Liquid Biochar Fertilizer Could Help Farmers Grow More With Fewer Nutrient Losses

A new field study published in Biochar shows that liquid biochar mineral complex fertilizers can substantially improve pasture yield, nutrient balance and farm-level economic returns, offering a promising pathway toward more efficient and sustainable fertilizer use.

As climate change, soil degradation and rising fertilizer demand place increasing pressure on global agriculture, researchers are searching for ways to help crops make better use of nutrients already applied to the land. Conventional fertilizers often suffer from low use efficiency, meaning that significant amounts of nitrogen and phosphorus can be lost through leaching or runoff instead of being taken up by plants.

In the new study, researchers tested four novel liquefied biochar mineral complex fertilizers, known as BMCs, in a pasture cropping system in New South Wales, Australia. These liquid products were designed to combine the soil-improving properties of biochar with mineral nutrients in a form suitable for broadacre agricultural application.

The team compared two non-enriched micronized BMCs, one phosphorus-enriched BMC and one nitrogen-enriched BMC. Each was applied with and without conventional co-fertilization, and the researchers measured soil chemistry, plant nitrogen and phosphorus uptake, nutrient balances, pasture yield, microbial responses and economic returns.

The nitrogen-enriched formulation, BMC4, delivered the strongest performance. Pasture yield under BMC4 reached 42.20 t ha⁻¹, compared with 18.75 t ha⁻¹ in the fertilized control and 11.53 t ha⁻¹ in the non-fertilized control. This result suggests that carefully designed liquid biochar-based fertilizers can do more than simply add nutrients. They may help plants access and use those nutrients more effectively.

“Our findings show that the form and nutrient enrichment of liquid biochar fertilizers matter greatly,” said corresponding author Prof. Shahla Hosseini Bai. “The nitrogen-enriched BMC not only increased pasture production, but also improved nutrient balance, which is critical for both farm profitability and environmental protection.”