EM Fermented Compost Effect on Radioactive Cs Transfer to Grass - Pilot TestJapan
Progress Report by R&D Dept., EMRO
After the accident at Fukushima Daiichi Nuclear Power plant,we at EMRO dispatched a researcher to Fukushima to study the effect of EM on the radioactive contaminated soil.
Since May 2011, EMRO have been measuring the radioactive cesium level in the crops and soil of the farms in Fukushima, which uses EM Technology.
Also, we are conducting several tests on the suppression of transfer of radioactive cesium from soil to crops and reduction in radioactive contamination by EM Technology.
In this experiment, we used the same EM fermented manure compost that the livestock farmer actually uses for his pasture, and conducted the test in planter boxes.
This study was conducted to determine the difference of the effect of EM fermented cow manure compost and regular cow manure compost on suppression of transfer of radioactive cesium from soil to grass.
Materials and MethodsFor the contaminated soil in which the total radioactive cesium (134Cs and 137Cs) is approx.9,000Bq/kg, 4 tons of EM cow manure compost (EM Compost) and regular cow manure compost (Compost) per 10a (=0.1ha) were mixed separately.
Also,the exchangeable potassium content of each type of compost was measured beforehand and adjusted the content so that the exchangeable potassium content was equal for all samples.
One hundred (100) kg of chemical fertilizer 14-14-14 per 10a of contaminated soil was mixed for the Control.
The three treated soils were put into planters and seeded with Italian ryegrass.
After 52 days,grass weight,radioactive cesium in the grass and radioactive cesium in the soil were measured.
As for measuring radioactive cesium in grass,qualitative and quantitative analysis on radionuclides was conducted using a Germanium semiconductor detector.
Nal (TI) scintillation spectrometer was used to measure radioactive cesium in soil.
Italian ryegrass fresh weights per planter were 100±11g for the Control area, 128±9g for the Compost area and 134±6g for the EM Compost area.Compared with the Control area, the Compost area had a significant difference at the 0.05 level.
The Compost area had a significant difference at the 0.01 level.
However, there was no significant difference between the Compost area and the EM Compost area.
The sum of 134Cs and 137Cs in the grass was 88Bq/kg in the Control, 61.3Bq/kg in the Compost area and 45.3Bq/kg in the EM Compost area.
The EM Compost area had a significant difference at the 0.01 level compared with the Control area and had a significant difference at the 0.05 level compared with the
Compost area (Graph 1).
Transfer factor for the Control, Compost, and EM
Compost areas were 0.01035, 0.00643 and 0.00496,respectively (Graph 2).
The EM Compost area had a 52% reduction in the transfer factor compared with the Control area.
The exchangeable potassium content in the soil (mg/dry soil 100g) at the time of harvest were 68±26g in the Control area, 72±21g in the Compost area and 98±4g in the EM Compost area, no significant differences were observed.
ConsiderationThis experiment showed that by using EM fermented cow manure compost, the effect of suppression of transfer of radioactive Cs to grass was enhanced compared with regular cow manure compost.
The collaborative research with the Institute of Radiobiology of the National Academy of Science of Belarus in 2013 reported that application of EM or EM Bokashi on the soil degreases the rate at which water-soluble Cs and exchangeable Cs was absorbed through plant roots.
It would be considered that the effect of suppression of transfer in this experiment was due to the same mechanism.
In this planter experiment, there was no significant difference for the yield of grass between the Compost area and the EM Compost area.
However, according to an eleven year field experiment conducted by university researchers in China,long term application of EM compost significantly increases wheat straw biomass,grain yields,straw and grain nutrition compared with traditional compost (Hu & Qi, 2013).
Therefore, we would expect in further experiment that continuous application of EM manure compost to pasture, will not only suppress the transfer of radioactive cesium to grass, but is also likely to increase they yield and nutrition of pasture grass.
Hu, C.; Qi, Y. (2013). Long-term effective microorganisms application promote growth and increase yields and nutrition of wheat in China.
European Journal of Agronomy. 46, 63-67.