The challenge of maintaining high crop yields is growing more difficult as soil health declines and the climate becomes less predictable. Farmers have traditionally responded by applying more chemical fertilisers, yet these are often inefficient, with a large portion of nutrients washing away before plants can use them. This waste not only hurts the farmer’s bottom line but also creates environmental pollution. A new study published in the journal Biochar by Negar Omidvar and her research team explores a highly innovative solution: turning biochar, a charcoal-like substance made from organic waste, into specialized liquid fertilisers. These liquid biochar mineral complexes are designed to be sprayed easily over large fields, delivering nutrients directly where they are needed most.

The researchers developed four different types of these liquid fertilisers to see how they would perform in a real-world pasture system. Some were simple blends of wood-based biochar, while others were enriched with extra minerals like phosphorus or nitrogen. The most successful version, a nitrogen-enriched blend, produced remarkable results. This specific formula increased pasture growth to over 42 tons per hectare. To put this in perspective, the areas treated with conventional chemical fertilisers produced less than 19 tons per hectare. The nitrogen-enriched biochar was so effective that it did not even require the usual “top-up” of extra chemical nitrogen that farmers typically apply during the growing season.

Beyond just growing more grass, the study looked closely at how well the plants absorbed nutrients. One of the biggest problems in farming is “mining” the soil, where plants strip away existing nutrients without replacing them. The nitrogen-enriched liquid biochar was the only treatment that maintained a positive nutrient balance. This means the fertiliser provided enough food for the rapid growth without exhausting the natural reserves in the soil. This efficiency is likely due to the way the biochar was processed. By grinding the biochar into tiny particles, a process called micronisation, the researchers made it easier for the material to move through the soil and reach the plant roots.

From a financial perspective, the results were equally encouraging. Farming is a business, and any new product must pay for itself to be useful. The study calculated a benefit-cost ratio for these new fertilisers that ranged from 1.94 to 2.54. This indicates that for every dollar spent on the biochar fertiliser, the farmer could expect more than double that amount in return from the increased yield. The nitrogen-enriched version provided the highest net return of all the treatments tested. This suggests that these liquid biochar products are not just a scientific curiosity but a viable tool for modern, large-scale agriculture.

Importantly, the study also checked if these new treatments would harm the invisible life in the soil. Soil is home to vast communities of bacteria and fungi that are essential for long-term health. The researchers found that even though the biochar fertilisers significantly boosted growth, they did not disrupt the balance of these microbial communities in the short term. This confirms that the new fertilisers can be used at relatively low rates to achieve high productivity without causing immediate ecological damage. This balance of high yield, economic profit, and soil safety marks a significant step forward in sustainable farming technology.

Source: Omidvar, N., Joseph, S., Dissanayake, L., Farrar, M. B., Reverchon, F., Burnett, R., Trubenbacher, K., Omidvar, N., Xu, Z., Zhang, M., Liu, H., Elliott, B., & Bai, S. H. (2026). Distinct forms of liquid biochar mineral complex fertilisers differently increase crop yield, nutrient balance and economic return. Biochar, 8(94).