Search Results (70)

Increasing global food demand has led to an intensive use of synthetic fertilisers. In this regard, the use of non-conventional streams such as swine wastewater (SW) and urban sewage sludge liquid fraction (USS) for the production of bio-based fertilisers can increase the sustainability of both the fertiliser industry and agriculture while reducing the reliance on imported nutrients. In this work, USS and SW were assessed for the production of struvite at different PO₄³⁻:Mg²⁺ ratios. Significant differences were found in terms of struvite crystals’ shape and size among both feedstocks due to the different saturation indexes, and it was concluded that PO₄³⁻:Mg²⁺ ratios of 1:2 for SW and 1:1 for USS were the most suitable for obtaining big crystals suitable to be used for direct fertilisation. In addition, it was observed that the crystallisation process is highly dependent on the presence of interfering ions (mainly Ca) that can result in the formation of hydroxyapatite instead of struvite. Finally, recovering struvite from SW and USS could potentially reduce the European import of P by up to 6.5%. Full article

Macroalgal extracts are widely recognised as biostimulants that enhance crop productivity and plant growth under both optimal and stressful conditions. They offer a sustainable approach to mitigating the adverse effects of abiotic stress on crop development. This study investigates the efficacy of macroalgal-based fertilisers in enhancing tomato (Solanum lycopersicum L.) growth, yield, and fruit quality, as sustainable alternatives to chemical fertilisers. Different seaweed species (Sargassum muticum, Ulva ohnoi, Furcellaria lumbricalis, Ascophyllum nodosum, and a commercial A. nodosum extract) were evaluated as foliar treatments. The results showed that while the leaf fresh weight and chlorophyll content were not significantly affected, the fruit morphology and biochemical composition exhibited notable variations. Sargassum muticum-treated fruits displayed the highest °Brix (6.57), indicating superior sugar accumulation, while Ulva ohnoi maintained near-neutral pH levels (avg. 3.94), suggesting balanced acidity. Ascophyllum nodosum extracts induced the highest proline concentrations (peak: 63.77 µmol/g), but also caused extreme acidity (pH 1.39–2.58). Furcellaria lumbricalis enhanced the fruit size (axial length up to 41.4 mm), but reduced the pH sharply (1.69–2.13). The commercial product underperformed in regard to sugar content and flavour complexity. The integrative analysis revealed species-specific flavour profiles: Sargassum yielded sweet, mildly acidic fruits; Ascophyllum produced intensely aromatic, acidic tomatoes; and Ulva resulted in bland flavours. These findings underscore the importance of algal species and extraction methods in tailoring biofertilisers for target fruit qualities. This study advocates for the use of macroalgal fertilisers in sustainable agriculture, but highlights the need for optimised formulations to balance crop yield, taste, and stress adaptation. Full article

Aiming to address a series of problems caused by inefficient nitrogen fixation in soybean within the maize–soybean rotation system under cold-region conditions in Heilongjiang Province, China—such as reduced crop yields, declining soil fertility, and increased dependence on chemical fertilisers—this study investigated the partial substitution of chemical nitrogen fertilisers with bio-organic fertilisers at replacement rates of 10%, 20%, and 30% during soybean cultivation. The treatments included bio-organic fertilisers (OB1, OB2, OB3), inactivated bio-organic fertilisers (O1, O2, O3), Bacillus subtilis (B1, B2, B3), and a control (CK) with the conventional application of chemical fertilisers. In the rotational maize cropping phase, a 50% nitrogen reduction was applied. The results showed that replacing 20% of soybean nitrogen fertiliser with bio-organic fertiliser (OB2 treatment) yielded the most significant increase in productivity and economic return. Compared with CK, the OB2 treatment increased soybean yield by 26.56%, maize yield by 26.69%, and nitrogen fertiliser use efficiency by 3–5%. According to the GRA-TOPSIS model, the OB2 treatment demonstrated the greatest capacity to improve quality and efficiency in the maize–soybean rotation system. At the soybean maturity stage, the OB2 treatment increased soil total organic carbon, available phosphorus, and soil protease activity by 25.36%, 22.20%, and 87.50%, respectively, compared with CK. At maize maturity, soil ammonium nitrogen and soil protease activity increased by 80.24% and 62.47%, respectively. Bio-organic fertilisers combine the benefits of organic fertiliser substrates with those of functional microorganisms. Correlation, cluster, and interaction analyses revealed that the synergistic mechanisms between maize–soybean rotation and bio-organic fertilisers in cold regions are primarily reflected in improved soil quality, enhanced nutrient cycling efficiency, increased nitrogen fixation in soybean root nodules, stimulated microbial activity, and greater resilience to environmental stress. Sustainable agricultural production in cold regions can be achieved through the integrated functioning of these system components. This study provides a theoretical basis for enhancing yield and efficiency in maize–soybean rotation systems under cold climatic conditions. Full article

This study investigated the sustainability aspects of implementing a small-scale biogas digester project at the EARTH Centre, a horse-riding facility for the disabled, in South Africa. Firstly, an energy audit of the facility was conducted. From this exercise, energy-saving opportunities through anaerobic digestion of horse manure were identified. Biomethane potential tests (BMPs) were then performed using the Automatic Methane potential test system II (AMPTS II) of BioProcess Control (Lund, Sweden). The horse manure BMP result was 106 L/kg.VS with the biogas averaging a methane content of 40%. This BMP was lower than that of common substrates such as cow manure which can range from 150–210 L/kg.VS. The gas production rate was almost constant in the first 13 days indicating a long hydrolysis period for horse manure. The microbial species in the digester did not change much during the incubation period although small changes were visible in the proportions of each species as the reaction progressed from start to finish. The energy audit showed that 47% of the EARTH Centre’s energy requirements, which equated to 14,372 kWh/year, could be secured from biogas or solar instead of obtaining it from the national grid which is powered mainly by unsustainable coal-fired systems. As a starting point, a 10 cubic meter biogas digester was installed to produce 5512 kWh of energy per year in the form of biogas. To boost biogas production and continue running the system smoothly, it was evident that the horse manure-fed digester would require regular spiking with cow manure as a bioaugmentation strategy. The digester also produced bio-fertiliser and several sustainable development goals were fulfilled by this project. Current efforts are focused on process optimization of this technology at the Earth Centre to further improve the sustainability of the whole business. Full article

Banana is the second-highest fruit produced in the world and is a staple food for over 400 million people. Only 40% of the crop is utilised, leading to 114 million tonnes of banana waste annually. Banana peel constitutes about ~40% of the whole fruit, and it is considered a domestic and food industry waste. It is enriched with macronutrients, micronutrients and bioactive compounds, which can provide antioxidant, anti-microbial, antibiotic, pharmaceutical and nutraceutical properties. Banana peels also have higher nutrient value than banana pulp, and they are used in traditional medicines to treat diabetes, diarrhoea, inflammation, ulcers, burns and cough. Given its diverse bioactive properties, banana peel waste is now being explored within the framework of a circular economy to promote waste recycling and reduce environmental impact. This review highlights the nutritional and health properties of banana peel while providing opportunities for waste reduction. Potential applications of banana peels include anti-cancer and anti-fungal agents, biosorbents, natural emulsifiers, reducing agents, biofertilisers, food industry ingredients for bakery products, natural preservatives and food fortification. Exploring banana peel waste potential not only contributes to sustainable waste management but also enhances environmentally friendly innovation for the benefit of human health and the environment. Full article

The European Union (EU) advocates for a sustainable agricultural model with reduced synthetic fertiliser use. This study compares different high-P organo-mineral pellet fertilisers (OMFs) and their effects on crop yield. A trial was conducted under controlled conditions in ryegrass (Lollium perenne L.) pots with different organo-mineral fertilisation strategies at sowing with adjusted doses of P (120 kg P ha⁻¹) and N (200 kg N ha⁻¹). Pellets were developed from compost enriched with bone meal (OMF-BON), struvite (OMF-STR), and monoammonium phosphate (OMF-MAP). Conventional fertilisers (Complex15 and MAP) and alternative unpelletised/pelletised sources (STR and BON) were also tested. The experimental design included an unfertilised control (C), and treatments were carried out in triplicate (N = 24). Over 40 days, three cuttings (10, 25, and 40 days) were collected to determine fresh/dry biomass, nutrient content, and N, P, and K extraction efficiency. Soil labile parameters were influenced by the application of fertilisers especially OMF-MAP, OMF-STR, and MAP. MAP and STR yielded the highest nutrient extraction and biomass production, followed by their pelletised forms (OMF-MAP and OMF-STR). These results highlight the potential of pelletised organo-mineral fertilisers as sustainable alternatives to conventional sources. Full article

Reducing the use of chemical inputs is becoming a major challenge in developing sustainable agriculture. Fungi, known as biocontrol agents (BCAs) and biofertilisers, are crucial in scientific research and are celebrated for their efficacy, eco-friendliness, and multifaceted roles. In this study, a bibliometric analysis was conducted on 5349 articles related to fungi as BCAs and biofertilisers over the past half-century using the Web of Science Core Collection (WoSCC) database. The publications on fungi, such as BCAs and biofertilisers, have increased significantly over the last 20 years, with a maximum growth rate of 33.7%. The USA and China lead in this field. Keyword clustering analysis revealed that entomopathogenic fungi, including Hemiptera, Coleoptera, and Lepidoptera, can be used to manage plant pests. It also showed that fungi can be used as biofertilisers to promote plant growth. The analysis of research trends shows that Beauveria bassiana in biological control is highly significant. This study also showed that entomopathogenic fungi control plant pests by infiltrating the insect cuticles. Trichoderma spp. exert biocontrol effects by producing antibiotics. Arbuscular mycorrhizal fungi can trigger plant defence mechanisms by modulating secondary metabolite synthesis. This study contributes to the current knowledge of fungi as BCAs and biofertilisers and can guide future research. Full article

The soil used for the field experiment was PLb-g4 Endohipogleyic Eutric Planasol. The research aimed to investigate the effects of different nitrogen fertilisation rates and biological preparations on yield structure elements and partial factor productivity of nitrogen in maize (Zea mays L.) grown for grain production. The factors studied were Factor A—nitrogen (N) fertiliser rates: (1) 100 kg ha⁻¹, (2) 140 kg ha⁻¹, and (3) 180 kg ha⁻¹, and Factor B—use of biofertilisers: (1) no biological preparations (BP) used, (2) biological preparation (AB)—nitrogen bacteria Paenibacillus polymyxa (1.0 L ha⁻¹), (3) biological preparations (AB + C)—nitrogen bacteria Paenibacillus polymyxa (1.0 L ha⁻¹) and cytokinin, and (4) biological preparations (AB + H)—nitrogen bacteria Paenibacillus polymyxa (1.0 L ha⁻¹) and humic acids. The research showed that the yield of maize grain was significantly increased not only by increasing the rates of nitrogen fertilisation but also by using biological preparations. The highest maize grain yield (11.5 t ha⁻¹) was obtained in 2020 using N₁₈₀ fertilisation, in combination with biological preparations AB + H. In all cases, the biological preparations and their combinations significantly increased the maize grain yield compared to the control field (no use of BP). The biological preparations in combination with N significantly increased the weight of 1000 grains and thus the grain yield per plant. The highest maize grain yield per plant (154.6 g) was obtained in 2020 using N₁₈₀ fertilisation, in combination with biological preparations AB + H. In most cases, positive, strong, very strong, and statistically significant correlations were observed between the different rates of nitrogen fertilisation and the indicators studied: r = 0.76–0.94 (p < 0.01, p < 0.05). No statistically significant correlation was found between nitrogen fertilisation rates and the number of grains per cob (p > 0.05). The highest partial factor productivity of nitrogen fertiliser (92.0 kg of maize kg⁻¹ of N) was obtained in 2020 using N₁₀₀ fertilisation, in combination with AB + H. Increasing the nitrogen fertiliser rates and not using biological preparations resulted in a decrease in the partial factor productivity of nitrogen fertiliser. Full article

The combination of techno-economic process modelling and life cycle assessment is an integrated methodology that addresses quantitative operational data, and evaluates the emissions associated with any process under development. In particular, the valorisation of waste streams within the context of the circular economy could be considered a valid and promising approach, especially regarding techno-economic and environmental indicators. This manuscript aims to evaluate the integral valorisation of apple pomace from the processing industry into bioethanol, and vinasses (a byproduct of the distillation process) into biogas and digestate as biofertiliser. In addition to biogas production, lagooning and composting were considered as strategies for vinasse management. After the conceptual design of the process options was completed, the environmental profile of bioethanol production was estimated across different scenarios. When biogas production was integrated to reduce the biorefinery’s energy demand, the carbon footprint was 1.13 kg CO₂eq∙kg⁻¹. This footprint increased to values around four when lagooning and composting were used as vinasse management strategies. Although the economic dimension posed a significant limitation due to high investment costs, the eco-efficiency analysis showed that the scenario of the co-production of bioethanol and biogas is the best alternative. Despite the promising results, further research is needed to explore the recovery of additional co-products to develop a high-potential strategy for apple pomace. Full article

The latest World Food Security Outlook predicted stabilization in global food security by 2024; however, nearly one billion people still face the threat of food insecurity. Fertilisers, crucial for maximizing crop yields, are the subject of scrutiny due to their environmental impact and health concerns. Efforts are being made to use fertilisers more efficiently and maintain soil nutrient balance to address these issues. In this research, different solid and liquid wastes from the food industry were used to granulate organic biofertilisers with a rotary drum granulator. This included buckwheat biomass (BBM), buckwheat husks (BH), buckwheat husk ash (BHA), bone meal (BM), molasses solution (MS), and beaten eggs (BE). Using standardized fertiliser testing methods, it was found that the biofertilisers produced by the drum granulator comply with the requirements for bulk fertilisers, as they are rich in plant nutrients, the static strength of their granules is high (7–14 N/granule), and their moisture content is higher (4–8%) than that of conventional mineral fertilisers, but the hygroscopicity of the granules when stored in standard conditions (30–60% humidity, temperature of 20–25 °C) is low. Due to their slightly alkaline pH, it is likely that such fertilisers could be used in acidic soils and would have a double effect—they would improve plant growth and soil properties (increase the amount of organic matter and reduce acidity). Full article

Determining nutrient-release patterns of organic manures can give an estimate of the potential amount of nutrients that a given material can contribute to crops along with chemical fertiliser. Nutrients released from organic manure depend on several factors, and temperature is one of them. To evaluate how different types of conventional organic manures release nitrogen (N) under varying temperature conditions, an incubation study was conducted at the Bangladesh Agricultural Research Institute. Six organic manures—poultry manure (PM), vermicompost (VC), bio-slurry (BS), cowdung (CD), water-hyacinth compost (WHC), and rice straw compost (RSC)—were evaluated at three temperature regimes (15, 25, and 35 °C) to study the dynamics of N incubated for 330 days. The N release was significantly influenced by the interaction of organic manures and temperature regimes. Poultry manure-treated soil incubated at 35 °C had the highest mineralisation of all parameters than other manures. The mineralisation of N followed the order: PM > VC > BS > CD > WHC > RSC > control and 35 °C > 25 °C > 15 °C. Across different temperatures, the mineralisation rate of PM was 15–55% higher than that of other manures. At 35 °C, the mineralisation rate was 10% and 20% higher compared to 25 °C and 15 °C, respectively. The first-order kinetic models predicted the organic N release from manures satisfactorily. The findings of the present study enrich the understanding of N-release patterns under different temperature regimes that prevail in different crop growing seasons in Indo-Gangetic Plains, providing valuable data for researchers and policymakers interested in sustainable integrated nutrient management practices. Full article

Azolla is the only plant with a co-evolving nitrogen-fixing (diazotrophic) cyanobacterial symbiont (cyanobiont), Nostoc azollae, resulting from whole-genome duplication (WGD) 80 million years ago in Azolla’s ancestor. Additional genes from the WGD resulted in genetic, biochemical, and morphological changes in the plant that enabled the transmission of the cyanobiont to successive generations via its megaspores. The resulting permanent symbiosis and co-evolution led to the loss, downregulation, or conversion of non-essential genes to pseudogenes in the cyanobiont, changing it from a free-living organism to an obligate symbiont. The upregulation of other genes in the cyanobiont increased its atmospheric dinitrogen fixation and the provision of nitrogen-based products to the plant. As a result, Azolla can double its biomass in less than two days free-floating on fresh water and sequester large amounts of atmospheric CO₂, giving it the potential to mitigate anthropogenic climate change through carbon capture and storage. Azolla’s biomass can also provide local, low-cost food, biofertiliser, feed, and biofuel that are urgently needed as our population increases by a billion every twelve years. This paper integrates data from biology, genetics, geology, and palaeontology to identify the location, timing and mechanism for the acquisition of a co-evolving diazotrophic cyanobiont by Azolla’s ancestor in the Late Cretaceous (Campanian) of North America. Full article

Plant growth and food security depend heavily on phosphorus (P). Recovering and recycling P from animal, municipal, and food waste streams can significantly reduce dependency on traditional mineral P. This is particularly pertinent in the EU regions with limited native P supplies. The agronomic performance of including P-based recycling-derived fertilisers (two struvite and two ashes) or cattle slurry was compared to a conventional mineral P fertilisation programme along with no P and no fertiliser controls over three years. A field-scale experiment was set up to evaluate the perennial ryegrass dry matter yield (DMY), P uptake, and soil test P effects. Struvite, ash, and cattle slurry proved effective in replacing P mineral fertiliser and produced yields similar to those of the mineral fertiliser programme. Differences were observed in plant P recovery, with struvite-based programmes achieving a significantly higher P recovery than ash-based programmes, which had the lowest plant P recovery. Differences in Morgan’s soil test P were also noted, with potato waste struvite (PWS) and poultry litter ash (PLA) showing significantly higher soil test P values. The findings strongly indicate that a range of recycled bio-based fertilisers from the bioeconomy can be used to reduce reliance on conventional imported mineral P fertiliser, with some programmes based on recycled fertilisers even surpassing the performance of conventional linear economy mineral fertilisers. Full article

In the quest for a sustainable future, energy-intensive industries (EIIs) stand at the forefront of Europe’s decarbonisation mission. Despite their significant emissions footprint, the path to comprehensive decarbonisation remains elusive at EU and national levels. This study scrutinises key sectors such as non-ferrous metals, steel, cement, lime, chemicals, fertilisers, ceramics, and glass. It maps out their current environmental impact and potential for mitigation through innovative strategies. The analysis spans across Spain, Greece, Germany, and the Netherlands, highlighting sector-specific ecosystems and the technological breakthroughs shaping them. It addresses the urgency for the industry-wide adoption of electrification, the utilisation of green hydrogen, biomass, bio-based or synthetic fuels, and the deployment of carbon capture utilisation and storage to ensure a smooth transition. Investment decisions in EIIs will depend on predictable economic and regulatory landscapes. This analysis discusses the risks associated with continued investment in high-emission technologies, which may lead to premature decommissioning and significant economic repercussions. It presents a dichotomy: invest in climate-neutral technologies now or face the closure and offshoring of operations later, with consequences for employment. This open discussion concludes that while the technology for near-complete climate neutrality in EIIs exists and is rapidly advancing, the higher costs compared to conventional methods pose a significant barrier. Without the ability to pass these costs to consumers, the adoption of such technologies is stifled. Therefore, it calls for decisive political commitment to support the industry’s transition, ensuring a greener, more resilient future for Europe’s industrial backbone. Full article

Recovering phosphorus (P) through combustion from waste streams, like wastewater sludge and animal manure, offers a promising solution. This research explores the P release patterns in different ashes derived from secondary raw materials, using a long-term soil incubation lasting 160 days. The study evaluated the P release dynamics in five types of ashes from enhanced biological phosphorus removal (EBPR) systems and pig slurry burned at different temperatures. According to the results, a primary effect was observed on P bioavailability during the initial incubation period. All tested ashes release more than 50% of the total P applied between days 5 and 10. Ashes from EBPR exhibited higher P release than those from pig manure, indicating ash origin as a key factor in P release. Additionally, combustion temperature was crucial, with higher temperatures resulting in increased P release rates. Furthermore, the Pearson correlation revealed a strong relationship between the characteristics of the ashes and the amount of P release. Overall, these findings suggest that ashes could be a valuable P-source for agriculture avoiding the process of wet chemical P extraction, thus reducing both economic and environmental costs. Full article