Soil- and plant-based countermeasures to reduce Cs-137 and Sr-90 uptake bygrasses in natural meadows: the REDUP project

The effectiveness of a set of soil- and plant-based countermeasures to redu ce Cs-137 and Sr-90 transfer to plants was tested in natural meadows in the area affected by Chernobyl fallout. Countermeasures comprised the use of a gricultural practices (disking + ploughing, liming and NPK fertilisation), addition of soil amendments and reseeding with a selection of grass species . Disking + ploughing was the most effective treatment, whereas the K ferti liser doses applied were insufficient to produce a significant increase in K concentration in soil solution. The application of some agricultural prac tices was economically justifiable for scenarios with a high initial transf er, such as Cs-137-contaminated organic soils. The use of soil amendments d id not lead to a further decrease in transfer. Laboratory experiments demon strated that this was because of their low radionuclide sorption propertius . Finally, experiments examining the effect of plant species on radionuclid e transfer showed that both transfer and biomass can depend on the plant sp ecies, indicating that those with high radionuclide root uptake should be a voided when reseeding after ploughing. (C) 2001 Elsevier Science Ltd. All r ights reserved.