Study on regional heterogeneity and varietal selection in fragile rice ecosystems in Asia

2019 Fiscal Year Final Research Report

• Project/Area Number: 16H05780
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 海外学術
• Research Field: Crop production science
• Research Institution: The University of Tokyo
• Principal Investigator: Kamoshita Akihiko 東京大学, アジア生物資源環境研究センター, 准教授 (10323487)
• Co-Investigator(Kenkyū-buntansha): 櫻井 武司 東京大学, 大学院農学生命科学研究科(農学部), 教授 (40343769)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 農業生態学 / 農業経済学 / 環境調和型農林水産 / 気候変動

Outline of Final Research Achievements

To assess effects of salinity intrusion triggered by global warming, paddy fields near the estuaries of Red River, Vietnam was studied. Rice production was greatly reduced nearby branch estuary where paddy and aquacultural ponds were not zoned by dykes, whereas yield of paddy close to the dykes in the mainstream estuary was just slightly reduced. Short-duration quality varieties reduced yield in response to salinity compared with hybrid varieties. In the tank irrigated rice in South India (i.e., non-system tank without connecting rivers), drought occurred frequently during 2010-2019, which lead more farmers to dug bore-wells for supplementary irrigation. The tail fields and long duration quality varieties popular in markets tended to yield lower due to drought. In Cambodia, dry season rice cropping with fewer varieties in the flood plain of Tonle Sap spread after the big flood damages in 2011. Mechanization in irrigated paddy and overall labor-saving cultivation became more popular.

Free Research Field

作物生態学

Academic Significance and Societal Importance of the Research Achievements

灌漑が十分に整備されておらず、干ばつや洪水の被害が頻発する水田や、海面上昇による塩水遡上を被る沿岸部の水田など、生産基盤の脆弱な熱帯アジアの水田に着目して、気象リスクと域内不均一性とを明らかにし、持続可能な稲作を設計するための知見を得た。条件の悪い環境での生産の改良のための総合的な提案をした。近年米の輸出を急増させてきた3国（インド、ベトナム、カンボジア）であるが、個々の生産現場の状況の違いも描いた。アジア以外の生産基盤の脆弱な地域、例えば、アフリカでの稲作の改良を考える際にも、応用することも可能である。