Study on change of soil and soil layers in rice field by modern farming technique and state of consolidation of field foundation

Research Project

Project/Area Number	09556051
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Single-year Grants
Section	展開研究
Research Field	Irrigation, drainage and rural engineering/Rural planning
Research Institution	Tokyo University of Agriculture
Principal Investigator	KOMAMURA Masaharu Tokyo University of Agriculture, Faculty of Regional Environment Science, Professor, 地域環境科学部, 教授 (60078194)
Co-Investigator(Kenkyū-buntansha)	NAKAMURA Takahiko Tokyo University of Agriculture, Faculty of Regional Environment Science, Lecturer, 地域環境科学部, 講師 (10287451) NARIOKA Hajime Okayama University, Faculty of Environmental Science and Technology, Associate Prefessor, 環境理工学部, 助教授 (70211448) SATO Teruo Akita Prefectural College of Akita, Professor, 短期大学部, 教授 (50073979)
Project Period (FY)	1997 – 1999
Project Status	Completed (Fiscal Year 1999)
Budget Amount *help	¥6,500,000 (Direct Cost: ¥6,500,000) Fiscal Year 1999: ¥1,200,000 (Direct Cost: ¥1,200,000) Fiscal Year 1998: ¥2,000,000 (Direct Cost: ¥2,000,000) Fiscal Year 1997: ¥3,300,000 (Direct Cost: ¥3,300,000)
Keywords	Growing technique of the rice crop / Consolidation of the paddy field / Physical property of soil / Soil pore structure / Well-drained and direct seeding method / no-tilled cropping / no-tilled transplanting of rice / Shallow underdrainage / 土壌水分動態 / 水田の水管理
Research Abstract	It is necessary that the production cost reduces for the paddy field rice crop in our country. The growing technique which is different from the conventional rice crop is necessary to do the becoming of the low cost which progress rapidly and for the labor productivity to improve. It is necessary to introduce the new technique which is represented by direct seeding and no-tilled cropping which should change to the rice paddy planting. The purpose of this study is the establishment of the state for where the rice field basis to the new technique is desirable. The investigation field were the rice field implementing the modern rice crop growing as follows : - The rice field which is implementing no-tilled cropping (Akita prefecture) - The rice field which is implementing plowing and direct seeding (Chiba prefecture) - The rice field which is implementing no-tilled and direct seeding (Okayama prefecture) In the case in Okayama and Chiba prefecture which is implementing dry rice field direct seeding, the workability in the dry rice field condition improved, didn't make yield so decline, and it was seemed favorite from the labor productivity. Also, the attention point of consolidation of foundation as dry seeding rice field, too, was put in order. By the case of no-tilled cropping at Hachiro-gata, Akita prefecture, the yield didn't decline and the productivity was improving, the various creatures are inhabiting the paddy field, and it was the way of growing to have considered the ecosystem. By also the rice field of no-tilled direct seeding, There are progress of the soil structure and improvement of the soil physical properties, there was not a problem in the productivity compared with the transplantation growing of the practice. Of the future, The relation between the new way of growing and the rice field soil, especially, grasp the change of the soil layer structure and its characteristics, or the change of the ecosystem must be taken.