Agrichemicals Archives | Sustainable Food Trust

Chemicals on the plate: A conversation about food and health

Alice Frost — Tue, 06 Jan 2026 12:51:31 +0000

What’s really in our food these days and how might it be affecting our health? In this conversation on the Sustainable Food Trust podcast, Patrick Holden, founder and CEO of the SFT, and Stuart Oates, founder of the Fossil Free Farm project, discuss what chemical residues and ultra-processed foods might mean for our health, and consider possible solutions.

Patrick:
Let’s discuss the influence of what we eat on our health. I’ve recently come across a couple of reports: the first was a retraction by a well-known journal that published a report, I think about 15–20 years ago, saying Roundup was safe. Last week, they retracted it because they realised that a lot of Monsanto employees had intervened and influenced the research, making it unsound. I think that’s big because Monsanto, and more recently Bayer, have been relying on that report.

Roundup is widely used all over the UK and the world – on arable farms for weed control and as a pre-harvest desiccant, which is how it mainly gets into our food. Even if it breaks down quickly in the soil, it’s still on the crop at harvest. The first thing we should fix is that pre-harvest desiccant – that’s the biggest problem.

Stuart:
Yeah, you’re absolutely right. That pre-harvest desiccant is the biggest concern.

Patrick:
It ties into the broader conversation about chemicals in our food…and, as well as what’s applied to our food on the farm, there are also other kinds of chemicals in what we’re eating: the additives, the flavourings, all that stuff that’s put into food after it leaves the farm – particularly ultra-processed food.

There was a report in The Lancet recently looking at ultra-processed foods and other additives and the effect on the human microbiome. It sounds incredibly worrying. Basically, a lot of these additives are things our microbiome can’t cope with, and that’s almost certainly behind the exponential increase in previously uncommon diseases.

You have to ask why it is that one in two of us are now getting cancer. Surely that’s partly due to what we eat – and what we wouldn’t want to be in our food. I think The Lancet is drawing attention to that.

Stuart:
Yeah, absolutely. I think we’re only at the very beginning of that kind of research. For some reason, food has been completely unlinked from health for so long. I have lots of friends who are doctors, and not a single day of their course is spent on healthy eating and diet. That’s crazy.

That should be a big part of their training, because that’s preventative medicine – that’s what helps us live healthier lives along the way. Did you see the Panorama programme?

Patrick:
Yes.

Stuart:
That’s the next level. It’s looking at these forever chemicals.

Patrick:
That is quite scary.

Stuart:
Forever chemicals are going to be a big topic over the next decade. They’re only just being talked about in the mainstream, but they’ve been around for a very long time.

They’re deliberately designed not to break down. They have incredibly strong bonds, so they’re used for things like Teflon coatings on frying pans or waterproofing on jackets.

What shocked me in the Panorama programme was learning that there are forever chemicals in the sprays used on our food – pesticides and fungicides. They’re designed to stick to the surface of leaves and stay there. And that then gets into our food, our bloodstream, our bodies.

They’ve found forever chemicals in every single person they test. Every single one. You can’t understand how anyone thought that they were a good idea in the first place. Can you imagine, Patrick?

Patrick:
One chilling bit in that programme was when the presenter was offered a glass of red wine. Before asking if she wanted to drink it, the researcher explained that forever chemicals – which are active ingredients in pesticides – are sprayed onto grapes.

They explained that these chemicals are in the wine. Then they asked her if she still wanted to drink it. There was a grimace, and she said no. That was powerful.

I wonder whether red wine sales will drop this week – and whether organic red wine sales might rise. Because these issues really haven’t been brought to the public’s attention.

I don’t think the organic movement ever adequately described the extent to which unwanted chemicals get into our food and affect our health.

Stuart:
I think this is the big opportunity for organic. And we’re bound to say that, Patrick, as organic farmers and proponents of organic agriculture. But organic farming doesn’t allow forever chemicals – never has. That was part of the standards, even if we weren’t talking about forever chemicals when organic began.

If people really knew how their food was grown, things would change. I don’t want to attack other forms of agriculture – everyone is doing their best – but people need to know the truth so that standards and regulations can be higher.

In the UK, we’ll never compete globally on volume. But we could be the source of good, healthy, high-end food that’s environmentally responsible and careful about agricultural chemicals. We could be world leaders in that – if we choose to take the opportunity.

This extract is from an episode of the SFT podcast and has been lightly edited for readability. To hear the full conversation, click here. You can find all our episodes on the main podcast page.

The post Chemicals on the plate: A conversation about food and health appeared first on Sustainable Food Trust.

Reviving land, inspiring farmers: Lessons from Sri Lovely

Alice Frost — Tue, 30 Sep 2025 15:19:05 +0000

At the Sustainable Food Trust, we are always inspired by stories that show how farming can regenerate soils, strengthen communities and offer viable alternatives to industrial agriculture. Sri Lovely Organic Farm in Malaysia embodies these principles, demonstrating how sustainable approaches can transform abandoned land into thriving farming systems.

Sri Lovely Organic Farm was set up in 2009 by retired army major Zakariah Kamantasha – who goes primarily by the nickname ‘Captain’. Having been stationed in this remote jungle region during his military days, Captain saw the adverse effects that rural depopulation and increased reliance on conventional, chemical-heavy food production were having on local communities.

He wanted to help give young people, in particular, a reason to stay. Working with others and local authorities, he also wanted to help in addressing a local health crisis that was seeing rapidly increasing rates of diet-related illnesses (such as diabetes) and health conditions associated with exposure to chemical sprays (including cancer and lung disease).

The result, after months and years of working with local families and landowners to clear and consolidate a 10-hectare parcel of land that had been overtaken by the jungle, was the establishment of Sri Lovely Farm. A few years later, it became Malaysia’s first certified organic rice farm. And today, it has become an important education and knowledge-sharing centre, helping to encourage a new generation of Malaysian farmers wanting to create a more sustainable future.

The back plots of grain at Sri Lovely Organic Farm in Malaysia

A brief history of Malaysia’s ‘rice bowl’

The northern state of Kedah has long been known as Malaysia’s ‘rice bowl’ (jelapang padi), providing about half of the country’s rice production today. Rice has been grown here for millennia [p.45], but centralised production was ramped up under the Siamese rule of Kedah in the 19th century. This was largely to feed the tin mines, trading ports, sugar and pepper plantations of neighbouring British Malaya, of which Kedah officially became a part with the Anglo-Siamese Treaty in 1909.

After that, however, a combination of cheap and plentiful rice coming from other British colonies (especially Burma) and the onset of a global ‘rubber boom’ that had (and continues to have) immense consequences on Malaysian landscapes and agriculture, the British rulers largely lost interest in rice from Kedah, and little changed for local rice farmers until independence in 1957. At that point, however, everything changed.

Living with the legacy of the Green Revolution in Malaysian rice

The domestic production of rice – a staple food for most of the population – became a key focus for post-independence Malaysia, and commercial, government-led production, with Kedah at its centre, increased dramatically in the 1960s. Despite some initial resistance from local farmers to the new “miracle rice” IR8 variety (which came out in 1966 and essentially marked the starting point of rice’s involvement in the so-called Green Revolution), the entire Kedah region was eventually transformed to conventional, high-input production systems by the end of the 20th century.

This shift, based on high-yielding modern varieties and synthetic inputs, caused the total volume of Malaysia’s (and Kedah’s) rice production to double between 1970 and the early 2000s.

Unsurprisingly, however, this also brought bigger problems: over the years, soil fertility decreased drastically, and farmers who could not afford the rising costs of chemical sprays and synthetic inputs simply abandoned their land, many heading to the city to find work. Together with ongoing urbanisation and a generational shift away from agriculture (not to mention the expansion of water-thirsty rubber plantations, which in addition to deforesting large swathes of land, have killed off much of the rich diversity of natural plants on which many communities, both human and ecological, previously relied), rural depopulation has been pronounced in these areas.

Innovation and adaptation – applying a System of Rice Intensification (SRI) principles at Sri Lovely

In response to this setting, after several years spent clearing the former farmland area which had been abandoned for over 30 years and observing what species grew or lived in the area, Captain set about establishing the farm in keeping with its surroundings as best he could. Working first on reviving and regenerating the soil, Captain began helping to restore natural soil ecology by selecting for some plants and animals, allowing the spontaneous dispersion of others. He then focused on the rice, favouring heritage varieties and traditional species (acquired from a local seed bank) that are better suited to Kedah’s conditions.

Following the principles of SRI (a low-input system of rice production first developed by French Jesuit monks in Madagascar, then codified and championed by Norman Uphoff of Cornell University), young rice seedlings are planted individually in a meticulously measured grid pattern (at least 25 cm apart), limiting nutrition competition between the plants while ensuring ample space, air and sunlight for each one.

This system, which has been applied all over the world, often results in a much higher yield per plant (if occasionally lower yield per plot) than conventional systems. More importantly, it requires drastically fewer inputs: up to 90% less seed, half as much water usage, and less need for chemical fertilisers.

At Sri Lovely in Kedah, what Captain also likes about SRI is that it encourages adaptation to particular settings and environments. Farmers used to be great innovators, he says, but we’ve “become lazy” because synthetic inputs take away the need to innovate or improvise.

When it comes to pest management, for example, Captain finds the best way is to “let the pests kill each other”. A number of selected plants, which attract certain types of insects, are planted as a ‘perimeter’ around the rice, maintaining a more natural equilibrium of predator-prey relationships and diminishing the risk of any one particular pest damaging the rice.

Lokman and Jun threshing the grain

Big problem, local solution – addressing rice’s methane problem

As well as contributing to much healthier soils, local ecosystems and local environments (by eliminating the use of chemical sprays), Sri Lovely also sets an example for more climate-friendly rice production on a global scale.

Worldwide, rice production accounts for over 10% of total methane emissions. The vast majority of these come from organisms dying and decomposing in anaerobic environments, such as when paddy fields are flooded, which also reduces soil diversity, killing off beneficial soil organisms such as worms and bacteria.

At Sri Lovely, however, the rice plots are not flooded but rather kept ‘moist’, and often drained. This exposes them to more weeds, but the rigid grid shape of rice plantings in SRI allows much easier weeding (done by driving a wooden stick with nails attached to it up and down the rows, wiping out any would-be weeds before they can establish themselves and without hitting any of the rice plants).

In terms of soil nutrition at Sri Lovely, fertiliser is fermented in blue tubs based on a combination of what the plant needs (which Captain trains people to determine by sight) and what is lying around the farm: some rotten dates leftover from Ramadan for potassium, maybe some baby bamboo shoots for phosphorus, or a few nitrogen-rich glaceriya leaves to help boost a droopy plant stem, for example.

Young plots of grain in the second garden

Spreading the love, maximising change

Once it was clear that this adaptable system was working, Captain has put more and more emphasis on the second part of his mission: to provide education, training, support and dialogue for others wanting to create positive, more sustainable, socially aware and ecologically harmonious food systems.

Education and sharing is a huge part of what Sri Lovely is about. Several of the dozen or so wooden, bamboo and thatch buildings dotted around the farm are explicitly dedicated to teaching: one a purpose-built classroom with an encyclopaedic library, another an open-air workshop and demonstration space, one a ‘mini paddy’ garden plot with an adjoined hut, where everything from initial seed selection to on-field weeding techniques to the concoction of those organic fertilisers, can be demonstrated. Hardly a week goes by at Sri Lovely without some sort of educational gathering or workshop taking place, whether it’s for local school children, the farm’s many international volunteers, foreign academics, other local farmers, government officials, and even Malaysian royalty.

In particular, however, Captain wants to encourage dialogue among farmers. Not only rice farmers, he says, but anybody wanting to learn from his experience or wanting to do something “in their own way”. This includes joining forces with other small farmers in order to discuss common issues, brainstorm potential solutions, and present a unified voice for actionable and impactful changes on a government and policy level (including the distribution of subsidies, which typically favour intensive conventional systems and even more damaging industries like palm and rubber plantations).

Lokman harvests the grain

One such initiative, launched in 2019, was the Local Farmers, Local Food gathering, where dozens of small farmers and natural farming advocates from around Malaysia were hosted for several days at Sri Lovely. The first gathering of its kind in Malaysia, this resulted in the presentation of a “Farmers Declaration” to Kedah’s Chief Minister, which has subsequently been built into a wider movement in recent years.

While the on-farm activities and daily life at Sri Lovely have changed little in the past 10 years, every year it seems that the dedication of Captain and his hard-working team is attracting more and more attention. It’s no surprise that, with the growth of demand for organic products rising both within Malaysia and internationally, more and more interest is being shown from producers and industry players to see how they can take advantage.

Luckily for them, and for many of us, people like Captain were at least 20 years ahead of them in this thinking. So, there is a well-established framework and network, one that can be crucial for encouraging a push towards more sustainable, equitable and healthy food systems.

It may only be one example from one particular part of the world, but the Sri Lovely story speaks to a more universal theme: that going your own way and setting an example for achievable, workable solutions can generate a ripple effect of change, inspiring action among grassroots changemakers and those shaping policy alike.

To read more from David, see his previous piece for the SFT about a similar project in Cyprus which is using chickens to help restore soils and reduce reliance on chemicals. You can also visit his website.

All images courtesy of David McKenzie.

The post Reviving land, inspiring farmers: Lessons from Sri Lovely appeared first on Sustainable Food Trust.

It’s not the plough, but the how!

Alice Frost — Tue, 14 Jan 2025 16:02:11 +0000

As news of weedkiller resistant plants hits the headlines, Patrick Holden reflects on discussions at the latest Oxford Real Farming Conference, highlighting why the plough may not be the worst option when it comes to nature-friendly cultivation.

Last week I attended the Oxford Real Farming Conference (ORFC), one of two events hosted in that city at this time of year. ORFC was launched around 16 years ago as a spoiler to the more conventional Oxford Farming Conference (OFC).

Since the first gathering of around 100 people, the attendance has mushroomed, so much so that more than 2000 people attended this year’s event, nearly four times the number of attendees at the traditional conference down the road!

I was encouraged and inspired by one of the 150 sessions, which took place in the Court Room of the Town Hall. This room has a rather dark atmosphere as you might imagine, reflecting sentences passed on hundreds, even thousands of criminals, but this session really countered that Court Room gloom!

The theme was how ploughing and cultivation can be good for soil health. Both of these practices have been somewhat demonised by the regenerative agriculture community, who assert that soil cultivation in general, and ploughing in particular, is bad for soil health and especially for soil carbon.

It was so refreshing to hear the experiences of two farmers, Richard Gantlett of Yatesbury House Farm, a 1500+ acre beef and arable holding in Wiltshire and Iain Tolhurst (a.k.a. Tolly), a small-scale organic grower in the Thames Valley near Pangbourne, both of whom have experience over several decades which runs counter to this orthodoxy.

After 35 years of growing on a couple of fields by the Thames, Tolly reported that his earthworm counts, soil carbon and general soil health were excellent, despite regular ploughing and cultivation. The point he made, I think very compellingly, is that if your farming system is right in its key elements, sensitive and shallow ploughing plus appropriate cultivation will not fundamentally destroy soil health.

In parallel, Richard Gantlett, who is somewhat of a data geek (I mean that as a compliment!), has been assiduously gathering evidence on the carbon outcomes of his farming system for more than 20 years. Richard reports, stunningly, that he is sequestering 10 times more carbon than the farm is omitting, and this is despite the fact that he built his fertility with beef cattle. It has been estimated that were his mixed farming system to be taken to scale right across the arable east of the UK, the soil carbon sequestered could offset a very significant percentage of total UK greenhouse gas emissions.

“What we need is more public pressure for change! I wonder how many people have noticed but not quite realised what is going on, as they drive around England at this time of year – that quite a lot of the arable fields have a strange orange hue about them. They should know that this is the colour of dead plants or weeds after being sprayed with Roundup.”

Linked to this, another thought occurred to me which didn’t come up in the discussions – but I think it’s highly relevant and sometimes overlooked – is namely that the repeated use of Roundup on fields across the east of Britain, and many in the west as well, is having a devastating impact on in-field biodiversity.

I am old enough to remember when arable weeds were an integral part of crop production, not threatening the yields too much, but nevertheless providing nourishment for a vast range of species higher up the food chain. The use of pesticides in general, and herbicides in particular, have eliminated this biodiversity habitat, which collectively accounts for 90% of the total farmed area of the UK. That is why we have witnessed such a catastrophic decline in biodiversity during my farming lifetime. Somehow the nature conservation organisations have overlooked this, instead advocating the introduction of stewardship strips around the edges of otherwise intensively farmed land.

I’ve often wondered why this might be the case. I think it could be because they have no practical experience of agriculture. They doubted the potential for chemical-free agriculture to go to scale, having been told by authoritative lecturers at their universities while studying for environmental degrees that, while well-meaning people who farm organically should be affirmed, they would always be in a minority, since grown-up farmers needed to use chemicals to provide food security and feed the world.

Stewardship strips around the edge of otherwise factory-farmed fields which are devoid of weeds, insects and most other forms of life (other than the crop itself), will do no more than mitigate the damage caused by intensive arable farming. Yet this is the predominant strategy currently informing the Defra post-Brexit farm support schemes. I brought this issue up at one of the Defra consultation sessions at the conference, but I’m not sure whether it made any impact.

What we need is more public pressure for change! I wonder how many people have noticed but not quite realised what is going on, as they drive around England at this time of year – that quite a lot of the arable fields have a strange orange hue about them. They should know that this is the colour of dead plants or weeds after being sprayed with Roundup. It is these very weeds that provided the main food source for pollinators, butterflies, farmland birds and a vast range of other species which used to depend on these habitats to nourish themselves in winter.

I find it sinister and rather shocking that the chemical companies refer to pesticides as ‘plant protection products’. The equivalent impact in the pastures of the west of the UK is when you see a field that that suddenly goes yellow. That is also Roundup. A large number of farmers in the west of Britain now routinely use Roundup instead of ploughing to reseed because they had been told that ploughing is bad for soil carbon.

It’s also more cost-effective, so please don’t blame the farmers. It is up to us as citizens to protest about the way in which chemical agriculture has become the norm on more than 90% of the farmland of the UK.

The post It’s not the plough, but the how! appeared first on Sustainable Food Trust.

More things in Heaven and Earth: Mycorrhizal fungi, ploughing, no-till and glyphosate

Alice Frost — Wed, 14 Jun 2023 15:13:00 +0000

Over recent years, no-till farming has been widely advocated as one of the ways to make farming more sustainable. It is also one of the paid options under Defra’s Sustainable Farming Incentive. But will the current trend away from ploughing towards direct drilling and the accompanying use of glyphosate bring the benefits advocates claim, or could this make matters even worse? Richard Young follows on from his article, Speed the plough or the direct drill and sprayer?, this time looking at mycorrhizal fungi and contrasting the impacts of ploughing, direct drilling and glyphosate on them.

With earthy humour in two well-known passages in Hamlet (4,iii,17-31 and 5,i,191-209), Shakespeare demonstrates an understanding of what early organic farming advocates termed ‘The Cycle of Life’ (seen in this very dated Soil Association film made more than seventy years ago). This refers to the natural processes by which all living things eventually die, decay and under normal circumstances return to the earth to be recycled. In Antony and Cleopatra, Shakespeare gives us one of the basics of sustainable farming, with the line, “Our dungy earth alike feeds beast as man,” (1,i,42-3).

What he could not have known is that the processes he describes, depend, amongst other things, on the action of mycorrhizal fungi. Early microscopes had recently been invented when he wrote these plays in the early 1600s, but they could only magnify up to 30 times normal size. To see mycorrhizal spores under a microscope, you need a magnification of at least 400 times.

Mycorrhizae work in harmony with plants, and both the plants and the fungi benefit from the relationship. The complex, sophisticated and fascinating world of mycorrhizal fungi was recently brought to public attention by biologist and tropical ecologist Merlin Sheldrake, in his widely acclaimed book Entangled Life. He took a broad look at mycorrhizae within the plant kingdom. I am only considering them in relation to agricultural crops.

An historical perspective

One of the first people to point out that healthy soil is alive, not only with invertebrates such as earthworms and soil spiders but also with literally thousands of different microorganisms, was Lady Eve Balfour in her book, The Living Soil. Amongst those are mycorrhizal fungi. She tells us (p.70) that, “Thread-like structures within root cells of certain vascular plants were first observed in 1829 and by 1847 had been identified as fungus mycelium.” Despite the absence of scientific consensus in 1943, when her book was published, she quickly recognised the major importance of soil microbial life, in particular mycorrhizal fungi, for plant and soil health.

A claim repeated in various ways, is that a teaspoonful of healthy soil contains more living organisms than there are people on the planet. The UK Centre for Ecology & Hydrology estimates that “One teaspoonful of topsoil contains around 1 billion microscopic cells and around 10,000 different species.” The global population has increased eight-fold since 1800, so while the original claim would have been true 223 years ago, it would be more accurate to say that there are now eight times more people on the planet than living organisms in a teaspoonful of healthy soil.

I am being pedantic, of course, but this has a relevance we should not overlook, in that population growth is one of the principal justifications used for further intensification of farming, albeit under the banner of ‘sustainable intensification’ which makes it sound harmless. While some farmers are undoubtedly making real efforts to farm in more sustainable ways, all the indications to date suggest that the bulk of the food we consume will continue to be produced in exploitative ways that are associated with a wide range of negative impacts and increased risks, including reductions in important soil microorganisms.

In 1951, pioneering organic farmer, Frank Newman Turner, took up the theme in his book, Fertility Farming, referring to mycorrhizal associations he writes (p.50), “It is this process which is vital to the health of the plant, for it is known that it takes place only in the presence of humus and that plants deprived of it, either by ‘short-circuit’ feeding or by lack of humus, succumb to pests and disease.” By ‘short-circuit’ feeding, he means the use of artificial fertilisers. By ‘lack of humus’ he is referring to the increasing trend, even then, to dispense with returning organic matter to the soil, for example, in the form of composted farmyard manure, that was made possible by the development of synthetic fertilisers. This reached its most extreme level in the 1970s, when tens of thousands of acres of straw were burned in the fields every summer in the UK, sometimes setting fire to hedgerows as well. The practice was finally banned in the UK in 1993 after years of campaigning by environmental organisations, such as Friends of the Earth, but has been permitted again by Defra on blocks of up to ten hectares (25 acres), as part of attempts to control the persistent weeds that plague many of the farms which have continuous arable crop rotations.

Newman Turner became a Council member of the Soil Association in 1952 and concern about the harm caused to mycorrhizal fungi by agrochemicals, especially the use of water-soluble phosphates, became part of organic farming philosophy and eventually influenced the Soil Association’s standards for organic food production when they were first published in detail in the 1980s. The consensus view today on this issue is that phosphate fertilisers do not kill off mycorrhizae, but they do reduce root colonisation by them.

Mycorrhizal fungi

Mycorrhizae form mutually symbiotic (mycorrhizal) relationships with about 80% of plants overall, but with 90% of agricultural crop plants. Oilseed rape and sugar beet, however, are among the small proportion of agricultural crops that do not form normal associations with mycorrhizae.

The extent to which plants and mycorrhizae work together is simply remarkable. Water, made more readily available to the plants by mycorrhizal fungi, is transported from the roots to the leaves by osmosis (as we generally learn at school), seemingly defying the laws of physics in the case of tall trees. But that is only half the story. At the same time, carbon dioxide taken from the atmosphere by the leaves and converted to carbohydrates by photosynthesis, is transported in the opposite direction to feed the mycorrhizal fungi, in the form of root secretions (exudates) containing sugars, amino acids, enzymes and more.

Merlin Sheldrake recently posted a video on Instagram showing this taking place in real time.

In return for the supply of nutrients from the plant, mycorrhizae invade its roots and effectively extend them through filaments (hyphae) which form networks (mycelia). This increases the plant’s ability to take up water and minerals, with mycorrhizae also playing a key role in breaking down organic matter in the soil to humus, from which plants in the natural world and on farms where synthetic fertilisers are not used, derive most of their own nutrition.

No-till farming and mycorrhizal fungi

Advocates of no-till farming make the claim that by not ploughing their soils they are automatically increasing soil biodiversity, including mycorrhizal fungi, and there are plenty of scientific studies to support this claim. But is it as simple as that, and are the increases very significant? Let’s get more basic information on the table first, then consider the question in detail.

Mycorrhizae weeds, plant diseases and pests

Scientists have shown that mycorrhizae can suppress weeds. In a study of six weed species amongst sunflowers, two weed species were reduced by mycorrhizae by between 59% and 66% while the remaining four declined by between 20% and 37%.

It has also been shown that mycorrhizae help to protect plants against root diseases, including ‘take-all’, a disease of cereals. The researchers say, “Our results show a clear systemic bio-protectional effect depending on the degree of root colonization by mycorrhizal fungi.” Some studies have also shown protective benefits in relation to foliar diseases, for example against powdery mildew in wheat. However, the overall situation with plant diseases above ground is still not clear, as this detailed review published in 2019 shows. Overall, mycorrhizae appear to make plants better able to fight off disease, but in some cases, they have been found to increase, rather than decrease, a plant’s susceptibility to viral infections. Whether or not that is related to the specific mycorrhizal species that predominate in continuous arable rotations, appears not to have been researched.

Viral diseases of cereal crops, such as cereal mosaic viruses, are a concern and can cause yield losses of up to 50%, but fungal diseases are as significant in both economic and food security terms. Inoculation with mycorrhizae has been used successfully in conjunction with other soil fungi, known as Trichoderma, to control stem rust diseases in wheat crops. Although currently rare in the UK, scientists have raised concerns about the potential for their re-emergence here.

It is known, however, that some major viral infections are spread by insects and at least one study, detailed in the review cited above, found that plants colonised by mycorrhizae were better able to survive attack by insects – in this case, aphids. It looks as if there is still a lot more to learn about plant diseases and mycorrhizal fungi. As the reviewers say, “Despite their economic importance, information on the effect of the AM [arbuscular mycorrhizae – the type of mycorrhizae which colonises crops] symbiosis on viral infection is limited and not conclusive.”

Mycorrhizae and soil structure

Mycorrhizae also benefit soil structure. It has only been widely known since 1996 that this is largely because they secrete glomalin, a glue-like substance, which helps to hold soil particles together and may also have other benefits, including helping to increase carbon and nitrogen storage in the soil. The elaborate networks of mycorrhizal mycelia clearly also help to improve soil structure and resistance to erosion. This appears to be the main aspect that ploughing can disrupt.

Reproduction

Mycorrhizae reproduce in three different ways, but spores (which can survive for five years), appear to be the main method by which arbuscular mycorrhizae colonise successive crops. Fragments of hyphae, the other main method, only remain viable for a few months. Research on four farms in Yorkshire found that mycorrhizae which colonise autumn-sown crops tended to die off over winter and that the crops were recolonised in the spring, presumably by spores. This suggests that providing there are adequate levels of spores in the soil, ploughing will make little difference to the level of colonisation.

Ploughing

There is, however, research evidence from conventional farms (where agrochemicals are used) from Canada and Mexico to show that mycorrhizae are found in larger numbers when land is direct drilled with no cultivations, compared with being ploughed. How significant those increases are compared with, for example, the higher levels of root colonisation on organic farms (see below), is not clear. What is abundantly clear is that mycorrhizae have declined under intensive arable systems. One study, by scientists from Sheffield, Leeds and York universities, which reviewed five separate studies on this aspect, concluded, “There is increasing evidence that high-input arable cultivation and cropping reduces the populations and activities of ‘ecosystem engineers’, organisms that maintain soil structure and function, including root symbiotic arbuscular mycorrhizal fungi.”

There are similar indications from a few other studies, though I have found fewer than I expected for such a significant issue. For instance, a study in Switzerland found evidence of lower numbers of mycorrhizal spores in ploughed soils, though it also found that the diversity of species was very similar in tilled and no-tilled situations.

Research shows that fields converted from grass to long term arable cropping experience major changes in the diversity of mycorrhizae. However, in contrast to all the evidence cited so far, at least one major review, in the journal New Phytologist, claims that the benefits associated with mycorrhizal fungi have been overstated and that at the present time there is little evidence to justify taking either diversity or abundance into account when managing crops.

It needs to be pointed out that most studies are not comparing the effects of ploughing and no-till in healthy soils, where naturally larger numbers of mycorrhizal spores would be expected. Instead, they are undertaken on land that has been degraded by decades of continuous arable production. The soils on such land have already experienced a significant decline in organic matter (approximately half of which is carbon). This plays a key role in maintaining mycorrhizal populations – organic matter levels have declined in European arable soils, 38% of which are degraded in England and Wales.

It seems reasonable to assume that deep ploughing will dilute the numbers of spores in the top of the soil profile, as well as break up fungal mycelia from the previous year’s crop. In a recent conversation with 92-year-old former Worcestershire farmer, Barrie Kent, who ploughed with horses as a young man, I was told that horse ploughing never went deeper than five inches, even on the best soils. Organic farmers are advised only to undertake shallow ploughing, not deeper than six inches. While there is a lack of research data on the impact of ploughing on levels of mycorrhizal spores, spores buried one year would still be viable when they came back to the surface the next time the field was ploughed. Avoiding deep ploughing would nevertheless appear to be sensible in relation to mycorrhizal fungi as well as seedling establishment and nutrition.

A new agricultural inputs market in the making

Some studies, though, are not focused on the impact on naturally occurring mycorrhizae at all, but on the benefits of using mycorrhizal spores as commercial inoculants for agricultural crops. The potential market is assumed to relate especially to those farmers who wish to reduce their dependence on expensive synthetic fertilisers. An international market for mycorrhizal spores has in fact been developing since at least 2008. However, a recent review of 25 commercial mycorrhizal inoculants concluded that only one of the inoculants resulted in higher yields. In addition, the study, referred to above, by scientists from Sheffield, Leeds and York universities, found no benefit from using commercially available mycorrhizal spores in a three-year trial in connection with ploughing and disc cultivations.

Fertilisers

Most studies that compare ploughing and no-till, do so in soils where both fertilisers and pesticides are being used; both groups of products can have negative impacts on mycorrhizae. Studies have found that where typical levels of phosphate and/or nitrogen fertilisers are applied to crops, the mycorrhizae decline, as the plants no longer rely on them to supply these essential elements from the soil. According to the analysis of a long-term study, which included regular applications of nitrogen fertiliser, “plants and soil microbes have a consistent response to long-term fertilization – both richness and diversity of plants and soil microbes are significantly decreased, as well as microbial functional genes involved in soil carbon (C), nitrogen (N) and phosphorus (P) cycling”. Another study in semi-arid grassland concluded, “AM [arbuscular mycorrhizae] fungal communities from N fertilized soils are less beneficial mutualists than those from unfertilized soils.”

Scientists tell us that in addition to soil disturbance, a wide range of pesticides can affect the diversity of mycorrhizal fungi. There has, however, been an inadequate level of research to establish trends in the diversity and population numbers of mycorrhizal fungi in agricultural soils more generally, in particular, to differentiate between the effects of ploughing, fertilisers, herbicides and fungicides.

Fungicides

Given that mycorrhizae are fungi, it might be expected that the very widespread use and number of fungicides used on intensive farms today would have a negative impact on them. Surprisingly, however, there is less research to be found on this than I expected. One recent study, however, found that the fungicide, mancozeb, reduced mycorrhizae, while a biological fungicide did not. Fungicides for cereal crops in the UK first became available about 55 years ago. The first products were just to control mildew. Since then, an arsenal of products has come onto the market which are widely used to prevent or reduce infection from an equally large number of diseases that have become a progressively greater threat to cereal production, as yields have been increased by plant breeding and higher use of inputs. Similar products are also used in other agricultural and horticultural crops. There appears to be a need for more research on the unintended impacts of these products, for example on mycorrhizae, both individually and when applied in combinations, as they sometimes are.

The impact of glyphosate on mycorrhizae

Unintended impacts of herbicides on mycorrhizae have been found. Research in Finland established that glyphosate reduces mycorrhizae. The researchers also discovered that while soil cultivation reduced the number of mycorrhizae, this was only significant in soils with a long history of continuous cultivation.

Contrary to the original manufacturer’s claims that glyphosate degrades a few weeks after it is applied, the scientists found residues in plants in the following growing season, as well as reduced levels of beneficial mycorrhizae. The emerging consensus on this aspect appears to be that glyphosate will often degrade relatively quickly, but that various factors, including low temperatures, can slow this significantly. In Argentina, a country where glyphosate is used on GM crops, it has been suggested that it should be considered as a “pseudo-persistent” pollutant because, “application rates are higher than dissipation rates”. Speculating, this should, perhaps, be investigated in the UK in situations where glyphosate is used several times a year, such as post-harvest, pre-sowing and as a desiccant pre-harvest, especially in parts of the country where temperatures over winter are cold enough to slow its breakdown significantly.

Another study in Argentina found that when applied to the soil, glyphosate affected the viability of spores even at a very low rate of 0.8 litres per hectare. Total root colonisation with mycorrhizae was also reduced when glyphosate was applied to the soil or to foliage, with no difference between high and low application rates. While some studies have found positive, negative and neutral impacts depending on a range of factors, a 2014 study by German and Austrian scientists “found that herbicides [glyphosate in this study] significantly decreased root mycorrhization, soil AMF spore biomass, vesicles and propagules”. A 2013 study in Argentina found similar results and was able to quantify the impact. The viability of mycorrhizal spores in soils not treated with glyphosate was between 5.8 and 7.7 times greater than in soils that were treated with it.

Organic farming and mycorrhizae

Advocates have claimed for many decades that organic farming creates the best conditions for mycorrhizae and that this, in turn, is a key reason for its technical success given the non-use of synthetic inputs and relatively high productivity. While there is no direct evidence of the impact which mycorrhizae have on the yields of organic crops, there is good evidence to show that organic farming leads to healthier mycorrhizal communities. For instance, a Dutch study found that arable fields under organic management had more arbuscular mycorrhizal fungi species than conventionally managed ones, with the difference becoming increasingly significant as time passed, following conversion to organic methods. The same study also showed that organic soils had mycorrhizal communities which were more diverse, and more similar to those found under natural grasslands – a finding that was replicated in this Swiss study. Why this is the case is not known for certain, but it is assumed to be due to the avoidance of synthetic fertilisers and biocide use in organic farming.

An interesting observation to take from these findings is that tillage – a key feature of organic arable production, and therefore a practice whose impacts were captured in the studies mentioned above – can clearly be compatible with healthy mycorrhizal communities. Still, there is evidence from one study finding that a reduction in tillage intensity in organic production does lead to even higher mycorrhizal spore densities and species richness. With some organic farmers already experimenting with ways of reducing their reliance on ploughing (without, of course, using glyphosate or other herbicides), this is something which may spur further interest in this area.

Several other studies have also found higher populations of mycorrhizae on organic farms. A 2010 study found the highest levels of mycorrhizae in grasslands, somewhat lower levels in organically managed crop fields and significantly lower levels on conventionally managed fields. Another Swiss study found that a much greater proportion of plant roots were colonised by mycorrhizal fungi in organic arable systems compared with conventional ones.

The importance of grass

A key component of mixed organic farms, and by extension many regenerative farms, is that they include short-term grass and clover leys in their arable cropping rotations. This may be one of the main reasons that mycorrhizae are more plentiful in organically managed soils.

A recent study involving scientists from several UK universities found that introducing a grass/clover ley on land that had been in intensive arable production for more than 10 years resulted in a rapid recovery in earthworm populations with numbers four times higher than in an adjacent arable field after just two years. In the study by scientists from three UK universities (already cited twice, above) wheat achieved yields of 92–106% of national average yields following a three-year grass/clover ley, but with just 25% of the normal nitrogen fertiliser application rate and no use of fungicides. This study used herbicides on the growing crops and glyphosate with direct drilling to kill the grass ley. It would have been particularly interesting to the organic sector to have seen a comparison where the ley had been ploughed instead of treated with glyphosate.

Conclusion: How significant is the damage to mycorrhizae caused by ploughing?

Given the importance of mycorrhizae for the health, resilience (in the face of droughts and heavy rain) and (with the possible exception of inoculated crops), the productivity of croplands where low or no inputs are used, it is surprising that so little research has specifically addressed this question. Several teams of scientists suggest that more research is needed on a number of issues relating to mycorrhizae. There is sufficient evidence to say that soil that has been producing crops continuously for many years will have lower than ideal levels of mycorrhizae and an altered range of mycorrhizal species. Some reports suggest these can be very low, but levels appear to vary, and it is not obvious what the range is, or precisely which factors make the most difference.

It is, however, clear that in addition to ploughing and other cultivations which physically damage the mycelia, the use of synthetic fertilisers, glyphosate and at least some other pesticides have significant negative impacts on mycorrhizae. How might we explain the good yields of wheat in the study by Sheffield, Leeds and York universities despite the use of glyphosate and low use of nitrogen fertiliser? Two things seem worth pointing out. First, I have occasionally produced organic wheat yields in good years on my best land straight after grass, approaching 7 tonnes per hectare from milling wheat varieties (which are lower yielding than feed wheat varieties). In such situations nitrogen is not a limiting factor and I doubt if it would have made much difference if they had used no nitrogen fertiliser at all. Second, and here I can only speculate, it seems possible that over time repeated glyphosate applications would reduce yields in a low or no input situation, if, as several studies suggest, this is steadily degrading the mycorrhizae.

It seems possible, and if so ironic, that the negative impacts on mycorrhizae from fertilisers, herbicides, including glyphosate and fungicides, may be masked to some extent at present by increased use of the same fertilisers and pesticides that are reducing the mycorrhizae. When it comes to protection against disease, the picture is even less clear. There is increasing evidence of the role mycorrhizae play in providing partial immunity to disease, but insufficient evidence to say exactly which diseases can be repelled and which not.

From the perspective of organic and other mixed farms, where crops are grown in rotation with grass/clover leys, there is good evidence that this increases or maintains high levels of mycorrhizae, as the comparative organic and conventional studies cited above demonstrate. Ploughing, inevitably, does some damage, but with mycorrhizal spores able to colonise plant roots and start bringing benefits in just a month or so, and strong evidence that mixed organic farms are better for mycorrhizae than conventional ones, the careful use of ploughing is compatible with healthy mycorrhizal communities on organic farms.

However, given that organic farmland still only accounts for a relatively small proportion of total farmland, it is necessary to consider ploughing versus glyphosate in standard intensive systems. It may be that in such situations, no-till does bring advantages over ploughing. It should be noted, however, that since a range of herbicides (including glyphosate) is used on most conventional farms, a completely balanced, comparative assessment of ploughing versus no-till may not yet ever have been undertaken. Finally, the research I have read for this article is sufficient for me to suggest that regenerative farmers who want to make their farms as sustainable as possible, should not be frightened about giving up glyphosate and re-embracing the use of shallow ploughing

We would like to thank Professor Jonathan Leake (who read an early draft of this article and provided advice and information) and Philip Conford who kindly searched in vain for information on when the damage to mycorrhizae caused by water-soluble phosphate fertilisers was first raised in a Soil Association publication. Robert Barbour reviewed the organic studies and provided helpful comments.

Featured image licensed under the Creative Commons. Click here to view original.

The post More things in Heaven and Earth: Mycorrhizal fungi, ploughing, no-till and glyphosate appeared first on Sustainable Food Trust.

Farming’s umbilical dependency on glyphosate

Victoria Halliday — Wed, 03 May 2023 17:26:19 +0000

Imagine you are a farmer planning your cropping for the next few years to ensure everything remains healthy, productive and, especially, weed free.

While you’re busy at this task, you read in a respected magazine that there is a new spray which you can apply liberally that will kill all plants, except those genetically engineered to be tolerant to it, without causing any negative side-effects whatsoever to the natural environment or human health. At the same time, the use of this spray will save you an extraordinary amount of time and money, deliver carbon benefits and bring countless other efficiencies, all at an affordable price.

If you were that farmer and had taken at face value the compelling, seemingly evidence-based, advocacy about this product’s safety and efficacy which, by the way, tens of thousands of UK farmers already have, you would probably go ahead and use it.

And, if then, having incorporated it into the heart of your farming practice, some environmentalist troublemakers started concerns about potentially harmful and undesirable impacts upon the environment and human health, you might well lobby your farmers union to go on the offensive by highlighting the lack of conclusive evidence linking the product to negative health and environmental outcomes. This is exactly what has happened with a herbicide based on glyphosate, a chemical which, when mixed with so-called adjuvants – compounds which make the glyphosate more ‘sticky’ – increases its potency by 100 times, making it remarkably effective.

When you think about it, and appreciate how difficult it can be for farmers to remove glyphosate from their current practice, it is hardly surprising that the National Farmers Union (NFU) has been campaigning strongly for the last few years to prevent its withdrawal. This is despite growing evidence of glyphosate’s harm throughout the world, which has led many countries in the European Union to consider banning its use.

Farmers in the UK and throughout the world, have developed an umbilical dependency on the use of Roundup and other glyphosate-based herbicides, so they are understandably anxious about any possible withdrawal by regulators. This dependency is directly related to the predominance of the continuous cropping systems that have become the norm during my farming lifetime, now spanning over 50 years.

Until the 1950s and 1960s, most farms had crop rotations with a fertility building phase, normally of grass and clover, which not only restored to the soil the carbon that was released during the arable phase of the rotation, but also reduced weed populations. With the virtual disappearance of such rotational systems, which have been replaced by continuous arable cropping, it has become almost impossible to avoid a build-up of previously controllable arable weeds. The consequence is an ever-increasing dependence on the chemical sprays that are seen as a godsend in the eyes of many farmers.

I have made it my business to pay attention to the gathering body of evidence calling into question the safety of Roundup and other glyphosate-based herbicides over the last 10 years. The first major challenge was posed by a French scientist, Professor Gilles-Eric Séralini, who undertook a scientifically impeccable study on rats, precisely mimicking the study that Monsanto had undertaken as a necessary prerequisite for obtaining the EU pesticide safety certificate.

Séralini’s study involved feeding rats on genetically modified corn and Roundup at the prescribed minimum levels of their drinking water, not just for 90 days, which is what the regulators require, but for the full lifetime study of two years. He did this because, as a scientist who had access to the data which Monsanto lodged in the annals of the European commission, he noted that, at the end of the 90-day Monsanto trial, some of the rats were showing kidney and liver irregularities. In his replicated but longer trial, to his consternation, he observed that many of the female rats went on to develop mammary tumours and that kidney and liver irregularities worsened as the trial progressed.

Séralini was determined to publish and promote awareness of the data arising from this trial as widely as possible, but during the run-up to its launch the pesticide industry got wind of his intentions and organised a brilliant counter campaign, the result of which was to discredit Séralini as a scientist as well as to call into question the adequacy of the design of his study. This all took place in 2012 and, although the Sustainable Food Trust did its best to stand behind Séralini’s evidence, organising a press conference in London and speaking publicly about our conviction that the study was in fact well designed, the counter campaign undertaken by industry bodies was largely successful. As a result, it became unwise in journalistic circles to give any credence to Séralini’s study.

Fast forward another 10 years and there is a growing body of research suggesting that the use of Roundup poses long-term threats not just to the environment and biodiversity but also to the soil microbiome and human health. Some studies have gone so far as to suggest that the rising prevalence of previously uncommon diseases, ranging from diabetes, obesity, cancers, food intolerances and diseases of the nervous system is, in part, related to the capacity of Roundup to interfere with the genetic pathways of bacteria. Whether or not Roundup is eventually shown to be a causal factor in the development of these diseases and conditions, this disturbing evidence should surely be taken seriously and prompt further research.

As this newsletter goes to press, despite the cumulative evidence of Roundup’s harmful effects on life, these findings are yet to be taken seriously by government. Such has been the success of the industry campaign that it is still regarded as unorthodox and fringe to side with people who consider Roundup and its use to be unsafe.

A parallel might be observed in the history of the use of tobacco. When I was young, despite the large body of evidence showing its dangers, I continued to smoke. Most of my generation ignored the calls for caution. I started smoking in my mid-teens and can still remember the guilty pleasure I experienced with smoking my first Players No6 in my bedroom! Although I never was a chain-smoker, I settled at one or two roll-ups a day in my early 20s and continued smoking into later decades until a dose of pneumonia brought that abruptly to an end around 2010. As I like to say to people, if you need to quit smoking, try contracting pneumonia – it works brilliantly and, as I reflect now, it is so often the case that dangerous substances or practices finally get their comeuppance through health shocks.

If we follow the trajectory of smoking’s demise and apply the same bell curve to the use Roundup, we are perhaps still some years from the moment when, eventually, the Government steps in and either bans its use or introduces a range of measures to ensure that we reach the end of the Roundup chapter of agricultural history.

In the meantime, if you live anywhere near a farmed landscape, farmers are likely spraying Roundup to kill off grassland pastures and weeds in cereal stubbles, to enable the use of minimum-till systems and, increasingly, as the so-called ‘pre-harvest desiccant’. This means that, a week or so before harvesting a crop of wheat, barley or other grain, farmers will spray the ripening field, both to kill off any grasses or weeds in the understory of the crop and to hasten the ripening of the grain, as well as speed up the drying process to enable faster combining.

The pervasiveness of these practices mean that many of us are getting a daily dose of Roundup in our food. This is especially true of bread in the UK, but if we look across the Atlantic to America, Roundup has been found in virtually all rivers and water systems, in the rain and air, and in human urine.

Should we be worried about this? In short, yes, and in response, we should be calling for further research to identify the potential risks. In the meantime, if you want to take action, consider buying organic to minimise your potential exposure to Roundup residues.

For more on Roundup and its use within different farming systems, click here for an in-depth article by SFT’s Policy Director, Richard Young.

The post Farming’s umbilical dependency on glyphosate appeared first on Sustainable Food Trust.

Speed the plough – or the direct drill and sprayer?

Alice Frost — Wed, 03 May 2023 17:16:21 +0000

One of the key questions for farmers today is whether to continue using a plough. Land has been ploughed to grow crops for thousands of years. Arguably, urban societies and civilisation itself, owe their existence to the plough. But ploughing can damage soil structure and biological life. Soil erosion, phosphate pollution and CO₂emissions from ploughed fields on conventional farms are also higher than those from comparable fields under no-till and marginally higher than those under min-till.

As part of its Sustainable Farming Incentive, Defra is effectively paying farmers to abandon ploughing and embrace either no-till or min-till methods instead. But is this really informed by the latest science and in our best interests, especially when it depends on the herbicide, glyphosate, about which multiple concerns have been raised? Richard Young looks at the evidence on both sides of the argument.

In recent years, there has been an upsurge of interest in regenerative agriculture. In many respects, this is extremely welcome. Despite five very different forms of regenerative farming being identified and the lack of agreed definitions or independent monitoring, regenerative crop farmers tend to adopt longer and more diverse rotations and include cover and green manure crops. While many still use agrochemicals, they think like ecologists as well as food producers and are avoiding some of the worst aspects of continuous arable farming. Many of them are also recognising the value of re-introducing grass/clover breaks and grazing livestock into crop rotations to improve soil health and reduce nitrogen fertiliser use.

Over time, this should increase soil organic matter and make crops naturally stronger and better able to resist pests and diseases. Getting farmers to put grass and clover back into arable rotations has long been a central aim of the Sustainable Food Trust (SFT) and the Soil Association because it is a cornerstone of generating fertility on the farm and restoring the health of badly degraded soils.

What is less welcome is the fact that a high proportion of regenerative farms depend on the routine use of glyphosate. Like farms that grow arable crops year after year, most of them have switched from using ploughs to ‘no-till’ (the direct drilling of seeds), or ‘min-till’ (light soil cultivations prior to sowing). In both cases, with only rare exceptions, this cannot be done successfully without the use of glyphosate to control weeds.

The no-plough aspect, however, isn’t as clear cut as this makes it appear. Some no-till and min-till farmers still find it necessary to plough and/or sub-soil their fields every 3-4 years. One of the reasons for this is that soils on heavy land can become compacted, another is that persistent weeds, like blackgrass and couch, and pests like wireworms and nematodes, are difficult to control without ploughing. In addition, most vegetable crops cannot be grown without ploughing, so rotations which include potatoes or cabbages or onions, for example, still depend on ploughs almost as much as ever.

Used ploughs for sale. Demand has declined, not disappeared.

For most organic farmers who grow arable crops, there are few alternatives to using a plough within a sound rotation. But in a world of global warming and sustained population growth, the arguments are not all on the chemical-free side.

Is using glyphosate a deal with the Devil?

In Christopher Marlowe’s 16^th century play, Dr Faustus, the eponymous protagonist, a highly educated man who has reached the limits of human knowledge at the time, still thirsts for more. Despite warnings, Faustus manages to conjure up the Devil, using the black magic arts he has studied. The Devil does a deal with him. For the next 24 years Faustus can have and experience anything he wants, but after that the Devil gets his soul in Hell for eternity, which, as Rowan Atkinson, playing the Devil welcoming new arrivals, tells us, in one of his comic sketches, ‘Is a heck of a long time’!

Interestingly, the three examples included in the play of what Faustus wants, are all things we have gained access to over the last 50-100 years: the ability to fly around the world, the provision of out-of-season fruit over winter and the opportunity to see images of beautiful women, all of which have environmental or societal downsides. Faustus asks to see Helen of Troy (from Greek mythology) whose enchanting face and the desire it created, started the Trojan wars and ‘launched a thousand ships’. But how does any of this relate to glyphosate?

Glyphosate

Glyphosate was developed by Monsanto and first used as an agricultural herbicide in 1974, marketed as ‘Roundup’. Apart from enabling the use of no-till methods, it has several additional advantages over other weedkillers:

it kills the roots as well as the leaves, so weeds cannot regrow;
it kills all green plants on which it is sprayed, so there is no need to identify the weeds;
it greatly speeds up farming operations, reducing both labour and fuel costs;
it is also permitted as a pre-harvest desiccant, which reduces drying costs in a wet season.

I didn’t hear about Roundup until 1978 and, by then, I had been farming organically for four years, so I have never used it. But if it had become available when I was still using fertilisers and pesticides, I would probably have tried it on one field. That might have saved me days of back-breaking work trying to get on top of a couch grass infestation in a 22-acre field. So, I can see the attraction. I would not have known then that, 54 years later, couch grass would still be a problem and an even bigger one for no-till farmers, than for those who use a plough, as Bayer Crop Science explains.

As the days, then hours, then seconds of Faustus’s 24 years move inexorably towards their end, Faustus repents his foolishness and struggles ever more pitifully to find some way to save his soul from everlasting damnation – but to no avail. In most stage productions, we see him being pulled down to the fires of Hell, shortly before the play ends.

The downsides of glyphosate

My analogy with Dr Faustus is, of course, subjective and open to criticism. But while the 24-years allotted to him may have no particular significance, it is an uncanny coincidence that in 1998, twenty-four years after Roundup was first put on the market in the US, the Journal of Pesticide Reform published a short article and 13-page factsheet by Caroline Cox. She was at the time the staff scientist at the NCAP (Northwestern Coalition for Alternatives to Pesticides) in the US, detailing evidence indicating a range of negative human health and environmental impacts from glyphosate and Roundup. Time has shown her concerns to be justified and they have been added to by many subsequent studies. A 2016 review by the Pesticide Action Network details many of these, though further evidence continues to emerge.

Of most significance on the human health side, is the conclusion in 2015 of the World Health Organisation’s International Agency for Research on Cancer that glyphosate is “probably carcinogenic”. Following intense lobbying by Monsanto, the Environmental Protection Agency in the US, however, reached a different conclusion. The strongest evidence, so far, of a cancer link to glyphosate relates to the large number of cases of non-Hodgkin lymphoma (blood cancer) in people who have had exposure to Roundup (4,000 in California alone), but links to other cancers have also been claimed.

In individual cases, US courts have awarded very large sums in damages of up to $2 billion on one occasion, though this was reduced to $86.7 million after an appeal by Bayer, which bought Monsanto in 2018 for $63 billion. However, while many associations between glyphosate and cancer have been claimed, and courts have often accepted these, the evidence is not considered strong enough to establish a cancer link beyond doubt. Ever-cautious scientists and a lymphoma action group point out that the perceived association could be a coincidence and other factors may be involved. But for those who feel convinced their exposure to glyphosate was a factor that helped to cause their cancer, one could say they are in a kind of hell already.

A field that has been treated with glyphosate in Gloucestershire, UK

The numerous health and environmental downsides of glyphosate that have been identified in peer-reviewed studies are too many and varied to discuss in detail here. Some are likely to relate to indirect effects, such as reduction in food supply, rather than direct toxicity, but they include, established or suspected negative impacts on birds, aquatic life, amphibians, bees and other insects, earthworms, soil mycorrhiza, antibiotic resistance, and the, as yet, unknown impact of glyphosate on the oceans and sea creatures, where it is highly persistent. Many, though not all of these, describe the association they identify as relatively mild or in need of further research. But is a small effect over a long period of time from an agrochemical so widely used, not likely to have a significant impact?

Glyphosate’s biggest selling point today

Claims that using direct drilling – inevitably with glyphosate – will help in the fight against climate change by sequestering carbon are one of the chemical’s biggest selling points today with both policymakers and many environmentalists. One of the most influential studies was a 2002 review of evidence, which concluded that moving from ploughing to no-till methods would sequester over half a tonne (570 kg) of carbon per hectare annually (equivalent to over two tonnes of CO₂). These findings were taken up by influential bodies: as examples, in 2007, the IPCC concluded that conservation tillage (a term that covers both no-till and min-till) “can increase the SOC [soil organic carbon] stock for 25-50 years”. In 2013, the United Nations Environment Program’s Emissions Gap Report (p24) included no-till as a practice that could help to reduce agricultural greenhouse gas emissions. Less controversially, there is clear evidence that no-till farmers can reduce their diesel use significantly in the years they neither plough nor sub-soil.

For whatever reason, those original claims have become stuck in the agricultural psyche, despite a vast body of research which has called their accuracy into question since.

Does no-till farming sequester carbon?

One of the first studies to challenge the no-till (NT) soil carbon sequestration claims came from US scientists in 2007. They recognised that conservation tillage increased carbon in the top of the topsoil, but added, “The widespread belief that conservation tillage also favors carbon sequestration may simply be an artifact of sampling methodology.” A 2008 study from Canada found similar results, noting that at a depth of 21-25 cm average soil carbon was, “significantly greater under FIT [full inversion tillage, i.e. standard ploughing] than under NT.”

A significant number of review studies by different teams of scientists have found broadly similar results. These include a 2010 study from Australian and Chinese scientists which determined that “adopting NT did not enhance soil total C down to 40 cm”. They also concluded that continuous crop production for five years resulted in an average carbon loss of more than 20 tonnes per hectare, with no significant difference between conventional tillage and no-till. After adopting no-till, soil carbon increased by 3.15 tonnes per hectare in the top 10 cm of soil but declined by 3.30 tonnes, 20-40 cm down.

Some individual studies, for example, this one in 2013, have continued to claim significant carbon benefits from no-till and smaller benefits from min-till, by testing only the top few inches of soil. However, all comprehensive reviews of the evidence have found no significant net sequestration. Typical of many, a 2014 study by soil scientists at Rothamsted Research in the UK, argues that the role of no-till in climate change mitigation, “is widely overstated”. The scientists concluded that such claims, “ignore a large body of experimental evidence showing that the quantity of additional carbon in soil under no-till is relatively small,” and that any gains in the topsoil only offset losses deeper down.

A systematic review in 2017 drew similar conclusions, while a 2016 global study found that although no-till can increase yields in dryland regions (when two other principles, crop residue retention and rotations, are also met) “yields decrease with no-till regardless of whether the other principles are applied in humid climates.” A Farmers Weekly article in 2019 acknowledged that no-till results in lower yields, but argued that due to the 22% lower production costs, “no-till farms can afford to produce 1t [tonne]/ha less wheat”. As detailed on the valuable soil management blog site of organic farming advisor, Mark Measures, an even more recent UK study from 2021 has concluded that, “Overall, there is limited benefit in using shallow minimum tillage and zero tillage practices in the UK to increase soil carbon storage.”

It is hardly surprising then that the Emissions Gap 2022 report no longer makes claims about no-till and carbon sequestration, pointing instead to the greater use of legumes to reduce the use of nitrogen fertiliser, and better rice, manure and nutrient management as ways to reduce emissions. It also notes that the move to precision farming in the US has so far not reduced nitrogen fertiliser use. It sees the global increase in organic farming to almost 75 million hectares as positive. Despite all this, however, the myth persists in many circles, that giving up ploughing and embracing no-till will help us reduce food-related emissions.

Glowing in the dark

Such false claims are not so unlike the things that lured Faustus into his pact with the Devil. But, as a near contemporary of Marlowe wrote, “Glories, like glow worms, afar off shine bright. But looked into near, have neither heat nor light.”

Making things simpler

Controlling weeds with glyphosate has, however, made life simpler for farmers and enabled farms to get much larger. This has benefitted those that were already large, at the expense of the great number of smaller farmers who have been elbowed out, and the even larger number of people who would love to have a patch of land on which to grow things or keep animals themselves.

A field that has been sprayed with glyphosate in Worcestershire, UK.

Well, at least that’s how it was until Monsanto introduced the first crops containing the glyphosate resistance gene (Roundup Ready). As this 2021 study shows, this spread to a few weeds, and now at least 48 weeds in the US, South America and Australia are resistant to glyphosate and large amounts of more dangerous chemicals are being used to manage a problem caused by glyphosate. Explaining how this occurred, a US scientist behind the study says, “Just as humans have to think ‘outside the box’ when confronted with new challenges, weeds had to evolve ‘outside the box’ when confronted with glyphosate selection.” But if we accept that glyphosate and ploughing can both cause problems, where does a solution lie?

What we can learn from the past

In the opening line of his 1943 book, Plowman’s Folly (available online and also published in the UK as Ploughman’s Folly), Edward Faulkner states, “This book sets out to show that the moldboard plow which is in use on farms throughout the world, is the least satisfactory implement for the preparation of land for the production of crops.” His case, that it was better to keep crop residues on the surface, rather than bury them with a plough was neatly summarised in a 1944 short review in Nature. But while many of his arguments have stood the test of time, Faulkner was not a farmer. His book and even its sequel, A Second Look (later published in the UK as Ploughing in Prejudices), contain examples of significant exaggeration and a level of naivety not infrequently found amongst those who influence agricultural policy, but have never grappled with the vagaries of the weather and the multiple, practical obstacles faced by food producers.

As Jorian Jenks commented on one aspect of Faulkner’s case, in a review in the Winter 1947/8 edition of the Soil Association’s journal, Mother Earth (pp. 43-45), “The road to good husbandry is neither so short nor so straightforward as that.” In A Second Look, Faulkner does, nevertheless, row back somewhat from his original position and sets out a broader case. Amongst other clarifications, he states he is only opposed to deep ploughing, not all types of ploughing, and he recognises that his approach is not suitable for all soil types. He explains that his concern was with the worn-out soils on all-arable farms and not with farms where the soil is being maintained in good heart. He states, “While the book was intended to draw an indictment of the plow, the far more important purpose was to show the reader the need for highly developed biological activity in the soil.” No organic or regenerative farmer could disagree with that.

Ploughing on an organic farm, Cotswolds, UK. Photo: David Wilson.

Although, most farmers and agriculturalists of the day were not won over by Faulkner’s arguments, at least some organic farmers in the UK and the US supported his case. In his 1951 book, Fertility Farming, early organic farming pioneer, Frank Newman Turner, who farmed in Somerset, stated “I can support every word of criticism which the American Edward Faulkner had for the plough.” Despite his tireless work, a close reading of the book suggests that he had only partial success in controlling weeds without either ploughing or using herbicides.

In Philip Conford’s The Origins of the Organic Movement (pp. 108-110), Faulkner emerges as one of those who played a part in the development of organic farming philosophy and dissemination of key principles, even though he embraced some components of conventional agriculture. Faulkner is, however, silent on the issue of using herbicides to control weeds, even though the safety and wisdom of this was already concerning other organic farming advocates.

It seems possible that Faulkner’s success in controlling weeds without recourse to ploughing was not just due to the fact that his trials were carried out on light, free-draining soil, as he acknowledged, but perhaps also – here I only speculate – to the fact that weedkillers might have been used when needed? The selective weedkillers 2,4-D and MCPA both came onto the market during the 1940s.

What I deduce from all this is that progress doesn’t always run in a straight line. Faulkner has contributed something important – a better understanding of how to use the plough to best effect and minimise damage when possible. Like others, he also drew attention to the primary importance of maintaining good stocks of dark, stable organic matter in the soil, or humus as it has long been called by organic practitioners. Early estimates of soil carbon sequestration under no-till proved to be incorrect and simplistic. In a similar way, Faulkner’s ideas today need to be balanced with wider practical experience and information from other sources.

Finding a solution

The fundamental question is, can we grow good crops without either glyphosate or ploughing? As Mark Measures describes in To plough, or not to plough? (an article written to advise organic farmers), various approaches have been tried. A farmer on well-drained, easily worked soils in Wiltshire has been successful using a form of min-till, not so unlike Faulkner’s. But he is, nevertheless, cultivating the soil to a depth of 15-25 cm, i.e., up to 10 cm deeper than the shallow ploughing now advocated and used by most organic farmers. For me, this raises the question of whether this is better, worse or the same as shallow ploughing down to 15 cm?

The results of a long-term comparison of ploughing and reduced tillage on a biodynamic farm in Switzerland makes for interesting reading. There was a significant net increase in soil carbon in the top 10 cm of soil, as in the studies on conventional farms, no difference in the 10-20 cm band, but the phraseology ‘increased stratification’ in the 20 cm to 50 cm layer leaves me uncertain as to whether or not there was a net carbon gain with reduced tillage? Since substantial amounts of animal manure were applied during the trial (whereas no manure was applied in the other studies I have cited), one might expect differing results. There was, though, a very significant increase in weeds, with a suggestion that the increased cultivations needed to control this under biodynamic or organic husbandry, might cancel out any benefits under the no-plough system.

Other approaches using a machine developed in Germany called the EcoDyn or the crimper roller designed by the Rodale Institute in the US, have very limited uses, and both have shown variable results in the UK, most probably because they are less suited to the unpredictable weather patterns here. Additionally, a technique which allows wheat to be sown directly into a clover cover crop works effectively, but wheat yields fall significantly. So, no widely applicable solutions here, though a few options which individual farmers may be able to use, adapt and perhaps even improve on.

Evidence from multiple sources indicates that earthworm numbers have declined significantly due to intensive crop production, most of which, in the past, has been based on ploughing, some of it, deep ploughing. Other studies show clearly that numbers are higher under no-till than ploughing. However, research also shows that earthworms do well on organic farms and at least one study has shown this to be largely due to the use of farmyard manure. In the year following ploughing, there were higher numbers of juvenile worms, suggesting that some larger worms had been lost, but that numbers were recovering naturally. As the title of a book from traditional farming advocate John Stuart Collis suggests, The Worm Forgives the Plough, at least it does if organic material is returned to the land.

But let’s just look at the basics. There have been very few long-term studies of soil carbon changes under different land management. However, a study undertaken at Rothamsted Research is significant. This was begun in 1938, though brought to an abrupt end in the late 1960s when central funding was cut, on the misguided assumption that synthetic fertilisers took away the need to maintain organic matter. Amongst other things, this found that grassland converted to continuous cropping lost almost 40% of its organic matter and carbon over a 40-year period. In a mirrored trial, cropland converted to permanent pasture sequestered a similar amount of carbon. However, neither the losses nor the gains continued indefinitely; they eventually declined towards a new equilibrium.

In relation to arable land, the introduction of ley/arable rotations of 3-years grass, 3-years cropping, the sort typically used by organic farmers, the Rothamsted Research study shows that soil organic carbon increased by a minimum of the 4 parts per thousand per year (the target set by the International 4 per 1000 Initiative) for 35 years – when the grass phase was longer or the cropping phase shorter, even higher rates of sequestration were achieved. When sheep were also grazed on the grass, carbon sequestration more than doubled to 9 parts per thousand. Applications of farmyard manure (FYM) once every five years brought similar increases in soil carbon.

It appears, however, that no studies were undertaken to combine ley/arable rotations with both sheep and the application of FYM, a typical situation on a ley/arable (mixed) organic farm, where we would expect even higher rates of sequestration. We can assume that traditional plough-based cultivations were used. Broadly collaborating these findings, a review of trials from France, Denmark and Sweden reported carbon increases of 10.3%. In another recent study, a modelling exercise has concluded that both min-till and no-till offer little sequestration potential, whereas the introduction of leys into arable rotations could increase soil organic stocks by up to 16 tonnes per hectare. In all cases, including those where no-till increases carbon in the top few inches, the way percentages translate into tonnes of carbon, depends on soil type, past use of the land and the organic carbon content at the start of any study.

Conclusions

For continuous crop farmers, there are some benefits from adopting direct drilling, these include: more organic matter and associated better moisture retention in the top of the soil profile; more earthworms and reduced soil erosion on degraded soils; plus savings in time, labour and fuel.

Despite continuing assumptions to the contrary, there is now overwhelming evidence that when the full soil profile is considered, the claims of net carbon sequestration under no-till are simply false. There may still be a small net greenhouse gas benefit from moving to no-till, due to fuel savings, but overall the carbon benefits are much lower than widely believed. Even here, though, caution is needed. It is amazing how often what appears to be established science is eventually overturned as new perspectives are explored by researchers. One possible example of this is that recent research by the Game and Wildlife Conservation Trust has found that where soils are compacted (as they are more frequently under no-till than conventional tillage with a plough) emissions of the most potent of the main greenhouse gases, nitrous oxide, are 10-15 times higher.

The situation with organic farms is very different. Basic research on ley/arable rotations and organic farming suggests that where manure is composted and returned to the land and where rotations are not too exploitative, soil carbon will be slowly increasing (or maintained at a high level) and there will be high earthworm populations even though ploughing may result in short-lived reductions in their numbers.

Ploughing on organic farms “is not all bad”, as Mark Measures concludes in his article. As an organic farmer myself, you’d hardly expect me to disagree with him.

We would like to thank Ellis Machinery, David Wilson, Philip Conford, Mark Measures, Jasper Broadhurst, William Hodges, Robert Barbour, Imogen Crossland and Susanna Smith, for information and help with this article.

The post Speed the plough – or the direct drill and sprayer? appeared first on Sustainable Food Trust.

Is ammonia from green hydrogen a false prophet?

Imogen Crossland — Fri, 01 Apr 2022 11:00:00 +0000

Defra has just launched a package of measures to help farmers facing huge increases in the price of fertiliser.

The cost of nitrogen fertiliser is currently three times higher than it was last year. This makes it an appropriate moment to consider the dependence of intensive agriculture on synthetic nitrogen and whether the prospect of green hydrogen to make fertiliser with a lower environmental footprint offers a long term solution.

A brief history of nitrogen fertiliser

Since the Second World War, synthetic fertilisers, especially those made from ammonia, have played a major role in agriculture on almost all farms except those using organic methods. These have driven a dramatic increase in production through higher yields, but that has come at a high environmental cost in terms of greenhouse gas emissions, air pollution from ammonia, water pollution from high levels of nitrate and biodiversity decline in terms of delicate wild flowers and plants outcompeted by ranker vegetation better able to ulitise nitrogen.

Today, the UK uses just over one million tonnes of nitrogen every year, in over three million tonnes of nitrogen fertiliser, with different products containing different proportions of nitrogen. Ammonia is produced by the Haber-Bosch process – named after German scientists Fritz Haber and Carl Bosch who developed a method to produce synthetic ammonia in 1911. This process turns the inert nitrogen in the air we breathe into reactive nitrogen, by breaking the triple bond which holds nitrogen atoms together in pairs, then forcing them to combine with hydrogen. This requires a temperature of 500°C, 250 atmospheres of pressure (approximately 120 times the pressure in a typical car tyre) and an iron catalyst.

The initial motivation was the prospect of war with Britain. Ammonia is essential for the production of explosives and had Haber and Bosch not made their breakthrough, the huge scale of the carnage during the First and Second World Wars would not have been possible.

At the end of both wars, the world was left with massive industrial capacity to produce ammonia for which there was suddenly no demand. However, in the 1940s it was realised that this ammonia could also be used to create nitrogen fertilisers, with the Rockefeller Foundation in the US pioneering their development for use in Mexican agriculture. While the programme was not well suited to Mexico, the experience gained underpinned the promotion of synthetic nitrogen fertilisers in developed countries from about 1950.

Haber and Bosch originally produced the hydrogen they needed to make amononia by passing an electrical current through water. However, producing hydrogen through electrolosis in this way is extremely energy intensive and it was later found that by using natural gas as the source of hydrogen the amount of energy needed could be reduced considerably. Even today, however, the process of making ammonia still requires a lot of energy. It accounts for 1.4% of global carbon dioxide equivalent emissions (much of this in the form of nitrous oxide and CO2) and consumes 1% of the world’s total energy production. Hydrogen (and the ammonia produced with it) is currently made using either Steam Methane Reforming or Auto Thermal Reforming with natural gas. This is known as grey hydrogen (or blue hydrogen, when the associated CO2 emissions are captured and stored underground). Given the significant contribution to the climate crisis, finding an alternative, less carbon intensive method of creating ammonia has long been desirable. This is where green hydrogen comes in.

Green hydrogen

The concept of ‘green hydrogen’ is now being promoted as a new climate friendly way to create and store energy to reduce our dependency on fossil fuels, with the potential to make greener nitrogen fertilisers as well. Green hydrogen production relies on the original Haber-Bosch method of splitting water by electrolysis (using electricity from renewable energy sources), which results in only two outputs: hydrogen and oxygen, neither of which directly contributes to global warming or air pollution. The hydrogen can be stored safely under pressure in fuel cells and the oxygen can be vented to the atmosphere with no negative impact. There are many uses for green hydrogen, including a potentially important role within agriculture as a replacement for the fuel used by tractors and other heavy machinery. However, of greater interest to many is that green hydrogen fed into the traditional Haber-Bosch process can be used for ammonia production which is then used to make fertilisers like ammonium nitrate.

Since this green ammonia is 100% renewable and largely carbon-free switching to green ammonia would greatly reduce the carbon footprint of nitrogen fertiliser production. This is a good thing. In theory, it would help us get closer to net carbon zero. Any steps we can take to reduce our global carbon footprint are clearly essential to the efforts to limit global warming to below 1.5 degrees by 2050 and 2 degrees by the end of the century, avoiding the worst predicted aspects of climate change. As such, it makes sense to support a switch to green ammonia from both grey and blue ammonia production. Price, however is still a limiting factor. The cost of green hydrogen is currently still high, but given the impact of the Ukrainian conflict on energy prices and the finite nature of natural gas reserves, the option to produce ammonia from green hydrogen is appealing since it is expected that at some point over the next 5-10 years, it will become lower in price and possibly also less susceptible to price fluctuations than when grey (or blue) hydrogen is manufactured and used. This could eventually help farmers, already under financial pressure and worried about rising input costs – a challenge that Defra is partly addressing though a package of measures unvailed recently.

But might green hydrogen be a false prophet?

One big advantage of green hydrogen is that it provides a way to store energy from wind turbines and solar panels to use overnight and on days when the wind isn’t blowing and the sun isn’t shining. But one of the biggest questions is whether it will be possible to produce enough renewable electricity in the UK to make sufficient green hydrogen for all our needs? As already mentioned, using electricity to make hydrogen for fertiliser production instead of natural gas is significantly more energy intensive overall. There is a great deal less pollution, but much more energy is needed in total. Given the need to use hydrogen to replace diesel and the dramatic increase in renewable energy we will need to achieve net zero carbon emissions by 2050, the scale of the problem is huge. There has to be a further question over whether we have enough land in the UK for sufficient solar panels and windmills, without taking excessive areas of land out of food production? As such, it seems likely that we will remain dependent on other countries for much of our energy needs, even once green hydrogen becomes a financially viable option. The obvious place to produce energy from solar power is in deserts, but the hydrogen would need to be made close to vast sources of water as, according to our initial calculations, it will require approximately six litres of water to make enough hydrogen to replace one litre of diesel.

Seeking an altogether greener approach

The current model of industrial agriculture relies on artificial inputs to maintain high yields and productivity. This has been achieved to the detriment of the environment and human health. Agriculture is the source of over 80% of ammonia emissions in the UK and ammonia is a major cause of air pollution. Even if it is possible to produce a ‘greener’ form of synthetic fertiliser at scale, green ammonia-based synthetic fertilisers will still cause some of the same environmental problems associated with current nitrogen fertiliser use, including fertiliser run-off into streams, which creates dead-zones in rivers, lakes and even some oceans through eutrophication. Producing enough hydrogen to make the 190 million tonnes of fertiliser nitrogen used globally each year could also put additional strain on the planet’s already inadequate supplies of fresh water in many regions.

Recognising the damage caused by synthetic fertiliser, the SFT and others in the sustainable farming sector have long been advocating a switch toward more agroecological farming systems. We believe that we need bold change if we want to create a more sustainable food and farming system. A switch to agroecology would be that change. Agroecology employs natural methods of nutrient cycling to build soil health. For example, using forage legumes in grassland, in rotation with crops and as cover crops, which bring natural nitrogen into the soil. The benefits of adopting such methods is that this allows farming to function in harmony with nature and available natural resources, it also aims to reduce negative externalities while still ensuring a productive and viable farming sector.

Of course, it is unrealistic to think that the world will ditch its dependency on nitrogen fertilisers overnight, and so where these continue to be used green hydrogen is likely to have a valuable role in reducing the emissions associated with their manufacture. Yet, green hydrogen should not be viewed as the primary solution to the nitrogen fertiliser ‘problem’. Ultimately, as opposed to challenging that long-entrenched dynamic of high-input industrialised agriculture, switching to green hydrogen could merely maintain the status quo of ammonia-dependent and polluting farming systems. Despite lowering the carbon footprint, it may create additional problems while enabling food to be produced with the same high levels of synthetic fertiliser, without introducing more fundamentally sustainability components into production methods.

Conclusion

As a result, adopting an approach that sees green ammonia as a solution to creating a more sustainable farming system might be misguided. It could help a little but it is not a panecea. Rather than moving towards the systemic change and a shift to agroecological practices that is needed, this could undercut delay the urgent need to transition in the direction of agroecology. We need to continue to push for bolder change, ultimately ensuring we stay within all planetary boundaries, allowing us and future generations to maintain a healthy and habitable planet.

The post Is ammonia from green hydrogen a false prophet? appeared first on Sustainable Food Trust.

Are glyphosate-based herbicides poisoning us and the environment?

Anna Kilcooley — Fri, 05 Feb 2021 16:27:00 +0000

A new study, published on 27^th January in the journal Environmental Health Perspectives, conducted by an international team of scientists led by Dr Michael Antoniou of Kings College London, found that exposure to glyphosate and its commercial Roundup formulation, can disrupt the function of the gut microbiome (bacteria and fungi) and internal body systems with potentially serious effects on human health.

In controlled laboratory animal experiments, glyphosate was found to alter the composition, and more importantly, the biochemical function of the gut microbiome by the same mechanism through which the chemical acts to kill weeds (inhibition of the shikimate biochemical pathway), even at doses claimed to be safe by the regulators. Roundup was also shown to be more toxic than glyphosate alone, underpinning existing evidence that the additional substances present in commercial products, collectively known as ‘adjuvants’, are not ‘inert’ as claimed by its manufacturers and regulators but highly toxic in their own right.

In-depth biochemical analysis of both the gut and the blood of the test animals showed that they were put under ‘oxidative stress’, a highly damaging process, by glyphosate and to a greater degree by Roundup.

From my reading, this research appears to go a long way towards vindicating the conclusions of the many organisations and individuals throughout the world who were convinced from the very beginning that it would be unlikely in the extreme that this herbicide, an agricultural poison which has the capacity to kill all green plant material except that which has been genetically modified to be tolerant to it, would not have adverse effects on the human health.

The new research builds on the work published in September 2012 by Professor Gilles-Eric Séralini, who showed that exposure to an extremely low dose of Roundup in rats over two years led to a highly statistically significant disturbance in the animals’ physiology, and most dramatically an increase to breast tumour incidence.

The SFT organised a London press release to highlight the findings of the Séralini study, only to encounter a sustained and brilliantly successful campaign by leading members of the industry and its allies within the academic community to discredit the integrity of the science behind the study.

Before the BBC got cold feet, their science correspondent David Schuchman interviewed Professor Mustafa Djamgoz, an eminent cancer specialist who stated that, although the number of rats in the study was small, the statistics were sufficiently alarming to justify an immediate replication of the trial. The filmed interview was scheduled to be shown on Newsnight but this did not happen due, I suspect, to the BBC’s confidence in running the interview being undermined by individuals and organisations who had vested interests in the continuing use of Roundup.

My conclusion from these events is that, just like tobacco, challenging an orthodoxy can be a lonely and nerve-racking business, and the scientific media are not exempt from these pressures!

In the eight years since the Séralini research was published, it has yet to be replicated with a relevant lifetime study. This is quite possibly because if you are a researcher in that field, to be associated with research which discredits pesticide manufacturers is probably going to limit your career prospects. In this connection, it is sobering to reflect that the journal which published the Séralini study was effectively pressured into withdrawing it a staggering 14 months later, but with the findings subsequently being published elsewhere in another peer reviewed journal.

What should happen next? Exactly what was suggested by Professor Mustafa Djamgoz, all those years ago. Today, glyphosate-based herbicides such as Roundup are the most widely used class of pesticides in the world. They are used in gardens and parks, advertised on television, routinely sprayed onto all glyphosate resistant genetically modified (GM) corn, soy and cotton crops, as well as being used as a pre-harvest desiccant on silage and grain crops which are subsequently harvested and eaten by human beings in bread and other food stuffs.

This is a poison which is so pervasive that it is now present in food, air, rainwater and tap water. Surveys of human populations have shown that people in both the US and Europe have glyphosate in their urine, suggesting constant daily exposure from different sources.

This new research indicates that glyphosate, especially in its commercial Roundup formulation which contains additional toxic substances, has a disruptive effect on the composition of the rat microbiome, the biochemical function of the microbiome and internal body systems. Worryingly, I understand that this metabolic interference is linked to processes that can damage organs, cells and DNA, potentially leading to serious diseases including cancer.

It should not be forgotten that since 2000, feed rations of UK farm animals, particularly poultry and dairy cattle, have included significant quantities of GM maize and soy which are likely to contain residues of glyphosate-based herbicides with obvious potential impacts on their gut microbiomes.

A similar disruption caused by glyphosate and Roundup in the gut microbiome is also occurring in the soil, which effectively is the stomach of the plant. Soil microorganisms (such as bacteria and fungi) are known to exist in a symbiotic relationship with plants and thus are crucial to their health and crop performance. The application of glyphosate-based herbicides has been known to disrupt the soil microbiome (as well as cause toxic effects in earthworms) which can in turn lead to compromised plant health, crop performance and nutritional value. There is a vital need to explore these impacts further and better understand the effect this can have on human health.

In summary, faced with this evidence and knowledge gaps, any responsible government would instigate the introduction of a regulatory framework which would minimally restrict the use of glyphosate-based herbicides, progressively phase them out and eventually eliminate their use.

Photograph: Aqua Mechanical

The post Are glyphosate-based herbicides poisoning us and the environment? appeared first on Sustainable Food Trust.

The impact of air pollution on crops

Anna Kilcooley — Fri, 03 May 2019 13:07:00 +0000

Air pollution’s damaging impact on human health is well established – but apart from its links to illnesses including heart disease and asthma, pollutants are also damaging the yield of food crops and their nutritional quality and safety, imposing a major risk to food security.

In India, air pollution is cutting yields of wheat and rice crops in half, according to a study from 2014. Researchers mostly attribute this to ground level ozone (O3), a short-lived pollutant that exists in the atmosphere for weeks or months. O3 gas is formed when nitrogen oxides, which are produced in combustion processes and mostly released from power stations and vehicles, react with air pollutants, including vehicle exhaust, oil refining, petrochemicals and bushfires during sunlight.

Researchers found that between 1980 and 2010 yields were up to 36% lower than what they would have been without air pollution trends. In 2010, this loss was the equivalent of more than 24 million tonnes of wheat in India, worth around $5 billion.

“A main precursor of O3 is vehicle pollution in cities, and levels of O3 are much greater in hot sunny conditions,” says Fiona Marshall, professor of environment and development at the University of Sussex. As the earth’s temperature increases with global warming, this will further increase levels of O3. Marshall further adds that polluting industries are often moved out of cities into areas surrounded by agriculture, where emissions are closer to crops and therefore have a more immediate impact on yields.

In India, these high levels of pollutants – which, in major cities, often surpass the safe limit – don’t look set to change any time soon.

“An increasing proportion of agricultural land is being affected by air pollution in India as cities expand and agriculture land use is interspersed with built-up areas and industry,” says Marshall.

Ozone has a damaging impact on plants. When O3 is absorbed via the pores on the leaf surface, it forms free radicals that attack cell membranes. This causes yellowing, cell injury, irregular spots, bronzing and reddening that affects the flowering and growth of crops, reducing their yield. It is thought to be the most important air pollutant affecting crop growth and productivity, says Lisa Emberson, centre director of Stockholm Environment Institute at the University of York.

“Current estimates suggest that O3 is causing between 5% and 12% yield losses globally in staple crops, which include wheat, rice, maize, soybean,” she says. Associated economic losses from affected crops are estimated to be up to $20 billion per year.

Research by the UK’s Centre for Ecology & Hydrology estimates that 03 reduces the yield of wheat, rice, maize and soybean by up to 227 million tonnes a year globally, including in North and South America, India, China, the US, Bangladesh and Indonesia. The highest production losses caused by 03 for soybean are in North and South America, for wheat, they are in India and China, for rice, in parts of India, Bangladesh, China and Indonesia, and for maize, in China and the US. The most affected areas are also often at risk of high losses from pests and diseases and heat stress.

The critical levels set by the United Nations as a target for O3 pollution control in 2016, are exceeded in many areas of the world, says Katrina Sharps, spatial data analyst at the Centre for Ecology & Hydrology at the Environment Centre Wales.

“The highest ozone levels are in many of the world’s important crop growing regions. Ozone concentrations are increasing in rapidly developing regions – for example, East Asia and Southeast Asia – and are predicted to continue to increase over the coming decades,” she says.

Sharps has found through research that O3 impacts were predicted in areas of the world where the largest yield gaps occur, including parts of South America, Sub-Saharan Africa and East Asia, where factors such as nutrient limitation and irrigation availability are known to be affecting yield. This could be detrimental to food security since it would directly impact farmers in Africa who rely on subsistence farming, growing enough food to feed themselves and their families.

“Crop losses due to ozone may reduce the likelihood of meeting the United Nations Sustainable Development Goal to end hunger, achieve food security, improve nutrition, and promote sustainable agriculture by 2030,” Sharps says.

“It is anticipated that considerably greater production of grain crops such as wheat, soybean, maize and rice will be required. Our research shows that the total ozone effects on wheat yield were twice as high in developing countries [than] in developed countries, where more yield is urgently needed to feed the growing population.”

Emberson says the future damage to food security caused by O3 depends on how emission reduction is implemented in future decades. Research has found that European ozone levels have increased rapidly since the 19^thcentury, although peak concentrations recorded in 2003 and 2006 were around half that of levels recorded in 1976.

“Cause for concern is that in many parts of Asia, where O3 impacts are high in important agricultural regions such as the Indo-Gangetic plain and Eastern China, emissions look to continue for the next few decades, which may exacerbate already high O3 levels and associated yield losses,” she says.

Overcoming this won’t be easy, says Sharps, and it requires global action.

“Ozone pollution is a global problem requiring investments from industry and governments from around the world,” she says. “Further international agreements on reducing ozone pollution are urgently needed, however, this is a long-term goal which will take time to be implemented.”

Researchers are also looking at short-term solutions, including breeding new varieties of crop that are more resilient to ozone; better timing of irrigation, which has been found to promote ozone uptake; and the development of non-toxic agrichemicals, as toxic agrichemicals generate pollution. They say most crop breeding programmes have been targeted at increasing or maintaining the yield rather than increasing stability of yield under stress.

Researchers and farmers can also work together to avoid high levels of O3, Sharps says.

“Under certain conditions such as warm, sunny, weather, ozone episodes can occur, with ozone concentrations in the air peaking for several days at a time. It may be possible for researchers to forecast when an ozone episode may be about to occur and advise farmers to reduce irrigation during this time.”

Another short-term option, Marshall says, is to routinely screen crop varieties that are going to be grown in polluted areas for air pollution resistance, alongside other tests for tolerance to drought or salinity, enabling resistant varieties to be developed.

“Local farmers who are able to select their own seed may be already selecting those that are resistant to air pollution, but this won’t be the case for the increasing proportion of farmers that are dependent on large-scale seed suppliers,” she says.

In India, some farmers are finding they are unable to save their seeds and plant the varietals they want, due to their contracts with agribusiness.

Marshall says there needs to be more field research to help quantify the impacts of air pollution on crop yield and quality – but says it won’t be easy. “We need to know more about how it affects different types of crops and farming practices, and the implications for different groups of people, in terms of food security.

“A first step is to have a more formal recognition of the threat that air pollution poses to crop yield, and potentially to nutritional value and quality. As a largely invisible threat, this is challenging.”

The post The impact of air pollution on crops appeared first on Sustainable Food Trust.

The supply chain of fats: Rapeseed oil

Imogen Crossland — Thu, 26 Jul 2018 15:55:00 +0000

Bright yellow fields of oilseed rape have become a feature of the British countryside only within living memory. It produces one of the most popular vegetable oils, but, grown as a monoculture over vast tracts of farmland, its impact on the environment, biodiversity and even some people’s health leaves a lot to be desired.

Oilseed rape (or ‘canola’ as it is known in some countries) is one of the world’s major oil crops and of the 70 million tonnes produced annually, 2.2 million tonnes is produced in the UK. It is one of the most common break crops here, taking up 522,000 hectares of farmland in 2017, according to The Department of Environment, Food and Rural Affairs (Defra). The crop is processed into rapeseed oil, though it didn’t really take off in Britain until after 1973 when Canadian scientists bred varieties that were lower in erucic acid and glucosinolate, which can give the oil a bitter taste and make it unsafe for human consumption. Since then its acreage has steadily increased and over the past decade the popularity of rapeseed oil has soared. It has lower amounts of saturated fatthan other cooking oils and relatively high levels of omega-3 polyunsaturated fat, adding to its popularity.

Rape is a high input, high output break crop. In recent decades it has become an important crop for intensive arable farmers, as it can provide a good income and goes well in a rotation with wheat, which is often the most profitable cereal crop.

Despite this, oilseed rape is not particularly sustainable in the way it is often grown. To maximise yields and profitability farmers generally use high applications of nitrogen fertiliser, some of which is washed into rivers and ground water by heavy rain. The crop is also extremely vulnerable to a large number of pests and diseases which are generally treated with a range of fungicides and insecticides.

In looking closer at the impacts of oilseed rape production, I asked two English oilseed rape farmers and a processor how the supply chain works.

The average yield is 3.2 tonnes per hectare, but, as one farmer explains, farms cannot make much money with less than 4 tonnes per hectare. He is producing 6 tonnes per hectare on his 3,500 hectare farm, so is well above the average. This suggests that there are some British farmers who are making a loss from oilseed rape production and that it can be financially unsustainable, sometimes even with high inputs of agrochemicals.

One explanation for this could be that some farmers trying to maximise income from wheat are growing rape one year in three instead of only one year in five as recommended. Another reasonfor falling yields has been the ban on the use of neonicotinoid insecticides, due to their harmful impact on pollinating insects and other wildlife. Yet in a way these two aspects are linked. If rape was not being grown so frequently in rotations, the evidence suggests that levels of disease and pest damage would be lower.

United Oilseeds, a farmers’ cooperative, is the middle man in this farmer’s supply chain. The oilseed farmer explains that the price United Oilseeds pays for his product is dependent on the world market and it is his responsibility to decide the best time to sell. He jokes that he often gets it wrong.

United Oilseeds then trades the crop to Archer Daniels Midland (ADM), a multinational oilseed and cereals processor. While the farmer makes about 2-3% profit on the crop, ADM makes around 15-20%. The farmer considers the profits taken by the processors unreasonable in comparison to what the producer receives.

“We’re forced to take the price offered on the contract by the purchaser or they will just change supplier,” he explains.

The last stage in the supply chain, the retailer, is so far removed, that farmers do not even know if the majority of their crop goes for oil, animal feed or biofuel. The farmer realises that he could be buying a product from the supermarket that contains some of his crop, but that there is no way of tracing it.

It is a common concern in agriculture that the power and the profit is concentrated with the retailers, according to a report by the Fairtrade Advocacy Office, Who’s Got the Power? The value of the oilseed rape crop gets higher and higher as it moves through the chain and becomes the packaged oil on our supermarket shelves.

Some farmers are choosing to take control into their own hands by processing their crops themselves. Charlie Beldam, who farms in Worcestershire, set up a crush – Cotswold Gold – during the 2008 recession, in order to diversify his family farm’s income.

Cotswold Gold produces cold-pressed rapeseed oil, using only Mr Beldam’s crops. On its website, the health benefits of cold-pressed rapeseed oil are highlighted as an important selling point. Studies have shown that quality indicators are higher for cold-pressed rapeseed oil than for hot-pressed, which explains why some consumers are prepared to pay a higher price.

By pressing his own oil, Mr Beldam feels he has more security. There is a great deal of uncertainty about the viability of the farming industry. Although subsidies should continue at least until March 2022, there is still uncertainty about how Brexit will impact the economy in the long-term. Currently, 84% of the UK’s total farming income comes from EU subsidies.

Diversification, such as oil pressing, is one way for farmers to improve their resilience, and to increase traceability of products. To some extent, diversification can help oilseed farmers to improve their environmental practices – a topic they insist they are concerned about. Mr Beldam’s farm aims to protect the environment where possible. He explains they are careful to choose a time to spray crops that minimises the risk to insect pollinators. Neither of the farmers I spoke with, like relying on chemical inputs, but both recognise consumers want food at a certain price and that they have to be efficient to meet demand.

Through speaking to farmers, it is clear that the supply chain of conventionally produced British rapeseed oil is neither traceable nor particularly environmentally friendly. And there are other problems with the crop too. Many people claim to be allergic to rape pollen and suffer weeks of unpleasant symptoms every spring when it is in flower. Also, despite the early success in reducing the levels of erucic acid, levels in some crops have increased due to the spread of weeds like charlock which looks almost identical to rape and which is very difficult to control with chemicals. At present rape used by the food industry can contain up to 5% erucic acid. The EU is proposing to reduce this to 2%, though what will happen in the UK post-Brexit is currently unknown.

Farmers often feel they have to deliver high outputs to be economically viable, resulting in intensive practices. Although diversification and cooperative working could enable farmers to increase their power in the supply chain, and to be in a better position to act on their environmental concerns, the larger question of how farmers can transition into more sustainable production in all-arable systems, while competing on the world market remains a tricky one.

The post The supply chain of fats: Rapeseed oil appeared first on Sustainable Food Trust.