Johnston Group Members

Gnanasiri S. Premachandra (Prema) Research Agronomist. Prema coordinates the experimental work in the lab and conducts independent research.

Kiran Rana (current Ph.D. student) Kiran has recently completed her M.Sc. thesis ‘Influence of low molecular weight organic acids on the release of P from highly weathered soils in Brazil and Kenya’ and is now starting her Ph.D. looking at the adsorption mechanisms of of dioxins, PCBs, and PAHs.

Eric Johnson (current M.Sc. student) Interaction of glyphosate in soils. Eric is studying the molecular mechanism of interaction between glyphosate and soil constituents.

Susan Crow Comparison of the chemical alteration trajectory of liriodendron tulipifera litter among forests with different invasive earthworm activity. Susan worked in my lab for a few months resulting in a recent journal article submission to JGR (Postdoc in Earth and Atmospheric Science at Purdue University with Tim Filley)

Alfredo de Campos (Ph.D. graduated 2007) Effects of Redox on the soil solution chemistry and aggregate stability of Midwest Upland soils. Current position: Assistant Professor of Soil Chemistry - Universidade Federal de Goiás. Instituto de Estudos Sócio-Ambientais, Cx.P.131, Goiânia, G.O., Brasil.

Balwant Singh (Visiting Professor – 2006) Balwant is Professor Soil Chemistry at the University of Sydney, Australia and spent a sabbatical at Purdue working with Darrell Schulze and myself in the areas of soil chemistry and mineralogy.

Elizabeth Haack (Postdoc 2005-2007 at the Center for Environmental Science and Technology at the University of Notre Dame; advisor Patricia Maurice).

Dongqiang Zhu (Postdoc 2004-2005) Geochemical Controls on the Adsorption, Bioavailability, and Long-term Environmental Fate of Pesticides.Mechanisms. Don is an Assistant Professor at the State Key Laboratory of Pollution Control, School of The Environment, Nanjing University Nanjing 210093, P.R. China

Katerina Dontsova (Ph.D. 2002) Ca2+ and Mg2+ effects of water and ammonia adsorption by soil clays. (Advisor - Darrell Norton). Current position: Research scientist working at US Army Corps of Engineers, Vicksburg, MS.

Maurilio Fernandes de Oliveira (Postdoc 2001-2003) Spectroscopic studies of pesticide sorption on soil minerals. Maurilio is now a staff scientist working for EMBRAPA in Sorghum and Maize, Brazil.

Shan Li Wang (Ph.D. 2002) Spectroscopic and structural studies of aluminum oxides. Current position: Assistant Professor of Soil Chemistry at National Chung-Hsing University, Taichung, Taiwan.

Beáta Emoke Madari (Ph.D. 1998) The effect of tillage on the nature and properties of humic substances. Current position: Embrapa Solos Ministério da Agricultura, Brasil. Beata received her Ph.D. from Godollo Agricultural University, Godollo, Hungary. (co-advised with Prof. Erika Micheli).

Christopher A. Guest (M.Sc. 1997) Synthetic soil from composting coal combustion byproducts and an industrial biosolid. Current position: Private consultant working in the U.K.

Weizong Xu (M.Sc. 1997) Vibrational probe studies of sorbed water, structural hydroxyl groups and surface acidity on montmorillonite by FTIR/Gravimetric methods. (Went on for Ph.D. in physical chemistry at Purdue University) Staff scientist working for Alcoa.