STRESSED OUT? ASSESSING TRACE METAL UPTAKE AND STRESS IN PLANTS GROWN IN COAL FLY ASH-AMENDED SOILS

Trace element uptake by vegetation growing in soils amended with varying concentrations of fly ash were evaluated and compared to spectral reflectance obtained from the same plants. Seeds of basil, dwarf sunflower, tomato, and zucchini were planted in soils amended with 5, 10, and 20 weight percent fly ash, as well as in unamended soils as a control. Leaves and stems from each plant were harvested on three separate occasions (four-week intervals between each harvest) and submitted for analysis by inductively coupled plasma emission spectrometry with a mass spectrometer (ICP-MS) to determine the extent of trace metal uptake. Preliminary results from the first harvest show that plants in the amended soils contain slightly elevated concentrations of Tl and Mo. Basil and sunflower also contain slightly elevated As, sunflowers slightly elevated Cd, and zucchini slightly elevated Ni and Zn.

Plant stress was systematically monitored twice daily by measuring visible and near infrared reflectance of the vegetation during the growth period from July to October. Spectral signatures were obtained from new growth using a spectrometer. Initial evaluation of the spectral data for tomato only shows that reflectance differs over time and with varying concentrations of fly ash, indicating that remote sensing may be used to map and monitor crop health in landscape to regional areas where soil has been amended with fly ash.