Effects of a glyphosate-based herbicide on soil ecosystem | Hacker News Reader

Effects of a glyphosate-based herbicide on soil ecosystem

nature.com

109 pointssaalweachter34 comments

So the only way they evaluated Roundup was when they also used a hoe? Which they also proved was just as detrimental of a process to the underlying micro-organisms? Why not use roundup alone? I feel like this was written solely to argue “roundup is no more detrimental to soil health than conventional hoeing practices.”

I immediately thought the same thing when I read the study. Most of the glyphosate applications I see are not followed by tilling, discing or other forms of “hoeing.” The R plot is conspicuously absent and it doesn't explain why that choice was made (it explains many other decisions/choices) for the study.

A lack of difference in a W and R plot would have bolstered the findings and seems an obvious thing to test?

Is there anything wrong with arguing that, with evidence?

I don't know why the study was done the way it was, and a follow up should certainly look at roundup alone, I don't think that invalidates this study though.

Not at all. We should all be free to pursue whatever interests us. :)

> In our study, we focused on the trophic groups of soil micro and mesofauna rather than on their taxonomy.

hum, mumble, mumble... You need some taxonomy to be able to find trophic groups. Nematoda taxonomy in particular can be hard but similar species can be in different trophic levels.

No data available about species of animals or species of weeds in the area when this is basical to understand allelopathy (and allelopathy is basical to explain why some animals could be fleeing the area or be atracted to it).

Strange numbers of predators in some months with relatively low numbers of preys...

I couldn't find also a clear explanation of what is in each trophic group

This elicit more questions than answers to me...

An interesting outcome.

Kudos to the authors for publishing a (kind of) null result, especially one that goes against the grain of popular thinking.

I'm not sure if those goes against popular thinking. It only looked at one small part of the ecosystem (i.e., what's in the soil). In that one small part they may have found a null result, as you call it.

I would be curious to see something that aggregated the research of the different parts of the ecosystem to look at a more holistic impact.

> Kudos to the authors for publishing a (kind of) null result, especially one that goes against the grain of popular thinking.

It is important to note that the experiment was started in May 2016.

Glyphosate is not just used for weeding. It is used in much larger quantities to dry plant stems before harvest.

For those interested in this topic, it’s called desiccation.

"We found that killing plants by hoeing had drastic effects on soil fauna and functioning, and apparently, distinguishing these effects from direct glyphosate effects is profoundly important when evaluating glyphosate risks in soils. In contrast, the effects of Roundup on soil fauna and functioning were minor and transient and no glyphosate remains were found in the soil at the end of the experiment. These results suggest that side-effects can be minor and glyphosate degradation effective also in soil under northern climatic conditions."

This is over a 2 year period. I'm curious if this continues to occur after 5 or 10.

I think its a dubious comparison - like comparing the physiological effects of a drug, with a physical altercation.

Hoeing (chopping and mixing the soil) has a radical effect on its biology, which the researchers mention as "the inevitable indirect effects caused by the destruction of live vegetation". The effects of rare pollutants tend to be more subtle, yet they only look for glyphosates effects in hoed soil, which is already very disturbed.

Surely the scientists have something better[0] to do than spend a few man0-decades chasing a null result. Research resources, like anything, are limited. From a Bayes' POV, the prior of finding glycophosphate in soil after 5-10 years is now much lower after the initial results.

[0] Like research the effects of a pesticide that they haven't just found to 'effectively degrade in soil'

The Bayes prior was already low since Glyphosate was already well known to degrade quickly in soil.

If only it wasn't a likely human carcinogen (https://www.iarc.fr/featured-news/media-centre-iarc-news-gly...)

Out of the hundreds and hundreds substances IARC has studied, they have placed only one in their group 4: "probably not carcinogenic to humans". Caprolactam.

https://monographs.iarc.fr/wp-content/uploads/2018/09/List_o...

https://en.wikipedia.org/wiki/List_of_IARC_Group_1_carcinoge...

https://en.wikipedia.org/wiki/List_of_IARC_Group_2A_carcinog...

https://en.wikipedia.org/wiki/List_of_IARC_Group_2B_carcinog...

https://en.wikipedia.org/wiki/List_of_IARC_Group_3_carcinoge...

https://en.wikipedia.org/wiki/Caprolactam

Also in that list: fryer emissions, red meat, coffee, and 65+ °C beverages.

They also classify "coffee, mate, and very hot beverages (drinking)" under the same category.

Also in the same category: "Hairdresser or barber (occupational exposure as a)", "Shiftwork that involves circadian disruption".

Speaking as a biologist, the IARC made a huge bungle here deciding policy on incredibly limited data.

Which IARC decision? The rough draft or the final version?[1] Or the 2016 one that effectively reversed the 2015 conclusion?[2]

[1] https://www.reuters.com/investigates/special-report/who-iarc... [2] https://www.chemistryworld.com/news/who-clarifies-glyphosate...

I'm also a biologist and I believe IARC was right based upon the available evidence.

based on the sprague-dewaley "cancer rats" experiments? Those aren't sufficient evidence.

Why they are called "cancer rats":

https://cancerres.aacrjournals.org/content/canres/33/11/2768...

There were 269 cited studies, they reviewed literally all the relevant literature on glyphosate in the public domain. So your attempt to dismiss IARC's work seems to be less motivated by the evidence and likely more motivated by ideology.

Here is a list of agriculture, chemicals and food safety agencies that have published reports or statements that they don't consider glyphosate a cancer risk:

European Food Safety Authority (EFSA), European Chemicals Agency (ECHA), United States Environmental Protection Agency (EPA), New Zealand EPA, Australian Pesticides and Veterinary Medicines Authority (APVMA), Canadian Pest Management Regulatory Agency (PMRA), Korean Rural Development Administration (RDA), Food Safety Commission of Japan (FSC), World Health Organization (WHO) and Food and Agriculture Organization of the United Nations (FAO) in a joint statement, Swiss Federal Food Safety and Veterinary Office (BLV/OSAV), French Agency for Food, Environmental and Occupational Health & Safety (ANSES).

https://thoughtscapism.files.wordpress.com/2016/09/glyphosat...

Here is a list of agencies that have published reports that they do consider glyphosate a cancer risk:

IARC

If you care for an in-depth back and forth between the IARC and the ESFA, I can recommend this[1] collection of letters between the head of the ESFA and the head of the IARC at the time. If you are interested in the particular scientific criticisms of the IARC Monograph by the ESFA you can read this amazing letter[2], which is also in the collection mentioned above.

It's in the annex of that document. It's a very good read.

------

[1]: http://www.efsa.europa.eu/en/press/news/160113

[2]: http://www.efsa.europa.eu/sites/default/files/EFSA_response_...

Great exchange, thanks for the link. Doesn't necessarily shine the best light on ESFA eh?

Any idea if that bilateral meeting between IARC and ESFA ever happened? Doesn't look like they put up the minutes like they suggested they would, which leads me to believe it never happened. Maybe IARC felt like ESFA never did the corrections requested and the meeting fell through. Either way, that exchange is a beautiful illustration of scientists respectfully getting frosty with eachother.

https://twitter.com/i/status/1147775558195011585

They used glyphosate based herbicide, but report only detection of glyphosate and AMPA, and not other ingredients that some people claim are the main problem with Roundup.

> killing plants by hoeing had drastic effects on soil fauna and functioning...In contrast, the effects of Roundup on soil fauna and functioning were minor and transient

Not 100% sure what this "hoeing" is, but we need to ban it now before it destroys the planet.

Chopping roots and undigging plants with a hoe: AKA agriculture

Plowing and the like is very out of fashion in big agriculture: the harm that hoeing is bad for the soil has been well known to farmers for a long time. (as long as I can remember which puts us in the 1970s) That isn't to say plowing isn't part of big ag, but they have found ways to plow that disturb less soil while still getting the benefits they want.

Glyphosate is a major part of big ag's anti-plowing system: by killing weeds they don't have to plow them up. Thus saving the soil. As a bonus, spraying uses much less fuel ($$$ for farmers, CO2 and global warming for the rest of us) than plowing.

More generally, mechanical manipulation of the soil. I learned at a recent Rutgers University seminar that overworking of soil is surprisingly hazardous to its health.

Soil is more akin to a living tissue than a mineral substrate.

https://en.wikipedia.org/wiki/Mycorrhiza

https://en.wikipedia.org/wiki/Mycelium

https://en.wikipedia.org/wiki/Mycorrhizal_network

https://www.pbs.org/wgbh/nova/nature/wood-wide-web.html

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