Dorset Farmers in Nitrogen Efficiency Drive!
Despite the fact that Poole Harbour in Dorset is a designated Special Protection Area and Site of Special Scientific Interest, the amount of nitrogen entering the harbour has more than doubled in the last 50 years, resulting in a deterioration of water quality and a negative impact on local wildlife.
A look out over the harbour’s mudflats will reveal that the area is now covered in green algae, thanks to nitrogen entering the site that amounts to approximately 2,300 tonnes per year. This, in turn, has smothered saltmarsh and sea grass, affecting wetland birds, wildlife and other ecosystems.
However, the situation has not gone unnoticed and now local farmers in the Poole Harbour catchment are taking steps to become some of the most nitrogen efficient in the UK to help bring the harbour back to life.
Nutrient management schemes are now being developed so that farmers can be more responsible for reducing their nitrogen losses from the soil to the point where no harm to the environment is caused.
The move comes after Poole Harbour Consent Order Technical Recommendations were published by the Environment Agency and Natural England, stating that nitrogen loads should be reduced to 1,500 tonnes per year and orthophosphate loads from approximately 51 tonnes to 22 tonnes per year.
Agriculture is the largest contributing source of nitrogen to the catchment, as well as contributing a significant amount of phosphorus. The Environment Agency has now set new emission limits and measures for farmers to follow so that their operations don’t cause harm to the water environment.
New resources are also being provided, such as the Agricultural Compliance Tool and the Nitrate Leaching Tool, which can be used by farmers to calculate the amount of nutrients that are being lost to the environment so they can ensure they remain compliant with existing regulations.
Manager for Natural England Nikki Hiorns said: “Poole Harbour is a unique and special place for wildlife and people. Everyone wants to keep it that way so setting these new tighter water quality targets is an important start to restoring water quality in the harbour and improving the catchment.
“Reducing the nutrients entering the catchment and restoring the harbour is achievable, but only by continuing to work with farmers and other stakeholders.”
In excessive amounts, nitrogen can be very damaging to the climate, the natural environment and our health. Buildup of nitrogen in the environment represents one of the biggest threats to global biodiversity, damaging plant species and unbalancing the ecosystem.
Nitrogen pollution also impacts fish and other aquatic life because it’s soluble, so it can make its way into watercourses easily. This then encourages plant growth and algal blooms, where light and oxygen levels in the water are reduced, which kills fish and alters plant communities.
Using climate and nature-friendly growing methods and avoiding using synthetic fertilisers can help mitigate the effects of nitrogen pollution, as can joining Environment Agency-approved schemes to maximise efficiency.