The improvement of soil fertility by the mixing of the rice straw into the paddy field after the stripping top soil off decontamination

研究成果の概要（和文）：本研究は、稲わらによる有機物補給機能を重視した、新たな地力増進手法を開発することを目的とした。2011年の原発事故後、原発より40km北西に位置する農業の盛んであった福島県飯舘村の農地では、削り取り除染や客土が行われた。そのため、以前に蓄積された肥沃な土壌や土壌有機物含量が低減する恐れがあった。継続的な土壌および水稲中の放射性セシウム濃度の観測結果より、飯舘村の除染後水田において、国の流通基準を大幅に下回るコメを栽培できることが確認された。また、生育調査および収量調査結果より、削り取り除染直後の水田においては、有機物、特に稲わらの施用施用が生産量回復に有効であることが示唆された。 研究成果の概要（英文）：The agricultural fields were contaminated by the radionuclides after the Nuclear Power Plant accident in Iitate Village. Since 2011, decontamination work such as stripping-off the top soil had been ongoing. Although decontamination is essential, the soil fertility could be decreased. Here, we examined the use of organic matter to quickly recover the fertility of the agricultural top soil. We transplanted rice crops into three paddy plots: mixed with rice straw, with cattle manure, and without anything as a control after decontamination. The rice yield from the rice straw plot was higher than others in first year. After that, there were no differences depend on the treatments. Radioactive Cs concentrations in the new rice from all plots had been lower than the maximum Japanese governmental allowed level through this research. These results revealed that treating soil with rice straw might have great potential to aid a paddy field recovery just after the decontamination