Where do pesticides and their degradation products go once they enter the soil? And how long does it take them to get to groundwater or drainage systems? That depends on a number of factors, but researchers at Aarhus University have come a step closer to finding quick answers. For the first time ever, they have used visible/near-infrared spectroscopy to predict the transport of dissolved chemicals through intact soil.
The ability of soils to transport dissolved chemicals depends on the soil’s texture and structure. Tracking the travel time of these solutes is usually carried out in the laboratory by measuring breakthrough curves, where the application of a solute at the soil surface and its appearance over time at the bottom are recorded. Obtaining breakthrough curves from laboratory studies is extremely expensive as well as time consuming and labour intensive, so the team of scientists from Aarhus University and Aalborg University decided to think out of the box and use visible/near-infrared (vis–NIR) spectroscopy to predict breakthrough curves – for the first time ever.
Applying technology in new way
Vis–NIR spectroscopy is well recognised for its measurement speed and its low data acquisition cost. It can be used for quantitative estimation of basic soil properties such as clay and organic matter.
The team of scientists used vis–NIR spectroscopy to predict the breakthrough curves of the solutes on a large variety of intact soil columns from six representative fields in Denmark. Averaged across the individual field, the new technology estimated the breakthrough curves with a high degree of accuracy.
Read more at Aarhus University
Image: Researchers from Aarhus University have developed an improved method for following the transport of chemicals through the soil. (Credit: Janne Hansen)