Carbon-friendly farming techniques

How can farms be optimised to sequester carbon, without sacrificing productivity?
31 August 2021

Interview with 

Becky Wilson, Farm Carbon Toolkit & Sophie Alexander, Hemsworth Farm


A red barn in a farmer's field


The Cambridgeshire Fens pose some unique challenges for farming in a carbon friendly way. But across the country, farmers are going to be vital as we push to make the UK net carbon zero by 2050. Agricultural land makes up about 70% of the land area in the UK; that’s a massive potential area for storing carbon. Becky Willson is the technical director for the Farm Carbon Toolkit, a farmer led organisation that’s translating all the carbon sequestration research into simple, practical management techniques that farmers can implement. She spoke with Sally Le Page who wanted to know, right now, do farms tend to be net emitters or net sequesters of carbon?

Becky - There are a complete mix of activities that happen on a farm. Some of those will be emitting greenhouse gas emissions, and then depending on how we manage our landscapes in terms of what we're doing with cropping and cultivation and grass, all that sort of thing, that will be pulling carbon in, out of the atmosphere in terms of being held in our soil. For the vast majority of our farms, a lot of those processes that are taking place on farms in terms of how we apply our fertiliser, what we're doing in terms of livestock management and other bits and pieces, are generating those greenhouse gas emissions. Those emissions that are going back up into the atmosphere that are causing climate change. But farming is unique in its opportunity to actually provide one of those climate solutions, depending on how we manage our land.

Sally - Can you tell me how can a farm draw down and store carbon from the atmosphere?

Becky - There's two key areas that farmers need to really focus on. Firstly, it's protecting their asset that they've currently got in terms of the carbon that's already in the soil. Soil is an incredibly large carbon store and we need to make sure that we protect that existing carbon and don't release it back up into the atmosphere through our management practices. That's area number one. Area number two is then looking at understanding how much carbon we've already got and then looking at the potential that we have to improve that. That improvement comes very much down to how we're managing that land. If we're talking about a cropping based system, it's very much focusing on what we're growing in terms of the length of time that the crop's in the ground, how diverse that rotation is. Are we growing the same crops over and over again, or are we making sure that those times that we're not growing those annual crops we're protecting that soil and we're covering it through the use of cover crops? How often we're disturbing that soil.

Sally - Why does ploughing make a difference?

Becky - Ploughing makes a difference because when we turn that soil over, which is the action that we have through plowing, that sudden flush of oxygen that goes into the soil that has been nicely asleep underneath, suddenly stimulates the soil bugs that live within the soil to respire madly. Obviously a byproduct of respiration is carbon dioxide, which goes back up into the atmosphere. If we move over to our livestock systems, which predominantly are focused on grass, quite often the question and the discussion there is because we've got crops that aren't cultivated every year, because grass tends to be down for many seasons, is there potential for those areas to be able to sequester more carbon? Then it very much comes down to how is that grass now being managed? How are you grazing it? Are you continually stocking? So, you're putting the same number of animals on that grassland and leaving them there throughout the whole grazing season or are we actually starting to move those animals around? What species are in that grassland? There are lots and lots of opportunities, but it very much comes down to management. The really exciting thing for farmers is actually there is really good correlation with improved soil carbon and improved soil function. Actually, if we can pull more carbon into our soils, we're actually going to get a much more healthier functioning soil, which is going to be able to hold more water when we're in these periods of drought. To be able to do all the things that actually allow us to have this really healthy functioning soil ecosystem that not just provides brilliant food quality for us as consumers, but also allows those farmers to have a real resilient business that can deal with these different climatic conditions that are coming.

Sally - Farmers aren't helping us save the climate at the expense of their farm business? It can actually help their farm business too?

Becky - Definitely. That's what's been really exciting over the last few years with the farmers that are starting to really get on board with these sort of practices. They're seeing that they may not be achieving record-breaking yields, but actually the inputs and their costs that need to go into generating those yields are much lower. There are significant economic benefits that can be had, and also as I say, we are generating those benefits in terms of soil health and resilient ecosystems for the future.

Sally - Do you have any figures or numbers after farms have implemented some of the suggestions from the Farm Carbon Toolkit? How they've reduced their carbon emissions or even gone carbon negative?

Becky - Absolutely. On all farms that we work with it's fairly simple to reduce their carbon footprint by about 10%, all those things, which actually are just efficiency measures. I challenge every farm. Every farm can reduce their carbon footprint by 10 to 15% without having to make any significant changes. We've got farms that we've also been working with over the last few years, which we have transitioned from being a net emitter to a net sequesterer. Taking a hundred cow dairy unit, taking it from contributing about 815 tons that's then sequestering about a hundred tons, so removing about 900 tons out the atmosphere. Also within the arable sector; those farms which have been emitting anything between about five and 600 tons, taking those to sequestering 200-300 tons. It is possible.

Sally - That's an incredible difference.

Becky - It is, and that's about taking account of what's going on within our soils, because what's important to remember is that you don't have to be doing a huge amount of building organic matter to actually be sequestering a lot of carbon, the numbers can be quite staggering. If you can build your soil organic matter within your soil 0.1%, that sequesters an additional nine tons of carbon per hectare

Sally - At the moment the farming sector as a whole and the food production sector does contribute a large amount of the UK's greenhouse gas emissions. With changes in land management do you think that overall it will be able to actually remove carbon from the atmosphere? Be a net carbon negative for the UK?

Becky - I think it's a challenge. We've always got this issue in terms of the fact that we're not just producing these emissions for the sake of producing these emissions. We're producing these emissions because we're producing food. Agriculture is responsible for about 9% of total emissions from the UK. Yes, we are a significant sector, but we do have some of these solutions. To offset all of our emissions with the current technologies that we have out there, it's going to be a real challenge, but just because it's going to be a challenge doesn't mean that we don't need to have a go. I think that's really trying to highlight the benefit that actually improved soil health will not just improve carbon sequestration, but it will also help the resilience of our landscapes and our ecosystems, and allow our farmers to continue to do what they need to do in terms of producing food but doing that in a way which is environmentally restorative.

Sally wanted to hear from a farmer who has been putting some of these carbon management techniques into practice in a financially viable way. Sophie Alexander manages a 400 hectare organic farm in Dorset with a mix of arable crops and livestock. Does someone with a large farm to run and a bottom line to meet still think about carbon when farming?

Sophie - I've always thought about the soil health. Particularly because it's an organic system. It begins and ends with the soil and there are no other get-out avenues of applying something short term. Actually calling it carbon sequestration, carbon farming, is a more recent terminology but storing carbon and looking after the soil are really synonymous.

Sally - How do you as a farmer who has to make a livelihood off a large farm - we're not talking about some smallholding where you can do everything by hand - how do you go about adding carbon to your soil in a financially stable way?

Sophie - The single most important aspect of boosting the carbon content of my soil is probably my livestock enterprise. The cows are outside 24/7. They're grazing the grass and then also fertilising the ground with their dung. Then when we're growing crops, which is the other half of our rotation, I chop straw nearly always, I hardly ever bale it. That's adding soil organic matter and nutrients.

Sally - We were hearing earlier in the show about the effects that ploughing can have on the soil and its ability to store carbon. Have you been looking at your ploughing regimes to see if that can improve your soil health?

Sophie - Yes, definitely. It's a very hot topic, obviously. For instance, in my system we plough maybe three times out of six or seven years. There's time for the organic matter to build up, the carbon in the soil to build up, and then we are reducing it when we start cultivating to establish grain crops but then we build it up again. It's not a direct line of improvement. It's a gradual improvement.

Sally - Two steps forward, one step back, but overall you make progress.

Sophie - Something like that.

Sally - Do you think that farmers all around the UK should be prioritising climate change mitigation?

Sophie - Yeah, I think everyone should. I don't think just farmers. It applies to all of us: day-to-day in your garden, the chemicals you're using, what you're flushing down your drains. But yes, farmers are absolutely on board to play their part.

Sally - You think that the farming community is willing to prioritise...

Sophie - I can't speak for the whole farming community, of course I can't! But the people I meet and talk to, yes. Most farmers really take it as a responsibility and a huge privilege to be looking after a large part of the natural world.


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