Piumi Amasha Withana, Ph.D. - Environmental Soil Science Research Portfolio
This portfolio presents research on plastic pollution in soils, biodegradable plastic degradation, biochar in environmental management, nutrient dynamics in soil and water, and sustainability reporting. It includes academic background, research projects, publications, events, and contact information for collaboration and scholarly communication.
Research Focus
The research focus connects soil science, environmental pollution, material degradation, waste valorization, and sustainable management. Soil systems can receive plastic residues from agricultural films, compost, biosolids, packaging, runoff, and unmanaged waste. Once in soil, plastic fragments interact with mineral particles, organic matter, microbial communities, water movement, and plant roots. Understanding those interactions is necessary for assessing ecological risk and designing practical mitigation strategies.
Biodegradable plastics require careful field-relevant evaluation because degradation depends on polymer chemistry, temperature, moisture, oxygen, microbial activity, soil texture, and management conditions. A material that performs well in industrial composting may not degrade at the same rate in agricultural soil. Research therefore needs to distinguish visible disappearance from fragmentation and complete mineralization.
Biochar research considers how carbon-rich materials made from biomass can influence soil fertility, contaminant immobilization, carbon storage, and circular economy goals. Biochar is not a single uniform product; its behavior depends on feedstock, pyrolysis conditions, ash content, pH, surface chemistry, nutrient content, and the receiving soil. Responsible application requires characterization, soil testing, field evidence, and long-term monitoring.
Nutrient dynamics research examines how nitrogen, phosphorus, potassium, and other nutrients move through soils, sediments, plants, microbes, and water systems. Efficient nutrient management supports productivity while reducing leaching, runoff, and water-quality impacts. This work links laboratory measurements, field observations, and environmental decision making.