Texas A&M University
620 Heep Center
The Water Program
213 Teague Hall
College Station, Texas 77843
Dr. Jacqueline Aitkenhead-Peterson
M.S. Soil Science, University of Aberdeen
B.S. Environmental Science, University of Stirling
Effect of urbanization on soil and surface water chemistry, contribution of green roof growing medium and species selection to leachate chemistry, chemistry of turfgrass runoff, linkages between groundwater chemistry and human health, soil taponomy, international and domestic agriculture, environmental services of soil
1. The effect of urbanization on soil and surface water chemistry.
Collaborators: Terry J. Gentry and Raghavan Srinivasan
One post-doctoral research associate (Santhy), two Ph.D students (Young and Steele), six MS students (Harclerode, Holgate, McCrary, Watson, Cioce and Govil) and one undergraduate student (Ausley) under the supervision of Aitkenhead-Peterson have been involved in past and on-going research under this topic. Development of a new method using NIR spectroscopy to source track watershed contributions to surface waters is currently under way (Steele, Cioce and Govil). If successful, this methodology will be a significant advancement in source tracking organic nutrients in urban streams. Completed studies included: a) urban stormwater runoff (Young), b) sodicity of urban watershed soils and streams and the affect on nutrient transport (Steele), c) irrigation water chemistry effect on nutrient leaching and microbial community composition (Holgate), d) utilization of a nested system to source track E. coli and nutrients in surface waters (Harclerode), e) drivers of recovery and regrowth of E. coli (McCrary), f) examination of landuse and land management on stream chemistry in NE Texas (Watson), g) sources and fates of dissolved organic carbon in rural and urban streams (Cioce) and h) adsorption of organic C and organic N in rural and urban soils (Cioce and Ausley).
2. Contribution of green roof growing medium and species selection to leachate chemistry.
Collaborators: Astrid Volder (Horticulture), Bruce Dvorak (Landscape Architecture), Anthony Camarino (Texas AgriLife Extension Services) and Jeff Mickler (Jacob White Construction, Houston, TX).
One set of experiments on an intensive green roof are completed. Water quality of drainage water and soil chemistry of growth medium from several extensive green roofs on LEED Platinum buildings in Houston is currently underway.
3. Chemistry of turfgrass runoff: Effect of municipal tap water, climate and soil amendments.
Collaborators: Richard White, Kevin McInnes and Ben Wherley (Soil and Crop), David Chalmers (Texas AgriLife Extension Services) and Steve Kelly and Phil Dwyer (Scotts Company).
Funding was obtained from Scotts Company Gift Fund and the Scotts Miracle Grow Company to construct one of the largest turf runoff facilities in the nation. Infrastructure for this study is almost complete. Expectations are that the facility will provide graduate and undergraduate training and research opportunities for students in Soil and Crop Sciences and Water Management and Hydrological Sciences commencing 2012.
4. Linkages between groundwater chemistry and human health.
Collaborators: Raj Arveti (S.V. University, Tirupati, India), Scott Senseman (Soil and Crop)
Drinking water tube wells in several villages in Andhra Pradesh were evaluated for fluoride concentrations. A second project evaluating pesticide and nutrient concentrations in drinking water wells in Mexico will commence in summer 2012.
5. Soil Taphonomy
Collaborators: Joan Bytheway (SHSU), Jeff Tomberlin and Aaron Tarone (FIVS), Michelle Hamilton and Kate Spradley (Texas State University), T.C. Crippen (USDA), Eric Benbo (Dayton U. Ohio), Mike Strickland (Yale), Kyle Wickings (U. New Hampshire), Cheryl Johnston (University of Western Carolina).
It has proven easier to examine the decomposition products of humans relative to those of other mammals that may contribute to the increased carbon and nutrients observed in soil and surface water along the urban to rural gradient. Buried dogs in urban gardens, road killed deer along urban freeways and culling of feral hogs in rural environments are all contributors to carbon and nutrients transport at a watershed scale.
One PhD student (Alexander) under Aitkenhead-Petersons supervision and one undergraduate student (Owings) under the joint supervision of Dr. Joan Bytheway and Aitkenhead-Peterson are responsible for cadaver decomposition product projects in Sam Houston State Forest. Three undergraduate students, two from the Entomology department and one from Bioenvironmental Science department have shown interest in conducting directed research in soil taphonomy during summer and fall 2012. Vultures and scavengers will feed on remains which make it virtually impossible to determine post mortem interval using traditional entomological methods. Soil chemistry and near infrared diffuse reflectance spectroscopy has a huge potential in filling that gap. Texas has many incidences of dumped corpses and scattered remains. Work with Dr. Kate Spradley and Dr. Michelle Hamilton of Texas State University on Freeman Ranch, San Marcos will develop methods to determine post mortem intervals of scattered remains.
The fundamental concept being tested in research efforts is that of decomposition products and associated changes in soil nutrient and carbon chemistry can be identified by NIR spectroscopy and furthermore can be used to determine post mortem interval in conjunction with climatic variables. Preliminary research shows that grave soil below and around a decomposing corpse has a distinct NIR signature and furthermore that water extractable soil DOC, DON, orthophosphate-P and ammonium-N are increased for at least two years and are transportable downslope during precipitation events. Current work is also examining decomposition products of feral hog, chickens and sheep as well as humans in Sam Houston State Forest.
6. International and Domestic Agriculture
Collaborators: Bill Payne (Borlaug Inst.), Richard Loeppert, Fran Hons, Terry Gentry (Soil and Crop) and Carmen Chavez-Gonzalez and Rogelio Carrillo (University de Postgraduados, Texcoco, Mexico).
Two PhD students’ (Verbree and Davies) and one MS student (Sturm-Flores) under the joint supervision of Dr. Aitkenhead-Peterson and Dr. Bill Payne are responsible for three international agriculture projects. One project examined application of effective microorganisms to soil under coffee bushes in Costa Rica and one project examined zinc and iron uptake by sorghum in Mali, West Africa. A further project in Ghana will examine nutrient cycling and carbon sequestration in soils under different tillage will commence in 2012.
A domestic agricultural study examined glomalin production, dissolved organic carbon and soluble nutrients under long-term research plots in Texas.
7. Environmental Services of Soil
Two undergraduate students (Elizabeth Evetts and Sarah Robinson) were involved in research under this topic which examined the adsorption of dissolved organic matter in soils collected from the Sikfokut Forest, Hungary in June 2006. More research in environmental services of soil is planned in urban and rural environments.