Glyphosate: harmful or harmless?


Over the last 2 weeks, the herbicide glyphosate has again been in the news.

On 12th August, a San Francisco jury ruled that glyphosate had caused a former groundskeeper’s terminal cancer and ordered the manufacturer Monsanto to pay him $289m in compensation.

In the subsequent media frenzy, there has been much debate about whether glyphosate is harmful or safe for use in agriculture.

It’s hard to find a simple answer to the question because many competing interests are involved.  Even the World Health Organisation (WHO) has been accused of allegedly falsifying one of its major documents on the issue – more below.

I’m not a scientist.  Before the last fortnight, my knowledge of glyphosate was pretty sketchy to say the least.  Being aware of the media reports, but also a little sceptical of the universal farmers’ opinion that glyphosate is harmless to people and soil, I decided to try doing my own research.  Not an easy task!

After many hours and late nights of trawling the internet for research papers, news articles and reports from international health organisations, I gathered enough information to get the broad picture and form an opinion.

So here it is:

From my understanding, and as far as we know at the moment, glyphosate seems pretty safe. But there seem to be areas of research that haven’t yet been undertaken, which probably should be.

Here is my explanation for that conclusion.

What is glyphosate?

Glyphosate is a broad-spectrum (non-specific) herbicide, used widely in agriculture and gardening.  It was introduced in 1974 and was rapidly accepted because of its relative safety in comparison to other weedkillers.

It’s absorbed by leaves and transported to the plant’s growing points, including the roots. It works on a biological system found only in plants – not in animals – and stops the production of an essential plant enzyme.  This kills the plant within a few days.

Once it reaches the soil, glyphosate is inactivated almost immediately.  One of  its advantages is that new crops can be sown within a few days of treating the weeds.

Many articles talk only about ‘Roundup’.  This was the original product introduced by Monsanto, but there are now hundreds of different glyphosate products manufactured by many companies worldwide.

How is glyphosate used?

  • Here in the UK, one of the main uses of glyphosate is on stubble fields after the harvest, when the weeds left behind are just beginning to grow.  Treatment with glyphosate means the weeds are eliminated before the next crop is sown in the field.
Stubble field with weeds pre-treatment 3
One of glyphosate’s main uses in the UK – eliminating newly-growing weeds like this after the harvest, before sowing the next crop
  • By killing the weeds immediately before planting the next crop, they don’t have time to become a problem.  Consequently, the farmer doesn’t have to till (plough or harrow) the land as much.  Minimum-till (‘min-till’) techniques are now becoming widely adopted – less ploughing means that there is less leakage of greenhouse gases such as CO2 and nitrous oxide into the atmosphere. (You can find interesting stuff about keeping carbon in the soil here.)  Min-till also makes the soil healthier as it’s not constantly being compacted by heavy farm machinery.
  • In the UK, glyphosate is also used before harvesting certain crops, e.g. oilseed rape, to stop the ripe plants from growing .  As the crop is already ripe, glyphosate is not absorbed by the seeds.
  • In Britain, glyphosate is not used on actively-growing crops as it would kill them.
  • In the US, genetically modified (GM) crops designed to be resistant to glyphosate have been widely planted, so it can be sprayed onto crops without killing them.  No GM crops are grown in the UK.

Problems with glyphosate

There has been some concern that glyphosate may cause cancer, particularly for people who use it in their work.  So far, there doesn’t appear to be conclusive evidence for this, and the research is contradictory (see below).

Much of the research into this field has been done on glyphosate alone, but there is a suggestion from some researchers that added ‘inert’ chemicals in commercial products may make it more harmful.  Further research on this has been recommended.

Because glyphosate can be used on crops genetically-modified to resist it, it appears that where these crops are grown, particularly in the US, more of it is being used than is necessary.

There is some concern that, because it is used so widely, weeds may become resistant to glyphosate, which means it may not work in the future.

Controversy in the WHO and EU

In the last few years, there has been controversy over official reviews of the cancer risk posed by glyphosate.

In March 2015, the International Agency for Research on Cancer (IARC), an arm of the World Health Organisation (WHO), stated that glyphosate is probably carcinogenic to humans.

However, in November the same year, the European Food Standards Agency (EFSA) and the European Chemicals Agency (ECHA) disagreed with this finding, stating that glyphosate is unlikely to cause a carcinogenic hazard to humans.  This prompted Dr Chris Portier, an expert on environmental health data relating to cancer, to write to the president of the European Commission to complain that EFSA and ECHA had not carried out the reviews correctly.  The heads of the two organisations wrote a letter in reply, explaining why their research was robust.

In September last year, after the EU re-authorised the use of glyphosate, EFSA was again  accused of carrying out the review incorrectly.  It published a statement defending its methods and findings, also suggesting the criticism was part of an ‘orchestrated campaign to discredit the scientific process behind the EU assessment of glyphosate.’

In other words, EFSA claimed its findings didn’t ‘fit’ the widely accepted belief that glyphosate causes cancer. The EFSA website carries a video explanation of the process involved in reviewing pesticides.

Even more surprising was the allegation by Reuters news agency last November that the 2015 IARC report had been significantly changed from its original draft.  The report shows evidence that the first draft of the document had originally stated that glyphosate is unlikely to be carcinogenic.  The journalist alleged that 10 changes had been made to the draft document, including ‘the removal of multiple scientists’ conclusions that their studies had found no link between glyphosate and cancer in laboratory animals.’

Other research

Just a sample of the research out there.

A toxicology study looking at reasons for the different interpretations of cancer risk between the IARC and EFSA.  It recommended that research should be carried out into other chemicals present in commercial glyphosate formulations, (e.g ‘Roundup’ and ‘Touchdown’). Some studies have shown different results between commercial products and glyphosate alone, which could mean that the added chemicals make it more harmful. These chemicals include surfactants that help to spread the herbicide evenly.

This line of further research has also been suggested by other studies.

A study published in a German food safety and consumer protection journal concluded that evidence from urine samples showed no health concerns for food consumers, or for workers who applied glyphosate.

The Agricultural Health Study, a huge 20-year ongoing study of American farming families, (89,000 people, all licensed pesticide applicators), looks at the incidence of cancers and other diseases related to pesticide and herbicide use.  In May this year, it reported that there was no association between glyphosate and any ‘solid tumours’ (cancers) including non-Hodgkins lymphoma; however there was an increased risk of acute myeloid leukaemia in workers with the highest glyphosate exposure, although this wasn’t statistically significant.

What would happen to farming if glyphosate was banned?

  • Farmers would have severe problems trying to control pervasive weeds like couch grass and black grass. These weeds compete with the crop, reducing the yield.
  • More ploughing and cultivating of land would be needed to kill the weeds.  The result would be an increased release of greenhouse gases, more diesel used and greater damage to soil.
  • Farmers would have to use greater quantities of selective (hormone) weedkillers instead, which are sprayed directly onto the growing crop.
  • Planting of winter crops may not be possible, due to longer weed-killing processes.  Spring crops yield less grain.
  • Elimination of weeds would be more expensive.  This could put up food prices.


We will need to produce more food in the future to feed the increasing global population.

Glyphosate is an extremely useful tool in modern-day farming which can help to achieve this.  It encourages better farming techniques which help to protect soil and reduce greenhouse gases entering the atmosphere.  Without it, farmers would have to spend a lot of time cultivating the soil and would possibly need to use other chemicals on crops.

However, there are questions that need to be answered.  For instance, are commercial formulations containing other chemicals more harmful than glyphosate by itself?

I don’t think this topic will be disappearing any time soon.

Traditional mixed farming: better for the world than vegan crops?

Cattle and fence207044

Last Saturday’s Guardian newspaper (25th Aug) contained a fascinating article by Isabella Tree who, along with her husband, has vastly improved their business and restored the health of their land by changing from pure arable farming (growing crops) to traditional mixed farming of crops, beef cattle and pigs.

The article, If you want to save the world, veganism isn’t the answer, is a great illustration of how mixed arable and livestock farming is self-sustaining, preserves healthy soil and helps prevent release of greenhouse gases into the atmosphere.

In mixed farming, artificial chemicals are not necessary as manure (or muck, as we say in Yorkshire), is produced on the farm.

Ms Tree compares this traditional method to the intensive practices used to grow huge amounts of vegan foods such as maize and soya, which require a massive input of herbicides, pesticides and fertilisers.

Food for thought.


Rain at last!



I know this may not be a popular view, but the recent heavy downpours have been brilliant.  A definite godsend for farmers.

Unfortunately, the rain arrived too late to help the harvest.

Because of the long spell of hot, dry weather, the oil-seed rape and the corn (wheat and barley) ripened early.  The combine harvesters started working in the fields two weeks before the usual time and they are still busy in many areas of the country.  But the harvest is not great.  The yield – the amount of grain produced – is below normal,  which means the price of milling (flour) wheat will go up, as well as the price of barley for animal feed.

Farmers are used to occasional poor harvests.  But before the rain came last week, desperation was beginning to set in for a different reason.  Farmers everywhere in Britain were wondering how they were going to grow enough grass to make hay for animal feed during the winter.

Now they can breathe a little easier – at least for a short time.  The grass here in Yorkshire, as elsewhere, is just beginning to grow again.

But the rain we’ve had is not nearly enough.  The UK needs much more rain over the next two months, to make sure enough grass grows for cutting in September, or even October. If farmers can make enough hay or silage before the grass stops growing, the winter won’t be as grim as it’s looking now.

I know that isn’t what everyone wants this autumn.  Sorry folks  – we need it.

I’m off to do my rain dance …


How much of UK land is farmed?



Before I can answer this, we need to do a bit of maths.  Yes, I know, maths wasn’t my strong point at school either, but an idea of how land is measured will help us understand this question.


In the UK, land was traditionally (and still is) measured in acres.  In the Middle Ages an acre was defined as ‘the area of land one man could plough in a day with one ox’.

An acre = 4840 square yards or 4046.86 square metres.

That’s 60% of a soccer pitch. Or a car park containing 150 cars.  An acre can be any shape, long and thin, round or square, as long as it covers this area.


Nowadays land in the UK and Europe is also measured in the more modern, metric hectares.

A hectare (abbreviation ha) is 10,000 square metres (the equivalent of a square measuring 100 x 100 metres).

That’s 0.01 square km.  Or, if you like, 2.47 acres.

An easier way to think of a hectare is pretty much the area of an international rugby field (1.008 ha); or the area covered by Trafalgar Square in London.

So now we know what we’re talking about, back to the main question.

How much land is used for growing food crops?

There are slightly different categories and varying estimates of land use by different organisations, but all of them suggest that only about 6% of land is built on (urban land), with a further 2.5% being ‘green-urban’ – parks, cemeteries and private estates.

According to DEFRA – the UK Department for Environment, Farming and Rural Affairs –  72% of UK land was being used for agriculture in 2017, equivalent to an area of 17.5 million ha.

About a third – 6.1 million ha – of the agricultural land was arable land for growing crops, while the other two thirds was grassland.  Cereal crops (mainly wheat and barley) and oil-seed rape covered 3.2 million hectares.



So, as 72% of our land is agricultural and a third of this is used for growing crops, that means that about 25% of UK land is croppable (able to grow crops).


Non-arable farmland 

The agricultural land that isn’t used to grow crops is mainly grassland, or ‘pastureland’, which still produces our food because the grass is used to feed cattle, sheep, pigs and other animals. See previous post Grass – the original sustainable crop.



What is the remainder of the land used for?

The remaining non-agricultural and non-urban land is covered by forests, mountains, moorlands, beaches and wetlands.  Many of these are extremely important habitats for numerous species of mammals, birds, amphibians reptiles and insects.


Farming in the UK is big business and is very important for producing our food. However, food crops are actually grown on a relatively small area of land. Which may not be obvious when you’re contemplating combine harvesters working in the seemingly endless fields of the British countryside.


What actually happens in the crop fields, and in the rest of the farming landscape, will be discovered in future posts.



A visit to a small agricultural show – Tockwith, North Yorkshire


Around the country at this time of year, there are many agricultural shows, large and small.  All of them have the same aim – highlighting the best that farming has to offer. Exhibitors young and old take great pride in presenting their animals and their produce in the best way possible.  Most of the visitors to agricultural shows are not farming folk, and for them it’s simply a great, interesting day out.




Tockwith Show last weekend was no exception.  And of course, the hot sunshine helped enormously.

One of the stands belonged to Ken Horner, a local man who started making walking sticks and shepherds’ crooks when he retired 20 years ago.

In that time, he has donated over £50,000 to the Yorkshire Air Ambulance and the MacMillan nursing service.  He’s still going strong.


Tockwith is a modest village and has only two documented claims to fame – the ‘petals’ of the amazing London 2012 Olympic cauldron were made here; and Oliver Cromwell stayed in the village on his way to the battle of Marston Moor.

To me, there is a third – its great annual agricultural show.

Farming flowers


A new government scheme to help preserve habitats for birds and insects and to encourage the growth of rare species of wild flowers is being tested on farms in Wensleydale and Coverdale in North Yorkshire.

Natural meadows

The scheme, like similar ones before it, involves the farmer receiving a subsidy for leaving hay meadows unimproved – using no fertiliser or herbicides, and not mowing until the flowers have seeded. This not only helps to preserve many varieties of wild flowers, it also provides a natural habitat for many pollinating insects including bees.

But more flowers in the meadows means there is less grass, and therefore less winter feed for farm animals, which could threaten their survival. There are also strict regulations attached to the original scheme, such as limits on the number of animals that can be grazed and specific dates for mowing, which many farmers find it difficult to comply with.


Payments dependent on outcome

This pilot is different, however, because the farmers are paid by results and the regulations are less onerous.

Each farmer is given a scorecard on which to record the species of flowers he or she sees in the meadow. Some plants get a positive score, some a negative one. The more positive-scoring species and the fewer negative-scoring ones, the higher the payment received.

The scheme is also being piloted in three other areas of the UK.  So far, the nineteen Yorkshire farmers involved seem positive about it.

It will be interesting to see what happens.


Summertime – and the living is uneasy


This summer has become a big problem for all types of farming. A prolonged heatwave and no rain for months means grass everywhere in the UK has simply stopped growing. A lot of pasture land resembles the fields of the American mid-west – dry and dead.



Cattle and sheep have no fresh grass to eat, so farmers are having to feed them the winter supplies of hay. Quite a worry, as they will still need hay over the winter too.

And grass has now become expensive. Normally, a ton of hay (3 or 4 big round bales) costs about £80. At the moment, it’s about £120.



This year’s cereal crops – mainly wheat and barley – and rape-seed are not as plentiful as they should be. The drought means the grains haven’t fattened up enough, so the amount of grain harvested will be less, which in turn will increase the price. A lot of barley is used for cattle fodder – so feeding cows will become more expensive.


The sunshine and warmth are a wonderful change from our normal summer experience, perhaps especially here in the north, and definitely after the snow-laden ‘Beasts from the East’ earlier this year!

And of course, farmers love sunshine just as much as everyone else. But when your workplace is the great outdoors, too much of it can be a problem!