Glyphosate Risks

With all this talk about glyphosate, what’s a gardener to do? Trying to calculate the actual risk to the environment is not easy.

The top terrace of the new terraced area needs levelling but the grass is growing fast and to level it I need to dig or rotavate over before raking it. I sprayed with glyphosate to kill off the existing sward and when it’s died off and been levelled I’ll re-sow with a poultry ley for the hens.

Glyphosate Risks

There’s been quite a bit of talk about glyphosate risks recently which I’ve been following. My take on it is that used, as I do, occasionally, exceptionally and minimally for clearing land or killing off persistent weeds like bindweed, glyphosate is pretty safe and presents no real risk to the environment or myself.

That’s not the same thing as a farm worker spraying large amounts regularly and being exposed to both spray on the skin and breathing it in.

There’s a massive amount of glyphosate based weedkillers used in the UK. From what I gather it’s often used when there’s a gap between crops to clean off any weeds and reduce competition.

In the USA another use for glyphosate is to weed genetically-modified crops that have been made resistant to the weedkiller.

I’m not convinced that the frequent use of large amounts of glyphosate based weedkillers is without harm to the environment.

There’s a massive difference in risk. Putting it another way, taking an aspirin for a headache once is very safe but take a high dose 4 times a day for a week or two and you’ll most likely develop stomach problems.

Vitamin C is supposed to help if you have a cold but megadoses will cause an upset stomach. It’s all a matter of quantity.

It’s hard to sort the fact from fiction on the interweb, some sites in the US see dark conspiracies by companies such as Monsanto and cite studies that were suppressed. I think most likely the reputable scientific press found them lacking in rigour.

And, of course, companies like Monsanto have much to gain by being economical with the truth, should they be so minded.

In the end I think it’s important to remember that glyphosate is approved by DEFRA and their equivalent organisations like the US EPA abroad. However, Friends of the Earth have produced a report critical of the testing and approval process.

Sometimes you just have to take a view as to risk versus reward.

I know I could use sheets of black polythene to kill off the grass but it takes longer and with the wind here the plastic is most likely to end up as bits flying around the fields. Not to mention that plastic is made from oil and is pretty ugly. I don’t think it’s the ideal solution for me.

Posted in Allotment Garden Diary
19 comments on “Glyphosate Risks
  1. Louise says:

    This is timely for me, thank you. I have gardened organically for nearly 40 years and for the last 10 have been using permaculture principles. My understanding of Permaculture is that it is pragmatic and scientific based on observations and working with nature. I have come to realise that includes my nature! I don’t have a lot of strength or energy and have a job keeping on top of things. I have completely failed to eradicate nettles, couch grass and brambles from the edges of some of the veg. beds and have reluctantly decided that since it is important to ‘obtain a yield’ the best solution is to apply glyphosate hopefully as a one off or occasional solution for the very same reasons you outline. I have been influenced in this by reading your blog as well as the opinion of some other people I know on Facebook. So many issues get polarised into black and white when life is really shades of grey. Recently I’ve been, in light of more posts about the dangers of glyphosate I’ve been wondering if I had made the right decision so your post is very timely

  2. Loudbarker says:

    Re farmers using Glycophospate.

    As you say it is used (amoung other uses) to clear weeds after a crop and before planting the next. The alternative is ploughing in the crop which has the adverse environmental effect of releasing carbon dioxide from the soil and is very fuel intensive. Both of these (of course) increase greenhouse gas output.

    I’m not endorsing one agronomic practice over the other – both have their advantages and disadvantages. As the previous poster says – life is really shades of grey.

  3. jezza says:

    Hello I understand the risks with glyphosate. An example; some one I know put 7 tubes of weedol in to a 1 gallon can, they then put this on 20 square yards of drive! Another problem I encounter is that, because glyphosate takes 5-14 days to show any signs of working, people want weedkiller mixed stronger. Instead of 20 mls to a litre they want 40-50 mls for a quicker kill with out understanding the consequences.

    • John Harrison says:

      @jezza: That’s a good point, Jezza. Don’t forget that glyphosate comes in different strengths so it’s important to follow the instructions on the bottle.
      Also the mix for a spray needs to be stronger than the mix for application via a weeder bar from a watering can as less liquid per square yard is delivered by a sprayer.

  4. Allan says:

    Well here’s a farmers point of view ……

    Read the lable and stick to it. Yes it takes 7 – 14 days to kill what you have applied it to but generally it works…unless you put it on nettles or clover. It says and I have heard of farmers doing this….. 24 hrs after aplication it is ok to plough and sow. This time was to allow the chemical to travel into the roots of the plant which is where it kills it; not the folliage which dies naturally as the roots fail .

    When reseeding I use it to kill couch grass and other grasses that would compete with what ever I would be sowing. Thousands of acres per year of arable crops recieve a dose 7-14 days before harvest to aid drying before harvest. Now sunshine hopefully does its bit and the grain comes off and straight into the store with out any diesel / gas being used to dry it to a storeable moisture; fossil fuel saved .

    It has to be one of the safest chemicals we as farmer use. A long time ago I heard someone being told it was safe enough to put on your fish and chips. Trust me never tried that one and recommend no one does but that hints at its record and safety .

    I remeber one chemical …gromoxone ….. it stunk and it was for a reason …. poison was on the lable. I refused to have anything to do with that, but I ‘ve seen it on lables in the garden center in the past. I’m not sure if it’s still available.

  5. Derek says:

    The use of nettles as a weedkiller might be consider !

  6. Bernard says:

    Used as a spot weeder in a small garden can, I believe, create no problems.
    The big problem with all chemicals used by farmers is drainage into the rivers, where poisons and fertilisers alike cause havoc.

  7. Jacqui Thomson says:

    It may be pertinent to point out that glyphosate has just been given a ‘Probably carcinogenic’ qualifier by the WHO, after looking at the results after many scientific studies. They wanted to give it a Class 1 rating of ‘Carcinogenic’, but were brow-beaten by the usual suspects who have an eye to their profits.
    I keep my allotment completely organic, as it on an organic farm, here in Devon. My nettles, and those around the field, all go into my liquid manure bin, along with the perennial weeds, and the resulting fibrous mush then goes into the manure heap. Nothing deters weeds as much as dogged determination and a daily hoeing.

  8. Clive says:

    I’ve been involved in the horticultural industry for nearly 40 years and have see numerous ‘safe’ chemicals withdrawn after a period of time when further research has found them not to be as safe as previously claimed.
    Glyphosate however has been around for most of that time and has gradually had its hazard rating reduced so now at most it only carries an irritant label.
    As previously stated, this is a translocated herbicide and depending on how ‘active’ the plant is in its growth can take anything from 5 days upwards to take effect.
    I have applied glyphosate in a cold early spring and it has taken up to a month to start to show effect, usually once the sun comes out and the plants start growing.
    Applying at a stronger rate than recommended is just wasting chemical and money as the efficacy is based on the speed the plant processes the chemical and putting on a higher rate will make no difference.
    There is also a risk if applying to hard surfaces such as drives that run off will get into drains then into the water system so using the prescribed application rate is doubly important in this situation.
    I have also heard ‘reps’ state it’s safe enough to drink but never actually see one brave enough to demonstrate! NOT RECOMENDED!!!!

  9. Bay Laurel says:

    If sprayed on a bright warm day Bees and otheer insects can collect the globules of liquid and take this back to their hive. Glyphosate is highly toxic to Bees and I am sure other benificial insects as well, therefore spraying in the evening or colder weather reduces this as bees do not fly much under 50°C.

  10. Geraldine McKenna says:

    As you yourself state responsible use and reading of instructions important. I have used Glyphosate to eradicate weeds in a new hedge and hopefully the hedge will be able to grow without competition this year. Even if there were side effects, in this type of situation they are not going to be a major factor. Around vegetables I would be reluctant to spray in the growing season although I did the garden at the same time as the hedge but creeping buttercup and dandelion seem resilient.

    A problem I had with the weedkiller was working out the dilution ratio to know exactly how much to put in back sprayer. I find this a regular problem with various sprays which are designed to be used by a sprayer on the back of a tractor and the rate is given in hectares rather than millilitres.

  11. Bernard says:

    ‘Safe to drink’ – it is reported that an overdose can kill. I don’t know what constitutes an overdose.

    Glyphosphate is destroyed by soil microbes but, relevant to my point above about it reaching rivers, it is not easily destroyed in water. It can persist in soil long enough to be taken up into vegetable crops. Any as yet unproven carcinogenic or toxicity properties might therefore be a worry.

    But used in the garden, this is not a problem and it is ironic that gardeners might be denied its use due to problems which are only relevant on a larger scale.

    As a chemist, I am sometimes exasperated by public fear of anything labelled as ‘chemical’. People overlook the fact that chemicals are common in the household – salt, bicarb, detergents and soaps, cosmetics…. and it is a little surprising that we still can obtain bleach – a violent poison – and even get away with pouring it down the drain. All poisons are only dangerous if misused. Agricultural use of glyphosphate might turn out to be misuse but I do not believe that this is so for use in the garden.

    • John Harrison says:

      @Bernard: You can’t legislate for common sense but you can educate. Even a fly spray is based on similar chemicals to nerve gas – when you realise that you’re a lot more frugal with it at least!
      I used to write for a magazine on frugal living and in one article I explained how caustic soda could be an effective cheap replacement for some sink unblocking fluids. They rejected the article on the basis it was too dangerous and their readers would ignore the safety stuff in the article and sue them if they had an accident.
      To me the reason for a ‘how to’ magazine is to educate and we parted company soon after to the relief of both of us I think.

  12. WOBBLY BOB says:

    to see the most up to date info on monsato and glyphosphate look on the website of dr mercola

  13. Alan James says:

    Most of the comments in here, seem to agree on one thing “Whatever you do, follow the instructions/guidelines on the label.
    It sounds straightforward enough, but is it? Many people don’t, and herein lies the problem. I do not just refer to amateur gardeners, I know farmers who are equally as guilty. So the question is, how do you legislate for common sense?

    I have a few examples I could quote, but I think this one is the best:

    Several years ago a friend with an allotment approached me with a problem. His seeds would germinate and then immediately collapse and die. I asked him if he had put anything on the soil lately. “Only some weed killer that I had from a friend who works for the Forestry” he replied.

    I asked him if he had diluted it correctly, he hadn’t; he had put it on neat! The thing is, he had been given a large drum for nothing, and his attitude was – it’s free, so why dilute it?
    I doubt if he was the first, or will be the last, but this sort of thing gives the chemicals a poor press!
    By the way, he could not grow anything there for a considerable time!

  14. RayM says:

    I used to use Glyphosate but stopped having read as much as I could find on the subject. I have bought Ammonium Sulphamate this year on ebay. It was quite amusing that they included a leaflet that pointed out that they were not allowed to sell it as a weed killer anymore which was used in the following ways. There was then given instructions on dilutions and usage! Gave me a laugh and also what I wanted. I already knew the dilutions from an old organic gardening book that I have.

  15. Uzzy says:

    •½ gallon of vinegar
    •½ cup of salt
    •2 tablespoons of dish soap
    The above is a substitute for Glysophate, works as well but is slower. I may have to give it a bash. Its what organic people use ??

    • John Harrison says:

      @Uzzy: I don’t know if that would work or be as effective – be interesting to find out. However, what worries me is the effect on the soil of the salt and vinegar – I suppose it depends on the application rate.

      Please note, in London it will be either Balsamic or at least white wine vinegar and sea-salt. North of Watford you can use malt vinegar and ordinary salt 🙂

  16. RayM says:

    Thought the following article from Farming Online might be of interest in this topic.
    Farmers most vulnerable to health effects of pesticides

    Thursday 14 May 2015

    Greenpeace has unveiled a report in which it claims that farmers are most at-risk from a range of health impacts associated with commonly used agricultural chemicals.

    Greenpeace is calling for more research funding for sustainable crop protection methodsSince 1950 the human population has doubled, yet the area of arable land used to feed these people has increased by only 10 percent. This has created huge pressures to provide food, at low cost, on land that is becoming more and more degraded as nutrients are stripped from the soil and the impacts of climate change become more pronounced. According to environmental campaigners, the reliance on external inputs – fertilisers and pesticides – to maintain yields is only a short-term solution, and one which carries side-effects for public health and the environment.

    On Tuesday, Greenpeace released a report which assesses available peer-reviewed science on crop protection products and looks at health effects with which certain chemicals have been linked. The environment group said there is strong evidence linking some pesticides to different types of cancer, whilst others have been connected (less strongly) to disruptions of the immune system and impacts on young and unborn children. Farmers and agricultural workers, and their families, are at the greatest risk of exposure, the report warns.

    The report states that it is difficult to point definitively to any chemicals as causing ill health, as other environmental factors and people’s genetic make-up also play a part in their susceptibility. However, its release was timed to follow on closely from a World Health Organisation (WHO) decision to re-classify Glyphosate, the most widely used herbicide worldwide, as a probable human carcinogen.

    Greenpeace claims that, given new research findings of harm that even low-level exposure may be causing, “There is a compelling case, and an urgent need to reduce human exposure to these hazardous chemicals.”

    On Tuesday, Greenpeace’s Ecological Farming Campaigner Christiane Huxdorff said, “It is shameful that those who produce our food suffer the most because of massive pesticide use on our fields. Farmers and their families carry the toxic burden of our failing system of industrial agriculture. This report clearly shows that pesticides can never be considered ‘safe’ and it demonstrates once more that we urgently need to move towards ecological farming – for healthy food and healthy farmers.”

    Farm lobby calls for risk-based approach

    However, the NFU, which has campaigned against EU measures to increase scrutiny of pesticides, responded on Wednesday that “The UK is fast becoming an over-regulated environment for British farmers who are losing their home markets to foreign farmers who have better access to more effective means of crop production.”

    Union vice president Guy Smith commented, “It is absolutely essential that farmers have regulation that is risk-based and that it follows sound science to ensure the farming sector keeps growing and contributing to the £97billion UK food and drink industry.

    “At a time when leading scientists are warning that within a generation the world could be facing a ‘perfect storm’ of food shortages, this is not time to be taking away the tools our farmers need to produce disease free, high yielding crops. British farmers need to be able to use the same, safe technology as their competitors if we are to have a productive agriculture producing healthy harvests.”

    Even so, Greenpeace’s Christiane Huxdorff continued, “We urgently need a shift of public research towards ecological farming to support farmers in moving away from the current reliance on synthetic-chemicals. It is time to adopt biodiversity-based tools to control pests and enhance farmlands, ecosystems’ and our farmers’ health.”

    In Europe, despite strong national variation, overall pesticide use has declined over the past two decades (though the European Environment Agency has suggested that new products, with more concentrated active ingredients have driven a decline in volume of pesticide use without a corresponding reduction in environmental impact). Now, with prices bottoming out for many key commodity crops, there has been speculation that farmers could seek to make savings in this area, in a bid to protect their margins.

    On Tuesday, agronomy firm Hutchinsons’ technical development director warned that a relatively low disease pressure this spring, and low grain prices, could lead many farmers to look for potential cost savings, and that some spray timings could be sacrificed as a result of the need to cut expenses.

    Nevertheless, pesticide use is predicted to grow worldwide, as companies expand to new markets; just last week the world’s leading manufacturer of agricultural chemicals, Swiss agribusiness Syngenta, turned down a takeover bid form Monsanto arguing that the seed company’s offer ($45bn) undervalued the inroads it had made into emerging markets around the world, and the potential for growth from this work.

    Greenpeace is calling for an urgent phase-out of synthetic-chemical pesticides and a shift towards ecological farming. A number of EU and national programmes are spearheading more targeted approaches to agricultural management, including IPM (integrated pest management), which many believe will enable food producers to reduce the impacts of agriculture on the environment whilst making food production sustainable in the long-term, through encouraging pests’ natural predators and using effective crop rotation and other natural means to stave off disease.

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