At first glance, the barley growing at Roland Andersson’s farm in Skane in southern Sweden looks no different than some of the most widely grown tillage crop you might find anywhere in Ireland.

But appearances can be deceptive.

Because although it would never be immediately obvious, the “fertiliser” for this particular barley is anything but typical.

Andersson’s farm is part of a pioneering project that is underway as part of Sweden’s Common Agricultural Policy (CAP) strategic plan to reduce the country’s dependence on synthetic fertilisers.

Like Ireland, chemical fertilisers are not manufactured in Sweden and in keeping with their counterparts in Ireland, Swedish farmers were initially exposed to record-high fertiliser prices when Russia invaded Ukraine.

The Swedish government, like the Irish government, is keen to reduce dependency on both chemical fertilisers and reduce emissions from fertiliser use.

One way Sweden is attempting to do this is by looking at what resources are currently available, particularly those that once may have simply been discarded as waste.

New fertiliser sources

Now under a EU Leader project – circularity from city to farmland – it is engaging with farmers in exploring how new fertiliser resources can be created from both food waste and other municipal waste and organic matter.

Together with five farmers in Northwester Scania and five key partners including NSVA, the public water utility for the area, the Swedish ministry of agriculture has financed an innovative project to “create a complete chain of recovered nutrients from urban areas to farmland and harvest”.

These recovered nutrients are the building blocks for what could be the next generation of sustainable fertilisers in Sweden.

Rudolf Tornerhjelm, who owns the Wrams Gunnarstorps estate, in northwestern Skane in Sweden, is a fifth generation farmer who has enthusiastically embraced the opportunity to become what he describes as “fertiliser self-sufficient”.

Six years ago, together with the German energy group, E.ON Bioerdgas, he developed a large-scale biogas production operation on the estate.

Through anaerobic digestion (AD), the plant processes 65,000t of food waste from the city of Malmo, pig manure, chicken manure and other organic waste each year.

The plant produces 2.5 million litres of fuel which is sold on to the local gas network, but it also produces enough biofertiliser to enable Tornerhjelm to spread 20,000m³ to 25,000m³ of biofertiliser each year on his farm covering 780ha.

But how the biofertiliser is produced is chiefly thanks to his partnership with EkoBalans, a Swedish green tech company which has a particular focus on “recycling nutrients”.

Tornerhjelm told Agriland: “I believe that now because of what is happening in the world, with the war in Ukraine, it is very important to be as self-sufficient as possible.

“But I also want to have a sustainable alternative to synthetic fertilisers and because of that I want to be able to use my own fertiliser. I spent some time researching how this could be done and I found the solution with EkoBalans.

“Last year we developed a processing plant which uses the digestate from our own biogas plant nearby to produce a natural biofertiliser and this has radically changed our approach to how we fertilise our crops, which also avoids leakage of nutrients into our water systems.

“Because we use precision farming on our farm, each field is fertilised only when and how it needs it. We don’t want to use too much nitrogen and so our own fertilisers contain not only phosphate and nitrogen and other nutrients from the process.”

According to Nicklas Froborg, chief commercial officer with EkoBalans, the biodigestate from the biogas plant is “upcycled” into two very distinct fertiliser products.

“We use processes like dewatering, drying and mixing the biogas digestate to arrive at the products,” he said.

“The two products are a nutrient water which can be used by Rudolf Tornerhjelm in irrigation systems for fertilisation at sowing and growing crops and this is a very specific business model because this liquid is processed and residue-free. 

“But we also produce renewable fertiliser pellets and these pellets can provide what is missing from the soil: Phosphorus, nitrogen, organic matter – they deliver lots of benefits, there is no over-fertilisation and they are very efficient.”

He added: “The pellets consist of 50% recovered organic matter and 50% recovered mineral nutrients such as struvite or ammonium sulphate – the exact mix can be tailor-made for each farmer in the final pellet.

“What we have is a climate-positive product that can be used with the farmer’s existing equipment and replace artificial fertilisers,” Froborg added.

One of the five farmers currently testing the “recycled” fertiliser in the form of the EkoBalans pellets is Roland Andersson.

The aim behind the trials is to see how the pelletised product performs against conventional fertilisers and whether there is any noticeable difference in the yield.

Researchers have found that the “pellet gives good yields against the fossil reference fertiliser which proves that plants can access nutrients inside the pellet during growth season”.

According to the project’s managers the final assessment of the trials will take place this December and they are “hoping for a good result”.

All being well, Nicklas Froborg said the next step will be for the fertiliser pellets to be launched as a commercial product in Sweden.