How a Cornish dairy curbed its carbon footprint

While cutting carbon emissions has come into focus over recent years, it has been a long-term priority for Cornish dairy farmer Andrew Brewer.

Farming in partnership with his wife, Claire, Andrew runs a 450-head crossbred, autumn block-calving herd at Ennis Barton, near Fraddon, rearing all its own replacements, and fed on a pasture-based diet of mainly herbal leys.

“We aim to graze with cows 365 days a year – even if it’s only for three hours a day.

We’ve got a competitive advantage in Cornwall that our milder winters means grass keeps growing, so if we can keep that grass in an active state, it’s still harvesting carbon and utilising that in the soil,” says Andrew.

“We’ve been using mixed species swards for almost 25 years, starting way back when we were outwintering stock and spring calving, so we’ve seen the benefits [in terms of carbon] of that for a long time.”

See also: How Cornish farms are innovating in bid to reach net zero

Carbon auditing

Why such a long-term focus on carbon? “Carbon footprint and profitability are pretty intrinsically linked,” he states.

Andrew carried out his first carbon footprint about 10 years ago, and has since repeated this regularly, with his most recent being carried out via the Farm Carbon Toolkit platform last year.

As well as this, he was part of the Soil Carbon Project, which ran from 2018 to 2021, and was launched to enable farmers to manage soils in a more sustainable and profitable way.

Andrew says he used this information to shape decision-making on farm.

“[To summarise,] I’d say we’ve gone from maximisation to optimisation. As an example, we used to use a lot of nitrogen – up to 300kg/ha – but now we’ve used no bagged [fertiliser] for four years.”

Instead, Andrew says he looks to clovers to fix nitrogen instead.

He uses grasses and herbs that provide resilience to forage production and grazing, as they do not dry up in summer, and they keep going through the winter.

Andrew Brewer © Farm Carbon Toolkit

Using herbal leys

Andrew says that growing a range of herbal ley mixes is vital to suit the varied soil types.

“For example, plantain is quite a vigorous weed in Cornwall.

“If I can get a well-bred weed, it’ll survive, so we use quite a bit of that – as well as red and white clover – and I do like a small amount of cocksfoot, festulolium and chicory,” he explains.

“Having different species with various rooting depths really allows us to utilise more of our top soils. Species like chicory can put down really big root systems – we’ve had them blocking land drains at 6ft [2m] deep.”

Ley management is through paddock grazing during summer and on-off grazing throughout the winter, which sees cows turned out after morning milking and brought in again at lunchtime.

A small amount of pre-mowing is done to ensure the quality is retained, he explains.

Grass growth and quality are measured weekly, with results used in the GrassCheck GB network, which uses grass samples and weather station data to predict grass availability.

Incorporating diverse leys in the rotation has not been to the detriment of production either: “We’re producing as much milk as we were when we were milking 150 more cows.”

With good-quality forage providing the basis of much of the diet year-round, Andrew has also been able to minimise his bought-in feed, further reducing his emissions, with only 700kg concentrates fed a cow a year.

Sequestration

As well as cutting carbon emissions, Andrew has also been seeking to sequester carbon where possible. This has included planting trees and hedges.

“We used to trim hedges annually, but we’ve got big hedges full of carbon in Cornwall, so we’ve now moved to much less frequent trimming to let them grow a bit more.”

He has also carried out a number of trials to better understand how much carbon he is sequestering in the soils.

This has included growing vegetables (savoy cabbages and potatoes) on the milking platform as a ground preparation technique for reseeding and looking at the impact on soil carbon levels.

“In one trial, we found that when we took a crop of vegetables off a field, the amount of carbon we sequestered halved our carbon footprint.

“If we can produce more human-edible food and sequester carbon by doing it, we’re winning from an environmental point of view, but also feeding a growing population.”

Andrew is also measuring pH, phosphorus, calcium, potassium and magnesium.

“This gives us a really good picture of our soils, which lets us be far more specific with what we do apply.

“For example, we’re using far more calcium than ever before – about 1t/ha on grassland where needed and 2.5t/ha on beet land,” he says.

“Nitrogen is great, but it covers a multitude of sins because it’s the easy option. If we can keep our crops healthy with the right nutrition, then there’s far less likely chance of a yield penalty.”

The accumulation of his environmental endeavours means his most recent carbon dioxide equivalent (CO2e) for a kilogram of fat- and protein-corrected (FPCM) milk sits at 0.67kg – well below the UK average of 1.2kg.

However this figure does not encompass the increases in soil carbon, which is being monitored through the Farm Net Zero project Andrew is involved in.

Andrew Brewer (far left) has developed rotational grazing to include herbs © Farm Carbon Toolkit

Carbon Farmer of the Year

In recognition of his continued effort to improve the sustainability of his farm, Andrew was recently crowned the 2024 Carbon Farmer of the Year – a competition run by Farm Carbon Toolkit.

The organisation’s Rob Purdew says the accolade was awarded as a result of Andrew and Claire’s long-term commitment to reducing emissions.

“He’s proven that it’s not just a box-ticking exercise – it has really benefited his business.

“Andrew has got a real understanding of emissions, which some struggle to get their heads around, and he has applied that to all aspects of his business.”

Andrew’s environmental endeavours are far from over. He says he is planning to plant more trees (with a target of 9,000) across the farm, and has recently received planning permission to put up solar panels, with sheep grazing underneath.

“If we can maintain our methods of rotational grazing under the panels, we’ll have very little loss of production.”

Reflecting on his journey over recent years, Andrew says that the most difficult thing to change is the mindset of the person – not the farm.

“I used to think I couldn’t farm without nitrogen, and now I wonder why I did [farm with it].

“My biggest piece of advice to anyone else starting out on this journey is to understand your soils, because that’s what drives your business.

“We can always be better; we can always do a little better. Change is always a good thing.”