ENHANCING SOIL FERTILITY THROUGH BIOCHAR APPLICATION: A SUSTAINABLE APPROACH FOR AGRICULTURAL PRODUCTIVITY AND ENVIRONMENTAL PROTECTION

Biochar for sustainable agriculture and environmental remediation: mechanism, application, and future perspectives.

Sustainable agriculture is increasingly challenged by soil degradation, environmental pollution, and climate change, necessitating the pragmatic and eco-friendly approach. This review systematically synthesizes the role of biochar as multifunctional soil management strategy in enhancing soil health and sustainable environmental management, with particular emphasis on the critical roles of feedstock type and pyrolysis conditions in governing biochar performance. To address existing knowledge gaps, we comprehensively evaluate recent available literature on biochar-based environmental remediation, focusing on key indicators of agricultural sustainability, including nutrients availability, soil biological activity, climate change mitigation, biochar-assisted phytostabilization, and crop productivity. Current evidence indicates that biochar application can achieve a net negative carbon footprint, mitigate greenhouse gas emissions and heavy metal contamination, and improve soil structure, fertility, and overall crop productivity on sustainable-basis. However, these benefits largely depend upon the various important biochar production factors including feedstock source, pyrolysis temperature, biochar stability, residence time, rate of application, and soil pH. Beyond its function as a soil amendment, biochar also serves as a multifunctional resource contributing to bioenergy production, waste reduction, and long-term carbon sequestration. At the same time, this review identifies critical research gaps, including the long-term field performance of biochar, mechanisms underlying the interactions between biochar and agronomic practices, and the environmental and human health risks associated with large-scale agricultural applications. Overall, this work highlights the importance of feedstock selection and pyrolysis parameters in designing biochar for environmental remediation and outlines future research directions to refine biochar engineering, application guidelines, and risk assessment frameworks for its sustainable use.

Biochar in Soil Fertility Management: A Review of Agronomic Benefits, Mechanisms and Practical Applications

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.

Impact of Organic Farming on Soil Health and Organic Farming as A Tool For Climate Change Mitigation

Organic Farming and Its Influence on Soil Structure, Soil Microbial Communities, and Agricultural Productivity: A Comprehensive Review

Organic farming is a sustainable method of production that allows the conservation of the environment and biological diversity as well as increasing agricultural productivity over the long-term and fostering soil health. Through minimizing the use of chemical fertilizers and pesticides and the encouragement of the management of ecological processes in agricultural landscapes via methods like composting, crop rotation, cover cropping, minimized tillage, and organic recycling of nutrients, organic farming methods significantly improve soil structure and enhance the soil microbial community, promoting soil stability and fertility. Increased soil aggregation, an increased amount of organic matter, increased water retention and increased carbon sequestration are the primary advantages of organic agricultural production systems. In addition organic farming stimulates soil microbial biomass and activities of beneficial soil microbial communities, particularly in enzyme activity, promoting the development of an agricultural system that encourages increased soil fertility, pest suppression and resistance to stresses. This extensive literature review seeks to present and assess the impact of organic agriculture on soil physical properties, microbial diversity and yield using data from anumber of meta- analyses and other literature sources that have examined organic farming compared with conventional systems across a number of studies. The evidence suggests that microbial populations tend to be greater and more active in organic soil, with increases in microbial biomass carbon and nitrogen, phospholipids fatty acid and activity (based on enzyme assay), compared with conventional systems, and that rotation, legumes, organic amendments and climatic conditions will have major impacts on soil microbial populations and activity. However, there are also disadvantages of organic farming including low availability of nutrients in the short term, need for a higher labor force, high costs of production, difficulty of certifying systems and the drop in production during conversion phases. Compared with conventional farming systems the production might be less in the initial period of organic farming because nutrient release is slow and adjustments of the soil processes are gradual. Long term studies have shown that organic farming system could obtain yields equal to conventional farming system and improve the sustainability and resistance of the soil system against global environmental change. It is suggested that future improvements inorganic inputs, technologies of precision farming and the implementation of favorable agricultural policy could increase the position of organic farming system in establishing robust and sustainable agricultural systems with capability to solve world issues as food security, climate change and natural resource preservation.

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.

Biochar and Sustainable Crop Performance: A Synoptical Review of Its Properties, Agronomic Potential and Constraints

Biochar has emerged as one of the most promising nature-based strategies for improving soil quality, enhancing crop productivity and supporting climate-smart agriculture. However, the agronomic performance of biochar remains highly variable because its effects are governed by complex interactions among feedstock characteristics, pyrolysis conditions, soil properties and management practices. This review synthesizes recent advances in biochar research (2019–2026), examining how production variables determine biochar physicochemical properties and how these properties subsequently influence soil functioning, plant performance and long-term agricultural sustainability. The review integrates evidence on feedstock selection, pyrolysis technologies, biochar modification strategies and the relationships between biochar properties and soil physical, chemical and biological processes. Particular attention is given to crop productivity, nutrient use efficiency, stress mitigation, contaminant immobilization, greenhouse gas mitigation and long-term soil resilience. Across the literature, the most consistent agronomic benefits were observed when biochar was applied to degraded or resource-limited soils and integrated with complementary management practices, whereas responses were often limited under fertile soils, low application rates or short experimental periods. Rather than identifying a universally superior biochar, the evidence indicates that agronomic performance depends on matching biochar characteristics to specific production objectives and environmental conditions. Based on these findings, this review proposes a transition from generalized biochar application towards optimized deployment strategies supported by standardized characterization, long-term multi-site validation and integrated environmental and economic assessments. This synthesis provides a comprehensive framework for guiding future research and facilitating the effective implementation of biochar within sustainable and regenerative agricultural systems.