Modern agriculture faces the dual challenge of feeding a growing population while protecting the environment. Farmers need effective, eco-friendly ways to improve crop yields, especially for vital staples like maize. A new study published in the European Journal of Biology by Dr. Tatyana Stefanovska, Dr. Victoria Tsygankova, and their colleagues investigates a promising solution: combining biochar with novel synthetic growth regulators. Their findings show this combination isn’t just effective; it’s synergistic, meaning the ingredients work together to produce results far greater than they could alone.

The research team focused on two key components. The first is biochar, a stable, carbon-rich charcoal made from plant waste—in this case, the energy crop Miscanthus x giganteus. Biochar is prized for its ability to improve soil structure, help retain water, and lock carbon away, which benefits the climate. The second component included three synthetic nitrogen-containing heterocyclic compounds: Ivin, Methyur, and Kamethur. These compounds act as plant growth regulators, mimicking natural hormones to spur development, and are effective in tiny, nanomolar concentrations, minimizing environmental impact. The question was, what happens when you put them together?

To find out, the researchers treated maize seeds with different solutions and grew them for three weeks on a neutral perlite substrate. They compared a control group (distilled water) against groups treated with a standard plant hormone (auxin, or IAA), biochar alone, and biochar combined with each of the three synthetic compounds.

The results were striking. While the standard IAA hormone gave the plants a good boost—increasing biomass by 48% and root number by 394% compared to the control—the biochar treatments often did even better. Biochar alone increased plant biomass by 55% and shoot length by 69%. But the combinations truly shined. The mixture of Biochar + Kamethur was the top performer for overall size, causing an impressive 78% increase in plant biomass. The Biochar + Methyur cocktail triggered explosive root development, increasing average root length by a massive 370% and the number of roots by 421%. These combinations clearly outperformed the standard hormone, demonstrating a powerful synergistic effect.

This growth wasn’t just superficial. The treated plants were also healthier on a cellular level. The biochar combinations increased the levels of chlorophyll a and b, the pigments essential for photosynthesis. This suggests the plants were more efficient at converting sunlight into energy. Perhaps most impressively, the biochar treatments significantly increased the total soluble protein in the leaves. Biochar alone boosted protein by nearly 51%, and the Biochar + Methyur mix increased it by 42%. The standard IAA hormone, by contrast, showed no statistically significant increase in protein at all.

This study demonstrates that a sustainable “cocktail” of waste-derived biochar and specific, low-dose synthetic compounds can be a powerful tool for agriculture. This combination enhances maize growth from the roots up, improving not just the plant’s size but also its fundamental biochemical machinery for producing energy and protein. This approach could lead to more productive and resilient crops, offering a promising strategy to help farmers meet global food demands sustainably.

Source: Stefanovska, T., Tsygankova, V., Klius, V., & Medkov, A. (2025). Enhancing the Vegetative Growth of Maize using Biochar from Miscanthus x giganteus Waste and Synthetic Nitrogen-Containing Heterocyclic Compounds. European Journal of Biology.