Ministry officials carried out the tests from May in areas near the radiation-spewing Fukushima Daiichi nuclear power plant.
Ministry officials said that sunflowers absorbed almost no cesium from contaminated soil.
MAFF discovered that of the numerous decontamination measures it has attempted in Fukushima prefecture, removing topsoil was the most effective. Taking away clumps of topsoil about 3 centimeters (2 inches) deep cut cesium levels by 97% in pastoral fields. Shaving 4 centimeters (2.75 inches) from topsoil in other areas reduced cesium by 75%.
Chemical hardening lowered cesium by 82%.