PhD Student Profile
Rohan Samaratunga
The University of Newcastle
My PhD research focuses on developing climate-smart, algae-based biofertilisers to improve crop productivity, resilience and soil health under Australian agricultural conditions. I have developed effective algal consortia in the laboratory and am currently evaluating their performance in soil-based greenhouse experiments, focusing on their ability to enhance soil functions and support sustainable crop production.
Following the selection of the best-performing consortia, my research will proceed to plant-based greenhouse and field trials with Australian crops to assess their agronomic potential under real-world conditions. In parallel, I am addressing scalability and commercial viability by developing low-cost growth media and optimising bioreactor-based cultivation and harvesting methods to produce practical, multi-form algae-based biofertiliser solutions for sustainable farming systems.
PhD Title: “Developing next generation biofertilisers for enhancing soil health & crop productivity towards resilient & climate smart agriculture”
PhD start date: July 2024
Supervisors: Prof Megh Mallavarapu (University of Newcastle), Dr Abinandan Sudharsanam (University of Newcastle), Prof Chengrong Chen (Griffith University)
What interested you about this research?
Farming in Australia plays a vital role in the national economy; however, it faces challenges due to a changing climate. As someone passionate about conserving nature, I considered using science and microbes, such as algae, which are underexplored in the soil arena, to help address this challenge. This motivated me to pursue a PhD that could have a meaningful impact. I believe my research has the potential to support Australian agriculture, strengthen ecosystems, and contribute to the development of sustainable biofertiliser technologies.
What do you love about soil?
Soil is a highly dynamic system composed of living organisms, weathered minerals, water, and air, all interacting to support plant growth. I am particularly fascinated by the complexity of improving soil health, as it requires understanding the roles and interactions of both macro- and micro-organisms, especially when introducing algae-based biofertilisers and ensuring their survival and symbiotic function. The challenge of developing biofertilisers that can persist, enhance soil health, and improve crop productivity under Australia’s harsh farming conditions is what makes soil research both demanding and deeply rewarding.
What do you love about your PhD?
A PhD is a highly collaborative journey, and I enjoy working with a wide range of people across research, industry, and farming communities. I particularly value working with my experienced supervisors, who are open-minded and supportive, encourage independent thinking, and help refine my research ideas and skills for my future career.
How will your PhD help to make a difference for farmers?
The successful development of algae-based biofertilisers could directly benefit Australian farmers by improving soil health, crop performance and farm sustainability.
Beyond the farm gate, this research contributes to broader ecosystem sustainability, as algae act as primary producers within soil systems and fix carbon. The outcomes may also support the fertiliser industry by providing sustainable alternatives and creating new pathways for researchers and industry partners to diversify and improve biofertiliser products.
What do you want to do when you finish your PhD?
I am open-minded about my future career and aim to pursue opportunities that allow me to continue learning, contributing and growing. After completing my PhD, I am open to pathways across academia, industry and applied research.
My long-term goal is to build a career that aligns with my skills and values, supports sustainable agriculture, and meets both organisational objectives and broader societal needs.
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