Nitrogen is essential for crop growth, yet much of the nitrogen supplied through conventional fertilizers is not efficiently used by plants. This inefficiency increases farming costs and contributes to environmental pollution. Now, researchers have discovered that tiny particles derived from biochar could improve nitrogen delivery in soybeans, increase grain production, and enhance nutritional quality, opening new possibilities for sustainable crop management.
In a study published in Sustainable Carbon Materials, researchers from Hebei University of Technology investigated whether nitrogen-enriched biochar nanoparticles could act as microscopic nutrient carriers inside soybean plants. Using advanced isotope tracing and imaging techniques, the team demonstrated that these particles could enter plant roots, move through plant tissues, and contribute nitrogen to essential metabolic processes.
"Our findings suggest that biochar nanoparticles can do much more than improve soil properties. They may also serve as tiny nutrient carriers that help crops use nitrogen more efficiently," said corresponding author Professor Fei Lian of Hebei University of Technology.
Biochar is a carbon-rich material produced by heating biomass under oxygen-limited conditions. While conventional biochar is widely studied for improving soil health, its nanoscale particles remain relatively unexplored as tools for nutrient delivery.
To investigate their potential, the researchers produced nitrogen-enriched biochar nanoparticles using corn stalk residues and nitrogen-labeled urea. They prepared two materials at different temperatures, 400°C and 700°C, and applied them to soybean plants grown under greenhouse conditions.
The results were striking. At an application rate of just 5 milligrams per kilogram of soil, the nanoparticles increased soybean grain numbers by 35% to 45% compared with untreated plants. Grain weight also improved, while the contents of individual amino acids increased by 6.5% to 97.1%, suggesting potential benefits for crop nutritional quality.
But the researchers wanted to understand how these improvements occurred.
By incorporating the stable nitrogen isotope ¹⁵N into the nanoparticles, the team could track nitrogen movement throughout the plants. The results revealed that one type of nanoparticle increased isotope enrichment in soybean root nodules by 127.8% and grains by 47.9%. Isotope enrichment in grain amino acids also increased substantially.
Microscopic observations provided further evidence that biochar nanoparticles could enter soybean roots and travel to aboveground tissues.
Additional experiments showed that nanoparticle treatments enhanced the activity of enzymes responsible for converting nitrogen into compounds required for plant growth. The researchers also identified changes in nitrogen metabolism-related genes, suggesting that the nanoparticles stimulated the plants' internal nitrogen-processing machinery.
The team proposed that some nanoparticles may partially break down inside plant tissues, releasing nitrogen-containing compounds that can eventually become available for plant metabolism. Laboratory simulations supported this possible transformation pathway.
Importantly, the treatments also influenced beneficial soil microorganisms without significantly altering overall bacterial diversity.
Together, these findings suggest that nitrogen-enriched biochar nanoparticles could provide a new platform for precision nutrient delivery, potentially helping farmers improve productivity while reducing dependence on conventional fertilizers.
However, the researchers emphasize that further field studies are needed to evaluate long-term environmental safety, practical application methods, and performance under different agricultural conditions.
The study provides new evidence that agricultural biomass waste could be transformed into valuable nanomaterials that support more resource-efficient food production.
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Journal reference: Geng Z, Zhang H, Wang M, Cheng J, Xu X, et al. 2026. Stable isotope evidence for biochar nanoparticles as potential nanocarriers boosting nitrogen delivery in soybean. Sustainable Carbon Materials 2: e033 doi: 10.48130/scm-0026-0028
https://www.maxapress.com/article/doi/10.48130/scm-0026-0028
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About Sustainable Carbon Materials :
Sustainable Carbon Materials (e-ISSN 3070-3557) is a multidisciplinary platform for communicating advances in fundamental and applied research on carbon-based materials. It is dedicated to serving as an innovative, efficient and professional platform for researchers in the field of carbon materials around the world to deliver findings from this rapidly expanding field of science. It is a peer-reviewed, open-access journal that publishes review, original research, invited review, rapid report, perspective, commentary and correspondence papers.
