Most people know glyphosate as a weedkiller. Fewer know it’s also used in a very different way—sprayed directly onto crops just before harvest to dry them out.
This controversial technique, known as pre-harvest desiccation, speeds up harvesting and increases crop uniformity. But it also raises the level of residue that ends up in our food.
In New Zealand, this practice isn’t just permitted—it’s enabled. With the Ministry for Primary Industries (MPI) now proposing to increase allowable glyphosate residue limits on several key crops, the timing raises uncomfortable questions. Especially as other countries—like those in the European Union—have banned or heavily restricted the exact same practice due to public health and environmental concerns.
Glyphosate: Not Just for Weeds
Glyphosate-based herbicides like Roundup were designed to kill weeds. But in modern industrial farming, glyphosate is often repurposed as a desiccant—sprayed on cereal grains, legumes, and oilseeds just days before harvest. The goal? Force the crop to die uniformly, dry out quickly, and be easier to process.
That might sound efficient. But here’s the catch: the closer glyphosate is applied to harvest, the more likely it is to linger on the food you eat.
Pre-harvest glyphosate use is one of the main reasons residues show up in breakfast cereals, pasta, bread, and baby food—even in people’s urine. And unlike spray drift or accidental exposure, this is deliberate.
Europe Says No — So Why Are We Saying Yes?
In 2022, the European Commission moved to prohibit the use of glyphosate as a pre-harvest desiccant. France, the UK, and several Nordic countries have also taken steps to restrict or phase out the practice. Their reasoning is simple: the risks outweigh the benefits.
In contrast, New Zealand is heading the other way. MPI’s proposal would allow even higher glyphosate residue levels on crops like wheat barley, and oats—many of which are likely to have been desiccated.
So the question becomes:
If other countries are backing away from this practice, why is New Zealand doubling down?
More Than a Residue Problem
Residues in food are a major concern. But the issue doesn’t end there.
Pre-harvest spraying extends chemical exposure beyond the growing season, just as pollinators are still active and waterways are already under pressure. Soil ecosystems take another hit. The “efficiency” of glyphosate desiccation may carry a hidden environmental cost—one that farmers, consumers, and ecosystems pay for in the long run.
And what about long-term health effects? Studies have suggested that chronic low-level glyphosate exposure may be linked to hormone disruption, reproductive issues, and even cancer. While industry regulators dispute this, the science is far from settled—and few risk assessments look specifically at desiccation-related exposure patterns.
Why It Matters for Farmers Too
Some farmers argue that desiccation helps manage harvests during wet seasons or when weeds interfere with drying. That’s understandable. But others have never used glyphosate pre-harvest and still produce successful, profitable crops.
If international markets start rejecting NZ grains due to high residue levels, could farmers find themselves on the wrong side of consumer demand?
And let’s not forget: regenerative and organic farming systems don’t allow glyphosate at all—and yet they continue to produce abundant harvests without chemical shortcuts.
Time for a Rethink
It’s easy to focus on residue limits and ignore the farming methods behind them. But maybe it’s time we stop asking, “How much glyphosate is safe?” and start asking, “Why are we still spraying our food before harvest at all?”
What’s efficient for industry may not be safe for consumers.
If Europe has moved on from glyphosate desiccation, why hasn’t New Zealand?
Final Thought
Glyphosate desiccation is a shortcut—one that raises residue levels, pollutes ecosystems, and quietly reshapes how we farm. But the public rarely hears about it. That silence benefits industry, not consumers.
It’s time to break that silence. Not just by questioning residue numbers—but by questioning the entire practice.
Resources and References
We didn’t set out to make assumptions—we set out to ask questions. And the more we dug into the practice of pre-harvest glyphosate spraying, the more unsettling the story became. The studies and sources below helped shine a light on the deeper issues behind this chemical shortcut. If you’re curious (or skeptical), they’re a great place to start.
Crop Desiccation
An overview of crop desiccation practices, including the use of glyphosate, discussing the benefits and potential risks associated with this agricultural method.
Read about Crop Desiccation here
Glyphosate as a Food Contaminant: Main Sources, Detection Levels, and Exposure Risk Assessment
This comprehensive review highlights the widespread presence of glyphosate residues in various food products, emphasizing the need for continuous monitoring and assessment of dietary exposure risks.
Read more here
Environmental and Health Effects of the Herbicide Glyphosate
This study discusses the accumulation of glyphosate and its degradation product AMPA in the environment, noting documented chronic low-dose effects on animals and humans.
Read this study on Science Direct
Glyphosate Use as Desiccant Doubles Human Contamination
An analysis indicating that the use of glyphosate as a desiccant significantly increases human exposure to the chemical, raising concerns about potential health implications.
Read this Cornucopia Institute article from 2017
Glyphosate Used as Desiccant Contaminates Plant Pollen and Nectar
Research demonstrating that glyphosate application as a desiccant can lead to contamination of pollen and nectar in non-target wild plant species, potentially affecting pollinator health.
Read the full study here
New Report Alleges ‘Mass Contamination’ of Foods from Use of Glyphosate to Dry Crops
A report highlighting concerns over the widespread presence of glyphosate residues in staple foods due to its use as a pre-harvest desiccant, calling for stricter regulations.
Read this article on Foodnavigator-USA
New Glyphosate Studies Find Risks with ‘On-Label’ Preharvest Use
Recent studies questioning the safety of glyphosate’s preharvest applications, suggesting that even label-compliant uses may pose health risks.
Safe Food Matters wrote about this study
PAN UK – Glyphosate in Cereal Crops: Pre-Harvest Use and Residue Levels
A comprehensive review of pre-harvest spraying practices and risks.
Visit PAN UK
This list isn’t exhaustive—but it shows there’s more to the glyphosate debate than residue limits alone. Farming methods, food safety, environmental impact—it’s all connected. We encourage you to read, reflect, and keep asking why things are done the way they are. Because until we question the system, we’re just accepting it.
Related articles on NoMoreGlyphosate.nz
Why Raising MRLs Threatens Public Health
How higher allowable limits can expose New Zealanders to more glyphosate than ever before.
Is Glyphosate the Real Gluten Villain?
Explore whether rising wheat intolerance could be tied to desiccation spraying practices.
Glyphosate and Hormone Disruption: What We Know So Far
Learn about the potential endocrine effects of glyphosate, particularly with long-term exposure.
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