By Janet Kanters

In a groundbreaking effort to reduce waste and promote sustainable agriculture, researchers and innovators are turning to the byproducts of everyday life to develop new sources of fertilizer.

By recycling food scraps, agricultural residues, animal manure and other biodegradable waste, this process reduces environmental pollution and promotes a circular economy. Indeed, the initiative, which is gaining ground in the agricultural sector, has the potential to revolutionize the global farming industry, reduce reliance on synthetic chemicals, and help address food security concerns.

One example of “waste into fertilizer” research is work being done at Australia’s University of Southern Queensland (UniSQ). Researchers have been trialing a raft of strategies to turn nutrient-rich animal waste into a bio-solution. UniSQ Centre of Agricultural Engineering (CAE) Director Professor Bernadette McCabe said the research was about offering solutions to the rapid rise of fertilizer prices. Over the last five years, a research team has been researching the agronomic benefits of biofertilizers. As part of this, the recent commission of a lab-scale granulator, funded by the Queensland Government’s Waste to Biofutures fund, the Fight Food Waste CRC and the University has expanded the research into the production of organomineral fertilizers.

“The granulator is a first of its kind in Australia and will enable the production of biofertilizers using various organic waste materials together with mineral fertilizers,” McCabe said.

The product, called an organomineral fertilizer or OMF granule, will have similar characteristics in terms of physical (particle density and diameter, size distribution), mechanical (particle strength) and aerodynamic properties to manufactured mineral fertilizers. Read more about this project, here.

Other research facilities are getting into the game as well. University of Illinois Urbana-Champaign (U. of. I) researchers show it’s possible and economical to prevent excess phosphorus from polluting downstream waterways, recycling that nutrient as a slow-release fertilizer. Researcher Hongxu Zhou used sawdust and lime sludge, byproducts from milling and drinking water treatment plants, respectively. They mixed the two ingredients, formed the mixture into pellets, and slow-burned them under low-oxygen conditions to create a “designer” biochar with significantly higher phosphorus-binding capacity compared to lime sludge or biochar alone. Importantly, once these pellets bind all the phosphorus they can hold, they can be spread onto fields where the captured nutrient is slowly released over time (read more here).

What “wastes” that are used are not just from organic sources. BiziSul Inc., a sulphur-based fertilizer products company in Blackfalds, Alberta, Canada, is getting nearly CA$2.6 million to set up a new manufacturing plant in central Alberta converting waste sulphur from oil and gas operations into a high-grade fertilizer.

Ryan Brown, BizSul Inc. director of business development, said the first products from their plant went to market last October.

“We sell a fair amount to the U.S. markets, the Midwest and the southern, mid- and northern Plains areas and the Pacific Northwest in Western Canada,” he said.

The plant employs about 20 people and can ship 100,000 tonnes of fertilizer, mostly by truck, to its customers per year.

Brown said the company’s products are ideal for crops that need high levels of sulphur replacement, such as canola, corn, cotton, sugar beet, alfalfa and potatoes. BiziSul produces a more sustainable, slow-release fertilizer that remains in the soil for a longer period of time.

Saving money, protecting the environment

For farmers, these new waste into fertilizers are not only environmentally friendly but also cost-effective, particularly in regions where access to traditional fertilizers is limited or where the cost of synthetic products is rising. Furthermore, the use of waste-derived fertilizers can improve soil quality by boosting microbial activity, increasing water retention, and reducing the need for excessive irrigation.

The success of waste-to-fertilizer technology also has the potential to alleviate the global waste crisis. According to the UN, an estimated 1.3 billion tons of food is wasted every year, much of which ends up in landfills, contributing to greenhouse gas emissions. By converting organic waste into fertilizer, these new technologies could help curb methane emissions while addressing both food waste and agricultural challenges.

Despite the promising prospects, challenges remain. Scaling up production to meet global demand for fertilizers will require substantial investment in infrastructure and technology. Additionally, regulatory frameworks must be established to ensure that waste-derived fertilizers meet safety and quality standards.

A consortium in Europe is tackling those challenges. In an ambitious stride towards promoting circular economy principles, the ReLEAF Consortium has officially signed the Grant Agreement 101156998 for a landmark project co-funded by CBE JU (Circular Bio-based Europe Joint Undertaking), UKRI (UK Research and Innovation) and SERI (Swiss State Secretariat for Education, Research and Innovation). This consortium, comprising 17 leading companies, technology developers, and research organizations from nine European countries, aims to revolutionize the bio-based fertilizer industry in alignment with the European Green Deal and the revised EU Bioeconomy Strategy.

The project focuses on the systemic transformation of the industrial sectors involved in the bioeconomy towards achieving climate neutrality, enhancing biodiversity, combating pollution, and reducing reliance on fossil resources. Through innovative solutions, the consortium plans to integrate novel technologies, establish sustainable value chains, and create circular business models. This will not only contribute to environmental sustainability but also to economic growth by creating new green jobs, fostering collaborations, and developing partnerships.

ReLEAF’s objective is to valorize widespread bio-waste streams across Europe – including sewage sludge, fish processing waste, mixed food waste and agri-food residues – to produce safe, sustainable and efficient bio-based fertilizers (BBFs). These BBFs are designed to improve soil health and quality, close nutrient cycles within the food value chain, and reduce dependency on imported mineral fertilizers. The project’s ambition is to leverage existing supply chains and sales channels of the ReLEAF partners to commercialize the developed solutions and products within the EU and globally.

Structured in seven work packages, the ReLEAF project aims to optimize feedstock requirements and technologies for compound extraction and ingredient production, demonstrate fertilizer formulation and production technologies, and assess fertilizer efficiency, soil quality and product safety. Additionally, it will engage in exploitation and value chain co-creation to ensure circularity, conduct environmental, economic and social sustainability assessments, and carry out dissemination, communication and project management activities.

Through its comprehensive approach, ReLEAF aims to address significant challenges such as dependency on foreign supply chains and petroleum-based resources for fertilizer production, while promoting waste valorization and security of supply at a regional level. The project will demonstrate the effectiveness and replicability of BBFs in varying climate conditions and soil ecosystems across Europe, engage regional stakeholders through co-creation activities for widespread acceptance, and facilitate the rapid scale-up and industrialization of proposed technologies.

As the ReLEAF Consortium embarks on this transformative journey, it contributes not only to the “A Soil Deal for Europe” mission objectives but also expands the BBF knowledge base throughout the continent, paving the way for a more sustainable and circular bioeconomy.

In the meantime, researchers and companies continue to investigate and trial new fertilizer from waste projects. Read more about some of those projects from our November/December 2024 issue, here, open access.