Researchers Convert Waste Geranium Leaves Into High-Value Biochar to Boost Soil Health and Plant Growth
A research team at the University of Hyderabad (UoH) has developed an innovative technique to convert waste geranium leaves from the essential oil industry into biochar, a soil-enriching material that significantly improves soil fertility and plant growth. This breakthrough not only reduces agricultural waste but also supports sustainable farming and carbon sequestration.
The findings were published in the November 2025 special issue of Biomass and Bioenergy (Elsevier), showcasing how scientific innovation can transform low-value biomass into a powerful environmental resource.
Study on “Recycling of Waste Geranium Leaves Into Biochar for Soil Amendment”
The study, titled “Recycling of waste geranium leaves into biochar for soil amendment,” was conducted jointly by the School of Life Sciences (SLS) and the School of Engineering Sciences and Technology (SEST) at UoH.
The project was led by Professor Appa Rao Podile (SLS) and Professor VVSS Srikanth (SEST), with research contributions from Dr. Danteshwari Chaudhary, Dr. Sarma PVSRN, Akshay Rao, Dharani Kumar, and Dr. Ravikiran.
Their interdisciplinary approach combined plant science and materials engineering to create an efficient process that transforms geranium residue into high-quality biochar.
High-Carbon Biochar With Rich Mineral Content
Extensive analysis revealed that geranium leaf biochar contains:
- ~65% carbon
- Essential minerals including calcium, potassium, magnesium, and phosphorus
- Naturally alkaline properties
These characteristics make the biochar particularly beneficial for improving soil fertility, restoring degraded soil, and enhancing overall plant health.
Proven Benefits in Plant Growth
When applied to soil, the biochar significantly boosted the growth of rosemary plants, demonstrating:
- Increased plant vigor
- Improved nutrient uptake
- Enhanced soil structure and fertility
The study confirms biochar’s dual role in agricultural productivity and environmental sustainability.
Low-Cost, Energy-Efficient Process With Strong Economic Potential
The researchers highlighted the economic value of utilizing abundant and low-cost geranium residues. Key advantages include:
- Low energy consumption (~9 kWh per batch)
- Lower production cost per kilogram compared to many commercial biochar products
- Strong potential for scalable, rural-friendly green technology
The project received support from the Department of Biotechnology (DBT) and made use of advanced facilities under DST-FIST.
Expert Insights From Lead Researchers
Professor Appa Rao Podile noted that the study demonstrates how essential-oil industry waste can be repurposed into a sustainable soil enhancer that promotes plant health, soil rejuvenation, and carbon sequestration.
Professor VVSS Srikanth emphasized that the collaboration between engineering and life sciences enabled a comprehensive approach—covering process design to agricultural application—and highlighted how such integration leads to meaningful environmental benefits.
A Scalable Model for Sustainable Crop Residue Management
The research offers a replicable and scalable model for managing aromatic crop residues across India. By converting geranium waste into value-added biochar, the study strengthens the foundation for a circular bioeconomy, benefiting both farmers and the environment.
