Fertilizers rich in potassium content can drastically reduce the amount of radioactive cesium absorbed by rice, a study shows.
Fertilizers rich in potassium content can drastically reduce the amount of radioactive cesium absorbed by rice, a study shows.
Researchers at the National Agricultural Research Center in Tsukuba, Ibaraki Prefecture, released their findings, which involved other institutions, on Feb. 24.
The team wanted to determine how rice paddies absorbed cesium under varying conditions and conducted field work with fertilizers in Fukushima, Ibaraki, Tochigi and Gunma prefectures following the disaster last March at the Fukushima No. 1 nuclear power plant.
The best result was achieved when 25 milligrams of what is known as exchangeable potassium was found in 100 grams of soil. Exchangeable potassium is easily absorbed by plants.
Increasing the level of potassium made no difference, the researchers added.
A potassium composition of 25 milligrams per 100 grams of soil is not particularly high compared with the generally recommended ratio of 15-30 mg/ 100 g in rice paddies.
The researchers said higher concentration of potassium could be particularly effective in rice paddies in eastern Japan where the current composition is 5 mg/ 100 g or less.