It’s easy to forget what we can’t see.
But beneath our feet, soil quietly remembers. And when Roundup gets involved, that memory can last longer than many realise.
For years, we’ve been told glyphosate—the active ingredient in Roundup—breaks down quickly and doesn’t pose a long-term threat to soil. But evidence is beginning to paint a different picture. One where the impact doesn’t end with the weeds it was meant to kill.
What Does “Long-Term” Really Mean?
When we talk about long-term effects, we’re not referring to what happens after a single spray. We’re talking about what builds up over five, ten, even twenty years of regular use. Soil that’s been repeatedly exposed to Roundup begins to change. And not always in ways we can see from the surface.
The Microbial Undercurrent: What Happens to Soil Life?
Good soil is alive—with bacteria, fungi, and organisms that support plant health, nutrient cycling, and water retention. But glyphosate doesn’t just go after weeds. It interferes with key microbial pathways, affecting the very organisms that make soil fertile.
Over time, this disruption can mean fewer beneficial microbes, less diversity, and weakened soil resilience. Earthworms? Fewer. Mycorrhizal fungi? Damaged. And without those partnerships, plants have a harder time accessing the nutrients they need.
Residues That Linger Longer Than Promised
We explore this persistence in more detail in our article on glyphosate soil accumulation. One of the most persistent myths about glyphosate is that it breaks down quickly. But in many soils—especially clay-rich or cooler ones—glyphosate residues have been detected months or even years after application.
This means every spray isn’t a clean slate. It’s a layer added to what’s already there. And with time, those residues can build up, subtly changing the soil’s chemistry and influencing what grows—or doesn’t—next.
As Carey Gillam uncovered in Whitewash, this isn’t just an environmental concern. It’s a story of corporate spin, silenced researchers, and a PR machine that kept inconvenient science out of sight.
Soil Fertility: When Chemistry Starts to Shift
Repeated Roundup use can change more than microbial life—it can alter the soil’s nutrient profile. Essential minerals like manganese, magnesium, and calcium may become less available, and shifts in pH can affect what nutrients plants can absorb.
It’s not just about what we put on the soil. It’s about what we lose in the process.
Stephanie Seneff explores this deeper in Toxic Legacy, linking glyphosate’s soil impacts to broader concerns about plant nutrition and human health. When soil suffers, the whole food chain feels it.
A Double-Edged Sword: Weed and Disease Resistance
Over time, Roundup can stop working the way it used to. Weeds adapt. They get tougher. They come back. And to fight them, many farmers are forced to use more chemicals, more often. We explore this growing issue in our article on the weed resistance crisis in New Zealand.
At the same time, with beneficial microbes depleted, harmful soil pathogens can flourish—leaving crops more vulnerable to disease. It’s a vicious cycle that undermines the very efficiency Roundup promised.
What This Means for New Zealand
While much of the data comes from overseas, the questions are just as relevant here. Our unique soils—from volcanic-rich North Island farms to the South’s diverse pastures—aren’t immune to these cumulative effects.
The truth is, we don’t fully know how glyphosate is shaping New Zealand soil long-term. And that’s a problem in itself.
Real Farms, Real Impact
Around the world, farmers have shared stories of declining yields, struggling crops, and soil that just doesn’t behave like it used to. In many cases, the common thread was long-term glyphosate use.
Once-healthy fields became chemically dependent. And rebuilding that lost fertility? It’s not easy—or cheap.
The Monsanto Papers, another must-read by Carey Gillam, takes you inside the legal battles that forced these issues into the open. When the courtroom became the only place the truth could surface.
Can Soil Recover?
The good news? Yes—if we stop repeating the cycle. Farmers switching to regenerative practices have seen real improvement. Organic weed control, cover cropping, composting, and smarter crop rotations all help rebuild microbial diversity and restore soil structure.
It’s not instant. But it’s possible.
A Few Questions Worth Asking
- Are we mistaking short-term convenience for long-term loss?
- What would our food supply look like if soil degradation continues?
- How much trust do we place in corporate science—and what might they still be getting wrong?
The Soil’s Quiet Message
Soil doesn’t shout. It whispers. But if we listen closely, it’s telling us something important: we can’t afford to keep ignoring what we’re doing to the ground beneath us.
Sometimes, the biggest warnings come without a sound.
Resources & References
If the soil could speak, it might point us to the voices that tried to warn us. These books dive deeper into what the studies often can’t say out loud:
Whitewash by Carey Gillam: An investigative deep dive into Monsanto’s control over the glyphosate narrative—and the science that was buried.
Toxic Legacy by Stephanie Seneff: A provocative and compelling look at glyphosate’s potential impacts on everything from soil to human health.
The Monsanto Papers by Carey Gillam: A courtroom drama turned exposé, revealing how one man stood up to the chemical giant and won.
A quiet revolution often begins with a single page. These reads won’t just inform you—they might reframe the way you see the ground beneath your feet.
Image Source & Attribution
We’re grateful to the talented photographers and designers whose work enhances our content. The feature image on this page is by VITstyle.
