Agriculture is a vital part of the UK’s economy, from supplying food and drink for domestic consumption, to the crucial economic and employment role it plays in supporting rural farming communities. It is also an important export for the UK – worth approximately £20.2bn in 2021 – and contributes considerable sums to the UK Exchequer. That said, the sector also accounted for an estimated 11% of the UK’s greenhouse gas (GHG) emissions in 2021, according to figures published by the Department for Business, Energy & Industrial Strategy in its annual UK Greenhouse Gas Emissions series.

Of its 11% contribution to GHGs, 58% of this was methane and 28% nitrous oxide. By contrast, agriculture accounted for only about 1.7% of total carbon dioxide emissions 2020. However, both methane and nitrous oxide are more destructive GHGs than carbon dioxide. According to NASA’s Vital Signs of the Planet, a molecule of methane traps more heat than a molecule of CO2 but has a relatively short lifespan of between 7 to 12 years in the atmosphere. Nitrous oxide is even more pernicious being nearly 300 times more warming than CO2 and stays in the atmosphere for an average of 114 years. Moreover, once there, it converts to nitrogen oxides that damage the ozone layer exposing the Earth to increased levels of solar radiation.

Methane emissions from agricultural activity are primarily derived from enteric fermentation (digestion processes) from livestock and from the decomposition of manure under anaerobic conditions. Nitrous oxide emissions mainly emanate from the use of synthetic fertilisers on agricultural soils. According to the report, although Agricultural-derived GHGs emissions have fallen by 12% between 1990 and 2021, they have since remained at similar levels. The question, thus remains, how does the UK agricultural sector continue to reduce its emissions of these two polluting GHGs?

Policy Paper

In its 2021 Policy Paper, ‘Net Zero Strategy: Build Back Greener’, the UK government outlined how it hoped to achieve its goal of reaching ‘Net Zero’ by 2050. While not addressing Agriculture directly, the subject was covered briefly in the section ‘Natural Resources, Waste & F-Gases’.  In it, the Government made some key commitments related specifically to agriculture and land management.

Among them that by 2030 75% of farmers in England would be be engaged in low carbon practices rising to 85% by 2035; it would increase investment in industry-led research and development into solutions to help deliver Net Zero in agriculture and horticulture, including through the Farming Innovation Programme; boost the existing £640m Nature for Climate Fund with a further £124m of new money; and work with stakeholders to increase the use of timber in construction in England to reduce embodied carbon – the amount of carbon emitted during construction of a building.

The detail of how the Government intends to address the agricultural net zero transition is set out in the Department for Environment Food & Rural Affairs (DEFRA) November 2020 report, ‘The Path to Sustainable Farming: An agricultural Transition Plan 2021-2024’.  The main theme of the report is the move away from EU-mandated ‘Direct Payments’ to farmers which, it is argued, ‘are arbitrary area-based subsidy payments…where the largest subsidy payments too often go to the wealthiest landowners,’ with the implication that these funds provide little incentive for farmers to adopt more sustainable practises. Instead, since 2021, DEFRA, has chosen to reduce – and eventually stop – Direct Payments, preferring to use funds saved from the EU scheme to pay farmers ‘to improve the environment, improve animal health and welfare and to reduce carbon emissions.’  

To achieve this aim, it has introduced a new Environmental Land Management policy, which has three main schemes. These are the:

·        Sustainable Farming Incentive Scheme which pays farmers to manage their land in an environmentally sustainable way.

·        Local Nature Recovery Scheme will pay for actions that support local nature recovery and meet local environmental priorities. The scheme began piloting in 2022 and will launch in 2024.

·        Landscape Recovery Scheme will support landscape and ecosystem recovery through long-term projects such as: restoring wilder landscapes, large-scale tree planting, and peatland and salt marsh restoration. The scheme began piloting around 10 projects in 2022 and will launch in 2024.

These schemes are intended to support the rural economy while achieving the goals of the Government’s ‘25 Year Environment Plan’ and a commitment to net zero emissions by 2050.

With the Government’s policy on agricultural net zero transition now in place what practical steps can those working in the sector do to reduce their emissions? Especially, because although the Government’s Agri-Climate Report 2022 says nitrous oxide and methane emissions have fallen since 2000, this was largely down to a reduction in the number of cattle and sheep.

Over the same period, rates of arable-derived emissions have largely remained stable. And while shrinking the agricultural sector is one way of reducing its GHGs, it would surely be a textbook case of throwing the baby out with the bathwater. Fortunately, there are other solutions to reduce GHG emissions from agriculture, some technology-based and some based on taking a more traditional – less industrial – approach to farming.

Methane reduction

The main sources of agriculture-derived methane come from cows burping out the gas as they feed and the escape of fugitive methane from manure and slurry lagoons. To address the former, one company, Zelp, has developed a cattle-wearable technology that reduces methane as it egresses from the animal. The device sits around the cow’s head and as it exhales, methane in the breath travels through a catalyst where it is oxidized and released into the air as CO2 and water vapor.

The company claims the device reduces methane emissions by 60% and can, importantly, be used in all livestock systems – currently 95% of the world’s 1.45bn cows spend part or their entire lives on pasture, according to the UN’s Global Livestock Environmental Model. Though not yet commercially available and with no prices published, the company says it is committed to ensuring the device is available to all farmers.

Other agritech companies have taken a different approach deciding instead to focus on feed solutions, which typically work in one of three ways: reducing the number of substrates for rumen microbes to live on; eliminating the methane-producing microbes or disrupting the methane production process; and re-directing hydrogen away from the methane-producing process.

Companies taking this approach are Mootral, Future Feed and Agolin, among others.  Mootral has developed a natural feed supplement, Mootral Ruminant, made from garlic and citrus extracts which the company claims reduces methane emissions by up to 38%. Future Feed’s solution uses Asparagopsis seaweed as a food additive which contains bio-actives that the company claims significantly reduces cow gut microbes’ ability to produce methane. And Agolin has developed a botanical food additive, Agolin Ruminant, that reduces the hydrogen available to gut fauna for methanogenesis which, the company claims, reduces methane emissions by 15%. Additionally, biotech company, Synomics, is taking a third approach to cattle-derived methane emissions. Its solution is to use AI and genomic data to develop herds that genetically produce less methane.  

Hungry bacteria

Livestock agriculture produces a great deal of waste organic matter – especially in the form of manure from cattle which is often swept into open air slurry lagoons. Bacteria feed on this waste in a process called anaerobic digestion producing methane as a by-product which escapes – fugitively – into the atmosphere. Cornish company, Bennamann, addresses this issue with a solution that encloses the lagoon to capture these escaping gases.

Once captured, the methane is then processed into CFM (Compressed Fugitive methane and LFM (Liquid Fugitive Methane) for use as carbon-neutral biofuel. Additionally, the material left behind in the lagoon – known as a digestate – is further processed and spread onto the land which reduces the need for artificial fertilisers. Alternative methods of reducing methane from slurry lagoons include covering them with permeable materials such as wood chips, acidification of the lagoon to inhibit the growth of methanogenic bacteria or adding additives to the lagoons to change its composition and capacity to produce methane.  

Nitrous oxide

For years farmers around the world have used synthetic fertilisers on their land to increase crop yields and to improve soil fertility. Cheap and plentiful, they have proved an economic and successful solution. The downside, however, is that both in their production and application they have led to a rapid increase in the GHG nitrous oxide.  

Traditionally, synthetic fertilisers are produced by combining nitrogen in the air with hydrogen in natural gas at high pressure and temperature over a catalyst – the Haber-Bosch process – to produce Ammonia, the main ingredient of nitrogen-based fertilisers. However, this process is extremely energy intensive and not only uses fossil fuels as an ingredient but also to power the process itself – releasing CO2 into the atmosphere as it does so. It is estimated the process accounts for 1.4% of global CO2 emissions and 1% of the world’s total energy production. Further, the reaction is not 100% efficient and nitrous oxide is formed as a by-product and released into the atmosphere.  

Secondly, when over-applied to agricultural land synthetic fertilisers’ high levels of nitrogen are not absorbed by the target plants and the excess is converted by soil microbes into nitrous oxide. Furthermore, they can disrupt localised microorganisms from cycling organic matter into plant nutrients – lowering soil quality – and, after heavy rains, can leach into watercourses causing further unwanted knock-on effects.  

Happily, there are new technologies in the pipeline that promise the production of ‘green’ fertilisers by replacing hydrogen from natural gas with hydrogen from water and using renewable energy sources to power the process. Among the companies pursuing this approach are fertiliser manufacturers such as Yara and Fertiberia and green energy companies including Siemens Energy, Iberdrola, and Hive Energy. Yara claims that its solution reduces the amount of nitrous oxide produced in synthetic fertiliser manufacture by 90%.

While some companies pursue technical solutions others advocate a fundamental change to current farming practises. In its latest report ‘Fixing Nitrogen – The Challenge for Climate, Nature and Health,’ the Soil Association is unequivocal in its conclusions on how to reduce the environmental impact of excess nitrogen: ‘The underlying urgent issue remains the need to dramatically reduce the quantity of reactive nitrogen being released into the environment through the creation of synthetic fertilisers.’ The solution, they say, is a return to more traditional – and less intensive – form of farming they call ‘Agroecology’. Agroecology, says the report, promotes ‘practices which cycle nutrients through animal manures and nitrogen fixing crops and avoids synthetic fertilisers.’

A digital future

Another way, advocates claim, where science can play a role in the reduction of agriculture-derived emissions is to use Digital Farming or Precision Farming techniques. These techniques use technology such as real-time nitrogen sensors, drones, and satellites that feed data into computers to provide farmers with information on soil health, optimal fertiliser blends and planting timings – enabling them to farm more efficiently, sustainably, and profitably. Bayers’s Climate FieldView and Yara’s AtFarm are two examples of these systems.

Environmental issues are continuing to gain traction in the public conscience – particularly when it comes to the cost to the planet of food production and consumption. And this is an important area that could provide additional impetus for the agricultural sector to really push its environmental credentials.

Downloadable apps like Floop, Reewild and Capture already enable consumers to see the climate effects of the foods they eat. With Reewild, by staying below a preset Carbon Calorie goal, users are rewarded with exclusive discounts to sustainable partners. While these apps and others are still in the early days of their development and accuracy, it does point to a future where demand pull could reward those producers with the lowest environmental footprints.

Allied to this is food labelling. While there is currently a glut of information printed on the back of the packets of food we buy, none of them relate to the environmental effect of its production. However, the government’s new Food Data Transparency Partnership (FDTP) could change this. It has been tasked to develop a system to measure and communicate Scope 3 emissions – those along the entire food and drink supply chain – and to establish a mandatory methodology for voluntary food eco-labels. Together with mobile apps, a new labelling regime could dramatically change consumer buying habits in years to come.

A way forward

There is now a clearly defined policy framework for the UK agricultural sector to reach Net Zero by 2050. But, as we have seen, problems remain: None of the solutions to methane reduction claim to be 100% effective and, unless there is a total cessation in the use of synthetic fertilisers, nitrous oxide emissions will remain on-going problem. Thus, there are still multiple opportunities for agritech other technology companies to find solutions to these important issues.

What will ultimately provide the incentive for producers – and the innovation of agritech companies – will be the market. In years to come an increasingly tech-savvy and environmentally aware generation of consumers will be able to see the precise cost to the planet of any potential purchase and may reject them outright. And those producers not measuring up will simply go out of business.  

Lastly, if as a country we are to produce food and drink with net zero emissions, this will inevitably result in an additional cost burden to producers. The problem for Government is then ‘how to protect domestic producers and suppliers from cheaper imports that have not been produced to the same environmental standards?’ That is a question that is beyond the scope of this article, but its solution will be crucial if the Government is to fulfil its 2050 Net Zero pledge while retaining a sustainable and thriving domestic agricultural sector.  

This article has attempted to outline the primary environmental challenges facing the UK’s agricultural sector as it attempts to a navigate towards net zero production and supply. While doing so, it has inevitably raised as many questions as it has hoped to answer. So, this is where you come in. Please join us in the GTT Agritech Forum to contribute your thoughts on the issues arising from UK Agriculture’s goal of achieving Net Zero by 2050. #