Henning Lyngsø Foged
Director
Organe Institute
Denmark
henning@organe.dk
Denmark stands out in the Baltic Sea Region for its high agricultural intensity, but also for its commitment to environmental responsibility. With the highest livestock density in the region and extensive farmland use, Denmark faces significant challenges in nutrient management. However, the country has taken a proactive approach, integrating nutrient recycling into its environmental and agricultural policies. By optimizing the use of nitrogen (N) and phosphorus (P), Denmark aims to balance food production with sustainability, setting an example for other nations striving for circular nutrient management.
Denmark has the highest livestock density in the Baltic Sea Region (BSR), with 1.59 Livestock Units per hectare of agricultural area. Around 61% of Denmark's land is cultivated, over twice the EU average. Additionally, Denmark is densely populated with 141 people per square km, second only to Germany in the region. This results in a higher turnover of nitrogen (N) and phosphorus (P) compared to other BSR countries. However, Denmark prioritizes environmental cleanliness for health and business reasons. Nutrient recycling, essential for reducing pollution and greenhouse gas emissions, is central to Denmark’s water action plans, which set concrete targets for reducing nitrogen and phosphorus losses.
Nutrient recycling facts
Looking at the facts, the Danish demand for nutrients for crop production is about 380 thousand ton, kt N and 53 kt P. To cover this, 216 kt N and 48 kt P are provided with livestock manures, 4 kt N and 1 kt P are recycled from wastewater, while 22 kt N and 10 kt P are recycled from other wastes, including food waste and industry wastes. Furthermore, 238 kt N and 11 kt P are provided with mineral fertilisers. Consequently, there is a surplus of 100 kt N and 17 kt P, which is lost to the environment. In addition, about 22 kt N and 5 kt P in wastewater is not recycled, but N mainly converted to nitrogen gas (N2), and P mainly precipitated as an inert compound. With other words, farming is responsible for about 90% of the total turnover of N and 78% of the P.
Since the above-mentioned surplus comprises a loss of 49 kt N and 9 kt P from manure field spreading, specifically caused by a regulated inefficiency in recycling of nutrients in livestock manures, the farming sector would need to have a dominant role in efforts to increase nutrient recycling. Today, almost one fourth of the N in livestock manures brought to the fields are not to be accounted for, neither any of the N losses from stables and stores, and P regulations introduced in 2016 have not proven to be effective for moving a surplus of P from the western part of Denmark to the eastern part with more intensive crop production and P deficit. Next to farming, there is a potential for higher nutrient recycling in the wastewater sector. The process of wastewater treatment was established decades ago and compromises several current policy areas. For example, it renders P inert, which is a depleting resource, and releases N as N2 gas, resulting in significant emissions of nitrous oxide. Overall, the current nutrient self-sufficiency is 51% for N and 98% for P. However, the self-sufficiency for P is in reality only around 50% due to the current lack of incentives for regional redistribution.
Denmark's nutrient recycling is good internationally, and the advanced and detailed way farms do nutrient accounting is probably a good example for any other country. But there is anyway considerable room for improving nutrient recycling.
Nutrients coherent policies
Given the role of nutrients in Danish policies it is characteristic that political negotiations about the way to reach Denmark’s goals for 70% greenhouse gas emission reductions in 2030, compared to 1990, led to an “Agreement on a green Denmark” in 2024, that despite from being unique in a global perspective by imposing a climate tax on farming, is seen as much as a nutrient accord, since it will greatly influence Denmark’s self-sufficiency with plant nutrients. The deal means that the N losses will be reduced with 13,780 ton and about 15% of the cultivated areas in the country converted to un-fertilised forests and other nature areas by 2030. The agreement means that the self-sufficiency could reach 55% for N and 109% for P.
Higher recycling and 100% self-sufficiency are feasible political choices
Achieving the EU's overarching policy goal of a circular economy for nutrients would offer significant benefits for our environment, climate, health, soils, biodiversity, nature, critical raw materials, and overall welfare. We are close to this milestone for P, with regional re-distribution incentives being the key to reaching it. For N, three principal focus areas provide a feasible path forward.
Firstly, it is viable to shift crop demands from crop economic optimal N dosing to society optimal N dosing, which would entail approximately 15% lower N doses, thereby reducing N demand by 57 kt. This approach was implemented in Denmark from 1999 to 2015 and largely did not affect crop productivity statistics.
Secondly, the unaccounted N share in livestock manures can be progressively reduced to half, utilizing existing manure handling technologies on a broader scale.
Thirdly, there is substantial potential in modifying crop rotations to include more nitrogen-fixing crops, adopting regenerative farming practices, and incorporating microorganisms that mimic the ability of nitrogen-fixing plants to absorb nitrogen directly from the atmosphere and mobilise P in soils.
Besides that, it is essential, but also fair and reasonable, that wastewater treatment plants and waste collection companies meet the same nutrient recycling standards as the farming sector.
Denmark has the highest livestock density in the Baltic Sea Region (BSR), with 1.59 Livestock Units per hectare of agricultural area. Around 61% of Denmark's land is cultivated, over twice the EU average. Additionally, Denmark is densely populated with 141 people per square km, second only to Germany in the region. This results in a higher turnover of nitrogen (N) and phosphorus (P) compared to other BSR countries. However, Denmark prioritizes environmental cleanliness for health and business reasons. Nutrient recycling, essential for reducing pollution and greenhouse gas emissions, is central to Denmark’s water action plans, which set concrete targets for reducing nitrogen and phosphorus losses.
Nutrient recycling facts
Looking at the facts, the Danish demand for nutrients for crop production is about 380 thousand ton, kt N and 53 kt P. To cover this, 216 kt N and 48 kt P are provided with livestock manures, 4 kt N and 1 kt P are recycled from wastewater, while 22 kt N and 10 kt P are recycled from other wastes, including food waste and industry wastes. Furthermore, 238 kt N and 11 kt P are provided with mineral fertilisers. Consequently, there is a surplus of 100 kt N and 17 kt P, which is lost to the environment. In addition, about 22 kt N and 5 kt P in wastewater is not recycled, but N mainly converted to nitrogen gas (N2), and P mainly precipitated as an inert compound. With other words, farming is responsible for about 90% of the total turnover of N and 78% of the P.
Since the above-mentioned surplus comprises a loss of 49 kt N and 9 kt P from manure field spreading, specifically caused by a regulated inefficiency in recycling of nutrients in livestock manures, the farming sector would need to have a dominant role in efforts to increase nutrient recycling. Today, almost one fourth of the N in livestock manures brought to the fields are not to be accounted for, neither any of the N losses from stables and stores, and P regulations introduced in 2016 have not proven to be effective for moving a surplus of P from the western part of Denmark to the eastern part with more intensive crop production and P deficit. Next to farming, there is a potential for higher nutrient recycling in the wastewater sector. The process of wastewater treatment was established decades ago and compromises several current policy areas. For example, it renders P inert, which is a depleting resource, and releases N as N2 gas, resulting in significant emissions of nitrous oxide. Overall, the current nutrient self-sufficiency is 51% for N and 98% for P. However, the self-sufficiency for P is in reality only around 50% due to the current lack of incentives for regional redistribution.
Denmark's nutrient recycling is good internationally, and the advanced and detailed way farms do nutrient accounting is probably a good example for any other country. But there is anyway considerable room for improving nutrient recycling.
Nutrients coherent policies
Given the role of nutrients in Danish policies it is characteristic that political negotiations about the way to reach Denmark’s goals for 70% greenhouse gas emission reductions in 2030, compared to 1990, led to an “Agreement on a green Denmark” in 2024, that despite from being unique in a global perspective by imposing a climate tax on farming, is seen as much as a nutrient accord, since it will greatly influence Denmark’s self-sufficiency with plant nutrients. The deal means that the N losses will be reduced with 13,780 ton and about 15% of the cultivated areas in the country converted to un-fertilised forests and other nature areas by 2030. The agreement means that the self-sufficiency could reach 55% for N and 109% for P.
Higher recycling and 100% self-sufficiency are feasible political choices
Achieving the EU's overarching policy goal of a circular economy for nutrients would offer significant benefits for our environment, climate, health, soils, biodiversity, nature, critical raw materials, and overall welfare. We are close to this milestone for P, with regional re-distribution incentives being the key to reaching it. For N, three principal focus areas provide a feasible path forward.
Firstly, it is viable to shift crop demands from crop economic optimal N dosing to society optimal N dosing, which would entail approximately 15% lower N doses, thereby reducing N demand by 57 kt. This approach was implemented in Denmark from 1999 to 2015 and largely did not affect crop productivity statistics.
Secondly, the unaccounted N share in livestock manures can be progressively reduced to half, utilizing existing manure handling technologies on a broader scale.
Thirdly, there is substantial potential in modifying crop rotations to include more nitrogen-fixing crops, adopting regenerative farming practices, and incorporating microorganisms that mimic the ability of nitrogen-fixing plants to absorb nitrogen directly from the atmosphere and mobilise P in soils.
Besides that, it is essential, but also fair and reasonable, that wastewater treatment plants and waste collection companies meet the same nutrient recycling standards as the farming sector.