Background
Nunwell Estate is our newest nutrient reduction scheme site, recently acquired on the Isle of Wight. It is an arable farm, near Brading, and is approximately 144 hectares, mainly consisting of cereal crops. Like Little Duxmore, our other nutrient reduction site, Nunwell was also receiving high amounts of nutrient inputs for cereal cropping, which were eventually entering the Solent.
The Nunwell Estate is owned by the Oglander family, who approached the Trust because of their interest in rewilding. The Trust were able to acquire a long-term lease of part of the estate in March 2022 and fund the ongoing management of the site through the sale of environmental credits.
Nutrient Reduction
The Trusts nutrient reduction scheme was set up to show how nature- based solutions can help mitigate and reduce the impact of nitrates on the Solent from planned housing developments. By restoring former intensively managed land, we are able to reduce the nitrates entering the Solent, which can provide mitigation to offset particular developments, depending on their location, and eligibility to our scheme.
The Nunwell Estate drains into the Monktonmead and Eastern Yar (lower) catchments, which feed into the Solent via Ryde and Bembridge respectively. This means Nunwell can offset the impact of new developments on the mainland- Fareham/Gosport/Portsmouth and Havant areas, which once occupied, will drain into water treatment works at Peel Common and Budds Farm as well as developments on the Island itself (within the Eastern Yar (lower) catchment) We screen all developments we provide credits to according to our ethical principles (link to webpage)
What’s next
Restoration has begun…. The site is now out of intensive production, and no inputs are being put on to the land. We are allowing natural processes to help shape the restoration, embracing a Wilder landscape whilst restoring key habitats such as chalk downland, wood pasture and hay meadows. Low intensity grazing will be introduced to help mimic a natural system and to help with the restoration and creation of key habitats.
Alongside the restorative works we will also be looking at ways to remove excess nutrients from the ground whilst simultaneously looking to restore soils and fertility. We will be looking at innovative regenerative farming approaches that can help restore soils that can complement the habitat restoration being undertaken.
Ecological surveys are underway to understand how wildlife utilise the site and enable us to monitor change in biodiversity as the site develops. So far we have found forty bird species, including skylark, mistle thrush, and linnet. Eighteen butterfly species have been found so far including brown argus, clouded yellow, green- veined white and small heath. We are planning plant, bat and earthworm surveys for this summer to get a full understanding of the site. Nutrient testing in the streams and ditches have confirmed high levels of nutrients present on site, and flowing off site. We will be monitoring the reduction in nitrates on site over the coming years.
Part of the Nunwell Estate is still in Countryside Stewardship, so we have a few obligations to meet for that scheme, including pollen and nectar, and wild bird seed mixes. Management of water will be an important aspect of our work on the site with a priority to provide more water on site through the provision of scrapes and ponds. Many of the ditches on site are incised, so we are interested in reprofiling and connecting them more with the land to create a range of wetland environments.
We are starting to sell nitrate credits for Nunwell now. We are also looking into opportunities for doing further enhancements and habitat creation to generate Biodiversity Net Gain (BNG) units. As with the nitrate credits, the selling of BNG units will provide funding for us to manage the site for biodiversity for 125 years