The essential element phosphorus is indispensable in Norwegian food production. Photo: Colourbox

Researchers work to promote phosphorus recovery and recycling

Here’s how Norway can limit the loss of an all-important substance, phosphorus.

A new report on phosphorus, an essential element for Norwegian agriculture and aquaculture, suggests measures to ensure the mineral is recovered and reused.

Phosphorus is one of the building blocks of life and therefore plays an indispensable role in food production.

Once phosphorus has been imported, there is much to be gained from keeping phosphorus in circulation by identifying sources and reusing the substance

Currently, large amounts of phosphorus enter the Norwegian food system from abroad in the form of mineral fertilizers, feed components, foods and micro-ingredients for fish and animal feed. However, only a small fraction of this phosphorus ends up as food for humans.

Unfortunately, most of it ends up accumulating in Norway’s soil and water systems. This has many disadvantages, especially for the environment.

According to the researchers behind the new report, phosphorus capture and recycling could help reduce supply risk and the risk of pollution. This is particularly relevant in Norway, where the government has ambitions to increase salmon and trout production from the current 1.5 million tonnes to 5 million tonnes by 2050.

Phosphorus: a critical commodity

“The supply of phosphorus is very important and is classed as a critical raw material by the EU,” says NTNU professor Daniel B. Müller, one of the authors of the new report.

He explains that phosphate rock, the main source of phosphorus for fertilizer and micro-ingredient production, is a limited resource that is only mined in a few countries.

More than 80 per cent of the world’s phosphate rock reserves are found in just five countries, and up to 70 per cent are located in Morocco and Morocco-occupied Western Sahara. This high concentration makes many countries vulnerable to geopolitical and economic instabilities, threatening food security.

However, the report says that once phosphorus has been imported, there is much to be gained from keeping phosphorus in circulation by identifying sources and reusing the substance. The EU describes a circular economy as “a model of production and consumption, which involves sharing, leasing, reusing, repairing, refurbishing and recycling existing materials and products as long as possible.”

Phosphorus is also a crucial ingredient in the aquaculture industry. Photo: Colourbox

“Norway has overlooked the potential of fertilizers and fish sludge as a resource. These can be used to meet not only domestic phosphorus demands, but also to make a high-quality exportable product,” says Avijit Pandit, a PhD candidate at NTNU and co-author of the report.

Reducing the risk of environmental pollution

Researcher Miguel Las Heras Hernández works at the Norwegian Institute for Air Research (NILU), and is also a co-author of the report. He points out that the linear phosphorus economy that currently prevails in Norway risks the accumulation of phosphorus where it isn’t necessarily wanted or needed.

“Many decades of overfertilization has led to a build-up of phosphorus in the soil, but also to high concentrations of phosphorus in the Norwegian water system,” says Hernández.

This increases the risk of a phenomenon called eutrophication, a process whereby zones of water become depleted of oxygen. This in turn can lead to fish and plant mortality.

Four steps towards a circular phosphorous economy

The researchers write that achieving a completely circular phosphorus economy will be a complex task.

They have analysed the benefits and feasibility of four strategies:

  1. Develop and maintain a national nutrient accounting system.
  2. Minimize loss and accumulation of phosphorus at the individual farm level.
  3. Establish infrastructures for the collection, processing, trade and use of fertilizers and fish sludge to produce high-quality recycled fertiliser products tailored to the needs of users in Norway and abroad.
  4. Adopt a regulatory framework to promote the market for recycled fertilizer products.

About the report

The report is based on work conducted under the MIND-P Project. The researchers studied a circular phosphorus economy in Norway for farm-level agriculture and aquaculture and investigated opportunities for increased circularity.

The project identified farm-level and structural obstacles to more efficient management of phosphorus resources. The MIND-P Project is a collaboration between NTNU and the Norwegian Institute of Bioeconomy Research (NIBIO).

The strategies were developed with the support of an advisory panel consisting of representatives from government, the business sector, industry organizations and NGOs.

The report can be read in full at NTNU Open and downloaded both in Norwegian and English: “Towards a circular phosphorus economy in Norway – Strategies for integrating agriculture and aquaculture at multiple scales.”

References: Müller, Daniel Beat; Las Heras Hernandez, Miguel; Pandit, Avijit Vinayak; Øgaard, Anne Falk; Reitan, Kjell Inge. Towards a circular phosphorus economy in Norway – Strategies for integrating agriculture and aquaculture at multiple scales. NTNU Open.