Global research on biochar has expanded significantly over the past decade as scientists seek sustainable solutions for soil degradation in vulnerable agroecosystems. In a new paper published in Discover Soil, authors Ana Beatriz Alves, Ana Luiza Veras de Souza, Ingrid Carla Ferreira de Lima, Laize Jorge da Costa, Leonardo Cordeiro da Silva, Marcondes Ferreira Costa Filho, Wellyda Keorle Barros de Lavor, Darliane Cristina Soares de Souza, Eulene Francisco da Silva, Daniel Valadao Silva, Rafael Oliveira Batista, Frederico Ribeiro do Carmo, and Luiz Fernando de Sousa Antunes mapped the global landscape of this critical environmental field. The team performed a comprehensive bibliometric analysis of scientific literature indexed in the Web of Science database from 2009 to 2024, screening 666 initial records to examine 505 core peer-reviewed articles and reviews.

The analysis revealed a dramatic upward trajectory in annual publication output, rising from a single publication in 2009 to a peak of 73 articles in 2024. China emerged as the central global hub for biochar scientific collaboration, leading all nations with 183 articles and 7,257 citations. The United States followed with 70 articles and 4,174 citations, while Pakistan ranked third with 49 articles and 1,821 citations. International collaboration networks showed strong partnerships between China and nations such as Pakistan, Australia, Saudi Arabia, and the United States, reflecting a shared priority to address soil degradation in arid and semi-arid regions. Among institutional authors, the Chinese Academy of Sciences generated the highest volume of papers with 29 articles, whereas Nanjing Agricultural University produced 11 articles that gathered 1,249 citations, demonstrating high scientific impact per publication.

Keyword co-occurrence and thematic mapping identified three primary research clusters driving the field: carbon sequestration, agricultural productivity, and soil remediation. Biochar acts as a charcoal-like material produced by heating organic biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More under oxygen-limited conditions, making it an effective soil amendmentA soil amendment is any material added to the soil to enhance its physical or chemical properties, improving its suitability for plant growth. Biochar is considered a soil amendment as it can improve soil structure, water retention, nutrient availability, and microbial activity.   More for capturing stable carbon. Studies showed that biochar applications increase soil carbon by an average of 61 percent, which promotes soil structure and reduces greenhouse gas emissions. Agronomic investigations demonstrated that biochar improves crop yields, boosting water and nitrogen use efficiency by more than 14 percent. Furthermore, biochar proved effective at adsorbing heavy metals and immobilizing environmental contaminants, providing a practical tool for restoring degraded farmland.

The evolutionary analysis of research topics indicated a transition from early characterization studies to field-level applications and climate mitigation strategies. In tropical and semi-arid agroecosystems, biochar alleviates severe soil constraints by increasing water retention in sandy soils and moderating acidity in nutrient-depleted tropical soils. In acid soils, biochar raises the pHpH is a measure of how acidic or alkaline a substance is. A pH of 7 is neutral, while lower pH values indicate acidity and higher values indicate alkalinity. Biochars are normally alkaline and can influence soil pH, often increasing it, which can be beneficial More level, thereby reducing toxic aluminum exposure and enhancing essential nutrient availability for plant roots. The material’s porous physical architecture provides protective microhabitats for beneficial soil microorganisms, which enhances microbial biomass, enzymatic activity, and nutrient cycling.

Despite the promising benefits, the study highlighted key operational barriers to widespread adoption. The effectiveness of biochar varies based on the raw biomass feedstockFeedstock refers to the raw organic material used to produce biochar. This can include a wide range of materials, such as wood chips, agricultural residues, and animal manure. More used, pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More temperature, application rate, and local climate conditions. The researchers noted a critical lack of long-term field data regarding the persistence and aging dynamics of biochar in soil over multiple decades. Additionally, the lack of standardized production protocols and ecotoxicological safety evaluations creates uncertainties for farmers and land managers. The authors concluded that consolidating biochar as a reliable agricultural technology requires standardized methods, long-term field trials, and stronger international research partnerships tailored to vulnerable ecosystems.

Source: Alves, A. B., Souza, A. L. V., Lima, I. C. F., Costa, L. J., Silva, L. C., Costa Filho, M. F., Lavor, W. K. B., Souza, D. C. S., Silva, E. F., Silva, D. V., Batista, R. O., Carmo, F. R., & Antunes, L. F. S. (2026). Trends and hotspots in biochar research for soil quality improvement in tropical and semi-arid regions based on bibliometric analysis. Discover Soil, 3, 115.