Opinion: The road to reach net zero
© Tim Scrivener The year 2040 may seem a long way off.
But it will soon come around and, by then, UK agriculture should be approaching our collective net-zero target set by NFU president Minette Batters at the Oxford Farming Conference in 2019.
The NFU represents some 60,000 UK farming businesses, and there remains a good deal of scepticism, even among its members, about this ambition.
But the reality is that the UK government has already enshrined a national target of 2050 in law.
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As farmers, we will increasingly come under pressure to demonstrate a climate-neutral direction of travel.
Not just from the government, but also from consumers, retailers and the banks and insurers with whom we do business.
Soon, consumers will eschew high-carbon products; banks will charge more interest to businesses with no plan for emissions reductions; and downstream businesses will require carbon insetting as part of any commodity contract.
In addition, climate change is already wreaking havoc: we must decarbonise because the alternative is unthinkable.
So what can a simple farm business do? There are two types of carbon accounting on-farm: those related to our emissions and those to our ability to sequester.
Decarbonisation
It might be tempting to think that we can sequester our way to net zero, and perhaps some farms can – some low-input graziers, especially in the uplands, may already be demonstrably in a carbon-negative position.
But for the majority, a huge element of farm decarbonisation will by necessity come from the reduction of emissions, or contribution to renewables generation.
It is worth considering that some 75% of the average UK arable farm’s emissions come from its fertiliser applications, while a similar percentage of the average livestock farm’s come from the livestock themselves and their manure.
Nationally, we only sequester some 2% of our annual emissions across all land-use types, including forestry; even if farmers claimed this entire amount for ourselves, that’s currently only offsetting 20% of our own emissions: we’re a long way from saving the world.
Allerton Project
At the Allerton Project, we’re devoting much time to researching how farms can reduce emissions and how we can sequester more carbon on-farm both in biomass and soil.
One flagship project is our long-term conservation agriculture trial in partnership with Syngenta, now entering its sixth year.
Across a five-field, four-crop rotation, we are comparing the difference between continuously ploughed, min-tilled and direct-drilled scenarios on our heavy clay soils.
Despite overall yield reducing by some 8% across the rotation, our overall net profit/ha is improved by 19% as a result of significant 47% fuel-use reductions, an increase in work rate of some 48% and a reduction in operational costs of 10%.
We have also seen a reduction in soil greenhouse gas emissions of 20% between the two systems.
Results on a lighter-land comparison site have been even more favourable, with an increase in profit per hectare of a remarkable 36%.
Simultaneous research elsewhere at the Allerton Project is also demonstrating a 10% increase in soil organic matter after a decade within a “conservation agriculture” system – one without the turbocharge of significant volumes of manures being returned to it.
Together, this is very promising data demonstrating the dual benefits to such a system of both reducing emissions and sequestering more soil carbon, while making more money.
Even if farmers are not of a desire to “trade” in soil carbon credits (and who would blame them in the current marketplace?), the benefits of increasing soil organic matter are reason enough to make the journey, essential as it is to soil productivity, health and structure.
For example, we can demonstrate a straight-line correlation between organic matter levels, compaction and water infiltration and storage.
Hedgerows
In other green capital, the Allerton Project is currently developing a Hedgerow Carbon Code, which from next year will sit alongside the Woodland and Peatland Carbon Codes as quality-assured schemes backed by government.
In England alone, 550,000km of hedgerows store some 9m tonnes of carbon worth £65m at today’s base price.
Although additionality will be key in unlocking future payments, soon hedges managed for both biodiversity and carbon may start to provide a valuable income stream to many farms, helping cushion loss of direct payments and the poorly funded Sustainable Farming Incentive.
On the livestock front, we are conducting trials into the feeding of willow leaves to ruminants, which are showing great promise in reducing the amount of volatile and polluting nitrous oxide, carbon dioxide and ammonia in their urine, while also showing benefits for intestinal health.
Alongside our work on deep-rooting grasses and diverse herbal leys and their potential to sequester more carbon, deeper into the soil profile, we are hoping to demonstrate that nature-friendly, sustainable and profitable food production can exist side-by-side in a thriving rural landscape.