University of Hyderabad researchers turn Geranium waste into soil-boosting biochar

Researchers at the University of Hyderabad have developed a method to upcycle waste Geranium leaves from the essential oil industry into biochar, a carbon-rich material that improves soil fertility and plant growth. Trials demonstrated enhanced growth in Rosemary plants, underscoring the agricultural value of the innovation.

Hyderabad: The University of Hyderabad (UoH) researchers have developed a method to upcycle waste Geranium leaves, an often-discarded byproduct of the essential oil industry, into a value-added material that can rejuvenate soils and enhance plant growth.

The research, ‘Upcycling of Waste Geranium Leaves into Biochar for Soil Amendment’, recently published in a special issue of the prominent journal Biomass and Bioenergy (Elsevier, November 2025), demonstrated how scientific ingenuity can transform agricultural waste into a powerful tool for environmental sustainability.

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The interdisciplinary team combined expertise in plant sciences and materials engineering to design an efficient process for transforming Geranium residues into biochar, a carbon-rich product known for its ability to enhance soil fertility and sequester carbon.

Comprehensive analyses revealed that the biochar derived from Geranium leaves possessed a high carbon content (~65%) and contained minerals such as calcium, potassium, magnesium, phosphorus, and exhibited alkaline properties, which are beneficial for improving soil fertility.

When used to amend soil, biochar, according to researchers, significantly enhanced the growth of Rosemary plants, confirming improvements in plant vigour and nutrient assimilation. These outcomes highlighted the dual environmental and agricultural benefits of biochar, reducing waste while improving soil productivity and supporting a circular bioeconomy, they said.

According to the authors, the process also has substantial economic potential, as Geranium residues are abundant and inexpensive. The energy requirement for the process was modest (~9 kWh per batch), and the estimated production cost per kilogram of biochar was substantially lower than many commercial biochar products available globally.

One of the project leads, School of Life Sciences, Prof. Appa Rao Podile said the work demonstrates how a waste product from the essential oil industry could be turned into a sustainable soil enhancer that supports plant health, soil restoration, and carbon sequestration.

Another project lead, School of Engineering Sciences, Prof. VSS Srikanth said the collaboration between engineering and life sciences enabled a holistic approach, from process design to agricultural application, showing how interdisciplinary research can generate tangible environmental benefits.

The research team also consisted of Dr Danteswari Ch, Dr Sarma PVSRN, Akshay Rao, Dharani Kumar, and Dr Ravikiran, each contributing to various aspects of the study.