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PhD award for predicting functional properties in soil layers

Cecilie Hermansen from the Department of Agroecology has been awarded Aarhus University Research Foundation's PhD Award 2020. The prize will be awarded 4 June.

2020.06.04 | Christina Troelsen

[Translate to English:] Cecilie Hermansen fra Institut for Agroøkologi modtager Aarhus Universitets Forskningsfonds ph.d.-pris 2020. Foto: Anne Kring.

Using new analytical methods, Cecilie Hermansen has made it easier to assess the risk that spraying a specific piece of land with pesticides will lead to contamination of the drinking water.

She has developed the methods through her PhD project at the Department of Agroecology in Foulum, attracting international attention for results, that show how use of the ‘clever instrument’, a so-called vis-NIR spectrometer, may be expanded.

 

Visible near-infrared spectroscopy illuminates a soil sample using various wavelengths in the visible near-infrared area. The spectrometer then measures the amount of light that is reflected. And the shape of the displayed spectrum is affected by the properties of the soil’, Cecilie Hermansen explains.

vis-NIR spectroscopy was already an established method for analysis of the composition of soil layers, e.g. its content of clay, silt and organic material. But Cecilie Hermansen discovered a shortcut to measuring the soil’s sensitivity to contamination from, among others, the herbicide glyphosate and the plant protection product phenanthrene.  

‘In my PhD I have added a package of functional soil properties to the list of soil properties that can be determined by vis-NIR, and that you need to know to assess the sensitivity to pesticide leaching’, she says.

In that connection, some of the main properties is the soil’s ability to transport and absorb water, that is, the degree to which some substances bind to the surface of the soil. It is expensive and time-consuming to do using traditional laboratory methods, just as you need a significant number of soil samples because the properties of the soil may vary quite a bit over a short distance. However, Cecilie Hermansen has succeeded in establishing a mathematical model which in a few minutes can predict the adsorption properties of the soil based on the shape of the spectrum from a vis-NIR measurement.

‘It may take a day to scan just under 100 soil samples using the spectrometer. By comparison, it took me a year using traditional methods to complete the measurements I needed for the mathematical model. However, what makes it great is that once you have the spectrometer measurements, you have a database that can be used to measure the other soil properties you wish to identify, i.e. based on the same measurements’, she says. 

Cecilie Hermansen is now a postdoc at the Department of Agroecology in Foulum,

Recognition of five PhDs

Aarhus University Research Foundation will present their PhD Awards on 4 June 2020 to to young and promising researchers, who have conducted research at an impressively high level .The five PhDs receive the DKK 50,000 prize in recognition of their research and dissemination hereof.

People, Department of Agroecology