Microalgae Chlorella Species as Biofertilizer: Towards Sustainable Crop Nutrition and Environmental Benefits

Biofertilization potential of Bacillus spp. in sustainable agriculture

The increasing demand for sustainable and environmentally responsible agricultural practices has accelerated the search for alternatives to chemical fertilizers. Microbial biofertilizers, particularly plant growth-promoting rhizobacteria (PGPR), offer a promising strategy to enhance crop productivity while maintaining soil health. Among these, Bacillus species have gained significant attention due to their ecological versatility and functional diversity. This review provides a comprehensive evaluation of the biofertilization potential of Bacillus spp. in sustainable agriculture. Prominent species such as Bacillus subtilis, B. megaterium, and B. amyloliquefaciens contribute to improved nutrient acquisition through nitrogen fixation, phosphate solubilization, and potassium mobilization. In addition, Bacillus spp. produce phytohormones, siderophores, and volatile organic compounds that stimulate plant growth and enhance tolerance to biotic and abiotic stresses. Their endospore-forming ability ensures high survival, prolonged shelf life, and reliable performance under diverse field conditions, supporting their commercial application as biofertilizers. This review also discusses interactions between Bacillus spp. and native soil microbiota, their influence on rhizosphere dynamics, and their role in improving soil fertility and crop productivity. However, inconsistent field performance, formulation challenges, and regulatory constraints remain key barriers to large-scale adoption. Recent advances in genomics, strain improvement, and formulation technologies present new opportunities to enhance the efficacy of Bacillus-based biofertilizers. Integrative approaches combining microbiology, agronomy, and policy frameworks are essential to realize their full potential in sustainable agricultural systems and global food security.

Algalbio-stimulants: recycling waste streams to improve crop quality and mitigate environmental impact

Assessment of Biofertilizers and Biozyme Application for Sustainable Chrysanthemum Cultivation

Chrysanthemum (Dendranthema grandiflora) is one of the most important ornamental crops because of its aesthetic value, diverse flower forms and commercial significance in the floriculture industry. Sustainable chrysanthemum production has received increasing attention owing to concerns about excessive dependence on chemical fertilizers and the need to maintain soil health and environmental quality. Biofertilizers provide a biologically based approach to improving nutrient availability, plant growth and soil fertility through the activity of beneficial microorganisms, including nitrogen-fixing bacteria, phosphate- and potassium-solubilizing microorganisms, plant growth-promoting rhizobacteria (PGPR), mycorrhizal fungi and microbial consortia. These microorganisms enhance nutrient cycling, root development, nutrient uptake and plant growth, while also contributing to improved tolerance to abiotic stresses such as drought, salinity and temperature extremes. Biozymes, as organic biostimulant formulations, further support physiological and metabolic processes that promote nutrient utilization, plant vigor and overall crop performance. The combined application of biofertilizers and biozymes through suitable methods, including soil application, seed or cutting treatment, foliar spray and drip irrigation, offers considerable potential for sustainable chrysanthemum cultivation. However, their effectiveness may vary depending on microbial strain, formulation quality, soil characteristics, crop stage and environmental conditions. This review summarizes the mechanisms, applications and benefits of biofertilizers and biozymes in chrysanthemum production and highlights current knowledge gaps and future research needs for developing efficient, climate-resilient and environmentally sustainable floriculture systems.

Biofertilizers and Biostimulants for Sustainable Rosaceae Crop Production

The Rosaceae family includes some of the most economically important fruit and nut crops worldwide, such as apples, strawberries, and almonds. Increasing market demand and climate constraints have intensified reliance on synthetic fertilizers, leading to environmental degradation and reduced ecosystem resilience. In response, sustainable alternatives, such as organic fertilizers, biofertilizers, and biostimulants, have gained increasing attention. Here, we review recent findings in the application of these ecofriendly inputs in Rosaceae crops, using almonds (Prunus dulcis) as a representative case study. We highlight the roles of plant growth-promoting rhizobacteria and arbuscular mycorrhizal fungi in improving nutrient availability, stress tolerance, soil fertility, and crop productivity through mechanisms including biological nitrogen fixation, phosphate solubilization, siderophore production, phytohormone modulation, and enhanced plant defense responses. Evidence from field, greenhouse, and controlled experimental studies has indicated that rhizobacteria and mycorrhizal fungi, as well as organic fertilizers, enhance nutrient uptake, photosynthetic efficiency, fruit yields, and quality while supporting soil biodiversity and long-term orchard sustainability. Despite their demonstrated benefits, the adoption of biofertilizers and biostimulants in almond orchards remains limited. This review discusses the current challenges, knowledge gaps, and future perspectives for integrating microbial-based solutions into sustainable Rosaceae cultivation systems.

Biostimulants for Sustainable and Resilient Agriculture

The growing pressure exerted by global food demand, combined with the excessive use of chemical and synthetic inputs, is prompting the agricultural sector to seek innovative and sustainable solutions to improve, or at least maintain, crop yields in a context of increased abiotic stress linked to climate change. Among the promising approaches, biostimulants are attracting growing interest, particularly those derived from natural sources such as seaweed extracts, humic acids, and beneficial microorganisms. These products work through various mechanisms, including osmotic regulation, activation of antioxidant systems, stimulation of root growth, and improvement of nutrient absorption. Many recent research and review articles have explored the optimal combinations of raw materials, formulation processes, target crops, and environmental conditions to maximize beneficial effects on plant growth, soil health, and tolerance to abiotic stresses. As a result, a growing range of commercial products is emerging, with diverse chemical compositions, formulations, and modes of application. However, the precise relationships between the biochemical composition of biostimulants and their physiological effects remain poorly understood, suggesting a key role for molecular synergies. This review provides a concise overview of recent advances in biostimulant research and their potential to enhance food security by improving crop resilience in the context of climate change.

Biochar Production: Toward Safe, Effective, and Sustainable Agriculture

Biochar, a carbon-rich product resulting from the thermochemical transformation of organic biomass under limited oxygen condition, is currently drawing much worldwide attention due to its multiple applications in carbon sequestration, soil improvement, environmental remediation, and biomass waste management. Initially, the focus of research was primarily on the technical possibilities of biochar production, its economic aspects, and its contribution to climate change mitigation through carbon sequestration and the promotion of sustainable agriculture. Nevertheless, recent research indicates the high complexity and dynamics of biochar interactions with the environment, driven by a combination of factors like feedstock type, process conditions, biochar properties, and other factors. While biochar exhibits multiple beneficial effects, including improving soil structure, enhancing nutrient retention, promoting microbial activities, and remediating contaminants, several environmental risks associated with biochar application have also been identified, namely the formation of polycyclic aromatic hydrocarbons (PAHs), heavy metal contamination, creation of persistent free radicals, changes in soil chemistry, and modification of soil microbial community structure. Such risks are greatly related to production process parameters, treatment methods, and biochar application practices. Moreover, differences in feedstock choice, pyrolysis temperature, reactor design, biochar application rate, and analytical methods used make comparative analysis of results difficult.