Agricultural aspects of radiocontamination induced by the Fukushima nuclear accident - A survey of studies by the Univ. of Tokyo Agricultural Dept. (2011-2016)

Immediately after the Fukushima nuclear power plant accident, a team of 40-50 researchers at the Graduate School of Agricultural and Life Sciences at the University of Tokyo began to analyze the behavior of radioactive materials in the fallout regions. The fallout has remained in situ and become strongly adsorbed within the soil over time. Cs-137 was found to bind strongly to the fine clay, weathered biotite, and organic matter in the soil; therefore, it has not mobilized from mountainous regions, even after heavy rainfall. In farmland, the quantity of Cs-137 in the soil absorbed by crop plants was small. The downward migration of Cs-137 in soil is now estimated at 1-2 mm/year. The intake of Cs-137 by trees occurred through the bark and not from the roots. This report summarizes the findings of research across a wide variety of agricultural specialties.