Sustainable Fertilisers: Innovations, Patentability, and Start-Up Support in Europe

Fertiliser is essential for global food production.  However, geopolitical conflicts driving up fertiliser prices, together with the agronomic challenges caused by climate change, are threatening agricultural productivity and food security.  This article not only highlights developments across Europe aimed at strengthening domestic fertiliser production and accelerating the transition towards greener and more sustainable fertiliser technologies, but also discusses the European patents that protect these innovations.  The article also details the support and funding opportunities available for the development of fertiliser-related technologies in both the UK and the EU.

Nutrients, particularly nitrogen, phosphorus, and potassium, are essential for crop growth.  Fertilisers replenish the nutrients removed from the soil by crops, and are therefore critical for maintaining high yields.  As a result, global food production is heavily dependent on fertilisers.

Geopolitical conflicts, such as Russia’s invasion of Ukraine in 2022, and the US-Israel war on Iran in 2026, have resulted in increased fertiliser prices and exposed the reliance of European farmers on imported fertilisers and fertiliser raw materials.  This is largely due to Europe’s dependence on natural gas, the price of which has increased as a result of these ongoing conflicts, to produce ammonia, the foundation of the nitrogen fertiliser industry.  Rising fertiliser prices can have significant impacts on agricultural productivity and food production.

In May 2026, the European Commission adopted the Fertiliser Action Plan, which aims to support farmers facing rising fertiliser costs.  In the short term, the plan seeks to improve access to affordable fertilisers.  Longer-term measures focus on reinforcing domestic fertiliser production, reducing dependence on fossil fuel imports, and promoting more sustainable fertiliser production through low-carbon, circular, recycled and bio-based nutrient sources.

Similarly, British farmers could benefit from access to new and innovative fertilising products under recent government proposals.  The UK Government, Scottish Government, Welsh Government and Northern Ireland Executive have jointly launched a consultation in March 2026 and call for evidence on modernising fertiliser legislation.

As Europe takes steps to strengthen domestic fertiliser production and transition towards greener and more sustainable fertiliser technologies, this article highlights innovations developed by European companies that are helping to shape the future of the fertiliser industry, as well as the European patents that protect these innovations.

A key requirement for the grant of a European patent (which can ultimately provide protection in the UK) is that the claimed invention must involve an inventive step (Article 52(1) EPC).  An invention is considered to involve an inventive step if, having regard to the state of the art, it is not obvious to a person skilled in the art (Article 56 EPC). This article therefore pays particular attention to those features of the invention that the European Patent Office (EPO) considered to be inventive, as well as to the data provided in the application that demonstrated a technical effect in support of inventive step.

The article also highlights support and funding opportunities available to researchers, start-ups, and scale-ups developing fertiliser-related technologies in both the UK and EU.

Green Ammonia

Ammonia-derived fertilisers are used globally due to their high nitrogen content.  However, conventional ammonia production via the Haber-Bosch process is highly carbon-intensive, relying heavily on natural gas, both as an energy source for the high operating temperatures required and as a feedstock for hydrogen production through steam methane reforming, which releases substantial amounts of carbon dioxide.

Green ammonia is produced using hydrogen generated from renewable electricity (i.e., green hydrogen) and is widely regarded as key to decarbonising industries that rely on ammonia, such as the fertiliser industry.  Green ammonia plants are increasingly being established across Europe, including Iberdrola’s Puertollano plant in Spain, the dynamic renewable ammonia plant developed by Skovgaard Energy, Topsoe and Vestas in Ramme, Denmark, and the Ammonia Synthesis Platform using Intermittent Renewable Energy (ASPIRE) plant near Oxford, UK.

Technology associated with green ammonia production is increasingly the subject of patent applications.

Due to the intermittent nature of renewable energy sources such as solar and wind power, green ammonia production is often subject to fluctuations that can impede continuous operation.  Stamicarbon, headquartered in Sittard, the Netherlands, is a world leader in the design, licensing and development of urea plants for the fertiliser industry. In EP4448453B1, Stamicarbon obtained European patent protection for a green ammonia production plant that addresses fluctuations in renewable energy supply.  During periods of abundant renewable energy, the plant operates in a charging mode. When renewable energy availability wanes, the plant switches to a discharging mode.

During the charging mode, air is compressed and the heat generated during compression is captured and stored.  The air is then compressed further and cooled until it becomes liquid air, which is stored.  The liquid air can subsequently be fed to an air separation unit to produce nitrogen for ammonia synthesis.  Renewable electricity powers an electrolyser that produces hydrogen from water, and the nitrogen and hydrogen are reacted to form ammonia.  Heat released during ammonia synthesis is also stored for later use.

During the discharging mode, the ammonia plant continues operating at a reduced production rate.  Less nitrogen and hydrogen are required, allowing the air separation unit and electrolyser to operate at lower rates.  A larger quantity of liquid air is withdrawn from storage, compressed, heated and expanded through a generator to produce electricity, helping to power the process during the discharging mode.  Stored heat generated during the initial compression and ammonia synthesis steps in the charging mode can serve as a further energy source during operation in the discharging mode.

The EPO found that the liquid air storage system, which enables the plant to switch between the two operating modes, provided a novel and inventive contribution over the prior art.

However, despite advances, green ammonia still faces challenges.  Production and energy costs remain high due to the substantial electricity requirements of green hydrogen production and the continued reliance on the Haber-Bosch process for ammonia synthesis.  There is a need, therefore, for alternative fertiliser sources.

Nitrogen Fixation

Nitrogen fixation is the chemical process by which inert nitrogen (N₂) is converted into bioavailable nitrogen compounds.  Inspired by nature, nitrogen fixation as an alternative approach to the Haber-Bosch process for synthesizing ammonia under ambient conditions has been attracting considerable attention.

The University of Iceland developed a technology in which ammonia can be produced electrolytically, which is patented in EP3155144B1.  In the claimed process, gaseous nitrogen is fed into an electrolytic cell and contacted with a cathode electrode surface comprising a vanadium, zirconium, chromium, niobium, or ruthenium nitride catalyst.  An electric current is then passed through the electrolytic cell, causing nitrogen to react with protons to form ammonia.

The use of these specific nitride catalysts allows ammonia to be produced under ambient temperature and atmospheric pressure. The EPO found that it was not obvious to use these particular nitride catalysts for ammonia production and found the process to be inventive.

Egill Skúlason, Professor of Chemical Engineering at the University of Iceland and named inventor of EP3155144B1, is also a co-founder of Atmonia.  Atmonia continues to develop electrochemical ammonia-production technology and has a pending European patent application directed to the production of ammonia using a transition-metal oxide catalyst enhanced with a transition-metal dopant (EP4739820A2).

Fertiliser via Photocatalysis

R-Leaf® is an innovative technology developed by Crop Intellect Ltd that converts atmospheric nitrogen oxides (NOx) into nitrogen fertiliser on the surface of plants. A titanium dioxide photocatalyst is applied to plants, which converts soil-derived atmospheric NOx into nitrate via photocatalysis, which can then be absorbed by the plant.  The photocatalyst can be included in liquid fertiliser and sprayed onto crops.

Crop Intellect acquired UK patent protection for R-Leaf® in GB 2601329 B, which claims a method of increasing plant growth comprising applying a TiO₂ photocatalyst to a surface of a plant.  The TiO₂ photocatalyst is a particulate material having a mean diameter greater than about 1 μm.

The mean diameter limitation was crucial for establishing an inventive step over prior art disclosing the application of nanoscale particles to plants.  It was successfully argued that a mean diameter greater than 1 μm prevents the photocatalyst from being absorbed by the plant, thereby retaining the photocatalyst on the plant surface and allowing the conversion of NOx to nitrate.  This effect was evidenced by the examples in the specification, which showed that application of the photocatalyst significantly increased wheat yield.  Corresponding European application EP4250931A1 was pending at the time this article published.

Circular Fertilisers

Secondary raw material streams, whether industrial, agricultural, or municipal, are excellent sources of fertilising nutrients. However, they often cannot be applied directly to crops in their raw form. Processing these materials allows nutrients to be recovered and recycled as fertilisers.  This not only reduces reliance on synthetic fertilisers, but also supports a greener, circular economy.

Digestate

Digestate is the material remaining after the anaerobic digestion of a biodegradable feedstock and is often generated as a by-product of agricultural and industrial waste treatment processes.  Although digestate can be applied directly as a fertiliser, it is often advantageous to separate it into liquid and solid fractions, which differ in their nutrient composition.

In EP3880834B1, Nature Energy obtained patent protection for a method of processing biomass digestate.  Through a series of solid-liquid separation and washing steps, phosphorus originally present in the digestate can be efficiently recovered in high yields.  In a later step, a solid wash fraction is post-treated, allowing the recovery of further biogas in a subsequent anaerobic digestion step.

The EPO considered that it would not have been obvious that the specific sequence of process steps would result in the observed phosphorus recovery and enhanced biogas production, and therefore found the claimed method to involve an inventive step.

CCm Technologies are an award-winning cleantech company that have developed technologies to convert waste streams into stable value-added material.  Their granted European patent, EP3408247B1, claims a method of producing a fertiliser composition from digestate.  The method comprises contacting partially decomposed organic matter, such as compost, with a composition comprising anaerobic digestate, calcium nitrate, and a source of ammonia. The resulting mixture is then contacted with a source of carbon dioxide, e.g. biogas. The patent also includes a claim directed to a fertiliser composition obtainable by this method.

This process is particularly advantageous because the resulting material is readily pelletised and therefore easy to transport, store, and apply. It can also utilise multiple waste streams, namely both the digestate and the biogas produced during anaerobic digestion.  The process can therefore be implemented directly at facilities that carry out anaerobic digestion.

Wastewater

Municipal wastewater contains significant quantities of ammonia and phosphate.  By adding magnesium salts and controlling the pH, struvite (NH₄MgPO₄·6H₂O) crystals can be precipitated, and then recovered from the wastewater stream.  Owing to its high phosphorus and nitrogen content, struvite is regarded as a promising fertiliser and is already used in several European countries.

Due to its relatively high magnesium content, struvite may not, however, be suitable for all crops or soil types.  In addition, struvite is only sparingly soluble in water, resulting in relatively slow nutrient release.

EasyMining, a Swedish company that develops, designs, and builds processes for producing clean commercial products from waste, addressed this issue in EP3976558B1.  The patent claims a process for decomposing struvite that allows nitrogen, phosphorus, and magnesium to be individually recovered from wastewater-derived struvite.  The method comprises dissolving struvite in sulphuric acid.  Phosphate ions are then extracted from the solution, before magnesium compounds are precipitated by increasing the pH.  The remaining solution comprises ammonium sulphate.

The extracted phosphorus and isolated ammonium sulphate can be used to produce fertiliser, while the recovered magnesium can be reused in wastewater treatment to precipitate further struvite.

The EPO found that the cited prior art did not suggest using sulphuric acid to decompose struvite in the claimed manner and therefore considered the claimed process to involve an inventive step.

Sewage Sludge Ash

Sewage sludge ash is the residual material produced by the incineration of sewage sludge.  However, despite its relatively high phosphorus content, sewage sludge ash is typically unsuitable for direct use as a fertiliser.  The phosphorus compounds formed during incineration exhibit low water solubility and are therefore not readily available for plant uptake.  Heavy metals present in the sludge, which can be hazardous to living organisms, also become concentrated in the ash.

In EP3623348B1, EasyMining patented a process for recovering high-quality phosphorus from sewage sludge ash with only minor heavy metal contamination.  The process initially comprises dissolving sewage sludge ash in a mineral acid.  Insoluble residues are then removed to form a leach solution, to which a base comprising iron hydroxide is added.  This results in the precipitation of phosphate compounds comprising iron and aluminium.  The precipitated phosphate compounds are subsequently removed and redissolved in an alkaline solution.  Iron hydroxide is then filtered from this second leach solution before the addition of lime, causing phosphate compounds to precipitate.  These phosphate compounds can be processed into valuable phosphorus products suitable for use in fertiliser.

The inventive aspect of the process was the use of iron hydroxide to remove phosphorus from the ash leachate, resulting in an exceptionally high phosphorus recovery efficiency.  Such a step was neither disclosed nor suggested in the cited prior art.  The process therefore enables the recovery of high-quality phosphorus with only minor heavy metal contamination, making it suitable for fertiliser production.

Ammonia Loss Reduction

Organic materials, such as manure, organic waste, and biogas-residue, are excellent nutrient sources and can be recycled back to the field as fertilisers.  Nitrogen is, however, often lost through microbial activity that releases ammonia into the atmosphere.

N2 Applied are a Norwegian company that have developed a plasma-based treatment for organic materials that reduces ammonia and greenhouse gas emissions thereby preventing nitrogen loss from the material. This process is protected by EP3870356B1, in which air is passed through a plasma generator to produce nitrogen oxides (NOx). The NOx-containing gas is absorbed into a liquid organic material, such as manure or slurry, producing nitric and nitrous acids that lower the pH below 6 and thereby suppress ammonia volatilisation. Unabsorbed NO is recovered in a secondary absorption loop and converted to nitrate and nitrite, with any remaining NO oxidised to NO₂ for further capture.

The EPO found that the use of multiple absorption loops to improve NOx capture, together with oxidation of NO to NO₂ in the second loop to facilitate subsequent absorption into additional liquid organic material, provided an inventive contribution over the prior art.

Biofertilisers

Biofertilisers contain beneficial microorganisms that improve nutrient uptake by plants, helping to supplement and reduce reliance on synthetic fertilisers.

Denmark-based biotechnology company Novonesis are world leaders in the production of industrial enzymes and microorganisms.  In EP2344610B1, Novonesis obtained patent protection for a composition to be applied to soil comprising inocula of two strains of the fungus Penicillium (NRRL 50169 and NRRL 50162), as well as a method of increasing the availability of phosphorus for plant uptake by introducing inocula of these strains into the soil.

It was discovered that the combination of the two strains exhibited a synergistic effect, allowing significantly more hydroxyapatite to be solubilised than either strain alone. The EPO considered this synergistic effect to be unexpected and therefore found the claims to involve an inventive step.  This case highlights how a synergistic effect, i.e. an effect that exceeds the additive effect of the individual components in a combination, can be a powerful tool for establishing the inventive step of a claimed combination.

UK based Azotic is a global leader in nitrogen-fixation technology.  Their flagship technology is a unique, patented strain of Gluconacetobacter diazotrophicus (Gd), a nitrogen-fixing bacterium capable of converting atmospheric nitrogen into a form that can be utilised by multiple crop species.  Gd rapidly enters plant cells through multiple pathways, including leaf hairs, stomata, and roots.  It then multiplies and fixes atmospheric nitrogen within the cells themselves.  Field trials have demonstrated significant increases in the yields of crops including maize, potato, and rice following inoculation with the Gd strain.

In EP3328989B1, Azotic obtained patent protection not only for a composition comprising the Gd strain and a method of enhancing the nitrogen-fixing ability of a plant by applying the strain thereto, but also for the bacterial strain itself.

The claimed strain was biologically deposited.  The claim to the strain in EP3328989B1 therefore refers to a deposit accession number, which is required to ensure that the invention can be reproduced.  When seeking patent protection for a novel microbial strain, care should be taken to ensure that a valid biological deposit has been made before filing the patent application and that the corresponding depositary institution and accession number is identified in the specification, or at least a reference that enables the deposit to be related to the later filed accession number.

Biostimulants

Biostimulants are substances or microorganisms that stimulate plant and soil processes.  This can result in improvements in, e.g., nutrient uptake, photosynthesis, water-use efficiency, and resilience to environmental stress.  By enhancing nutrient uptake, biostimulants can reduce the need for synthetic fertilisers.

UniferX’s patent EP4021186B1 claims a biostimulant agent comprising a protein hydrolysate proportion and a glycine betaine proportion in a defined mass ratio of 3:1 to 1:10.  The protein hydrolysate proportion contains various free amino acids, oligopeptides, and polypeptides.  Application of the agent to a plant or seed was found to improve stress resistance. As a result, the growth and yield of treated plants, or plants subsequently grown from treated seeds, can be improved.

Prior art was cited against the application disclosing a biostimulant composition having a protein hydrolysate-to-betaine ratio of 4:1, i.e. outside the claimed range.  UniferX referred to the data in the application, arguing that compositions within the claimed ratio range exhibited at least a two-fold improvement in stress resistance compared with D1’s 4:1 ratio.  The EPO found this improvement to be surprising and acknowledged that the claimed subject-matter possesses an inventive step over D1.

EP4021186B1 highlights the value of comparative data in demonstrating that a claimed invention provides an improvement over the prior art.

Spanish biotechnology company Seipasa’s application EP4529765A1 claims the use of diformylamine as a plant biostimulant.  Although diformylamine is a known small molecule, its biostimulant properties were previously unknown.

The data in the application showed that diformylamine could improve the stress resistance of various plants.  One example studied the effect of diformylamine on pepper plants subjected to drought stress. The diformylamine composition was compared with a fertiliser solution comprising the same amount of nitrogen. Significant differences were observed in both leaf chlorophyll content and nitrogen concentration following application of diformylamine relative to application of the fertiliser solution.

Although not granted at the time this article published, Seipasa received a positive communication from the EPO in July 2026 indicating that the Examining Division considered the claim directed to the use of diformylamine as a plant biostimulant to be both novel and inventive.

French start-up LIPOFABRIK acquired patent protection in EP3422858B1 for the use of certain lipopeptides naturally produced by Bacillus subtilis, such as mycosubtilin, to stimulate plant growth. The examples in the application demonstrated that these lipopeptides can stimulate plant growth, which can in turn facilitate the assimilation, passage, and use of nutrients. LIPOFABRIK successfully argued during prosecution that there was nothing in the prior art to suggest that the claimed lipopeptides would stimulate plant growth and thus that the claimed use involved an inventive step.

EP4529765A1 and EP3422858B1 therefore highlight the patentability of the use of known compounds as plant biostimulants.

Fertiliser Efficiency Technologies

It is inevitable that not all nutrients contained in a fertiliser will be taken up by plants. A proportion is typically lost to the environment, where it can cause significant harm.  Against a backdrop of disrupted fertiliser supply chains and rising fertiliser prices, improving fertiliser-use efficiency (FUE) is vital to maintaining crop yields, reducing fertiliser costs, and minimising environmental impacts.

Nitrogen fertiliser is often applied in the form of ammonium, or in a form that is converted to ammonium in the soil, where it is subject to nitrification. In the first step of this process, ammonium is oxidised to nitrite by ammonia-oxidising microorganisms. Nitrite is then oxidised to nitrate by nitrite-oxidising bacteria in a second step. The resulting nitrate is highly mobile in soil and can leach into watercourses, contributing to drinking water pollution and harmful algal blooms.  During nitrification, N₂O, a potent greenhouse gas, can also be produced as a by-product and released into the atmosphere.

Nitrification inhibitors suppress the microbial oxidation of ammonium to nitrite, thereby slowing the formation of nitrate and reducing leaching and greenhouse gas emissions.

EP3826982B1 (BASF) claims the use of substituted thiazolidine compounds having a general formula as nitrification inhibitors, as well as compositions comprising such compounds for reducing nitrification. During prosecution, the EPO cited prior art disclosing substituted thiazolidines with fungicidal activity. However, the claimed compounds differed in the substitution on the nitrogen atom of the thiazolidine ring. Experimental data in the application demonstrated nitrification inhibitory activity, enabling BASF to argue successfully that this effect arose from the distinguishing structural feature and that it would not have been obvious from the prior art that the compounds would possess nitrification inhibitory properties.

In EP4377441B1, Spanish soil experts Fertiberia claimed a biological approach to preventing nitrate leaching. The patent claims a fertiliser, such as a nitrogen fertiliser, comprising a specific strain of Bacillus subtilis and/or Bacillus megaterium. These aerobic rhizospheric microorganisms are capable of reducing nitrate to ammonium and were found to be effective in reducing nitrogen leaching from soil. Such fertilisers therefore provide a more environmentally friendly solution for reducing nutrient losses without relying on synthetic nitrification inhibitors. The patent also highlights the interplay between chemistry and the life sciences in the development of greener fertiliser technologies.

Urea is a widely used nitrogen fertiliser due to its high nitrogen content, cost-effectiveness, and ease of storage and application.  Following application, urease enzymes, which are ubiquitous in soil, hydrolyse urea into ammonia, which can then form ammonium for plant uptake.  Hydrolysis at the soil surface can, however, result in nitrogen losses to the atmosphere as ammonia gas.  Urease inhibitors slow this process, increasing nitrogen retention in the soil and improving nitrogen-use efficiency. Urease inhibitors such as N-(n-butyl)thiophosphoric triamide (NBPT) and N-(n-propyl)thiophosphoric triamide (NPPT) are well known and have been used successfully in agriculture for many years. Nevertheless, advances are still being made in the urease inhibitor space.

Fertinagro Biotech discovered that pulcherrimin, an iron chelate and natural metabolite produced by Metschnikowia pulcherrima, inhibits urease.  In EP3130578B1, Fertinagro obtained patent protection for a fertilising composition comprising a nitrogen source and a pulcherrimin extract, as well as for the use of a pulcherrimin extract as an inhibitor of urease activity in a nitrogen fertilising composition. Data in the application showed that the presence of pulcherrimin significantly slowed the decrease of urea present in soil.

During examination, the EPO cited prior art documents disclosing the antifungal properties of pulcherrimin.  However, these documents were silent with respect to any urease-inhibitory properties. The EPO therefore concluded that it would not have been obvious to use pulcherrimin as a urease inhibitor or to incorporate it into a nitrogen fertiliser, and accordingly found the claims to involve an inventive step.

EP3130578B1 is a great example of the patentability of a new use of a known natural product.

Summary

Significant and exciting developments are being made across Europe to reduce reliance on imported inorganic fertilisers and their raw materials, and to transition towards a greener, circular, and more sustainable agricultural sector.

The cited European patents also highlight the patentability of the technologies underpinning these developments, which relate to production plants, nutrient recovery processes, new uses of natural products, fertilising or biostimulant compositions, and even strains of microorganisms.  These innovations span multiple technical fields, including chemistry, life sciences, and engineering.

It is likely that European agriculture will need to rely on a combination of these technologies, alongside legislative reforms and government support, to overcome the geopolitical and environmental threats facing the industry.

Support

A range of support and funding schemes aimed at the development of agricultural technologies, including fertiliser-related innovations, are available in both the UK and the EU.

The Farming Innovation Programme, delivered by Defra in partnership with Innovate UK, funds projects that benefit farmers, growers and foresters in England.  An aim of the programme is to use science to develop solutions to practical challenges in agriculture and horticulture.  The programme offers funding through competitions.  Depending on the stage of work, different competitions are available with varying amounts of funding

The UK Agri-Tech Centre is a UK-wide organisation focused on helping high-potential agri-tech businesses access the right tools and support to reach market readiness.  They offer agri-tech businesses support and can provide advice and access to commercial farms and state-of-the-art testbeds.  They can be contacted by filling out the form on their homepage.

Outside the UK, Horizon Europe is the EU’s flagship funding programme for research and innovation.  It has a budget of €93.5 billion running until the end of 2027, with a budget of €175 billion proposed for the 2028-2034 programme period.  Funding opportunities, together with information on application procedures, can be found on the EU Funding & Tenders Portal, where specific funding opportunities can be searched for using keywords.

In 2023, the UK agreed to associate with Horizon Europe, meaning that UK researchers are eligible to apply for Horizon Europe funding and that successful applicants are covered by the UK’s association agreement for the remainder of the programme.

HGF

HGF is a leading European IP firm with a multidisciplinary team of experts and a wealth of experience in drafting and prosecuting European patent applications relating to agricultural technology.  Please feel free to contact the author, hgregson@hgf.com, with any questions about the patentability of your agri-tech innovations.