記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Irrigation and Drainage  

Alternate wetting and drying (AWD) irrigation is effective at reducing methane (CH4) emissions in rice cultivation. To investigate the effect of the infiltration rate on AWD effectiveness in terms of CH4 emissions, rice was cultivated in pots with three different infiltration rates under AWD. Under intermittent irrigation, the soil was more oxidative than is generally required for CH4 production (redox potential [Eh] > −150 mV), regardless of the infiltration rate. CH4 emission was suppressed by at least 37% compared to continuous flooding and no-infiltration conditions; however, temporarily elevated emission caused by drainage below saturation was observed 1–2 h after the flooding receded. This result is important for accurately determining CH4 emissions in water management techniques such as AWD. CH4 emissions during the heading stage, including temporarily elevated emissions after flooding receded, were greatest under the highest infiltration rate (18 mm day−1). The infiltration rate did not affect the rate of soil Eh reduction; however, the total organic carbon concentration in the drainage water suggested that more carbon, a methanogen substrate, migrated to the bottom of the pot with increasing infiltration rate, which likely increased CH4 emissions. This study will aid in the examination of ponding water management techniques to control CH4 emissions in rice production.

DOI： 10.1002/ird.2756

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85139007086&origin=inward

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：42nd Asian Conference on Remote Sensing, ACRS 2021  

Shiga Prefecture, Japan, is one catchment that constitutes a large basin surrounded by mountains such as Mt. Hiei, Mt. Hira, Mt. Ibuki, Gozaishodake and Suzuka Mountains. In the center, there is Lake Biwa occupying one-sixths of the total area of the prefecture. Lake Biwa has been a precious water source for Osaka and Kyoto. We created a landscape image of the entire catchment by overlaying the SRTM_DEM image measured by the space shuttle Endeavor in 2000 and Landsat image. From this image, we attempted to forecast the impacts on the regional environments due to the wind trail crossing Lake Biwa, microclimates along the lake coast, training at the time of typhoon visit, development of a large-scale housing complex, mega solar power plant project, and so on. In order to foresee the regional environments and disaster risks, we believe that an extensive systematic structure including hydrology, remote sensing and geographic information system becomes necessary from now on. Considering the disastrous cases in the recent several years in Japan such as landslides and flooding engulfing houses, understanding of detailed landscape architectures in each region is strongly encouraged from the standpoint of risk management when construction of a mega solar power station or a large-scale housing complex is planned on a slope of a mountain or a wetland regarded as a retarding basin.

Scopus

その他リンク： https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85127417623&origin=inward

記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：農業土木学会   参加形態：共同（主担当）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：農業土木学会   参加形態：共同（主担当）  

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：日本熱帯生態学会   参加形態：共同（副担当）  

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：愛媛県松山市  

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：福島市  

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：福島市  

消防用ホースにミシン針で穿孔した地中灌漑用のホースを作成し、コマツナ栽培で既存の散水試験と各3反復で比較した。その結果、総給水量は散水灌漑の62％と5%有意水準で有意に低く、水利用効率も1.38倍と良好であった。よって、ホース内の水圧を制御することで、水ストレスを与えずにコマツナが栽培できた。なお、地中灌漑の給水強度はホース内の水圧に対応したが、ホース内部に藻が詰まるなどの課題があった。

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：鹿児島市  

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：鹿児島市  

AWDは移植後と開花期を除いて間断灌漑を繰り返し、収量を落とさずメタン排出量を抑制する手法であるが、その際に土壌環境の変化を詳細に調査した事例は皆無である。そこで、ポット栽培にてAWDを実施して、メタン排出速度、ORP、含水率、地温を測定し、水稲の成長段階との関係を調べた。その結果、稲があることで栽培期間を通して5倍以上のメタンが放出されたことがわかった。