Radiocesium uptake by one-year-old willows planted as short rotation coppice

High radioactivity concentrations in foodcrops grown in areas contaminated by the Chernobyl accident continue to justify the consideration of a change in land use. Production of biofuel may be one of the alternatives to food production. However, present knowledge about radionuclide cycling in such s ystems is limited. In the present study, radiocesium uptake and distributio n were measured in a willow (Salix viminalis L. var. Orm) short rotation co ppice (SRC) stand. This system allows production of energy from the harvest ed biomass. Experimental plots were established on two soil types of contra sting texture (loamy versus sandy), and contaminated with 8 X 10(6) Bq Cs-1 34 m(-1). Concentrations of Cs-134 were measured in wood, litter, roots, an d cuttings after 1 yr of growth. At the end of the growing season, only 0.0 012% (loamy soil) and 0.0065% (sandy soil) of the initial radiocesium was t ransferred to the plant biomass (including belowground plant parts). Stem w ood contained the lowest concentration of Cs-134 among all plant parts anal yzed. Wood radiocesium concentrations were 82 Bq kg(-1) for the loamy soil and 192 Bq kg(-1) for the sandy soil. These values are well below the exemp tion limit for fuel wood put forward in the Commonwealth of Independent Sta tes (CIS) (740 Bq kg(-1)). Even at this high soil contamination level, radi ocesium concentrations in wood do not exceed appreciably the naturally occu ring K-40 content in the wood (135 Bq kg(-1)).