Associate Professor- Soil and Environmental Chemistry
Biography and Education
Dr. Ganga Hettiarachchi is one of the world’s leading young scientists in the field of trace metal chemistry in soils. Her research at K-State focuses on understanding the chemistry of both nutrient and contaminant elements in soils, with the goal of developing solutions to agricultural or environmental problems. For example one of her current projects, goal is to find ways to remediate underutilized, mildly contaminated soils (often call “brownfields”) into soils suitable for productive use, such as community gardens. Another project focuses on understanding reaction products of fertilizers in soils to find ways to increase the fertilizer use efficiency.
Dr. Hettiarachchi was born and raised in a suburb of Colombo, the capital city of Sri Lanka. Although not from a farm, her father thought agriculture would become increasingly important in the future and encouraged her to study agriculture as opposed to any pure science field when she entered the university. She selected soil chemistry as her area of emphasis while getting her B.S. degree at the University of Peradeniya in Sri Lanka, then went on to get her M.S. and Ph.D. degrees in soil chemistry at Kansas State University.
After working in research positions at the US Environmental Protection Agency and Australia, and in a faculty position in Sri Lanka, she joined the Agronomy faculty at K-State in 2008. The opportunity to do both research and teaching, as well as the harmony of the faculty, are what drew her back to K-State.
While not involved in her work, Dr. Hettiarachchi enjoys spending time with her family including her two daughters and husband, and reading novels. She has always liked reading novels, and understanding different cultures.
Dr. Hettiarachchi advises students to find a niche for themselves in a field they enjoy and go with it as opposed to deciding on a field of study based strictly on the potential for job opportunities. She also advises students to take all the extra courses they can outside of their major.
Ph.D., Soil & Environmental Chemistry, Department of Agronomy, Kansas State University, 2000
M.S., Soil Chemistry, Department of Agronomy, Kansas State University, 1995
B.Sc., Faculty of Agriculture | Soil Science, University of Peradeniya, Sri Lanka, 1992
This departmental member does not currently have any extension information available for review, or does not currently have an extension appointment.
Staff and Students
Graduate Research Assistants:
- Chammi Attanayake - Ph.D. Student
- Phillip Defoe - Ph.D. Student
- Madhubhashini Galkaduwa - Ph.D. Student
- Ranju Karna - Ph.D. Student
- Joy Pierzynski - Ph.D. Student
- Pavithra Pitumpe Archchige - Ph.D. Student
- Joseph "Jay" Weeks - M.S. Student
- Dorothy Menefee - M.S. Student
- Zafer Alasmary - Ph.D. Student
Undergraduate Lab Assistants:
- Caleb Gravesen
- Dr. Sabine Martin - Dr. Sabine Martin | Program Associate
- Pushpika Munaweera Thanthirige | Lab Assistant
Previous Students | Research Assistants:
- Kasun Dissanayake - Assistant Scientist
- Vindhya Gudichutta - Graduate Research Assistant
- Conduct interdisciplinary research to understand the biogeochemistry of both nutrient and contaminant elements in the natural environment
- Apply knowledge of soil and environmental chemistry to develop solutions to environmental problems
Soil Biogeochemical Transformation
My research program in Soil and Environmental Chemistry involves laboratory and field experiments on agricultural soils, contaminated urban soils, and mine-impacted soils/geomaterials in order to understand biogeochemical transformation of nutrient and potentially toxic elements and their role in controlling soil-plant transfer, mobility, and attenuation processes. Primary focus areas presently include:
- “In situ” soil remediation involving the formation of stable solid phases, chemisorption, and phytostabilization to reduce soil-plant transfer of potentially toxic elements and/or reduce transportation of contaminated soils by air and water
- Understanding complex redox transformations of potentially toxic trace elements and interactions between molecular level and macro-scale biotic and abiotic processes on the health of our soil/geo environments and water bodies
- Determining reaction products of different P fertilizer sources in soils to understand their relationship to potential availability and plant uptake. The objective is to aid in the design of better and more efficient P fertilizers and P management practices
- Evaluating the impacts of contaminants on food safety from urban gardens and other types of local farming activities on brownfield sites
- Investigating the role of soil mineralogy and chemistry to aggregation and soil C sequestration in agroecosystems
Additional Links to Dr. Hettiarachchi's Research
Khatiwada, R., G.M. Hettiarachchi, D. Mengel, and M. Fei. 2012. Speciation of Phosphorus in a Fertilized Reduced Till Soil System: In-Field Treatment Incubation Study. Soil Sci. Soc. Am. J. (Accepted 8/19/2012)
Baker, L., G.M. Pierzynski, G.M. Hettiarachchi, K.G. Scheckel, and M. Newville. Speciation of Zn as Influenced by P Addition in a Pb/Zn Smelter Contaminated Soil. J. Environ. Quality (Accepted 7/25/2012)
Jassogne, L., G.M. Hettiarachchi, A. McNeill, and D. Chittleborough. 2012. Characterising the chemistry of micropores in a sodic soil with strong texture-contrast using synchrotron X-ray techniques and LA-ICP-MS. Soil Res. 50, 424–435.
Premarathna, L., M.J. McLaughlin, J. Kirby, G.M. Hettiarachchi, S. Stacey, and D. Chittleborough. 2012. Selenate-enriched urea granules are a highly effective fertilizer for selenium biofortification of paddy rice grain. J. Agric. Food Chem. 60: 6037–6044
Premarathna, L., M.J. McLaughlin, J. Kirby, G.M. Hettiarachchi, D. Beak, S. Stacey, and D. Chittleborough. 2012. Influence of submergence and subsequent drainage on the partitioning and lability of added selenium fertilizers in a Fluvisol. Eur J Soil Sci. 63:514-522
Milani, N., M.J. McLaughlin, S.P. Stacey, J. K. Kirby, G.M. Hettiarachchi, D.G. Beak and G. Cornelis. 2012. Dissolution kinetics of macronutrient fertilisers coated with manufactured zinc oxide nanoparticles. J. Agric. Food Chem. 60:3991-3998
Brown, S.L., I. Clausen, M.A. Chappell, K.G. Scheckel, M. Newville, G.M. Hettiarachchi. 2012. High Fe biosolids compost induced changes in Pb and As speciation and bioaccessibility in contaminated soils. J. Environ. Qual. 41. doi:10.2134/jeq2011.0297
De Livera, D. Beak, M.J. McLaughlin, G.M. Hettiarachchi, and J.K. Kirby. 2011. Release of dissolved cadmium and sulfur nanoparticles from oxidizing sulfide minerals. Soil Sci. Soc. Am. J. 75: 842- 854.
Lombi, E., G.M. Hettiarachchi, and K.G. Scheckel. 2011. Advanced in situ spectroscopic techniques and their applications in environmental biogeochemistry: Introduction to the special section. J. Environ. Qual. 40:659-666.
Beak, D., J.K. Kirby, G.M. Hettiarachchi, L.A. Wendling, M.J. McLaughlin, and R. Khatiwada. 2011. Cobalt distribution and speciation in spiked soils: Effect of aging, intermittent submergence and in situ rice roots. J. Environ. Qual. 40:679-695
De Livera M.J. McLaughlin, G.M. Hettiarachchi, J.K. Kirby, and D.G. Beak.2011. Cadmium solubility in paddy soils: effects of soil oxidation, sulfide equilibria and comp