How the Nutrient Neutrality Scheme bought Lyscombe: Andrew Livingston looks at the strategic approach to saving Poole Harbour

Take a walk alongside Poole Harbour: you only have to peer into the water to see the effects of water pollution on our waterways and coastline. It’s undeniable that nitrates in our water courses are an issue.
Green algae, which feeds off nitrates, is in the harbour bed, the mudflats and the wetlands that make up Poole’s natural harbour, and is slowly killing the ecology and biodiversity of the harbour – which is designated a Special Protection Area (SPA), Site of Special Scientific Interest (SSSI) and Ramsar (international wetlands) site. Seagrass and salt marshes, which feed the wetland birds, have been smothered, and the water is increasingly becoming more and more poisonous for the fish and molluscs that live there.
It is a big problem.

Natural regeneration
But both Natural England and Dorset Wildlife Trust (DWT) believe that their acquisition of farmland north of Dorchester, 15 miles as the crow flies from the harbour, may help.
DWT celebrated its purchase of Lyscombe Farm, a Site of Special Scientific Importance (SSSI) between Piddletrenthide and Cheselbourne, at a launch event last month. Dignitaries from Natural England and DWT spoke to guests about the opportunities open to them now that the farmland has been taken out of traditional agricultural use.
The farm – 827 acres of chalk downland, grassland, woodland and wildflower meadows – was farmed organically by the previous owner, with half the acreage to grow cereal and the rest to run herds of livestock.
‘We aim to showcase sustainable land management here, natural regeneration, and we want to engage people in the rich heritage that is here,’ said DWT chief executive Brian Bleese at the event. ‘Our aim is to establish Lyscombe as an exemplar nature reservation. Ultimately, our ambition is for it to become a national nature reserve.
‘We are facing a global ecological crisis that threatens thousands of species and their habitats. Dorset is not immune to this – there are horrific statistics in Dorset when you delve into them; one in 40 species previously recorded in Dorset is no longer present. They’re locally extinct. That’s a pretty poor statistic, and one that we have to do better in correcting. Places like this can give us an opportunity to make that space for nature. It’s vital that we make space for nature in our landscapes.’
Returning the farm to nature will inevitably allow for the biodiversity on the land to grow and improve. But not everyone agrees that this is the right use of public money. George Hosford farms near Blandford, and is deeply passionate about environmentally friendly, sustainable food production methods. He is sceptical about the effectiveness of the scheme, and suggests the money would be better spent educating local farmers on the responsible use of nitrogens.

House building with nature
However, the question is how does land near Dorchester save Poole Harbour? Natural England’s answer… The Nutrient Neutrality Scheme. There are two main causes of nitrates in our water; agriculture and sewage discharge. Natural England has set up the scheme to allow funding of new nature recovery projects which offset additional pollution from new houses. They then sell these benefits as credits to developers so they can offset the pollution from new homes, quickly get planning permission and enable the building of much-needed new homes.
At the event, Natural England chief executive Marian Spain explained how the scheme is designed to save our waterways and coastline.
She said: ‘I came down for a visit about five years ago to look at some of the issues on the coast path, and I couldn’t ignore the green algae. It has stayed with me ever since. When we talk about pollution, it is not an abstract thing, it is something that the people living and working on Poole Harbour are seeing and feeling and smelling on a day-to-day basis. It really struck home to me, what a big thing this was.
‘We clearly couldn’t just stop house building. We didn’t want to and we couldn’t. Contrary to what you might read in some parts of the press, it is not our job to stop house building. It is our job to enable house building that works with nature.
‘The other thing that I and Natural England are increasingly becoming aware of is that this is going to be how conservation happens going forward. It is no longer enough just to look after protected sites or to designate national parks. When I started this job, more than 30 years ago, conservation was pretty easy – we just looked after the stuff we owned or the stuff we controlled. The job now is about looking after the whole ecosystem, reducing pressures where we can – because those ecosystems are going to have to absorb new pressures.’
Natural England has calculated that the acquisition of Lyscombe Farm will enable 3,700 new homes to be built around the waterways that feed into Poole Harbour across Dorset. Figures released by Dorset councils in 2016 suggested that 100 new homes (60 houses and 40 flats) in the catchment area of Poole Harbour would produce 0.185 tonnes of nitrogen per year – suggesting that 3,700 homes would produce 684.5 tonnes of nitrogen a year. Building developers will now be able to purchase nitrogen credits from Natural England to be able to build new homes.

Value for our money
The removal of farmland from high nitrogen input to low nitrogen input to allow for an offset to build houses is called indirect mitigation. Direct mitigation would be the improvement of nitrogen stripping at the Wessex Water sewage treatment works, or introducing natural means of nitrogen stripping in the water, such as reed beds and wetlands.
George Hosford believes that the removal of Lyscombe Farm as farmland will make no difference to the nitrate level in Poole Harbour. He told the BV: ‘There won’t be any impact from this farm on what actually pitches up in Poole harbour and causes any pollution in the years to come.’
The Blandford farmer suggested that the money spent acquiring the farm could have been better spent on local farmers in the Poole Harbour catchment area, helping to educate them further in the responsible use of nitrogens on their land.
‘I would like to have seen some of the public money that went on this farm go into helping the 500 farmers in the Poole Harbour catchment to learn how to farm more efficiently with their fertilisers and their manures.
‘Because, as well-educated as an awful lot of them are, the technology and the science needs to understand from how much nitrate is applied to your crop, how much of it is used by the crop and how much gets washed through below the rooting zone where the plant can’t reach it. There’s still an awful lot to be understood – should we be applying a little at a time rather than a big slug all at once? Should we only apply it just after rainfall, or just before it starts to rain?
‘Many farmers I’ve spoken to actually want an effective nitrate-leaching tool, so they can better understand what happens to the manures and the artificial nitrogen that they apply to their fields. And also just how much of it is leaching, ending up in the water, the rivers and eventually into Poole Harbour – which is what we’re all concerned about.’

Farmers are aware that nitrates are running off from their farms, but George doesn’t believe that they are all to blame. He said: ‘Some of those nitrates are coming from farms. I think we’re all happy to acknowledge that. But an awful lot, we don’t know exactly how much, are coming from the sewage treatment works. There are 28 in the catchment. And there has been no monitoring of this, or very, very limited monitoring of the amount of sewage outflow that has been treated or untreated.’
Members of Dorset Wildlife Trust and Natural England wanted to make it clear during the event that the acquisition of Lyscombe Farm will help to put pressure on the sewage companies to work harder to minimise the number of nitrates that are leaking from their treatment plants.
‘Now, the Natural England chap tried to persuade me that the water companies are going to be forced to clean up their act,’ continued George. ‘And he sounded rather confident about that. But I have serious misgivings. A lot of the coverage we’ve seen recently leads me to feel sceptical about that. But he says he feels confident that once we’ve got the water companies cleaning up their act, and there’s no more crap going in the water from them, then we’ll just have the farmers to deal with.’

Reverse the decline
There is no doubt that we have an issue with pollution in our waterways, and there is also no doubt that there is a housing crisis across the United Kingdom. But, it shouldn’t be forgotten that there is also an issue with food security. As a nation we are not self-sufficient when it comes to the production of food – latest figures suggest that only just over half of the food we eat in this country is grown here.
Wildlife Trust chief executive Craig Bennet said that in 2022 the UK government signed up to ambitious biodiversity framework targets at the UN Biodiversity Conference in Montreal: ‘That global biodiversity framework requires all those countries to try and get 30 per cent of land and inland waters and sea in recovery for nature, by 2030, just six or eight years away now. And in the UK, in England, we’re at less than five per cent. So we’ve got a long way to go to get to 30 per cent in the next six years.
‘So, seeing this acquisition today, through this partnership between Natural England and Dorset Wildlife Trust, it’s a brilliant example of how we can do this, how we can start to turn things around. I don’t know about you, but I’ve been fed up for decades. I’ve seen all these graphs of nature going downwards … well, we don’t want to just slow the decline, we want to reverse the decline and bring nature back! That’s absolutely crucial. We want to do it fast. As fast as we possibly can.’