PHOSPHORUS: A local journey in a global cycle

PHOSPHORUS: A local journey in a global cycle

October 17, 2019 0 By Stanley Isaacs


Glasson Dock on the Lancashire coast. A shipment of phosphorus is being unloaded. Phosphorus is an essential nutrient for all life
and a vital fertiliser for food production globally. Without it, we wouldn’t be able to
feed the world’s population but it’s a finite resource that is mined as
phosphate rock in only a few countries. This shipment comes from Russia. The UK has no phosphorus mines
so we have to import it making us part of a global phosphorus cycle. But we’re also part of a local cycle
which starts here at Glasson Dock. The phosphorus unloaded at the dock travels
six miles down the road to Glasson Fertilisers Here it’s mixed with other nutrients and
packaged up ready for delivery to farms. In the North West of England phosphorus fertiliser is
mainly applied to pasture to help the grass grow providing food for cows
which are kept for milk production. Some of the phosphorus that
is taken up in the grass eaten by the cows can be recycled back onto the
fields as slurry and manure. Some of the phosphorus remains in the soil
and the rest ends up in the cows milk. Here at Wallings Ice Cream,
three miles from Glasson Fertiliser they produce milk from their own herd of dairy cows and turn it into their famous dairy ice cream. On average about half of the
phosphorus used as fertiliser gets absorbed by plants and crops
and ends up in the food we eat the remaining half staying in the soil or sometimes small amounts are lost
to rivers and streams. Adults like myself only absorb a small
proportion of the phosphorus in our food most of it passes straight through us and travels through the sewer network to a wastewater treatment works like this one
six miles from Wallings Ice Cream and just up river from Glasson Dock Here around 65 to 85 percent of the phosphorus contained in the sewage is removed and processed into digestate which will be spread back onto agricultural land and again help the grass grow. The remaining phosphorus not removed
is discharged into the river Lune and travels downstream past the dock
where it arrived, out into the sea meaning it’s lost from our local cycle. Globally our current phosphorus use is inefficient. Phosphorus that is lost from
different stages of our food system is not only a waste this valuable resource but can cause environmental problems such as eutrophication and algal blooms. We need better stewardship
and new technologies that help improve the circularity of local and global
phosphorus cycles. Researchers at Lancaster University, the Centre for
Ecology & Hydrology and the N8 AgriFood program work on all aspects of the phosphorus cycle to help improve phosphorus stewardship
both globally and locally.