Back Issues

If you are like us, then you don’t know where to start when it comes to other reading apart from farming magazines.
However, there is so much information out there that can help us understand our businesses, farm better and
understand the position of non-farmers.

We have listed a few more books you might find interesting, challenge the way you currently think and help you farm better.

Teaming with Microbes: The Organic Gardener’s Guide to the Soil Food Web

Smart gardeners know that soil is anything but an inert substance. Healthy soil is teeming with life not just earthworms and insects, but a staggering multitude of bacteria, fungi, and other microorganisms. When we use chemical fertilizers, we injure the microbial life that sustains healthy plants, and thus become increasingly dependent on an arsenal of artificial, often toxic, substances. But there is an alternative to this vicious cycle. We can garden in a way that strengthens the soil food web the complex world of soil-dwelling organisms whose interactions create a nurturing environment for plants. “Teaming with Microbes” extols the benefits of cultivating the soil food web. First, it clearly explains the activities and organisms that make up the web.

Next, it explains how gardeners can cultivate the life of the soil through the use of compost, mulches, and compost tea. The revised edition updates the original text and includes two completely new chapters on mycorrhizae (beneficial associations fungi form with green-leaved plants) and archaea (single-celled organisms once thought to be allied to bacteria). With Jeff Lowenfels’ help, everyone from devotees of organic gardening techniques to weekend gardeners who simply want to grow healthy, vigorous plants without resorting to chemicals can create rich, nurturing, living soil.

The Omnivore’s Dilemma: A Natural History of Four Meals

For the past twenty years, Michael Pollan has been writing about the places where the human and natural worlds intersect: food, agriculture, gardens, drugs, and architecture. His book The Omnivore’s Dilemma, about the ethics and ecology of eating, was named one of the ten best books of 2006 by the New York Times and the Washington Post. He is also the author of In Defence of Food, The Botany of Desire, A Place of My Own and Second Nature, and the upcoming Food Rules: An Eater’s Manual.

The Hidden Half of Nature: The Microbial Roots of Life and Health

The Hidden Half of Nature lays out the astonishing reality we’ve been missing in the soil beneath our feet and right inside our bodiesour world depends on a foundation of invisible life. Montgomery and Bikle share a captivating story of the least-loved part of nature, taking readers through major milestones in agriculture and medicine to untangle our uneasy relationship with microbes. From the challenge of turning their barren Seattle lot into a flourishing garden through Bikle’s struggle with a surprise cancer diagnosis, the authors discover the power nature’s smallest creatures wield over our lives. Stunning parallels in the relationships that microbes develop with plant roots and the human gut reveal ways that farmers can restore degraded fields and doctors can reverse the modern epidemic of chronic diseases. For in cultivating the beneficial microbes that make soil fertile and keep us healthy, we can suture rifts never meant to be.

The Diet Myth: The Real Science Behind What We Eat

Why do most diets fail? Why does one person eat a certain meal and gain weight, while another eating the same meal loses pounds? Why, despite all the advice about what to eat, are we all still getting fatter? The answers are much more surprising – and fascinating – than we’ve been led to believe. The key to health and weight loss lies not in the latest fad diet, nor even in the simple mantra of ‘eat less, exercise more’, but in the microbes already inside us. Drawing on the latest science and his own pioneering research, Professor Tim Spector demystifies the common misconceptions about fat, calories, vitamins and nutrients. Only by understanding what makes our own personal microbes tick can we overcome the confusion of modern nutrition, and achieve a healthy gut and a healthy body.

Small Is Beautiful: A Study of Economics as if People Mattered

How does our economic system impact the way we live? Does it really affect what we truly care about? Oxford economist E. F. Schumacher provides an enlightening study of our economic system and its purpose, challenging the current state of excessive consumption in our society. Offering a crucial message for the modern world struggling to balance economic growth with the human costs of globalisation, Small Is Beautiful puts forward the revolutionary yet viable case for building our economies around the needs of communities, not corporations.

Food in History

An enthralling world history of food from prehistoric times to the present. A favorite of gastronomes and history buffs alike, Food in History is packed with intriguing information, lore, and startling insights– like what cinnamon had to do with the discovery of America, and how food has influenced population growth and urban expansion.

The Englishman’s Food: Five Centuries of English Diet

Medieval gardens; cookshops; spices; ale, beer, wine and spirits; the food of peasants, labourers, townspeople, the wealthy, the poor and the country gentleman; fish, meat and game; the feeding of infants, children; dairy products; vitamins, proteins, fat and fibre; the adulteration of food; the four bottle man; bread; poaching; tea, coffee and chocolate; food in schools and institutions; sugar and sweetmeats; root crops; the agricultural revolution; the importance of ‘white meats’, the vegetarian diet; menus and recipes. . . The Englishman’s Food was first published in 1939, fully revised in 1957 and now appears with a new updating introduction. A ground-breaking book, it is a fascinating and authoritative survey of food production, consumption, fashions and follies over a period of five hundred years. Reprinted with a new introduction by food editor Tom Jaine.

Green and Prosperous Land: A Blueprint for Rescuing the British Countryside

News about Britain’s wildlife and ecosystems tends to be grim. In Green and Prosperous Land, Oxford economist and Natural Capital Committee chair Dieter Helm shares his radical but tangible plan for positive change. This pragmatic approach to environmentalism includes a summary of Britain’s green assets, a look towards possible futures and an achievable 25- year plan for a green and prosperous country. The bold generational plan assesses the environment as a whole, explains the necessity of protecting and enhancing our green spaces and offers a clear, financially sound strategy to put Britain on a greener path. Helm’s arguments expose the economic inefficiencies in our environmental policies and thus highlight the need for change. Leaving behind the current sterile and ineffective battle between the environment and the economy, this revolutionary plan champions the integration of the economy and the environment together to deliver sustainable, eco-friendly economic growth. There is hope, and there is time, but we must act now.

Welcome to another 100 pages of Direct Driller magazine. Pages that tell farmers so much about the mysteries of soil and the ways ingenious engineers and scientists have devised to handle it. This story has only recently become news. In recent years the world of media, politics and education have begun to grasp the story, but often in a negative way.

The headlines are about the final harvest being just 60, or is it 100, years from now. Farm chemicals polluting waterways; insecticides wiping out whole species of insects… we’re all too familiar with the stories. In a recent BBC broadcast Tony Juniper, chair of Natural England, echoed Sir David Attenborough’s evidence of unfolding global catastrophe, and agriculture was at the top of his list of ills which are reducing the population of the natural world of insects, plants, birds and animals.

The world, quite rightly, nods in agreement but does little more, continuing to buy fresh peas from Zimbabwe when the same crop was growing here in the UK. I wrote to him (no reply, naturally) saying that it was wrong to tar the industry with one brush. I reminded him that agriculture is highly diverse, ranging from the total sterility of poly tunnels to the improving habitat from cover cropping and No-till. I explained that farming is making giant strides in accommodating the natural world into their production systems, not to appease the campaigners but because it actually makes long term economic sense.

The world of microbes is being harnessed to help, and crop protection is changing out of all recognition as farmers learn to love the insects they had been brainwashed to hate. The inveterate old codger Dan Archer – “it’s all in the soil” – might have been onto something all those years ago, but his message was villified by all involved in modern agriculture.

Is his message being told on farms in Africa and other developing parts of the world?

Certainly no evidence when I visited Zambia, where centre pivot irrigation, ploughs and cultivators is the modern way of farming. What a shame it is that people with real influence can only think negatively. Imagine the results if the converse were true. Sir David telling his global audience how farming techniques are not set in stone, and modern farmers can and are working with rather than against nature. How the techniques of creating soil biomass are getting amazing results.

Where all that green waste which the world now takes to the recycling centre (dump) ends up. Stories that are positive for both the natural world and farming itself. Publicity which converts into funds for research, for knowledge exchange, globally. It’s a real honour to edit a magazine which does just this. I know that readers will be fascinated by the contents of this issue. The mixture of science, engineering, ethics and, of-course, the invaluable Farmer Focus articles.

Reading how farmers have coped with the savage season that was 2020, and what changes they have planned as a consequence are always interesting. Finally, a quick reminder that I am available to take on speaking engagements over the upcoming winter season.

As farmers, information is becoming very important to us. However, the ability to move information from one place to another is never easy. Thus, every platform we use requires us to add the information all over again. It’s something I point out to companies a lot, “that’s a great idea, but asking the farmer to enter that information all over again manually won’t be popular”.

The big question is why can’t information transfer be standardised?

The simple answer is of course, it can. At the moment we don’t have an ISOBUS standard for information – but it would be really useful and I do think it will happen. Afterall, it is your information, so you should be able to export it from any system and import it into another. We are just as guilty of this as every other company, it is something we have recognised and are trying to fix.

Our latest development project is called Farm Compare. It will allow farmers to share anonymised and rounded prices for crop protection products for free. It’s a great example of how to share information to gain business intelligence. Answers are immediate and the more farmers that use it, the more powerful it will be. You will be able to compare one buying group against another and even in the future compare whether serviced or supply would be best for your business.

However, you will do all this using your anonymous The Farming Forum username. No need to create another account to access another service. We are also talking to the crop management software companies to allow you to export the prices out of their systems and into Farm Compare. We have also recognised that it isn’t easy to manage your Direct Driller subscription. The plan over the next few months to incorporate your subscription preferences in with your TFF membership.

So that you can update your own address and whether you would like to receive the magazine in print or digitally. At this point, one username and password will give access to Direct Driller subscription, The Farming Forum and Farm Compare. A very small step forward in trying to make all your lives a little easier.

Written by James Warne from Soil First Farming

“I don’t care what colour it is, what it looks like or it’s consistency, it’s lime, get it spread” were words quoted to me recently by an agronomist who clearly didn’t understand the basics of some simple chemistry. The above quote was part of a conversation about the quality of liming material and in particular the particle size of lime delivered to farms in the UK. I was being accused of overcomplicating liming by requesting that ‘Ground limestone’ should be specified and should be tested to make sure the product meets the specification. My point being any lime particle larger than 0.6mm (600 microns) is not going to effectively neutralise an acid pH.

This little nugget of useful information is clearly stated on the Agricultural Lime Association website (www. aglime.org.uk). For greater clarity and understanding 0.6mm is about the same size as the full stop at the end of this sentence. Not all lime is equal, and certainly our experience is that there is a lot of mis-selling going on in the ag-lime supply trade. A few years ago we were so dismayed by the quality of some of the bulk lime products being delivered to farms that we invested in a set of laboratory quality certified sieves to test our theory. To date we have tested many samples of lime and have yet to meet one which meets the statutory requirements of the Fertiliser Regulations 1991.

Below is one of the worst samples we found to date. To the many reading this I suspect this looks like the lime you are regularly sold, but in reality it’s total rubbish. Read on to find out why. In case you can’t read the handwritten notes in the photo, they are as follows; Top left; larger than 5mm 26% (should be zero %) Top right; smaller than 5m, larger than 3.35mm 15% (should be maximum 5%) Bottom left; smaller than 3.35mm, larger than 150 microns 58% (should be ~5%) Bottom right; smaller than 150 microns 1% (should be minimum 40%)

All ag-lime sold in the UK must meet the requirements of the Fertiliser Regulations 1991 to be sold as lime, for the purposes of this article I will look at limestone only, but these regulations also apply to dolomitic limestone, chalk and many other types of lime. The table below is taken from the Fertiliser Regulations. Using the detail in the table above we can see that the lime in the photo above fails on the following;

• Only 74% has passed the 5 mm sieve, where it should be 100%.

• Only 59% has passed a 3.35 mm sieve, where it should be at least 95%

• Only 1 % has passed the 150 micron sieve, where it should be at least 40% if declared ‘Ground’ 

Why does this matter, after all if ‘it looks like lime and smells like lime’ it must be okay surely?! My agronomist or lime supplier can’t be wrong, can they?

Sadly, yes they can and this seems to be going on around the country as far as we can tell. Why is this important? Getting soil pH and soil calcium levels at the desired levels is fundamental to all cropping, whether arable or grassland, vegetable, fruit, flower or viticulture production. Once the levels start to decline the effectiveness of inputs also starts to decline and the return on investment declines alongside. The health of the crop suffers which results in an increase in inputs which are already under pressure. You can see this becomes an ever-decreasing circle of increased cost and decreasing output.

Focus on the detail of the basics and the output and profitability will follow. In order to substantiate the claims above please read on to discover the fundamentals of why and how lime works to ensure you are spending your hard-earned cash wisely. 

Neutralising value

NV is a figure given to the potential of a lime to neutralise the free hydrogen within the soil. The figure is based upon pure Calcium carbonate equivalence. A high-quality limestone will have an NV of 55. As stated above this is the potential of the product to neutralise the hydrogen ions in the soil solution which cause acidity. To give this some perspective consider the photograph below. This is oolitic Cotswold limestone as found in my garden and sold from many local quarries as a liming material.

Both the lump of rock and the ‘crushed’ pile are derived from the same piece of rock. I simply smashed a larger piece of rock with a hammer a few times to achieve the ‘crushed’ sample. Both of these samples, the lump of rock and hammer produced ‘crushed’ sample will have an identical NV. If lab tested I suspect it would have an NV of ~50. So which one is going to be more effective at neutralising acid pH soil? If the only information given to you by the lime supplier is NV, you could receive lime like that on the left, or on the right. NV is only part of the story.

So, taking the example above the ‘crushed’ sample on the right will work faster at reducing the soil pH because it has a much larger surface area and is therefore more reactive. The piece of rock on the left will do very little, if any, neutralising in a time scale that matters to you. The timescale for good neutralising is weeks to months if the lime is correctly ground, or years to decades, if larger than 0.6 mm.

Grind size

As mentioned above we now know that grind size is as important as neutralising value in determining whether the lime will actually do as intended. This is where the fertiliser Regulations 1991 become relevant because they set out the standards for lime quality as a fertiliser. If we consider these regulations for a moment it is clear that both the neutralising value and the specific material name must be given, in addition the percentage by weight passing through a 150 micron sieve must also be declared (the grind size). A limit of variation (tolerence) of 5% is allowed.

By grinding the rock finer we are increasing the surface area of the product. It is this increase in surface area which allows the lime to react faster and bring about quick reductions in soil acidity. If we calculate the degree of grinding and surface area we can see from the table below that ground limestone has a surface area nearly twice that of screened limestone, while prilled lime products can be four times the surface area of screened limstone. This increase will give greater reaction and therefore faster pH reduction.

So how fine does the rock need to be ground to be effective? The aglime website states that “coarser material requires a heavier application” and that “There is a considerable reduction in the effectiveness of liming materials containing particles above 600 microns (0.60mm, 60 mesh) unless the material is easily broken down”

This is supported by work taken from North Carolina University in the US shown top right;

This graph clearly demonstrates that lime in the range of 0.177 – 0.150mm (177-150 micron or 80-100 mesh) gave the quickest pH rise and most sustained pH rise. The larger particle size 0.841mm and above gave a very limited pH increase and took 18 months to achieve it.

Another response I have had is “I have been using the same products for years and never found a problem”. There are two responses to this proposition;

1, you have been using a good quality product all along; or

2, soil pH testing generally occurs every 4-5 yrs in line with regular soil analysis. Suppose that your soil testing shows a pH of 5.9 and you decide to apply lime in accordance with the recommendations, this will be around 8 tonnes/ha for a medium soil (RB209). But the product you use is of low quality and does not meet the specification. This will have little effect in raising the soil pH but you don’t go back to test again for another 4 yrs. This time around the soil test is registering around pH 5.8. You are almost expecting this as we are programmed to expect the pH to be low after 4 yrs of no lime so you go through the same routine again and again. But if you had used good quality ground limestone you may find that the pH has not dropped so far and therefore less is needed.

You may also find that output increases while your inputs decrease as crop health improves. But why doesn’t the pH drop lower 4 years after an application of low-quality lime? pH is a logarithmic scale which mean that each point difference in pH the hydrogen ion concentration changes ten-fold as shown in the table below. Therefore the number of hydrogen ions that need to be neutralised by the lime increases ten-fold for each unit drop in pH.

Cost comparison

If a routine application of granulated limestone extended to 200kg/ha/yr of product. Product cost is £125.00 tonne, the product cost is £25.00/ha plus a farmers spreading cost of £7.00/ ha. Total cost £32.00/ha To get an equivalent amount of useful lime from the sample shown at the beginning of this article assuming 10% fits through a 0.6mm sieve would require 2 tonnes/ha of aglime. Assuming a cost of £25.00/tonne delivered and spread. The total cost would be £50.00/ha. 

The way forward

I am not saying don’t use lime, quite the contrary, lime is essential where required, but pay special attention to the quality if buying ground limestone. There is a downside to using good quality ground limestone and that is watching your neighbours benefit from your investment if your lime spreader turns up on a windy day. For the most cost-effective lime applications I suggest regular (annual or bi-annual) small applications of a granulated lime. You can apply it yourself with your own machinery, it’s 95% finely ground lime, and best of all, every penny that you spend on it will work for you.

By Ralph Early (ralph@theethicalfoodie.co.uk)

Part one of this two-part article on agricultural ethics set out a thesis which argued that the development of farming as
an industrial activity during the 20th century, aided particularly by dynamic and commercially advantageous sciences and technologies, has brought us to a point where agriculture itself now presents a substantial threat to the natural world.

This is indisputable.

The UK’s State of Nature partnership’s 2016 report cites, for instance, that farmland birds have declined by 54% since 1970, while butterflies as an indicator of the wider countryside have declined by 41% since 1976. Sadly, many species of wild plants and animals indigenous to the UK have been subject to extirpation as a consequence of various farming and land management practices over the last century, while some of the country’s most iconic wildlife is threatened by extinction. People, like wildlife, need the land.

The health of the land as a resource for human food production, and the linked capacity for wildlife to flourish, depends on an abundance of biodiversity: the biomass necessary for nature’s ecological processes to function properly in maintaining the vigour of the land and nature itself. Isabella Tree comments in her book, Wilding, saying that Britain is “among the most naturedepleted countries in the world”.

It seems that Britain is on a path which risks possible ecological collapse, threatening the very food systems that support both people and wildlife. It is clear that if we do not rethink farming – and, it has to be said, urban planning which is increasingly defined by avaricious motives and corrupt Westminster politics – we may reach a tipping point where, for example, seemingly inexorable environmental decline and the loss of keystone species brings down the increasingly fragile house of cards that is our country, our wildlife heritage and our home. It is, after all, our choice.

Farmers are members of the moral community. They are moral agents. They have the capacity to understand moral concepts and to distinguish what is morally right from what is morally wrong. Indeed, by reference to objective moral values, which ideally calibrate their own moral compasses, farmers employ moral agency every day. They make decisions which are ethical in construction and which can be framed within the discipline of agricultural ethics. Such decisions may involve, for example, the management of farm staff, the welfare of farmed animals, the protection and preservation of the farmed and wider environment, the safeguarding of biodiversity dependent on farmland for survival, and interactions with those employed more widely in agriculture as well as others in the rural community, etc.

Indeed, there are farmers who, in the Greek philosopher, Aristotle’s conception, are incontestably virtuous persons. We can think of them as virtuous farmers who, by their character and intellect, are distinctive within the farming community. They cause good through their ideas and associated actions, serving as role models for farmers generally and for wider society. Many who read this article will know such individuals as exemplars of moral conduct within agriculture. They will be recognised as the people most likely to take the lead in rethinking farming to deliver the widespread ecological balances necessary to preserving the planet and achieving genuine environmental sustainability.

Farmers contend with many issues which embody moral dimensions. One of the most thorny is that of protecting and preserving the soil as the land, and the land as the countryside. Soil is essential to food production. Much of the quality of the soil we enjoy today was created by large herbivores grazing the land over the millennia, since the end of the European ice-age some 14,000 years ago. As a natural resource, soil is finite in terms of the amount available and its quality. In temperate climates, e.g. Britain, it takes about 4 lifetimes to produce 1 cm of soil, with around 10 lifetimes to achieve adequate levels of fertility.

We know that the nutrition quality of crops, e.g. cereals, fruit and vegetables, has declined over the last 50 years as soil quality has declined due to industrial farming and increased use of fertilisers, pesticides and irrigation. We also know that increased mechanisation and pesticide use have chased native flora, insects, birds and small mammals from the fields, while artificial fertilisers can trigger the eutrophication of water courses. British farmland soil is dying before our eyes and its capacity to produce food may not extend beyond another century. Yet supermarket strategies and the ambitions of governments place farmers under constant pressure to cut costs in order to produce cheap food. By utilitarian calculus, the production of cheap food may appear to deliver the greatest good for the greatest number.

However, given the intensive methods which farmers are often forced to use just to keep up, to what extent does cheap food policy diminish the soil and the land as our key food production resource? While farmers strive to feed people, an ethical lens reveals their undeniable moral obligation to preserve the soil, not just for use today, but as a resource upon which future generations will be dependent. The soil itself, and the land, are legacies of good which must pass from one generation to another and, morally, they should be preserved.

The protection of the environment and certain species can be achieved to a certain extent through legislation which frames legal rights. This may also reinforce moral rights. For instance, the hen harrier, with a UK breeding population of less than 1,000, is an endangered species protected by law. Hen harriers, individually and as a species, have a legal right not to be made extinct. The moral right of these birds to enjoy life and to flourish as a species is, though, not grounded in law. It is grounded in the fact that as moral agents we are able to know that hen harriers have the right not to be killed for sporting or commercial benefit and, consequently, to be forced into extinction. To do so would be an evil act. If we recognise the moral right of hen harriers to survive as a species, as rationally we ought because abundant biodiversity benefits humanity, ethically we and particularly land owners and farmers bear the correlative moral duty to ensure their protection.

Asserting moral rights for the protection of hen harriers constitutes an appeal to deontological ethics: an ethical domain concerned with notions of duty, rights and justice. The deontological philosopher, Immanual Kant (1724- 1804), stated that we ought to treat people as ends in themselves, not merely as the means to our ends: a value which is not necessarily restricted to the good of human beings. Normatively, when an animal species is facing extirpation or extinction we ought to respect the species as an end in itself and work to ensure its protection. It is the morally right thing to do and stems from the principle that abundant biodiversity is naturally good for nature and instrumentally good for human beings.

Land owners and farmers ought then to protect hen harriers, simply because it is morally right to do so. Such a notion of rightness by appeal to Kantian ethics can, however, also be applied to the protection of the soil and, hence, the countryside. Those who consider themselves as stewards of the land, take unto themselves particular moral duties or obligations. The claim of stewardship asserts an ethic of duty correlated with an ethic of care. To be a steward of the land, rationally and irrefutably implies a duty to care for the soil which constitutes the land. It follows that this imposes a duty to care for nature which co-exists with healthy and productive soils, as the land. In ethical terms, the soil ought to be regarded as an end in itself and not merely the means to the end of e.g. agricultural profitability. This then compels an intellectual shift which places priority on the soil for the common good of both people and wildlife, establishing, conceptually, the moral right of the soil to be preserved and enhanced.

Assigning value to the moral dimensions of agriculture by means of an ethical lens in order to support practical, on-farm decision making is not necessarily a simple and trouble-free activity. For instance, though we may assert the moral right of hen harriers as an endangered species not to be killed for commercial benefit, e.g. to protect grouse, how does this square with the fact that farmed animals are killed for food? Arguing from a hard animal rights position we may posit the philosopher, Tom Regan’s (1938-2017) view, that animals are subjects of a life and have inherent value: meaning, essentially, that their interest in living and enjoying life is fundamentally the same as that of human beings. Such a position demands, for instance, that animals have the right not to be eaten by human beings (although they may be eaten by other animals).

Meat eating is, however, a cultural norm in many societies and for many millions of often poor people, it can be an essential and not easily replaceable source of nutrition. There is not the space here to analyse the moral arguments for and against the human consumption of meat, but we should recognise that while the justification for granting hen harriers moral rights is based in the rarity of the species, commonly used domesticated food animals are abundant. Indeed, in evolutionary terms, we might consider their success is linked to the fact that they are food for human beings.

If animals are to be farmed, a fundamental moral principle which ought to govern methods of production concerns the ethical principle of nonmaleficence, meaning that whatever one does one should cause no harm. The utilitarian philosopher, Jeremy Bentham (1748-1832) expressed his concern for the well-being of animals, stating: “The question is not, Can they reason? nor, Can they talk? but, Can they suffer?”. Bentham was unconcerned about the use of animals to feed human beings. He believed though, that if they are so used, then as sentient beings capable of experiencing pain and suffering they ought to be kept in ways which prevent unnecessary suffering. Such a position coordinates with the Farm Animal Welfare Committee’s ‘Five Freedoms’, established in 1979, which express normative moral standards for ensuring the welfare of farmed animals: (1) Freedom from thirst and hunger; (2) Freedom from discomfort; (3) Freedom from pain injury and disease; (4) Freedom to express normal behaviour; (5) Freedom from fear and distress.

Agricultural ethics is a large and complex subject which, considered in detailed philosophical terms, can easily fill many text books. Consequently, some topics must be excised from consideration here. However, we cannot leave this review without considering examples of ethical issues which may affect farming in the future: particularly in light of Brexit and the British government’s apparent desire to replace EU policies and standards by integration with America’s corporate agrifood sector. The EU has long presented a barrier to certain patented US agricultural technologies, including, for example, GM (genetically modified) herbicide tolerant crops and genetically engineered recombinant bovine growth hormone (rBGH) (known as recombinant bovine somatotropin (rBST) in Europe).

In ethical terms, new agricultural technologies, which may present benefits and harms, ought to be weighed for approval on a case-by-case basis, objectively and independently of political lobbying and commercial pressures for approval. The EU employs the Precautionary Principle in such evaluations. It emphasises caution in advance and places the burden of proof of absence of unacceptable harms on vested interests seeking approval. However, some British MPs argue that Brexit will permit agricultural and environmental deregulation and they seek adoption of the Innovation Principle, which, in essence, means try it and if things go wrong, try to work out how to repair the damage. This is a morally dubious position.

The evaluation of new agricultural technologies should, of course, centre on scientific evidence, but it should also elicit appeal to different ethical theories. The moral right of people, animals and the environment not to be harmed solely as the means to the end of corporate profit can, for instance, be framed by deontological ethics. To give a few simplified examples, GM technology raises questions about the integrity of species and the right not to be altered by transferring alien genes. The use of routine rBGH injections with dairy cows to increase milk yields raises questions about a variety of consequential harms to cattle as well as the right of consumers not to drink milk containing increased levels of IGF-1 (insulin-like growth factor 1: a hormone associated with cancer in people)

The value of agricultural ethics to the evaluation of new agricultural technologies cannot be understated. It is an intellectual discipline which can provide clarity in problem solving through different ways of thinking. Importantly, it can cause difficult and often uncomfortable questions to be asked, but they are questions that should be asked. In this respect, agricultural ethics is a discipline which ought to be employed routinely by governments in decision-making affecting farming and food. Crucially, if agriculture itself is to continue to serve humanity long into the future, farming will need to adopt a continually reflective disposition which, assisted by ethical analysis, learns from the past in order to chart its path to a sustainable future. Fundamentally, if we as humanity are to survive – an outcome which is not obligatory – we must find ways to produce food which respect and benefit people, biodiversity and the environment. In this, agricultural ethics can play an unparalleled part.

Written by Chloe MacLaren As based on information found on Agricology (www.agricology.co.uk)

Chloe MacLaren is an ecologist at Rothamsted Research exploring how we can design resilient, sustainable cropping systems. Her PhD focused specifically on weed management, but now she works more generally on how different crops and management practices can be combined to maximise both productivity and environmental benefits. Chloe splits her time between the UK and sub-Saharan Africa.

For a long time, the pursuit of effective agricultural weed management tools and strategies was framed as ‘the war on weeds.’ We developed increasingly merciless mechanical and chemical weapons to rid our fields of unwanted greenery, striving toward a vision of pure crops from horizon to horizon.

These days, we’re slowly realising that war is not a helpful perspective on weed management. Sure, no one wants a field full of weeds, but not all weeds are bad, and sometimes the actions we take to get rid of them do more harm than good. That’s harm to both our farms and to our surrounding environment. Furthermore, weeds are proving to be irrepressible opponents; if they don’t like what is thrown at them, they quickly adapt, or a more tolerant species subs in from the sidelines. Making peace with the weeds will cost us less in the long run than trying to eradicate weeds from the fields.

The benefits of learning to live with weeds are illustrated by some recent studies showing that crop yield loss declines as weed diversity increases, and that retaining some weed cover can support beneficial insects as well as farmland birds. Perhaps most interesting is a study from France showing that some groups of weeds – typically diverse, and typically composed of small, lowgrowing species – have no detectable effect on crop yield at all, even when no weed management actions are taken.1 This, rather than weed-free fields, should be our goal.

How do we get there?

Managing weeds for net benefits rather than costs requires an understanding of why different numbers and types of weeds occur in different places, and what can be done to influence that. What, for example, led to the diverse, low-growing weeds occurring in the French study, and how can farmers obtain similar weeds in their own fields?

Current weed science is beginning to answer this question through exploring the ecological relationships between weeds and their environment (disturbance and nutrients) and other organisms (crops, livestock, and wildlife). In this blog, I would like to share some simple principles arising from the study of weed ecology that farmers can look to implement on their farms. These principles should help to reduce the likelihood of problematic weed outbreaks, whilst promoting beneficial weed diversity. 

Implementing each principle of ecological weed management should be done with the strategies and tools most suitable to everyone’s own farming system. They can fit conventional, organic or no-till systems, arable or perennial crops or livestock – although how you do it may be very different in each system. I have also shared a few practical ideas of how these principles can be put into practice, although the suggestions are by no means comprehensive (weed scientists have more work to do here, and many farmers may have better ideas about it than we do!).

A key point about following these principles is that they should not be extra work done simply for the sake of weeds. All could also be recommended for managing pathogens and insect pests, contributing to soil health, increasing resource use efficiency and improving yield stability.

Think of weeds as a reminder to manage the farm in a resilient, sustainable manner. Weeds keep us in check as we keep them in check; the more monocultures we farm, the more fertilisers we apply, the more we disturb the soil, and the more chemical tricks we use, the more weeds get out of hand in the long run. If we keep these things to the absolute minimum that we need to support crop or animal growth, then weeds will slowly become more manageable, and possibly even beneficial.

Increase diversity in all its forms

Crop rotation, crop mosaics, crop mixes, intercrops, forage mixes, integrated crop-livestock systems, organic matter sources, nutrient sources, hedgerows, margins, trees, wildlife, microbes. All these are avenues for farm diversification that help to limit weed numbers and to promote weed diversity, by varying conditions in space and time across the farm and landscape, and promoting the natural enemies of weeds. Diversification ensures that no weed species encounters uninterrupted favourable conditions that would allow its population to continuously grow. It also helps to sustain weed diversity, by reducing the chances that some species encounter consistently unfavourable conditions and are lost (think of cornflowers).

Diversification in farm practices can also reduce selection for weeds that behave like crops. The best way for a weed to survive a rigorous management regime is to mimic the crop: germinate with the crop to avoid tillage, tolerate the same herbicide regime as the crop, utilise the fertilisers applied to the crop. This means that the most competitive weeds – the ones that want the same resources at the same time as the crop – are most likely to survive intensive control. If the same crop is grown consistently, its weed mimics will thrive (think of blackgrass in winter wheat).

‘Little hammers’ not ‘sledgehammers’

The phrase ‘many little hammers’ has long been used to encourage diverse weed management practices, and it is increasingly apparent that those hammers must indeed be ‘many’ and ‘little.’ Really big hammers, such as using every herbicide and tillage tool you can get your hands on all in the same season, get rid of most weed species but can select for specific strategies that a few weeds use to avoid all of these. For this reason, variable germination times, fast growth rates and herbicide crossresistance underpin many of the most problematic weeds worldwide. Instead try to rotate tactics between years rather than using everything at once.* ‘Little hammers’ can also be used to shift weeds to more desirable types, by disadvantaging the weeds you don’t want.

For example, taller weeds tend to be more competitive, so tactics that kill tall weeds but allow short weeds to survive can promote a less competitive weed community – mowing, topping or weed wipers might be appropriate, depending on the farm type. *NB: to delay or avoid resistance to herbicides, the evidence so far suggests that using mixes of herbicides each year is better than rotating single herbicides between years, but rotating different mixes of different herbicides is better, and using non-chemical tools in rotation with herbicide mixes is best.

Reduce resource availability

Weeds will grow wherever there is enough nutrients, light and moisture, so try to reduce these opportunities. Competitive crops are a good way to capture resources and keep them away from weeds – choose competitive cultivars, sow as densely as appropriate, and consider intercrops or crop mixes. Combinations of crops with different growing times and growth forms can more effectively utilise available resources than single crops.

Minimise fertiliser applications, and where possible, use slow-release fertilisers (green manures and composted animal manures are a good example). This avoids a big flush of nutrients being available to weeds before the crops can make use of the nutrients. High resource availability also promotes types of weeds that grow quickly – their life strategy is to grab as many resources as fast as possible before anything else (like the crop) does, and this makes them more competitive. In contrast, low resource levels select for weeds that grow more conservatively and impose less intense competition.

Take advantage of the positive effects of weeds

Weeds help to support natural enemies such as lacewings, ladybirds and beetles that eat aphids and other pests. Some weeds also taste better to pests than crops, and help to distract the herbivores. Weed flowers and seeds, as well as the bees, the birds and the butterflies they support are all needed for wider ecosystem health. Weeds can help to shelter the soil from the weather, while leguminous weeds can provide free nitrogen and the long taproots of weeds like dock can bring nutrients up to the surface that will be available when the plant decomposes. Managing for a diverse weed community is the best way to maximise benefits while minimising competition with crops.

Of course weed control will always be necessary to some extent, but in some situations, the cost of the weed control (in terms of money spent, fuel used, soil disturbed and ecosystem function lost) may be greater than the cost of the weeds. The more we learn about weeds, the better we will be able to judge this, improving our capacity to maximise farm productivity and profitability whilst sustaining a healthy environment.

1Adeux G, Vieren E, Carlesi S, et al (2019) Mitigating crop yield losses through weed diversity. Nat Sustain 2:1018–1026.

Header image © Rothamsted Research

Visit www.agricology.co.uk to view this profile in full and see video footage of the farm. Agricology is an independent collaboration of over 40 of the UK’s leading farming organisations sharing ideas on sustainable farming practices. We feature farmers working with natural processes to enhance their farming system, and have a wide range of farmer videos on our YouTube page. We also share the latest scientific learnings on agroecology with the farming community from our network of researchers. Our website hosts over 400 articles on different agroecological practices. In response to social distancing we are hosting a series of online virtual field days on a range of agroecological practices in collaboration with our partners. Subscribe to the newsletter or follow us on social media @ agricology to keep up to date and share your questions and experiences with the Agricology community