Carbon audit highlights priorities for net-zero success

A 10-year sustainability plan put in place just over a year ago at Squerryes Estate in Westerham, Kent, has provided a framework for the business as it navigates its way through the agricultural transition.

With six priorities – access, community, terroir, ecology, flooding and carbon – the plan was developed to show how the estate could continue to create joy for future generations; reflecting its motto “Licet Esse Beatis” (it is permitted to be joyful).

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Owner Henry Warde explains that the sustainability plan encompasses everything that is important to the 1,000ha estate, which has already diversified into sparkling wine production, retail and hospitality to increase revenues and complement its arable farming operations.

“We’ve got our sustainability goals – now we need a baseline for our farming activities so that we make the right decisions about improving our position, reducing emissions and delivering progress,” he says.

“Having set out our aims and ambitions until 2031, we need to make the year-to-year changes that will help us to achieve them.”

Carbon audit

For this reason, Mr Warde opted to carry out the carbon emissions and efficiency audit on offer from the Future Farming Resilience Fund, which was set up by Defra to offer free support and advice to farming businesses.

The audit, by Ceres Rural, was done on the 400ha arable enterprise, with the aim of focusing on the farming practice, not the wider estate.

Cropping at Squerryes includes winter wheat, winter oilseed rape, winter and spring beans and winter oats, along with a small area of forage maize in some years for a local anaerobic digestion plant.

Cultivations are being reduced, wherever possible, without compromising yield.

The farm is moving away from rotational ploughing and min-till techniques as direct drilling is trialled on suitable fields – the first crops established in this way will be harvested later this year.

In line with most arable farms, the carbon audit identified nitrogen fertiliser as the main emissions culprit, accounting for about 80% of the farm’s carbon footprint due to the nitrous oxide emissions arising from its use.

Henry Warde © Squerryes

Other areas, such as fuel use, were contributing much less.

“Overall, emissions were 50% higher than the net-zero position we would like to get to,” reveals Mr Warde. “Discovering that figure gave us the impetus to start to get the balance right.”

The audit also showed the effects of reducing nitrogen rates by up to 40kg/ha, for example, as well as how the use of cover crops could help to retain carbon in the farming system.

“It explored various scenarios, so that we could make decisions relevant to our situation.”

Recommendations

The carbon audit report produced by Ceres Rural contained recommendations for the farming operation, many of which are now being implemented.

These include making rotational changes, using digestate on the farm, looking for other ways to reduce reliance on bagged nitrogen fertiliser and introducing techniques to improve nitrogen use efficiency.

A focus on soil health has also been implemented, so that soil organic matter levels improve and nutrient cycling starts to take place.

“The start was a good look at the rotation,” explains farming consultant George Catchpole of Ceres Rural.

“Beans came in to replace second wheats and provide a fertility benefit, cover crops have been introduced ahead of spring crops for their ability to scavenge nutrients and improve soil function, and maize is being dropped due to soil damage concerns.

“The use of digestate was also recommended to improve soil health and provide nutrients, mainly nitrogen and potassium, while reducing bagged fertiliser costs,” he adds.

© Tim Scrivener

In addition, fertiliser applications are now being matched to yield potential and crop requirements, so that inputs and outputs are more closely aligned.

“Targeting of fertiliser is an easy win,” adds Mr Catchpole. “Not only by reducing rates on less-productive sites, but also by using fine-tuning techniques such as sap testing and leaf analysis.”

Mr Warde confirms that these initial actions are under way.

“Being able to discuss the recommendations with Ceres Rural has been very helpful and I’m now getting my head around more regenerative practices.”

Other opportunities

The report also highlights future opportunities for reducing emissions and for carbon sequestration.

For this, it included other areas of the estate, looking at the role of hedgerows and field corners, not just the productive arable land.

“Some of these areas on the farm are hiding in plain sight,” says Mr Warde. “They help to simplify the decision-making between carbon and economic crop production and will have a role in delivering public goods.”

Already, there are two woodland Higher-Tier Countryside Stewardship agreements in place, as well as a Mid-Tier Countryside Stewardship scheme on arable and grassland.

The farm is also in the Darent Valley Partnership, a large-scale initiative working at scale for nature recovery and one of Defra’s selected Landscape Recovery projects.

“Small changes made at the farm level can have a big effect,” says Mr Warde.

“Being part of a project like this shows the potential of what can be achieved when we work with others, and highlights what more can be done.”