SUSL Staff Directory

Professor PI Yapa



Doctor of Philosophy in Soil and Environmental Sciences, Department of Soil Science, The University of Reading, 2003

Master of Science, Department of Soil Science, University of Peradeniya, 1996

Bachelor of Science, Faculty of Agriculture, University of Peradeniya, 1990


I am the first Professor in Ecological Agriculture in Sri Lanka, due to my extensive international and national contribution, experience, knowledge, and international collaborations in the field of ecological agriculture. I also possess vast experience in organizing, implementing and handling of large-scale, multi-disciplinary projects, both at national and international levels. I have successfully completed a number of research projects with grants obtained from various funding sources.

Research Interests

Ecological Agriculture

Forest die-back studies

Soil Remediation and Rehabilitation

Urban Waste Management 

Mitigation of Green House Gas (GHG) emission in Agriculture

Current Research Projects

  • SUSL/RG/2016/04 "Environmentally Induced Forest Die-back in Horton Plains: Sources of Contaminants, Their Fate, and Mitigating Toxicity with Natural Geo-sorbents.”  2017 – 2019 (3 years), Sabaragamuwa University of Sri Lanka (Principle Investigator)

Recent Publications

Refereed Journals

  • Gunadasa, H. K. S. G. and Yapa P. I. (2015). Forest Dieback as Affected by Soil Pollution with Special Reference to Montane Forests - A Review, International Journal of Plant and Soil Science.
  • Gunadasa, H. K. S. G. and Yapa, P. I. (2015). Soil Chemical Quality and Forest Dieback. International Journal of Environmental Science and Development. 6(1).
  • Moulin, A. P., Glenn, A., Tenuta, M., Lobb, D. A., Dunmola, A. S., and Yapa, P. I. (2014). Alternative transformations of nitrous oxide soil flux data to normal distributions. Canadian J. of Soil Sci. 94(1): 105-108.
  • Yapa, P. I., Gunadasa, H. K. S. G., Ranasinghe, G. N. L. M. and Wijesundara, W. R. A. T. P. (2013). Ecological agriculture as a sustainable alternative to green revolution–type agriculture in the north central province of Sri Lanka, International Journal of Agricultural Science and Development.
  • Gunadasa, H. K. S. G, Yapa, P. I., Nissanka, S. P., and Perera, S. P. (2012). Soil Pollution and Forest Dieback: Will the Compost and Mycorrhizal Treatments be Effective in Mitigating Forest Dieback, International Journal of Chemical Engineering and Applications vol. 3, no. 2, pp. 108-113.
  • Yapa, P. I., Gunadasa, H. K. S. G. (2012). Mitigation of Soil Pb Toxicity by Soil Organic Matter. International Journal of Agriculture Innovations and Research, Volume 1, Issue 3, ISSN: 2319-1473

Refereed Conference Proceedings

  • Gunadasa, H. K. S. G. and Yapa, P.I. (2015). Mitigation of Pb Induced Forest Dieback in Sri Lanka: Use of Soil organic Matter. International Conference on Agricultural, Ecological and Medical Sciences (AEMS-2015), Feb. 10-11, 2015 Penang (Malaysia).
  • Bandara, T., Hewage, B., Herath, I., Kumarathilaka, P., Yapa, P., Wekumbura, C., Rajakaruna, P., Dissanayake, S., Vithanage, M. (2014). Role of Woody Biochar on Soil Microbial Activities, Organic Fraction and Heavy Metal Immobilization in Serpentne Soil. Proceedings 2nd International Symposium on Driving Research Towards Economy Opportunites & Challenges. November 13-14, Sri Lanka Academy of Young Scientists (SLAYS). 
  • Somaratne, R., Yapa, P. I. and Yapa, P. N. (2013). Use of different carrier materials for culture and storage of native forest soil microorganisms. In: Proceedings of the 3rd International Conference on Ecological Environmental and Biological Sciences (ICEEBS’2013). Planetary Research Centre, Singapore. 29-30 April 2013