When I first began gardening, dealing with soil was the most challenging and least interesting part for me. I remember thinking soil was just the dirt you put plants in. Outside I went, shovel in hand, slicing through what was basically just dust and clay. I buried those poor, Home Depot transplants—tired, waterlogged little things straight from the store shelves—into this depleted mess of a grave, hoping the magic of “planting” would take over.
But the plants didn’t “take over.” They barely held on. Those stunted transplants always yellowed immediately. Disease, fungus, bugs—they all moved in, like I’d set out a welcome mat for plant woes. I burned them with fertilizer. I stripped them with fungicides. I overwatered them. I gave up early. It got too hot to care.
Of course the issue wasn’t the plants, it was the soil, or more accurately, the lack of life in the soil. I started reading about the soil microbiome, discovering that healthy soil is like a bustling underground city, filled with microbes, fungi, worms, and roots all working together to nourish the plants and keep disease at bay.
Soil, I learned, is more than just dirt. It is alive and the literal foundation for every living thing above it. And our soil is in trouble.
Most large-scale agricultural and land use practices have contributed to a significant loss of topsoil in the United States and around the world. Topsoil is that precious, nutrient-dense layer—usually just a few inches deep— where plants sink their roots, where earthworms and microbes hustle, and where organic matter and minerals team up to create a mini-ecosystem for growing food, sequestering carbon, and filtering water. This thin, delicate crust is responsible for 95% of our food production, but we’re losing it 10 to 40 times faster than it can naturally regenerate.
Soil is full of living organisms—microbes, fungi, insects—that are crucial for storing carbon and providing nutrients to plants. These organisms need organic matter and a stable environment to thrive, but as topsoil erodes, the living elements within it also decline. This loss of life makes soil less resilient and less capable of supporting plants, which in turn reduces its ability to retain carbon.
Topsoil Loss Is Closely Linked to Carbon Emissions
Soil stores roughly twice the amount of carbon found in the atmosphere, so when soil erodes, this stored carbon is released, contributing directly to greenhouse gas levels. Practices like deforestation, overgrazing, and tillage break down the soil’s natural structure, making it more vulnerable to erosion. As soil erodes, it loses carbon, which then contributes to global warming.
Climate change intensifies droughts and heavy rains, which both negatively impact topsoil. Drought leaves soil dry and exposed, while intense rainfall washes soil away, especially if it lacks plant roots to hold it in place. Degraded or bare soil can’t retain water effectively, so it’s prone to erosion during floods and becomes dust-like in droughts. This cycle of alternating extreme weather events makes it harder for soil to recover, causing further degradation.
Carbon Exchange Between Plants and Soil Organisms
In healthy soil ecosystems, plants and soil organisms engage in a dynamic carbon exchange that is essential for both soil fertility and climate stability. Plants capture carbon dioxide from the atmosphere during photosynthesis and convert it into carbon-based sugars, which they send down through their roots to feed soil-dwelling organisms like bacteria and fungi. These soil organisms, in turn, release nutrients that plants can absorb, creating a beneficial cycle where carbon is stored in the soil as organic matter. This stored carbon helps improve soil structure, increase water retention, and sustain a balanced ecosystem of organisms.
Impact of Soil Disturbance on Carbon Release and Climate Change
When soil is disturbed by practices like tilling, plowing, or deforestation, this delicate carbon exchange is interrupted. Disturbing the soil exposes organic matter to oxygen, which accelerates decomposition and causes the stored carbon to oxidize, releasing it back into the atmosphere as carbon dioxide (CO₂). This release not only diminishes soil health by reducing organic matter but also contributes to climate change, as CO₂ is a greenhouse gas that traps heat in the atmosphere. By adopting low-till or no-till practices, maintaining plant cover, and adding organic matter, we can minimize soil disturbance and help soil act as a carbon sink, capturing and storing carbon rather than releasing it.
Carbon Sequestration
Plants and soil microorganisms play an essential role in carbon sequestration, the process of capturing and retaining carbon in the soil. Through photosynthesis, plants pull carbon dioxide from the atmosphere and convert it into carbon-rich compounds, which are transported to their roots. These compounds are then released into the soil, where they feed microorganisms like bacteria and fungi. In turn, these soil organisms break down organic material, cycling nutrients and creating stable forms of carbon that remain in the soil for extended periods. This process not only enhances soil health but also reduces the amount of CO₂ in the atmosphere, helping to mitigate climate change.
How We Lose Topsoil
Topsoil loss happens through a few main processes, some natural and some not, but most of which are accelerated by human activity.
Tilling and Plowing
Regular tilling and plowing disturb soil structure, breaking down soil aggregates and exposing organic matter to air, where it quickly oxidizes and releases carbon. This weakens the soil’s ability to hold together, making it more susceptible to erosion by wind and water.
Tillage disrupts soil-dwelling organisms, such as fungi and earthworms, which are essential for maintaining soil structure and nutrient cycling. This leaves soil exposed, leading to loss of both organic matter and topsoil.
Monoculture Farming
Planting the same crop repeatedly depletes specific nutrients from the soil without replenishing them, reducing soil fertility over time. For example, corn and soybeans, commonly grown in monocultures, heavily deplete nitrogen and other essential nutrients.
Monoculture fields also lack biodiversity, which leaves soil more vulnerable to pests and diseases, often leading to increased reliance on chemical inputs that can degrade soil health.
Deforestation and Land Clearing
Clearing forests and natural landscapes for agriculture removes tree roots that stabilize soil and protect it from erosion. In areas where the soil was originally held by deep-rooted plants, like forests or grasslands, the sudden removal of plant cover leads to rapid topsoil erosion.
In tropical and temperate regions, deforestation and land clearing expose soil to intense rainfall, which easily washes away topsoil layers.
Synthetic Fertilizers and Pesticides
Synthetic fertilizers provide immediate nutrients but do not support the long-term health of the soil. They can disrupt the soil microbiome, which is essential for nutrient cycling and organic matter breakdown.
Pesticides and herbicides kill beneficial organisms that help build soil structure and fertility, weakening the natural processes that sustain healthy topsoil.
Soil Sealing
Urbanization leads to soil sealing, where soil is covered with concrete, asphalt, and other impermeable materials. This process prevents natural water infiltration, which is crucial for nutrient cycling and organic matter accumulation.
Soil sealing also destroys natural topsoil layers and disrupts local ecosystems, often causing runoff that leads to erosion in surrounding areas.
Intensive Irrigation Practices
Irrigation in arid and semi-arid regions can lead to salinization, where salts build up in the soil, rendering it less fertile and leading to erosion as soil structure degrades.
Over-irrigation also contributes to erosion, particularly when fields are flooded or improperly drained, washing away valuable topsoil.
Each of these practices contributes to the degradation and loss of topsoil, which takes hundreds of years to regenerate naturally. Sustainable and regenerative practices, like cover cropping, crop rotation, reduced tillage, and agroforestry, are now increasingly emphasized to protect and restore topsoil health.
What It Means for Food Security and Local Ecosystems
Without fertile topsoil, food production faces serious threats. Healthy soil is the foundation of our agricultural systems, and as it depletes, food security becomes precarious. Just a century ago, topsoil was often 20 to 100 inches deep in some regions, but today, it’s commonly reduced to less than a foot—or in some cases, little more than a thin, dusty layer. This depletion translates into lower crop yields, an increased need for synthetic fertilizers, and more fragile ecosystems. The result is a cycle where the land produces less, prompting more chemical inputs, which in turn further degrade the soil.
The loss of topsoil doesn’t only affect agriculture; it ripples through ecosystems. Rich soil ecosystems support a variety of plant and animal life, from native plants to wild pollinators and natural pest predators. As topsoil erodes, it reduces habitat for these species, weakens biodiversity, and contributes to runoff that pollutes waterways with soil particles and agricultural chemicals. Healthy ecosystems—such as forests, wetlands, and grasslands—depend on stable, nutrient-rich soil to retain moisture, nurture plant diversity, and sequester carbon. When soil health declines, these ecosystems lose resilience and their ability to support both plant and animal communities.
Ways To Rebuild Healthy Topsoil
While topsoil loss is a global challenge, there are steps each of us can take to help protect and restore soil health:
Composting
Composting food scraps and yard waste creates a nutrient-dense, carbon-rich material that improves soil structure and fertility, making it healthier and more resilient.
No Bare Soil
Covering soil with mulch, plants, or cover crops helps prevent erosion, retains moisture, and provides a habitat for beneficial soil organisms. Covering soil is especially important in areas exposed to wind and rain.
Local Advocacy for Soil-Friendly Practices
Supporting policies that encourage regenerative permaculture practices, reduce tillage on public lands, and fund community gardens can make a difference. Advocating for soil health means advocating for long-term food security and environmental stability.
Reducing Chemical Dependency
Limiting the use of synthetic fertilizers and pesticides helps preserve soil life, from microbes to worms, and prevents the further breakdown of soil structure. Instead, organic methods and natural pest management can maintain soil health over time.
Each of these actions contributes to a healthier, more resilient soil ecosystem, helping to protect food security and support local biodiversity. By fostering soil health, we strengthen the foundation of both our food systems and the natural world.
Limit Soil Disturbance
Try no-till solutions to prepare your garden beds. Lasagna gardening, also known as sheet composting, is a no-dig gardening method that builds rich, healthy soil by layering organic materials right on top of existing soil. Much like layering ingredients in a lasagna, you start by alternating “brown” layers, such as cardboard, newspaper, or dried leaves, with “green” layers, like kitchen scraps, grass clippings, and compost. This creates a thick, nutrient-dense bed where microbes, earthworms, and other soil organisms work together to break down the layers over time, transforming them into rich, dark soil. Lasagna gardening reduces the need for tilling, weeds are often smothered out naturally, and water retention improves as the layers decompose. It’s a simple, permaculture-inspired way to create fertile soil and start a garden bed from scratch, especially in areas where the soil is poor or compacted. Plus, it’s a great way to recycle yard and kitchen waste into something that directly benefits your garden.