The article deals with an alteration in specific activity and transfer factor of naturally occurring radionuclide 40K from soil with a loamy structure to the segments of root vegetables – an ordinary carrot (Daucus carota L.) and red beet (Beta vulgaris L.). The paper establishes the specific activity of 40K in soil and vegetable segments and evaluates transfer factors (TF). The obtained data show that the transfer factor of naturally occurring radionuclide 40K from soil to the segments of the ordinary carrot (Daucus carota L.) varied from 0,28 to 0,99 while that of the red beet (Beta vulgaris L.) – from 0,53 to 0,96. The results of the study could be used for estimating 40K transfer in the system “soil-plant” and accumulation of radionuclide in composting garden waste.

Artilce in Lithuanian