Cost
$ 128 /credit
Credits
Lowland Calcareous Grassland Creation - Halnaker Hill, England
Halnaker Hill is a 130.35 hectare downland farm being transformed from intensively cultivated arable land into a rich mosaic of habitats. Within the Earthly site, lowland calcareous grassland is being restored. This grassland supports a remarkable diversity of plant species, such as the pyramidal orchid and common spotted orchid. It also provides a vital habitat for insects and an important food source for farmland birds such as the yellowhammer. The Earthly site also offers views towards Halnaker Windmill, originally constructed in the 1740s. The windmill stands within a Neolithic enclosure dating back to between 3700 and 3500 BC, adding a remarkable layer of ancient history to this evolving landscape.
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Project information
Restoring Sussex farmland into wildlife-rich chalk grassland
Located near Chichester, West Sussex, the site has been continuously farmed with arable crops for approximately 40 years. Classified as Grade 3–4 agricultural land, it has long been managed as high-input farmland reliant on fertilisers and agrochemicals, resulting in significant soil degradation and a marked decline in biodiversity.
In response, the project is creating a diverse mosaic of habitats, including species-rich grassland, hedgerows, scrub, and woodland, guided by a management plan that sets out a clear timeline for how each habitat will be created, enhanced, and maintained, alongside defined target conditions for each habitat type. Within the Earthly site, this work centres on the restoration of lowland calcareous grassland, one of the most iconic and ecologically rich habitats of the South Downs and a regional conservation priority. Once widespread across the landscape wherever suitable substrate occurred, it has suffered a decline over the past 70 years, driven by agricultural intensification and urbanisation.
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Intervention
Habitat creation
Location
England
Standard
Biodiversity Net Gain (BNG)
Credit Type
Biodiversity credits
Sustainable Goals
Project performance
The Earthly rating
The Earthly rating is the industry-first holistic project assessment. Earthly researchers analyse 160+ data points, aggregating information across the three vital pillars of carbon, biodiversity and people. Projects in Earthly's marketplace all exceed a minimum score of 5/10.
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Carbon
454
rural trees will be established over the project lifetime
Biodiversity
2
dew ponds have been created to date, with both aquatic and riparian flora successfully established
Social
10
local suppliers have provided services at the farm to date
Project impact
Local impact
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Positive for people
The project is located on privately owned land held by Halnaker Hill Natural Capital, with habitat creation and enhancement delivered under the planning oversight of the South Downs National Park Authority. The farm has a mixed history, shifting to intensive arable production in 1979, and its classification as Grade 3–4 agricultural land - requiring high inputs to remain productive - makes the transition to a regenerative model both justified and timely. Management now aims to produce organic food and restore nature in a way that meets local and landscape-scale socio-economic and environmental needs. Rather than restricting public access, the project has widened and improved an existing public footpath, and plans to install information boards along the route, helping visitors understand the habitats being created and the positive environmental impact of the work.
The project also supports local employment, with the initial planting of trees, hedgerows, and wildflower meadows generating work for local contractors and suppliers, and ongoing farm maintenance being outsourced locally wherever possible. Deep respect for the site's heritage runs throughout the project: archaeological remains and Scheduled Monuments - including a Neolithic causewayed enclosure and a WWII emplacement - have been identified and inform the approach, and the Earthly site offers views of Halnaker Windmill, originally constructed in the 1740s and set within a Neolithic enclosure dating to between 3700 and 3500 BC.
Inspired by historical maps including the Yeakell and Gardner Map of 1795, the farm aims to revive the diverse landscapes that once characterised Halnaker Hill, restoring features such as hedgerows, woodland, and historic dew ponds - with Hilltop Pond and North Pond both restored in 2025 in their former locations. At a regional level, the project directly supports the South Downs National Park Authority's ambition to increase land managed for nature to 33% by 2030, contributing meaningfully to a landscape-scale vision for ecological recovery.
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Good for earth
The project is creating a diverse mosaic of habitats - including species-rich grassland, hedgerows, scrub, and woodland - directly addressing the ecological degradation caused by decades of intensive farming. The site has been continuously cultivated with arable crops, predominantly feed wheat, for approximately 40 years and, classified as Grade 3 - 4 agricultural land, has long depended on fertilisers and agrochemicals to remain productive, resulting in significant soil degradation and a sustained decline in biodiversity.
A baseline survey conducted by the principal ecologist at The Ecology Co-op found the site to be dominated by intensive arable land with cereal crops as the primary land use across the area. To reverse this trajectory, a detailed management plan sets out a clear timeline for how each habitat will be established, enhanced, and maintained, alongside defined target conditions for every habitat type. The restored habitats will deliver substantial ecosystem services. For example, the cessation of ploughing will reduce soil disturbance, erosion, and compaction, and the introduction of grasslands, hedgerows, ponds, and woodland will increase water infiltration and slow surface runoff.
Increased habitat diversity will support a greater abundance of natural predators, including birds, insects, and bats, and species-rich grasslands, hedgerows, scrub, and ponds will provide continuous foraging and nesting resources for pollinators throughout the seasons. Hedgerows, treelines, and ponds will further enhance landscape connectivity, enabling species to move more freely across the wider countryside.
The project is also expected to benefit several notable protected species, including the great crested newt, a UK Biodiversity Framework priority species set to gain from new ponds and improved grassland and deadwood habitat, the common lizard and slow Worm, both protected under the Wildlife and Countryside Act 1981, and the skylark, a Bird of Conservation Concern. The long-term integrity of these habitats is secured through a Section 106 agreement with the South Downs National Park Authority, ensuring they will be maintained and monitored for a minimum of 30 years.
Project gallery
Project pictures
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