Predicting soil water movement at a converted upland field by considering charcteristic of root water uptake

2018 Fiscal Year Final Research Report

• Project/Area Number: 15K18756
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Rural environmental engineering/Planning
• Research Institution: Hirosaki University
• Principal Investigator: Kato Chihiro 弘前大学, 農学生命科学部, 助教 (60728616)
• Project Period (FY): 2015-04-01 – 2019-03-31
• Keywords: 水田転換畑 / 土壌水分 / 数値計算 / ダイズ / 根の吸水

Outline of Final Research Achievements

Though predicting and controlling field soil moisture are required to assure a stable yield and the high quality of products, proper numerical model for predicting soil moisture in croplands especially under high soil moisture conditions is still under discussion. Here we evaluated a numerical model for predicting soil moisture in converted soybean fields. A soybean-growing experiment with a converted field model was conducted and spatial and temporal variation of soil moisture was monitored. Then a numerical simulation of soil water movement for this growing experiment was conducted with the HYDRUS-1D model. The simulation results improved with the consideration of root distribution variation, changes in evapotranspiration rate and LAI values.

Free Research Field

地域環境工学

Academic Significance and Societal Importance of the Research Achievements

農地における土中水移動現象の解明と作物生産現場への適用は，安定的な収量や品質の確保に重要である．本研究は，これまであまり検討されてこなかった，日本の水田転換畑に見られるような多湿な土壌環境下における，作物根の吸水速度の時空間分布を考慮した土中水移動モデルの構築に取り組んだものである．近年の気候変動や田畑輪換のような土地利用変化に伴い，その重要性・必要性は増すものと考えられる．