Glyphosate is a non-selective herbicide and is applied to the leaves of plants to kill both broadleaf plants and grasses. Since it is non-selective it will kill most plants by preventing them from making certain proteins that are needed for plant growth. Glyphosate stops a specific enzyme pathway, the shikimic acid pathway. The shikimic acid pathway is necessary for plants and some microorganisms.
The use of glyphosate-based herbicides, especially Monsanto’s Roundup formulation, has increased dramatically since the introduction of genetically modified (GM) glyphosate-tolerant crops, resulting in the contamination of our food, environment and water supplies. Glyphosate-based herbicides are now the most commonly used herbicides in the world and is still promoted as ‘safe’, despite evidence of serious harm to health and the environment. Its residues were recently found in 45% of Europe’s topsoil, in biscuits, crackers, crisps, breakfast cereals and in 60% of breads sold in the UK, and in the urine of three quarters of Germans tested, at five times the legal limit for drinking water. Furthermore, a 2015 study by the World Health Organisation’s IARC cancer agency found that it was “probably carcinogenic to humans”.
Not so strange that many environmentalists urge for a ban on glyphosate, but is now so widely used that a ban would have radical consequences. The broad spectrum weedkiller makes up a quarter of global herbicide sales. It is mostly used on maize, cotton, soya bean, oilseed and sugar beet crops genetically engineered to resist it. People in the industry say that the no-tillage system encouraged by glyphosate reduces soil emissions and protects against more environmentally damaging alternative herbicides. Scott Partridge, Monsanto’s VP for corporate strategy: "You would see increased costs for farming and decreased productivity, increased greenhouse gas emissions, loss of topsoil, loss of moisture.”
Glyphosate has reduced the need for more toxic alternative herbicides and also for deep ploughing which can be very damaging to soil fertility. But its use has also been associated with an increase in farm size and monoculture systems. Environmentalists say that glyphosate is congruous with continuous arable cropping and an acceleration of the “pesticide treadmill”. Furthermore, a report by Pesticide Action Network linked glyphosate to dramatic declines in earthworm populations and damaging soil microbial communities. The report said its use also destroyed food sources for pollinators, and made crops more vulnerable to pathogens and disease.
While the Environmental Protection Agency in the USA has deemed glyphosate safe for public use, its methodology was questioned by several of its own scientific advisers in December 2016. They noted an increased non-Hodgkin’s lymphoma risk of between 27-50% when epidemiological data that the EPA had disregarded was considered, causing criticism of the agency.
Glyphosate is also having a big impact on the honeybee. The National Agricultural Statistic Service has reported that the honeybee population in the US has declined from 5 million bees down to 2.5 million during the last decade, and glyphosate may be at least partly to blame. According to Don Huber, expert in chemical and biological warfare and professor emeritus of microbiology at Purdue University, glyphosate makes it difficult for crops to absorb micronutrients necessary for the health and nutrition of honeybees. This means that when honeybees collect nectar and pollen from crops and wild flowers deficient in micronutrients, they suffer because they don't get the beneficial microorganisms lactobacillus and bifidobacterium. Glyphosate acts as a powerful antibiotic against these bacteria and without these bacteria honeybees cannot digest nectar and honey and become disoriented in their foraging (and they cannot find their way back home to the hive). In addition, glyphosate disrupts the hormones of honeybees, which means honeybees “never learn to forage efficiently.” Not only do we need bees for their honey, they play an essential role in our food chain. Farmers rely on honeybees to pollinate their crops, and about $20 billion worth of food is pollinated by bees every year. If the bee population continues to decrease as dramatically as it is right now, less and less food is going to be produced, eventually leading to a food shortage for humans.
Banning glyphosate woud require a redesign of current farming practices. Shallow tilling at soil depths limited to 25cm has been shown to reduce weed density and improve long-term soil quality and biodiversity in some studies. Conservationists say that, together with greater crop diversity and rotation, crop rollers, and the use of green fertilizer to raise nitrogen levels, crop yields, soil fertility and carbon storage could all be kept at levels close to today’s.
An alternative to herbicides altogether is offered by Weedingtech, a UK company that offers herbicide-free treatments. They use foam and hot water to treat weeds and their services are being used by several glyphosate-free councils in the UK. They show that there is a better way to do this. Leo de Montaignac, CEO of Weedingtech: "There is a huge amount of scaremongering which says that viable alternatives are not available and it is simply not true.”
Petitions for a ban on glyphosate: