The disaster became so difficult to ignore that it helped transform American soil-conservation policy. In 1935, the United States created the Soil Conservation Service, the predecessor of today’s Natural Resources Conservation Service.⁸

The Dust Bowl was not caused by one thing. Drought was crucial, and land-management practices increased the vulnerability of exposed soils in parts of the region.

But its lesson was impossible to miss.

Soil that took generations to develop could become airborne and disappear.

THE GREAT LOSS OF SOIL

The Dust Bowl was dramatic enough to photograph.

Most erosion is less spectacular.

A little soil leaves one field.

A little more disappears during the next storm.

Then another.

Across enormous areas and long periods of time, those small losses add up.

Soil erosion remains a global problem today.

The Food and Agriculture Organization of the United Nations has reported an estimate of approximately 24 billion tonnes of fertile soil lost to erosion around the world each year.⁹

Twenty-four billion tonnes.

It is difficult to imagine a number that large.

And erosion is only one form of soil degradation.

Soils can also be harmed by compaction, salinization, pollution, nutrient imbalances, loss of organic matter and other pressures. The importance of each problem varies greatly from one region to another.

When soil structure deteriorates, water infiltration can decline and runoff can increase.

When protective vegetation disappears, erosion can accelerate.

When organic matter declines, important physical, chemical and biological properties of the soil can change.

When habitats change, the organisms living within them change too.

A landscape that once absorbed water and supported abundant plant life can gradually become less capable of doing so.

But this story does not have to end with destruction.

Because soil is not simply a substance.

It is a system.

And under the right conditions, damaged soil functions can recover.

CAN WE BRING DAMAGED SOIL BACK TO LIFE?

In many situations, we can improve them.

Farmers, gardeners, scientists and land managers around the world are learning how to protect soil while continuing to produce food.

There is no universal recipe.

A method that works beautifully on one farm may perform differently in another climate, crop or soil type.

But several broad principles appear repeatedly in modern soil-health management.

Minimize unnecessary disturbance.

Keep soil covered whenever practical.

Maintain living roots for more of the year.

Increase plant diversity where the farming system allows it.

Manage water and nutrients carefully.

These ideas reflect the soil-health principles promoted by the USDA Natural Resources Conservation Service: minimize disturbance, maximize soil cover, maximize biodiversity and maximize the presence of living roots.⁷

The goal is not simply to feed this year’s crop.

It is also to preserve the soil’s ability to keep functioning in the years ahead.

COVER CROPS: GROWING PLANTS FOR THE SOIL

Cover crops provide a beautiful example.

After harvesting a main crop, a field might otherwise remain bare for months.

Instead, farmers can grow another crop partly for the benefits it provides to the soil.

Its leaves protect the ground.

Its roots penetrate the soil.

Living roots continue supplying carbon compounds to organisms in the rhizosphere.

When the cover crop dies or is terminated, its remains can contribute organic material to the system.

And this isn’t merely an attractive theory.

A 2025 global meta-analysis combined results from 225 studies examining cover crops and 15 soil properties.¹⁰

Across the studies, cover crops increased water-stable aggregates by an average of 15.9%, total porosity by 6.1% and water infiltration by 37.2%. They also reduced soil bulk density by 3.2% and penetration resistance by 11.8%.¹⁰

The effects were not identical everywhere. Climate, soil texture, cover-crop type and management practices influenced the results.

That variation teaches us something important.

Regenerating soil is not magic.

It is ecology.

And ecology depends on context.

THE ELEPHANTS THAT CHANGED A MAN’S LIFE

Few stories illustrate that lesson more dramatically than the story of Allan Savory.

Savory was born in what was then Rhodesia and trained in zoology and botany. As a young research biologist and game ranger in Africa, he became deeply concerned about deteriorating landscapes and expanding areas of bare, desert-like ground.¹¹

At the time, Savory became convinced that large elephant populations were contributing to the destruction of vegetation and the degradation of the land.

His research helped support a recommendation to reduce the elephant population.

The government eventually carried out a massive culling program.

More than 40,000 elephants were killed.¹¹

The expected recovery did not happen.

According to Savory’s own later account, the land continued getting worse.

Imagine realizing that an idea you believed would save a landscape had helped justify the deaths of tens of thousands of magnificent animals—and that the landscape had not recovered.

Savory later called the episode the greatest blunder and tragedy of his life.¹¹

But instead of walking away from the failure, he spent decades trying to understand what had gone wrong.

One possibility fascinated him.

What if large grazing animals were not always enemies of grasslands?

What if, under the right conditions, they could be part of the system that helped maintain them?

In natural grasslands, large herbivores do much more than eat plants. They move across the landscape. They consume vegetation. They return nutrients through manure and urine. Their hooves disturb litter and soil surfaces. Their grazing changes how plants grow, and periods without grazing allow plants to recover.

Savory eventually developed an approach now known as Holistic Management, including Holistic Planned Grazing. It attempts to manage livestock movement, grazing periods and recovery periods in ways intended to reproduce some of the ecological effects of moving wild herds.¹¹

His ideas became influential—and controversial.

Savory has argued that properly managed grazing animals can help reverse desertification and restore degraded grasslands. Scientific studies, however, do not support treating any grazing system as a universal solution. Reviews show that grazing can have positive, neutral or negative effects depending on factors such as climate, grazing intensity, vegetation, soil, livestock type, timing and recovery periods.¹²

Heavy or poorly managed grazing can damage vegetation, compact soil and increase erosion.

In other settings, carefully managed grazing can contribute to nutrient cycling and can be compatible with healthy, productive grasslands.

The lesson is therefore more interesting than simply saying that animals are good or animals are bad.

Living landscapes are systems.

Take away the animals, change the vegetation, alter the rainfall, disturb the soil or change the timing—and the effects can ripple through everything else.

And sometimes, restoring a damaged landscape means bringing biological processes back rather than trying to remove them.

Managed grazing is one possible tool.

Trees and deep-rooted plants are another.

Together with fungi, microbes, soil animals, organic matter, water and time, they show what becomes possible when life is allowed to rebuild the land.

WATCH WHAT HAPPENS WHEN LIFE RETURNS

Imagine a piece of bare, degraded ground beginning to recover.

Plants begin covering the surface. Leaves intercept raindrops. Roots enter the earth. Photosynthesis captures carbon, and some carbon compounds eventually move below ground.

Microorganisms gather around living roots. Dead plant material accumulates and begins to decompose. Fungal threads spread through the soil. Small animals feed. Organic matter enters the food web.

On some grasslands, carefully managed grazing animals can become part of this process as well—consuming vegetation, returning nutrients and influencing plant growth while the land receives sufficient time to recover.

Trees can contribute in another way. Their leaves and branches add organic material above ground, while their roots move carbon below ground, interact with microorganisms and create biological pathways through the soil.

As soil structure changes, aggregates and pore spaces can become more stable, affecting how air and water move through the ground.

No single creature is rebuilding the soil.

The community is doing it together.

That may be one of the deepest lessons hidden beneath our feet.

A living soil is not created by one heroic organism.

It emerges from relationships among plants, animals, fungi, bacteria, archaea and other microorganisms interacting with minerals, water, air and climate.

Damage enough parts of that system and important soil functions can deteriorate.

Give the system better conditions, and biological and physical recovery can begin.

ONE OF EARTH’S GREAT FRONTIERS

There is something especially humbling about soil science.

Human beings lived on soil, grew food in soil and built entire civilizations upon soil for thousands of years without being able to see most of the organisms inside it.

Bacteria were invisible.

Microscopic fungal threads were largely hidden.

The chemical exchanges surrounding roots could not be watched.

DNA sequencing did not exist.

Even today, scientists are still trying to determine how much life exists below ground and what all of those organisms are doing.

The 2023 estimate that approximately 59% of Earth’s species live in soil came with an uncertainty of about 15 percentage points, and the researchers emphasized how incomplete our knowledge remains for many groups.¹

That uncertainty isn’t disappointing.

It is thrilling.

It means that one of Earth’s greatest biological frontiers has been beneath us all along.

We dream of exploring distant planets.

We send spacecraft billions of kilometers into space.

We descend into the deepest parts of the ocean searching for creatures no human has ever seen.

Yet step outside, kneel down, and scoop up a handful of earth.

You are holding another frontier.

A LIVING WORLD BENEATH OUR FEET

Every forest floor, prairie, garden and farm contains a world of competition, cooperation, construction, destruction and renewal.

Atoms move from minerals into organisms.

Carbon captured by plants enters roots and soil.

Microorganisms transform nutrients.

Fungi exchange resources with plants.

Animals feed, burrow, reproduce and die.

Organic matter is broken apart and rebuilt into new forms.

Life rises from the soil.

And eventually, life returns to it.

So the next time you hold a handful of healthy soil, don’t dismiss it as dirt.

Look closely.

You are holding the remains of ancient rocks and past generations of life.

You are holding habitat for organisms you can see and countless others you cannot.

You are holding a system that stores water, cycles nutrients, supports plants and helps make terrestrial ecosystems possible.

And somewhere inside that handful may be organisms science has barely studied—or perhaps has never formally described.

The greatest lesson of soil may also be the simplest:

There is an extraordinary world beneath our feet.

We have only begun to discover its secrets.

REFERENCES

¹ Anthony MA, Bender SF, van der Heijden MGA. “Enumerating soil biodiversity.” Proceedings of the National Academy of Sciences. 2023;120(33):e2304663120. doi:10.1073/pnas.2304663120. View Source

² U.S. Department of Agriculture, Natural Resources Conservation Service. Soil Biology Primer. View Source

³ Philippot L, Raaijmakers JM, Lemanceau P, van der Putten WH. “Going back to the roots: the microbial ecology of the rhizosphere.” Nature Reviews Microbiology. 2013;11:789–799. doi:10.1038/nrmicro3109. View Source

⁴ U.S. Department of Agriculture, Natural Resources Conservation Service. Soil Health Management. View Source

⁵ van’t Padje A, et al. “Temporal tracking of quantum-dot apatite across in vitro mycorrhizal networks shows how host demand can influence fungal nutrient transfer strategies.” The ISME Journal. 2021. doi:10.1038/s41396-020-00786-w. View Source

⁶ U.S. Department of Agriculture, Natural Resources Conservation Service. Soil Quality Test Kit Guide. USDA NRCS.

⁷ U.S. Department of Agriculture, Natural Resources Conservation Service. Soil Health. View Source

⁸ U.S. Department of Agriculture, Natural Resources Conservation Service. A Brief History of NRCS. View Source

⁹ Food and Agriculture Organization of the United Nations. FAO resources on global soil erosion and land degradation.

¹⁰ Yan F, Arthur E. “Cover crops alter soil physicochemical properties: A global meta-analysis.” Geoderma. 2025;460:117436. doi:10.1016/j.geoderma.2025.117436. View Source

¹¹ Savory A. “Bureaucratic Blundering Endangering Horses and Humanity.” Savory Institute. 2016. Savory recounts that his research led to the conclusion that excessive elephant numbers were causing land degradation, that the government subsequently killed more than 40,000 elephants, and that the land worsened rather than recovered. View Source

¹² Briske DD, et al. Reviews and experimental literature on grazing management, together with global analyses of grazing effects, show that ecological outcomes vary with grazing intensity, climate, ecosystem type, timing and management. See also: “Sustainable grazing management in rangelands: Over a century searching for a silver bullet.” Agriculture, Ecosystems & Environment. 2019;283:106561. doi:10.1016/j.agee.2019.05.020. View Source