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Department of Agronomy

Dr. Ganga Hettiarachchi

Dr. Ganga Hettiarachchi


Soil and Environmental Chemistry

Kansas State University
2107 Throckmorton PSC
1712 Claflin Road
Manhattan, KS 66506

Ph: +1-785-532-7209
Fx: +1-785-532-6094


Dr. Ganga Hettiarachchi is one of the world’s leading scientists in the fields of trace metal and nutrient 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


  • Pitumpe Arachchige, P.S., G.M. Hettiarachchi, C.W. Rice, J.J. Dynes, L. Maurmann, J. Wang, C. Karunakaran, A.L.D. Kilcoyne, C.P. Attanayake, T.J. C. Amado & J.E. Fiorin. 2018. Sub-micron level investigation reveals the inaccessibility of stabilized carbon in soil microaggregates. Scientific Reports. 8: 16810.
  • Karna, R.R., G.M. Hettiarachchi, J. Van Nostrand, T. Yuan, C.W. Rice, Y. Assefa, and J. Zhou. 2018. Microbial Population Dynamics and the Role of Sulfate Reducing Bacteria Genes in Stabilizing Pb, Zn, and Cd in the Terrestrial Subsurface. Soil Syst. 2: 60.
  • Ohno, T. and G.M. Hettiarachchi. 2018. Soil chemistry and the one health initiative: introduction to the special section. J. Environ. Qual. 47(6):1305-1309.
  • Galkaduwa, M.B., G.M. Hettiarachchi, G.J. Kluitenberg, and S.L. Hutchinson. 2018. Iron oxides minimize arsenic mobility in soil material saturated with saline wastewater. J. Environ. Qual. 47:873-883.
  • Pierzynski, J. and G.M. Hettiarachchi. 2018. Reactions of Phosphorus Fertilizers with and without a Fertilizer Enhancer in Three Acidic Soils with High Phosphorus Fixing Capacity. Soil Sci. Soc. Am. J. 82: 1124-1139).
  • Hsiao, Che-Jen, G. Sassenrath, L. Zeglin, G.M. Hettiarachchi, and C.W. Rice. 2018. Vertical changes of soil microbial properties in claypan soils. Soil Biology and Biochemistry, 121: 154-164.
  • Karna, R.R. and G.M. Hettiarachchi. 2018. Subsurface Submergence of Mine Waste Materials as a Remediation Strategy to Reduce Metal Mobility: An Overview. Current Pollution Rep. 4:35-48.
  • Hettiarachchi, G.M., E. Donner, and E. Doelsch. 2017. Introduction to Special Section: Application of Synchrotron Radiation-Based Methods for Environmental Biogeochemistry J. Environ. Qual. 46:1–7
  • Attanayake, C.P., G.M. Hettiarachchi, Q. Ma, G.M. Pierzynski, M.D. Ransom. 2017. Lead speciation and in vitro bioaccessibility of compost-amended urban garden soils. J. Environ. Qual. Published online 09/07/2017, doi:10.2134/jeq2017.02.0065.
  • Paredez, J. M, N. Mladenov, M. B. Galkaduwa, G.M. Hettiarachchi, G.J. Kluitenberg, S.L. Hutchinson. 2017. A soil column study to evaluate treatment of trace elements from saline industrial wastewater. Journal of Water Science and Technology. wst2017413; DOI: 10.2166/wst.2017.413.
  • Vega, M. A., H. V. Kulkarni, N. Mladenov, K. Johannesson, G. M. Hettiarachchi, P. Bhattacharya, N. Kumar, J. Weeks, M. Galkaduwa and S. Datta. 2017. Biogeochemical Controls on the Release and Accumulation of Mn and As in Shallow Aquifers, West Bengal, India. Front. Environ. Sci., 23 June 2017. 
  • Galkaduwa, M.B., G.M. Hettiarachchi, G.J. Kluitenberg, S.L. Hutchinson, L. Erickson, L. Davis. 2017. Transport and transformation of selenium and other constituents of flue-gas desulfurization wastewater in water-saturated soil materials. J. Environ Qual. 46(2):384-392. 
  • Datta, S, S.E. Vero, G.M. Hettiarachchi, and K. Johannesson. 2017.  Tungsten contamination of soils and sediments: Current state of Science. Current Pollution Rep. 3: 55-64.
  • Wijesekara, H., N. S. Bolan, M. Vithanage, Y. Xu, S. Mandal, S. L. Brown, G. M. Hettiarachchi, G. M. Pierzynski, L. Huang, Y. Ok, M. B. Kirkham, C. Saint, A. Surapaneni.  A review on the utilization of biowastes for mine spoil rehabilitation. Advancesin Agronomy. 138: 97- 173.
  • Brown, S., R.L. Chaney, and G.M. Hettiarachchi. 2016. Lead in urban soils -- A real or perceived concern for urban agriculture? J. Environ. Qual. 45: 26-36. OPEN ACCESS
  • Henry, H., M. F. Naujokas, C. Attanayake N.T. Basta, Z. Cheng, G.M. Hettiarachchi, M. Maddaloni, C. Schadt, and K. G. Scheckel. 2015. Bioavailability-based in situ remediation to meet future lead (Pb) standards in urban soils and gardens. Environ. Sci. Technol., 49:8948-8958.
  • Attanayake, C.P., G.M. Hettiarachchi, S. Martin, and G.M. Pierzynski. 2015. Potential bioavailability of lead, arsenic, and polycyclic aromatic hydrocarbons in compost-amended urban soils. J. Environ. Qual. 44:930-944. 
  • Milani, N., G.M. Hettiarachchi, D.G. Beak, M. J. McLaughlin, J. K. Kirby, and S. P. Stacey. 2015. Fate of zinc oxide nanoparticles coated onto macronutrient fertilizers in an alkaline calcareous soil. PLoS ONE 10(5): e0126275. 
  • Hartley, P.E., D. Presley, M. D. Ransom, G. M. Hettiarachchi, and L. T. West.  2014. Vertisols and Vertic Properties of Soils of the Cherokee Prairies of Kansas. Soil Sci. Soc. Am. 78:556-566.
  • Defoe, P.P, G.M. Hettiarachchi, C. Benedict, and S. Martin. 2014. Safety of Gardening on Lead- and Arsenic-Contaminated Urban Brownfields. J. Environ. Qual. 43:2041- 2078.
  • Khatiwada, R., G.M. Hettiarachchi, D. Mengel, and M. Fei.  2014. Placement and source effects of phosphate fertilizers on phosphorus availability and reaction products in two reduced-till soils: A greenhouse study. Soil Sci. 179: 141-152.
  • Sankar, M. S., M.A. Vega, P. P. Defoe, M. G. Kibria, S. Ford, K. Telfeyan, A. Neal, T.J. Mohajerin, G. M. Hettiarachchi, S. Barua, C. Hobson, K. Johannesson, S. Datta. 2014. Elevated arsenic and manganese in groundwaters of Murshidabad, West Bengal, India Science of the Total Environ. Vol. 488-489: 570-579.
  • Harms, A., D.R. Presley, G.M. Hettiarachchi, C. Attanayake, S. Martin, and S.J. Thien. 2014. Harmony Park: A Decision Case on Gardening on a Brownfield Site. Natural Sciences Education. Vol. 43, 33-41.
  • Attanayake, C.P., G.M. Hettiarachchi, A. Harms, D. Presley, S. Martin, and G.M. Pierzynski. 2014. Field Evaluations on Soil Plant Transfer of Lead from an Urban Garden Soil. J. Environ. Qual. Vol. 43, 475-487.
  • 17.  Baker, L., G.M. Pierzynski, G.M. Hettiarachchi, K.G. Scheckel, and M. Newville.  2014. μXRF, μXAS and μXRD Investigation of Pb Speciation after the Addition of Different P Amendments to a Smelter-Contaminated Soil. J. Environ. Qual. Vol. 43, 488-497.
  • Mladenov, N., P. Wolski, G. M Hettiarachchi, M. Murray-Hudson; H. Enriquez; S. Damaraju, M.B. Galkaduwa, D. M McKnight, and W. Masamba. 2014. Abiotic and biotic factors influencing the mobility of arsenic in island groundwater of the Okavango Delta, Botswana. J. of Hydrology. Vol. 518, Part C, 326-341.
To view a full listing of publications view Curriculum Vitae (PDF).


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:

  1. “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
  2. 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
  3. 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
  4. Evaluating the impacts of contaminants on food safety from urban gardens and other types of local farming activities on brownfield sites
  5. Investigating the role of soil mineralogy and chemistry to aggregation and soil C sequestration in agroecosystems

Staff & Students

Graduate Research Assistants
Undergraduate Lab Assistants