Mechano-chemical analysis of fluctuation range of paddy soil structure due to wet and dry cycle

2014 Fiscal Year Final Research Report

• Project/Area Number: 23380136
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Rural environmental engineering/Planning
• Research Institution: The University of Tokyo
• Principal Investigator: YOSHIDA Shuichiro 東京大学, 農学生命科学研究科, 准教授 (90355595)
• Co-Investigator(Kenkyū-buntansha): TAKAHASHI Tomoki 農業・食品産業技術総合研究機構, 東北農業研究センター, 主任研究員 (00355562) ; NISHIDA Kazuhiro 東京大学, 大学院農学生命科学研究科, 助教 (90554494)
• Co-Investigator(Renkei-kenkyūsha): NAKANO Keiko 農業・食品産業技術総合研究機構, 九州沖縄農業研究センター, 主任研究員 (40354089) ; SUZUKI Katsuhiro 農業・食品産業技術総合研究機構, 中央農業総合研究センター, 主任研究員 (90354068) ; ODAHARA Koji 福岡県農業総合試験場, 筑後分場, 専門研究員 (10514995)
• Project Period (FY): 2011-04-01 – 2015-03-31
• Keywords: 水田土壌 / 土壌構造 / 膨潤収縮 / 酸化還元 / 粘弾性的挙動

Outline of Final Research Achievements

Fluctuation range of swelling/shrinkage volume and pore-size distribution of paddy soil due to continuous application of organic matter or redox treatments is studied for the undisturbed and air-dried soil samples. Although the application of organic matter increased the fluctuation range of redox potential under the rotational cultivation of rice and wheat, the influence on the swelling/shrinkage characteristics was exclusively revealed for the air-dried disturbed soil. Even under the stable soil water potential, the volume ratio and volumetric water ratio temporally increased as the progress in soil reduction. Pore size distribution shifted upward by the reduction treatment and converged into narrow pore-size range by the remixing. Visco-elastic modeling is found to be effective in the analysis of selling /shrinkage of paddy soil under the influence of alternating redox condition.

Free Research Field

農業工学