A review published in the Journal of Soil Science and Plant Nutrition by Sahan Samuditha, Andrea Breverly Fernandez, Kadambot H. M. Siddique, Jayanta Kumar Biswas, and Meththika Vithanage shines a spotlight on the cutting edge of agricultural science, exploring how biochar acts as a dynamic modifier of the plant’s root environment. The authors emphasize that to truly unlock biochar’s potential in boosting plant health and soil fertility, conventional research methods must be replaced by multi-omics technologies. This shift in methodology is reflected in the literature: a bibliometric analysis revealed that scientific publications focusing on biochar’s impact on the rhizobiome using omics sciences have seen a remarkable increase, particularly since 2019, with the number of papers in this specific area jumping from around 5 in 2018 to 33 in 2023 in the SCOPUS database.

For decades, farmers and researchers have known that biochar improves soil quality by modifying its physical and chemical properties, leading to enhanced nutrient uptake and crop production. However, the new multi-omics evidence reveals that biochar is far from a passive 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; it’s an active agent of microbial selection and functional transformation at the molecular level. It does this by altering soil 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 and porosityPorosity of biochar is a key factor in its effectiveness as a soil amendment and its ability to retain water and nutrients. Biochar’s porosity is influenced by feedstock type and pyrolysis temperature, and it plays a crucial role in microbial activity and overall soil health. Biochar More, which, in turn, changes the composition of root exudates secreted by plants. These exudates are essentially chemical signals that selectively enrich specific microbial taxa—the “rhizobiome”—that are highly beneficial for the plant.

To understand these intricate interactions, researchers now rely on a suite of “omics” techniques, which together offer a holistic view of biochar’s influence: Metagenomics answers the question “Who is there?” by characterizing the entire genomic potential of the microbial community, revealing structural shifts like the increase of beneficial bacteria (e.g., Bacillus and Pseudomonas) and the suppression of pathogens (e.g., Fusarium) following biochar application. Metatranscriptomics addresses the question “What are they actively doing?” by analyzing the functional genes being transcribed into mRNA at the time of sampling. Studies using this approach have been crucial in unravelling differential gene expressions in pathways responsible for plant growth promotion and enhanced disease resistance, such as the upregulation of genes associated with nitrogen fixationNitrogen is a crucial nutrient for plant growth, but plants can’t directly absorb it from the air. Nitrogen fixation is a process where certain bacteria convert atmospheric nitrogen into a form that plants can use. Biochar can provide a home for these nitrogen-fixing bacteria, enhancing More and antigen processing in tomato and pepper plants, respectively. Metametabolomics focuses on the final metabolic products—the “metabolome”—in the soil, which are the real-time signals of plant-microbe interaction. This approach has confirmed biochar’s role in enhancing plant immune responses (via the accumulation of phenylpropanoid/flavonoid metabolites) and aiding in soil remediation by enriching organic pollutant and heavy metal removal pathways.

Despite these powerful tools, the authors stress that biochar’s effect is highly context-dependent. This variability has sometimes led to conflicting evidence, such as one study showing that bamboo biochar inhibited phenanthrene degradation due to a reduction in certain bacterial genes. These discrepancies highlight a critical need for standardized protocols for both biochar production and the omics analysis pipelines to ensure reliable and comparable results across the global scientific community.

Currently, most studies have incorporated only one or two omics technologies. However, the path forward involves the holistic integration of multi-omics approaches (genomics, transcriptomics, proteomics, and metabolomics) to overcome current limitations and provide a comprehensive, systems-level understanding of the complex biochar-plant-rhizobiome interactions. Such integrated research will enable the development of precision biochar applications—tailored formulations and application rates for specific soil and crop environments—which hold the potential to increase plant resilience and dramatically decrease reliance on chemical inputs, marking a pivotal step toward sustainable agriculture.

Source: Samuditha, S., Fernandez, A. B., Siddique, K. H. M., Biswas, J. K., & Vithanage, M. (2025). Exploring Biochar Impacts Through Omics Sciences: Enhancing Rhizobiome Understanding. Journal of Soil Science and Plant Nutrition. Advance online publication.