Study on the edaphic factor in low yield of rice paddy cultivated in rainy season and technical countermeasures to improve the soil condition in the Mekong Delta

2015 Fiscal Year Final Research Report

• Project/Area Number: 25304024
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 海外学術
• Research Field: Plant nutrition/Soil science
• Research Institution: Japan International Research Center for Agricultural Sciences
• Principal Investigator: IIZUMI YOSHIKO 国立研究開発法人国際農林水産業研究センター, 生産環境・畜産領域, 主任研究員 (00414996)
• Co-Investigator(Kenkyū-buntansha): KONDO MOTOHIKO 名古屋大学, 生命農学研究科, 教授 (00355538) ; WATANABE TAKESHI 国際農林水産業研究センター, 企画調整部, 科長 (40425525)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 水稲 / 生育障害 / 水田 / 灌漑水管理 / 土壌化学 / 作物生理 / メコンデルタ / ベトナム

Outline of Final Research Achievements

This study aimed to assess the low rice yield in the rainy season and identify its causes, and to show technical countermeasures for it.
The yield of unhulled rice cultivated in the rainy season was almost half of that in the dry season. The main cause of this low yield in the rainy season was decrease in spikelet number / panicle. It is suggested that disorders to growth occurred not only by excess soil reduction but also by meteorological factors, i.e. high temperature, strong wind and low solar radiation. It was revealed that mid-term drainage in the rainy season was effective to moderate soil reduction and keeping floodwater in paddy field from harvest of the dry season cultivation to the beginning of the wet season cultivation inhibits forming acid (sulfuric acid).

Free Research Field

環境農学