2025· Proceedings of the XI Workshop on Biosystems Engineering: WEB 11.0 1a Edition· pp. 11-15· 0 citations
Abstract
Nitrogen (N) is an essential nutrient for plant growth, but its use efficiency (UNE) is often limited by losses due to leaching, NH volatilization, and denitrification, impacting both productivity and the environment. Factors such as fertilizer type, soil characteristics, climate, and crop directly influence UUE, with sandy tropical soils being particularly susceptible to N losses. Biochar derived from organic waste has proven
effective in mitigating these losses, acting as a soil conditioner, increasing pH, moisture retention, porosity, and microbial activity, favoring greater N absorption by plants. This review summarizes recent evidence on the role of biochar in improving ENU, reducing N losses, and enabling innovative fertilizer formulations. Studies indicate that biochar modified or used as a coating for urea, as well as organomineral fertilizers, promotes the gradual release of N, increases macroaggregate stability, reduces leaching and gaseous
emissions, and increases productivity. In addition, innovative formulations incorporating lauric acid or Hermetia illucens by-products increase the multifunctionality of biofertilizers and contribute to circular economy practices. These strategies link nutrient management to waste valorization, contributing to more sustainable fertilization approaches.
The increasing need to ensure global food security and promote sustainable agricultural practices has necessitated the development of alternative approaches to the environmental problems caused by the use of traditional mineral fertilizers. This review article, prepared within this context, comprehensively examines the development of biochar-coated controlled-release fertilizers (BCSRFs) over the last decade (2015–2025). The study evaluates in detail the production techniques of BCSRFs, the properties of coating materials, nutrient release mechanisms, and the impacts of these systems on agricultural productivity and environmental sustainability. Furthermore, environmental gains such as increased nutrient use efficiency (NUE), reduced greenhouse gas emissions and nutrient leaching, as well as economic feasibility and scalability are discussed. With the potential to improve soil fertility and limit environmental losses, BCSRFs stand out as an innovative and promising solution for modern agricultural systems. This review aims to synthesize the existing literature and provide a scientific framework for future research and applications.
Hasine Elçi· Selcuk journal of agricultur...· 0 citations
Increasing nitrogen use efficiency (NUE) remains a major challenge in maize production due to substantial losses from conventional fertilizer applications. Efforts have been made to develop enhanced efficiency nitrogen (N) fertilizers by modifying the N release rate. Changing fertilizer microsite pellet chemistry by including suitable reactive surfaces could increase N retention and NUE. This study evaluated the field performance of biochar-based N fertilizers. Specifically, urea was coated with four biochars, i.e., iron (Fe)-aluminum (Al)- magnesium (Mg) pre-doped biochar, biologically active biochar, pristine biochar, and oxidized biochar at a ratio of 10:1, while potassium nitrate (KNO3) was blended with pristine biochar and Fe-Al-Mg pre-doped biochar. Urea was also blended with coal and pristine biochar. The surface charge of the biochars differed markedly, ranging from negative (−34 cmolc kg-1) in the chemically and biologically oxidized biochars, to nearly neutral in the pristine biochar (−2.6 cmolc kg-1), and becoming positive in the mineral-impregnated biochar (~ 1cmolc kg-1) at pH 7.0. The blending was performed by mixing 2 g biochar, 0.288 g urea/KNO3, and 1 g clay, respectively. These fertilizers were compared with neem-coated urea, guti-urea (urea super granule), and conventional prilled urea. Twelve treatments were tested in a randomized complete block design under field conditions. Among the formulations, urea coated with biologically activated biochar produced the highest grain yield (9.84 t ha⁻¹), representing a 174% increase over the unfertilized control (3.58 t ha⁻¹) and a 29% increase over conventional urea (7.63 t ha⁻¹). This treatment also achieved the highest NUE (74.4%), compared with 47.6% for conventional urea. This enhanced performance might be attributed to a relatively slower N release and improved plant N uptake than other treatments. These findings highlight the agronomic potential of biologically functionalized biochar-based fertilizers as a strategy that may reduce N losses and support sustainable maize production.
S. Alam, S. Mia, G. Saha et al.· Discover Plants· 0 citations
The sustainable management of phosphorus (P) and potassium (K) is becoming increasingly critical due to resource depletion and inefficient nutrient utilization in agricultural systems. In this context, biochar-based cascade systems are gaining attention for nutrient recovery, recycling, and efficient utilization. This review evaluates recent advances in biochar-based phosphorus and potassium recovery systems, with particular emphasis on nutrient dynamics, recovery mechanisms, modification strategies, and current research challenges. Low fertilizer-use efficiency in conventional agricultural systems has resulted in substantial phosphorus (P) fixation in soils and potassium (K) leaching, leading to nutrient loss, environmental pollution, and depletion of natural resources. Biochar, produced through the thermochemical conversion of biomass. It serves as a nutrient source, with the potential to retain, adsorb, and gradually release nutrients over extended periods, owing to biochar’s large surface area, high porosity, and abundance of surface functional groups that provide chemical binding sites for nutrients. The feedstock type, temperature, and conditions under which the materials are pyrolyzed, as well as post-processing of the resulting product, are key factors that define the nutrient dynamics of biochar. To enhance the performance of biochar for nutrient availability and recovery, ongoing investigations are exploring approaches to modification, such as co-pyrolysis, metal doping, nano-biochar production, and biochar-microorganism interactions. The biochar cascade enables sequential nutrient recovery, transformation, and utilization, forming a closed-loop pathway for Phosphorus (P) and Potassium (K) management. These systems mobilize immobilized soil phosphorus and potassium through physical and biological mechanisms to improve crop fertility and productivity. Despite these benefits, several challenges remain, including performance variability, lack of standardization, potential environmental hazards, and limited long-term field validation of the results. Future research should focus on long-term field validation, standardized assessment protocols, economic feasibility, and life-cycle assessment to facilitate the large-scale implementation of biochar cascade systems within sustainable agricultural and circular bioeconomy frameworks.
S. Kowsalya, Jennifer Flora, Varshini Kumar et al.· Frontiers in Agronomy· 0 citations
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.
O. E. Ojewumi, Gang Chen, M. Ojewumi· Green· 0 citations
Biochar, a carbon-rich solid produced through oxygen-limited pyrolysis of biomass, is increasingly considered a soil amendment for sustainable soil fertility management. Indian agriculture faces continuing pressure from soil degradation, declining soil organic carbon, nutrient depletion, crop-residue burning and climate variability, all of which constrain productivity and resource-use efficiency. This review synthesises literature and field-based evidence relevant to the use of biochar in Indian soil-crop systems. It discusses biochar production through slow, fast and flash pyrolysis using crop residues, woody biomass, and livestock or poultry manure at 300–700 °C, and relates these production conditions to key properties, including porosity, specific surface area, alkaline pH, fixed carbon content and nutrient composition. The review also examines the principal mechanisms through which biochar improves soil fertility, including modification of bulk density, water-holding capacity, aggregate stability, cation exchange capacity, soil reaction, nutrient retention and microbial activity. Evidence reviewed here indicates that biochar can reduce nutrient leaching, influence nitrogen and phosphorus dynamics, contribute to soil carbon sequestration, and mitigate selected greenhouse gas emissions, although responses depend on feedstock, pyrolysis conditions, soil type and crop requirement. Field observations from India suggest that applications within the range of 5–20 t ha⁻¹ can improve the productivity of rice, wheat, maize, legumes, oilseeds, plantation crops and vegetables, with stronger responses generally reported in acidic, sandy and degraded soils. The review further identifies practical constraints to adoption, including production cost, inconsistent product quality, limited standardisation, insufficient extension support and variable soil-crop compatibility. Integrating biochar with integrated nutrient management and decentralised residue management may support more sustainable soil fertility strategies in India.
Manoj Kumar, A. Pandey, Ashutosh Singh et al.· International Journal of Env...· 0 citations
Fertilizers play a central role in sustaining agricultural productivity and food security in India, yet the environmental and economic tradeoffs across fertilizer types remain a pressing policy concern. This study compares chemical, organic, and biofertilizers used in Indian agriculture with respect to nutrient composition, cost efficiency, yield performance, and environmental impact, drawing on secondary data from government reports, research journals, and agricultural institutions. The analysis shows that chemical fertilizers such as urea, DAP, and NPK deliver rapid nutrient availability and higher short term yields in crops like rice, wheat, and vegetables, but their sustained use is linked to soil degradation, water pollution, carbon emissions, and biodiversity loss. Organic fertilizers, including compost, farmyard manure, and vermicompost, enhance soil structure, water retention, and long term fertility, though nutrient release is slower and initial yield gains are modest. Biofertilizers, based on microorganisms such as Rhizobium, Azotobacter, and Azospirillum, improve nutrient availability at low cost with minimal ecological damage, but face storage and shelf life constraints. Fertilizer consumption data from 2013 to 2025 indicate that chemical fertilizers continue to dominate the Indian market, accounting for roughly 83 percent of market share, even as awareness of organic and biofertilizer alternatives grows. The comparative evidence suggests that integrated nutrient management, combining all three fertilizer types, yields better productivity and soil sustainability outcomes than reliance on any single type. The study concludes that balanced and integrated fertilizer policy is essential for achieving productivity growth alongside environmental protection and long term soil health in India.
B. G., A. Ahamed, G. Ramu· International journal of bus...· 0 citations
