A5102786370- Soil and Water Nutrient Dynamics
- Soil Carbon and Nitrogen Dynamics
- Isotope Analysis in Ecology
- Groundwater and Isotope Geochemistry
- Wildlife Ecology and Conservation
- Ergonomics and Musculoskeletal Disorders
- Soil and Unsaturated Flow
- Remote Sensing in Agriculture
- Atmospheric and Environmental Gas Dynamics
- Marine animal studies overview
- Remote Sensing and Land Use
- Plant nutrient uptake and metabolism
- Hydrology and Watershed Management Studies
- Remote-Sensing Image Classification
- Microbial Community Ecology and Physiology
- Fish Ecology and Management Studies
- Agriculture and Farm Safety
- Groundwater flow and contamination studies
- Soil Geostatistics and Mapping
- Livestock Management and Performance Improvement
- Ecology and biodiversity studies
- Color perception and design
- Peatlands and Wetlands Ecology
- Regional Development and Environment
- Adsorption, diffusion, and thermodynamic properties of materials
Advanced Analysis Center
2018-2024
National Agriculture and Food Research Organization
2016-2024
National Institute for Agro-Environmental Sciences
2000-2021
Hokkaido Research Organization
2010-2015
University of Shiga Prefecture
2012
National Institute for Environmental Studies
2012
Industrial Research Institute
2002-2009
Waseda University
1998
Remote Sensing Technology Center of Japan
1997
Chiba University
1995-1996
Agricultural soil is the largest source of nitrous oxide (N2O), a greenhouse gas. Soybean an important leguminous crop worldwide. hosts symbiotic nitrogen-fixing bacteria (rhizobia) in root nodules. In soybean ecosystems, N2O emissions often increase during decomposition Our previous study showed that reductase can be used to mitigate emission from fields nodule by inoculation with nosZ++ strains [mutants increased (N2OR) activity] Bradyrhizobium diazoefficiens. Here, we show reduced at...
Abstract Indirect emission of nitrous oxide (N 2 O), associated with nitrogen (N) leaching and runoff from agricultural lands is a major source atmospheric N O. Recent studies have shown that carbon dioxide (CO ) methane (CH 4 are also emitted via these pathways. We measured the concentrations three dissolved greenhouse gases (GHGs) in subsurface drainage field lysimeter had shallow groundwater table. Aboveground fluxes CH O were monitored using an automated closed‐chamber system. The annual...
We reviewed the available data of NO 3 − and dissolved N 2 O concentration in leached water agro‐ecosystems from 11 published papers four unpublished studies, to reevaluate IPCC default emission factor (N O‐N/NO ‐N) for indirect agro‐ecosystems. The was estimated be 0.0024, indicating that IPCC's present (0.015) estimate are too high. Using value 0.0024 as revises global leaching runoff downward 1.6 0.80 Tg y −1 sum direct due agriculture 6.3 5.5 .
Abstract Nitrogen (N)‐containing fertilizers, such as slurry and ammonium nitrate (NH 4 NO 3 ), can significantly increase soil nitrous oxide (N 2 O) emissions following addition to agricultural soil. Biochar amendment has been observed suppress N O in a number of studies. However, the effect varies depending on many factors, including when biochar is added concurrently with organic or mineral fertilizers. An incubation was conducted which bamboo (created at 800°C) an ex‐rice paddy (1% rate)...
Movement of nitrous oxide (N2O) produced in subsoil and shallow groundwater is important determining the direct indirect N2O emissions from agricultural soils. From results our previous study a lysimeter-contained Gray lowland soil summer, we hypothesized that if large amount near table it will diffuse upward to atmosphere. To examine this hypothesis, conducted one-year experiment same lysimeters for cultivation soybean–wheat double cropping (SW) or upland rice (UR). Dissolved concentration...
Quantitative evaluation of denitrification by the dual isotope approach, which measures stable ratios nitrogen (δ15N) and oxygen (δ18O) in nitrate, has been hampered wide range values reported for ratio enrichment factors 15N 18O (15ε 18ε, respectively) during denitrification. The objectives this study were to determine 15ε 18ε at different rates under controlled conditions, infer possible mechanisms 18ε/15ε is influenced conditions. Column experiments conducted 25, 15, 10°C, enabled...
Abstract Anthropogenic foods such as agricultural crops have potential to give large impacts on wildlife populations. However, few studies addressed the impact of anthropogenic food consumption individual performance and then population long‐lived mammals herbivores. In this study, we investigated effect crop physical characteristics reproductive performances sika deer ( Cervus nippon ) in central Japan. To investigate relative dietary contribution for each individual, performed nitrogen...
Denitrification hotspots in riparian aquifers often develop a relatively narrow zone at the upland-riparian interface, where nitrate-rich ground water of upland origin interacts with available soil organic carbon. In paddy fields, denitrification aquifer has received less attention than that surface and soil. This study aimed to determine situ activity hotspot formed vertical interface between alluvial diluvial around depth 2.0 m below perimeter paddy, upwelling dominates recharge. The mass...
筑波山周辺の渓流水中の硝酸イオンの濃度と同位体比の夏季と冬季の俯瞰的な調査結果から,1)夏季と冬季の硝酸イオンの濃度特性を基に40流域は13流域からなるグループ1(濃度が低く,季節間差も小さい)と17流域からなるグループ2(濃度は低くないが,季節間差は小さい)と8流域からなるグループ3(濃度は低くないが,夏季に濃度が低下する)と2流域からなるグループ4(濃度は低くないが,冬季に濃度が低下する)に大別できた。2)グループ1では冬季にδ18Oの大きく上昇する地点が多く,グループ3では冬季にδ15N,...
硝酸イオンの窒素・酸素安定同位体比(δ15N,δ18O)はその高い起源推定能から海洋,湖沼,河川,地下水での物質循環の研究に用いられてきた。1990年代半ばに開発された脱窒菌法により,硝酸イオンのδ15N,δ18Oを微量で同時に測定できるようになった。脱窒菌法で多量のサンプルを短時間に精度よく測定するには前処理ライン(N2Oガスを質量分析計に導入するための前処理)が必要不可欠である。しかしながら,こうした前処理ラインの分析機器は高額(数千万円程度)である。著者らは多くの研究室に設置されている通常の固体粉末試料の同位体測定ライン(質量分析計と元素分析計がConflo IIIで連結された測定システム)を活用し,測定精度や処理速度を落とすことなく,安価に自動前処理できるラインを開発することに成功したのでここに報告する。
Abstract Conflicts arising from the consumption of anthropogenic foods by wildlife are increasing worldwide. Conventional tools for evaluating spatial distribution pattern large terrestrial mammals that consume have various limitations, despite their importance in management to mitigate conflicts. In this study, we examined crop‐foraging sika deer performing nitrogen stable isotope analyses bone collagen. We evaluated whether lived closer agricultural crop fields during winter and spring,...
Rationale Hair is known to preserve diet history and other physiological information during its growth period often used in chemical analyses. However, the patterns turnover of hair vary according animal species or habitat, so understanding these target necessary for interpreting results In this study, we aimed elucidate pattern dietary winter coat captive sika deer ( Cervus nippon ). Methods Experiments involving hair‐staining shaving were conducted hair. A diet‐switching experiment was...