Papers - SUZUKI Shinji
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Impact of Soil Amendments and Alternate Wetting and Drying Irrigation on Growth, Physiology, and Yield of Deeper-Rooted Rice Cultivar Under Internet of Things-Based Soil Moisture Monitoring. Reviewed International coauthorship International journal
Amin, M. W., Sediqui, N., Azizi, A. H., Joya, K., Amin, M. S., Mahmoodzada, A. B., ... & Mihara, M.
AgriEngineering 7 ( 3 ) 69 - 93 2025.06
Language：English Publishing type：Research paper (scientific journal)
Effective water and soil management is crucial for crop productivity, particularly in rice cultivation, where poor soil quality and water scarcity pose challenges. The response of deeper-rooted rice grown in soils amended with different soil amendments (SAs) to Internet of Things (IoT)-managed alternate wetting and drying (AWD) irrigations remains undetermined. This study explores the effects of various SAs on DRO-1 IR64 rice plants under IoT-based soil moisture monitoring of AWD irrigation. A greenhouse experiment executed at the Tokyo University of Agriculture assessed two water management regimes—continuous flooding (CF) and AWD—alongside six types of SAs: vermicompost and peat moss (S + VC + PM), spirulina powder (S + SPP), gypsum (S + GS), rice husk biochar (S + RHB), zeolite (S + ZL), and soil without amendment (S + WA). Soil water content was continuously monitored at 10 cm depth using TEROS 10 probes, with data logged via a ZL6 device and managed through the ZENTRA Cloud application (METER GROUP Company). Under AWD conditions, VC + PM showed the greatest decline in volumetric water content due to enhanced root development and water uptake. In contrast, SPP and ZL maintained consistent water levels. Organic amendments like VC + PM improved soil properties and grain yield, while AWD with ZL and GS optimized water use. Strong associations exist between root traits, biomass, and grain yield. These findings highlight the benefits of integrating SAs for improved productivity in drought-prone rice systems.
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Water resources survey and model analysis in Dikhill area, Djibouti Reviewed International coauthorship
SUZUKI R., SUZUKI S., SAITO S., ADEN D., MALOW Fadoumo A.
Journal of Arid Land Studies 34 ( 3 ) 105 - 110 2024.12
Language：English Publishing type：Research paper (scientific journal) Publisher：The Japanese Association for Arid Land Studies
<p>The republic of Djibouti is a dry country with an annual maximum temperature and rainfall being 40 degrees Celsius and less than 150 mm, respectively. Geographical coordinates, groundwater depth, and condition of water use were evaluated at 17 sites within a small catchment in Dikhil. Half of the sites were established after the 1990s and unlisted in the database summarized by the government of Djibouti. The other half sites are listed but all of them had an error of geographical coordinates. Groundwater depth was analyzed using a simulation model (GETFLOWS) for the purpose of evaluating the potential of water resources, and the simulated water levels were in proportion to the observed water levels with the root mean square error (RMSE) being 9.4 m.</p>
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Improving Irrigation Water Use Efficiency and Maximizing Vegetable Yields with Drip Irrigation and Poly-Mulching: A Climate-Smart Approach. Reviewed International coauthorship
Bwire, D., Watanabe, F., Suzuki, S., & Suzuki, K.
Water 16 ( 23 ) 3458 - 3473 2024.12
Language：English Publishing type：Research paper (scientific journal)
Water management is a significant aspect of sustainable vegetable farming, especially in water-scarce regions. This, in addition to weed infestations, limits vegetable yields, which negatively affect food security in developing regions, particularly East Africa, where livelihoods chiefly depend on rain-fed agriculture. Vegetable farming, especially tomato cultivation, requires more water. By promoting mulching, a soil water conservation tool, we can control surface evaporation (E), which, together with irrigation, enhances effective water use and vegetable yields. The experiments for this study were conducted at the Tokyo University of Agriculture, Japan, to evaluate the influences of different irrigation conditions and poly-mulching on weed control, tomato yields, and water use efficiency. The study was conducted from May to September 2018 on a 30 m2 plot in an open-ended greenhouse using drip irrigation for tomato cultivation. Three predetermined irrigation conditions of 4, 3, and 2 mm/day were applied on black poly-mulched and bare ridges. Data on soil conditions—soil temperature, as well as meteorological variables, including solar radiation and temperature—were measured using thermocouple sensors and micro-hobo weather stations, respectively, during the tomato cultivation, while yield components—growth, yield, water productivity, and sugar content—were determined after harvest. The results of a two-way ANOVA show that irrigation conditions with poly-mulching reduced the weed biomass significantly, and improved yields and water use efficiency compared to the irrigation conditions on bare ridges. The application of 4, 3, and 2 mm/day irrigation with poly-mulching significantly reduced the weed biomass by 5% compared to the same irrigation conditions on bare ridges. Similarly, 4 and 3 mm/day irrigation conditions with poly-mulching significantly increased the tomato yield by 5% compared to 2 mm/day on bare ridges. The bigger roots were concentrated and widely distributed at the shallow soil depth (0–20 cm) of the ridges with high irrigation amounts, while the small and thin roots were in deeper soil layers (30–45 cm). This study provides scientific knowledge on the application of predetermined irrigation conditions that can be (i) integrated into irrigation scheduling and (ii) adopted for regions facing water scarcity and limited or no in situ meteorological data, to improve water use efficiency for vegetable cultivation.
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Estimating irrigation water amounts for tomato cultivation using observed meteorological data in Djibouti
WATANABE Fumio, SUZUKI Shinji, MOHAMED Tabarek Ismael, JITSUNO Masataka, OHSHIMA Hiroyuki, SANADA Atsushi, SHINOHARA Takashi, ABDALLAH Abdillahi Houssein
Journal of Arid Land Studies 32 ( S ) 95 - 99 2022.12
Language：English Publisher：The Japanese Association for Arid Land Studies
<p>Irrigation is essential for crop cultivation in arid and semi-arid areas with limited rainfall and water resources. Efficient and effective use of water resources is required and saving irrigation water is important. Djibouti is a very dry region with annual rainfall of about 150 mm and an average annual temperature of 28.6°C. Due to such meteorological conditions, water resources depend mostly on groundwater, and this makes water extremely scarce. Therefore, water saving in agricultural sector is indispensable. This study aims at promoting effective and efficient use of irrigation water in Djibouti. The appropriate irrigation water amounts for tomato cultivation were estimated using CROPWAT provided by FAO and observed meteorological data at Ali Farren farm in Djibouti. The conditions required for calculating the amounts of irrigation water were medium loam soil based on the laboratory results of soil particle size test, and the tomato cultivation period from October to March according to the local farmers. The result showed that the average monthly reference evapotranspiration was 5.7 mm/day annually. Reference Evapotranspiration was maximum in July and August with 8.4 mm/day and minimum in December with 4.6 mm/day. The amount of irrigation water from October to March was about 476 mm which corresponds to the local tomato cultivation period.</p>
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Preliminary study on improvement of soil water retention characteristics by <i>Spirulina</i>.
SUZUKI Shinji, WATANABE Satoru, OMAR Abdillahi Ismail, WATANABE Fumio, SHIMADA Sawahiko
Journal of Arid Land Studies 32 ( S ) 49 - 52 2022.12
Language：English Publisher：The Japanese Association for Arid Land Studies
<p>One of the measures to enhance the water use efficiency or to prevent desertification in arid and semi-arid countries is to improve water holding capacity (water retention) of soils. This study focused on<i> Spirulina</i>, a planktonic blue-green unicellular microalgae classified as cyanobacteria. Since the <i>Spirulina</i> inhabits strongly alkaline water body which is generally seen in the tropics, the <i>Spirulina</i> is expected as a locally available soil amendments. Further, the <i>Spirulina</i> secretes Extracellular Polymeric Substances (EPS). The current study assessed the effect of the <i>Spirulina</i> and the EPS powders to improve the soil water holding capacity. Slight addition (0.5 to 5%) of the <i>Spirulina</i> and EPS powders to sandy soils resulted in a significant increase of the readily available water content for crop growth (RAWCC). The effect of the <i>Spirulina</i> on the RAWCC of the sandy soils was similar of that of the bentonite. Meanwhile, soils with textures of Silty Loam and Sandy Loam had little increases in the RAWCCs with those amendments. In addition, the RAWCCs of the soils treated with both <i>Spirulina</i> and EPS powders did not decrease significantly after heat treatment indicating the persistence of the effect. The results of the current study demonstrated the efficiency and its persistence of the <i>Spirulina</i> and the <i>Spirulina</i>-derived EPS to improve soil water holding capacity particularly in sandy soils.</p>
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Meteorological characteristic and evaluation of hedgerow windbreak effect in agricultural lands in Djibouti based on wind dynamics simulation
IRIE Teruaki, SAITO Shuhei, MAY CUEVAS Sergio Azael, SUZUKI Shinji, WATANABE Fumio, SHIMADA Sawahiko, BARKAD Hassan A.
Journal of Arid Land Studies 32 ( S ) 193 - 197 2022.12
Language：English Publisher：The Japanese Association for Arid Land Studies
<p>This study aimed to clarify the meteorological characteristics of a farm at Dikhil in Djibouti and to evaluate the windbreak effect of hedgerows to plan and design a pilot farm in Ali Faren based on wind dynamics simulated using observed meteorological parameters. The analysis of meteorological observations at Dikhil farm showed that the east-northeast winds from October to April were twice as strong as the southerly winds from May to September. The computational fluid dynamics (CFD) analysis of the inflow from the east-northeast at a height of 3 m above the ground level confirmed that the windbreak effect of the hedgerows on the leeward side was effective in protecting the vegetable fields. The observations from the Ali Faren pilot farm indicated that the south-southeast prevailing winds blow throughout the year. The CFD analysis of the inflow from the south-southeast at a height of 3 m above the ground confirmed that the windbreak effect of several scenarios of hedgerow planning at the Ali Faren pilot farm was effective.</p>
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A comparative evaluation of lumped and semi-distributed conceptual hydrological models: does model complexity enhance hydrograph prediction? Reviewed International coauthorship International journal
Okiria, E., Okazawa, H., Noda, K., Kobayashi, Y., Suzuki, S., & Yamazaki, Y.
Hydrology 9 ( 5 ) 89 - 106 2022.05
Language：English Publishing type：Research paper (scientific journal)
The prediction of hydrological phenomena using simpler hydrological models requires less computing power and input data compared to the more complex models. Ordinarily, a more complex, white-box model would be expected to have better predictive capabilities than a simple grey box or black-box model. But complexity may not necessarily translate to better prediction accuracy or might be unfeasible in data scarce areas or when computer power is limited. Therefore, the shift of hydrological science towards the more process-based models needs to be justified. To answer this, the paper compares 2 hydrological models: (a) the simpler tank model; and (b) the more complex TOPMODEL. More precisely, the difference in performance between tank model as a lumped model and the TOPMODEL concept as a semi-distributed model in Atari River catchment, in Eastern Uganda was conducted. The objectives were: (1) To calibrate tank model and TOPMODEL; (2) To validate tank model and TOPMODEL; and (3) To compare the performance of tank model and TOPMODEL. During calibration, both models exhibited equifinality, with many parameter sets equally likely to make acceptable hydrological simulations. In calibration, the tank model and TOPMODEL performances were close in terms of ‘Nash-Sutcliffe efficiency’ and ‘RMSE-observations standard deviation ratio’ indices. However, during the validation period, TOPMODEL performed much better than tank model. Owing to TOPMODEL's better performance during model validation, it was judged to be better suited for making runoff forecasts in Atari River catchment.
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Identifying minimum number of observed rainfall events required for optimal TOPMODEL parameters in mid-sized equatorial catchments Reviewed
Okiria, E., Okazawa, H., Yamazaki, Y., Kobayashi, Y., Suzuki, S.
International Journal of Environmental and Rural Development 10 2020
Language：English Publishing type：Research paper (scientific journal)
水収支モデルであるTOPMODELについて感度解析を行い，重要なパラメーターをいくつかに絞り込んだ。
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Effect of Recent Changes in Precipitation Distribution Pattern on Agricultural Fields.
SUZUKI Shinji
Research for Tropical Agriculture 13 ( 1 ) 37 - 39 2020
Language：Japanese Publisher：Japanese Society for Tropical Agriculture
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Applicability of Tank Model in Mid-Sized Catchments in Eastern Uganda
OKIRIA EMMANUEL, OKAZAWA HIROMU, YAMAZAKI YURI, KOBAYASHI YUKIMITSU, SUZUKI SHINJI
International Journal of Environmental and Rural Development 11 ( 2 ) 31 - 37 2020
Language：English Publisher：Institute of Environmental Rehabilitation and Conservation, Research Center
<p>Long-term stream discharge data is indispensable in irrigation and drainage design. However, in Uganda, this data is poor and insufficient, limiting irrigation system design. Conversely, the rainfall monitoring network is denser than the river flow monitoring network. Therefore, we attempt to build a model that calculates river discharge from input of rainfall. In this study, the lumped parameter Tank Model was applied. The model was applied to the Namatala River catchment (155 km<sup>2</sup>) in Eastern Uganda. The study sought to ascertain the applicability of a lumped parameter model to a mid-sized catchment. Specifically, the objectives were: 1) To calibrate the numerical values of Tank Model parameters, 2) To verify the Tank Model parameters. This Tank Model required daily rainfall, evapotranspiration and river discharge data during calibration. Data for years 2015 and 2016 was used for calibration and validation respectively. During calibration, Monte Carlo simulation was used to find the numerical values of 16 Tank Model parameters. The best performing calibration parameter set had Nash-Sutcliffe (<i>NS</i>) efficiencies of 0.608 and 0.257 in calibration and validation respectively. However, among the 2015 calibration parameter sets, the one with a calibration <i>NS </i>of 0.502 performed best in validation (<i>NS </i>= 0.526). Equifinality was observed during parameter calibration. By using Tank Model, simulated discharge was divided into its surface runoff, interflow and base flow components. Tank Model was adaptable to Namatala River catchment.</p>
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Characteristics of seasonal changes in soil water in an agricultural field in Okhotsk-Abashiri region with soil freezing. Reviewed
Shinji SUZUKI, Tomomi SAEKI, Hirotake ITO, and Fumio WATANABE
Journal of the Japanese Society of Soil Physics 142 5 - 11 2019.07
Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japanese Society of Soil Physics
In the current study, continuous monitoring of soil water movement was undertaken in an upland field of Okhotsk-Abashiri region, Hokkaido, Japan during the period from July 2011 to June 2012. Particularly, this study focused on clarifying characteristics of the soil water movement caused by soil freezing-thawing and infiltration of snowmelt water. The annual maximum soil frost depth was 0.28 m. The maximum surface soil water content was observed immediately after surface soil melted. The magnitude of downward water flux at a depth of 0.40 m recorded in early April (freezing period) was higher than the magnitude recorded in June (non-freezing period) with large amount of rainfall. Changes in soil water content at deeper layer due to the soil freezing and snowmelt water infiltration were similar to changes of soil water content resulting from drying followed by rainfall infiltration in non-freezing period. Further, it is revealed that all snowmelt water (116.5 mm) infiltrated into the soil without ponding before the frozen soil layer melted. The results suggest that the soil frost with a depth of 0.28 m observed in the current study was insufficient to impede the infiltration of the snowmelt water associated with high porosity of the soil.
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Comparison of root distribution pattern between Gramineae and Legume species under various soil and climate condition Reviewed
Suzuki, S., Kobayashi, Y., Watanabe, F., Nakagawa, D., and Izumikawa, T.
28 ( S ) 189 - 192 2018.12
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal) Publisher：日本沙漠学会
イネ科の植物とマメ科の植物の根系の分布の特徴について調査した。作物の種類にかかわらず，また土壌の状態や気候の条件にかかわらず，根の空間的な発達に伴って，根長密度が指数関数的に増加することが明らかになった。また空間的な分布の特性から根長密度を推定する式を提案した。
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Determining the effective Eucalyptus leaves heating temperature that triggers water repellency using medium sand and soil from Kisima area of Samburu, Kenya
Kirui, S. K., Watanabe, F., Suzuki, S., and Souma, R.
28 ( S ) 173 - 176 2018.12
Language：English Publishing type：Research paper (scientific journal) Publisher：日本沙漠学会
ケニア国サンブル県でのウォーターハーベスティングを念頭に，炭化したユーカリの葉が土壌の撥水性の向上に及ぼす影響について検討した。
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Verification of availability of GSMaP rainfall data based on the comparison of observed rainfall data in Africa Reviewed
Kobayashi, Y.,Watanabe, F., Suzuki, S., Emmanuel, O., and Kanyike, T.
28 ( S ) 85 - 88 2018.12
Language：English Publishing type：Research paper (scientific journal) Publisher：日本沙漠学会
ウガンダ東部において，Global Satellite Mapping of Precipitation (GSMaP)の降雨情報と地上での雨量計による観測データを比較し，GSMaPの特徴や精度について検討した。
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Optimal water use on low pressure drip irrigation system for tomato cultivation in Uganda Reviewed
Denis, B., Watanabe, F., Suzuki, S., and Kuga, S.
28 ( S ) 77 - 80 2018.12
Authorship：Corresponding author Language：English Publishing type：Research paper (scientific journal) Publisher：日本沙漠学会
簡易型で現地でも実施可能な点滴潅漑を利用し，異なる潅水量でトマトの生育を行った。トマトの終了や品質，可能蒸発量と比較することによって，最適な潅水量の算定方法について検討した。
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Estimating optimum irrigation discharge under furrow irrigation in Afghanistan Reviewed
Shams, H. k., Fumio Watanabe, F., Suzuki, S., and Kimura, M.
東京農業大学農学集報 60 ( 4 ) 219 - 224. 2016.03
Language：English Publishing type：Research paper (scientific journal)
アフガニスタンにおける畦間灌漑について，水収支式の積分方程式の解析解をもとに現地の水足試験からインテーク定数を決定し，給水量を適用効率を計算することにより，1 ha のトマト畑全体で1 回の灌漑につき5.1トンの節水が可能であることを明らかにした。
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Soil and hydrological survey for retrieving the characteristics of surface runoff on Kourtimalei reservoir watershed in Djibouti. Reviewed International journal
Toyoda, H., Shimada, S., Hirokane, T., Sekiyama, A., Malow, F. A., Hotta, T., Menjo, M., Suzuki, S., and Watanabe, F.
Journal of Arid Land Studies 25 ( 3 ) 241 - 244 2015.12
Language：English Publishing type：Research paper (scientific journal)
ジブチ国クルチマレ流域の流出特性について調査した。
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Seasonal changes in soil matric potential in an agricultural field in Abashiri region with soil freezing: Use of dielectric water potential sensors and examination on somotic potential of frozen soil. Reviewed
Suzuki, S., Katsuragi, T., Mitsui, T., Ito, H., and Okazawa, H.
Journal of the Japanese Society of Soil Physics 126 51 - 62 2014.04
Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal)
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Estimating pan evaporation in Kabul, Afghanistan. Reviewed
Shams, H. K., Watanabe, F., Suzuki, S., Takahashi, S., and Kashino, M.
23 ( 4 ) 167 - 172 2014.03
Language：English Publishing type：Research paper (scientific journal)
アフガニスタンのカブール市において，気象データからパン蒸発量を推定する方法を提案するとともに，ペンマン法と比較し，実用性について検討した
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Retrieving of the land surface information of a catchment in Djibouti using WorldView-2 and Landsat-8 imagery. Invited
Shimada, S., Malow, F. A., Hotta, T., Menjo, M., Hirokane, T., Suzuki, S., Watanabe, F., and Toyoda, H.
Journal of Arid Land Studies 23 ( 4 ) 247 - 250 2014.03
Language：Japanese Publishing type：Research paper (scientific journal)
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Trial for effective use of local resources such as rainwater, vegetation in East Africa drylands. Invited
Toyoda, H., Shimada, S., Suuzki, S., Tachibana, R., Sanada, A., Hirokane, T., Tajima, K., and Watanabe, F.
Journal of Arid Land Studies 23 ( 4 ) 229 - 233 2014.03
Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal)
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Taste of the Okuizumo-nita rice at the iron sand mining (Kanna-nagashi). Reviewed
Takahashi, S., Suzuki, S., Kawakami, S., Uno, K., and Takao, K.
( 12 ) 85 - 94 2013.09
Language：Japanese Publishing type：Research paper (scientific journal)
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Landscape characteristic of the rice terrace at the iron sand mining (Kanna-nagashi). Reviewed
Takahashi, S., Suzuki, S., Watanabe, F., Uno, K., and Takao, A.
( 12 ) 95 - 105 2013.09
Language：Japanese Publishing type：Research paper (scientific journal)
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Comparison between temperature gradient and heat flux plate methods and effect of heat storage for determination of soil heat flux at near soil surface Reviewed
S. Suzuki, K. Iiduka, F. Watanabe, S. Shimada, and S. Takahashi
Journal of the Japanese Society of Soil Physics 124 35 - 42 2013.07
Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal)
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Usefulness of Wood Plant Seeds Collected in Djibouti Invited
Tachibana, R., Ohno, A., Ismael, T. M., Sanada, A., Suzuki, S., Fukunaga, K., and Takahashi, S.
Journal of Arid Land Studies 23 ( 1 ) 29 - 32 2013.06
Language：Japanese Publishing type：Research paper (scientific journal)
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Soil mechanical impedance, water retention, and drainability of the experimental upland plots established by soil-dressing Reviewed
Suzuki, S., Watanabe, F., Takahashi, S., Mitsui, S., Iiduka, K., and Shao, L.
Journal of Agriculture Science, Tokyo University of Agriculture 58 ( 1 ) 13 - 20 2013.06
Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal)
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The survey of life water in Ethiopia Reviewed
Hosaka, M., Sanada, A., Suzuki, S., Homma, K., Wakana, N., Tanaka, E., Adachi, T., and Tachi, H.
Journal of Japan Health Medicine Association 22 ( 1 ) 52 - 57 2013.04
Language：Japanese Publishing type：Research paper (scientific journal)
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Water and nitrate movements in an agricultural field having different soil frost depths: field experiments and numerical simulation Reviewed
Iwata, Y., Yazaki, T., Suzuki, S., and Hirota, T.
Annals of Glaciology 54 ( 2 ) 157 - 165 2013.02
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)
土壌凍結深の違いが土壌水や硝酸対窒素の動態に及ぼす影響を調べ，モデルと比較し，そのメカニズムについて検討した。
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The climate and issues on NERICA cultivation in Uganda in the view of water utilization Invited Reviewed
Goto, A., Suzuki, S., Watanabe, F., Nishimaki, R., and Takahashi, S.
Journal of Arid Land Studies 22 ( 2 ) 403 - 407 2012.09
Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal)
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Ability of NERICA cultivation in semi-arid area of Ethiopia Invited Reviewed
Sanada, A., Suzuki, S., Nakamura, K., Watanabe, F., Takahashi, H., and Takahashi, S.
Journal of Arid Land Studies 22 ( 2 ) 391 - 395 2012.09
Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal)
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Current condition, issues and development for solution of agriculture in arid land of Africa Reviewed
Takahashi, S., Suzuki, S., Sanada, A., Tachibana, A., and Watanabe, F.
Journal of the Japanese Society of Irrigation, Drainage and Rural Engineering 80 ( 8 ) 633 - 636 2012.08
Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal)
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Fluoride in life water and health survey of farmers in arid and semi-arid basin in Ethiopia Reviewed
Homma, K., Wakana, N., Todoroki, K., Sanada, A., Shinohara, T., Suzuki, S., Hosaka, M., Ando, T., and Tanaka, E.
Journal of Japan Health Medicine Association 21 ( 2 ) 95 - 100 2012.07
Language：Japanese Publishing type：Research paper (scientific journal)
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Estimating the volume of surface runoff from in situ measured soil sorptivity. Reviewed
Watanabe, F., Kobayashi, Y., Suzuki, S., Hotta, T., and Takahashi, S.
沙漠研究 22 ( 1 ) 95 - 98 2012.06
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)
エチオピア中央部において，土壌に水が浸潤する際のパラメーターであるソープティビティを考慮して，表面流出量の推定を推定した。
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Evaluating the consumptive water use of Teff in consideration of soil water movement in central Ethiopia Reviewed
Kubo, A., Watanabe, F., Suzuki, S., and Takahashi, S.
沙漠研究 22 ( 1 ) 203 - 206 2012.06
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)
エチオピア中央部において，伝統作物であるテフの消費水量を観測によって求めた。
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Trial on supplemental irrigation technology during rainy season in semi-arid area of Ethiopia. Reviewed
Oya, T., Iada, K., Tutsui, Y., Lemma, G., Kebebew, B., Suzuki, S., and Takahashi, S.
沙漠研究 22 ( 1 ) 211 - 214 2012.06
Language：English Publishing type：Research paper (scientific journal)
半乾燥地であるエチオピア中央部での野菜栽培において，補給灌漑方法確立のための検討を行った。
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Terrace development applied as a water harvesting technology for stable NERICA production in Uganda Reviewed
Goto, A., Nishimaki, R., Suzuki, S., Watanabe, F., and Takahashi, S.
沙漠研究 22 ( 1 ) 243 - 246 2012.06
Language：English Publishing type：Research paper (scientific journal)
ウガンダでのネリカ栽培において，ウォーターハーベスティングのためのテラス栽培について検討した。
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The prevention methods of leak and evaporation for consecutive water reservoir Reviewed
Takahashi, S., Suzuki, S., Watanabe, F., Goto, A., and Kubo, A.
沙漠研究 22 ( 1 ) 287 - 290 2012.06
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)
エチオピア中央部においてため池を造成する際の底側面からの浸透防止対策について検討した。
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Effect of atmospheric pressure on evaporation in central Ethiopia Reviewed
Suzuki, S., Deressa, M., Sanada, A., Nakamura, K., Watanabe, F., and Takahashi, S.
沙漠研究 22 ( 1 ) 303 - 306 2012.06
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)
半乾燥地帯であるエチオピア中央部は，標高が高いために1年を通して気圧が低い。そのため蒸発が起こりやすい環境であることを，観測によって明らかにした。
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Application example of the small solar pumping system in the Djiboutian wadi agriculture Reviewed
Tajima, K., Suzuki, S., Shinohara, T., Sanada, A., and Watanabe, F.
沙漠研究 22 ( 1 ) 337 - 340 2012.06
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)
ジブチ国のワジ農業において，小型ソーラーポンピングシステムによる小規模灌漑について検討した。
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Current situation and issues on agriculture of Afghanistan Reviewed
Kawasaki, S., Watanabe, F., Suzuki, S., Nishimaki, R., and Takahashi, S.
沙漠研究 22 ( 1 ) 345 - 348 2012.06
Language：English Publishing type：Research paper (scientific journal)
アフガニスタン農業の現状について考察した。
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Experimental study on sample size for laboratory calibration tests of commercial dielectric soil water sensors. Reviewed
Suzuki, S., Hirota, T., and Iwata, Y.
Japan Agricultural Research Quarterly 46 ( 1 ) 73 - 79 2012.01
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)
市販されている4種の誘電土壌水分センサの影響範囲を実験的に明らかにした。解析の結果，電磁エネルギーの70%以上を含む必要があることが示唆された。
DOI： 10.6090/jarq.46.73
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Desertification in central Ethiopia associated with meteorological and soil characteristics Invited
Suzuki, S., Sanada, A., Watanabe, F., and Takahashi, S.
Journal of Arid Land Studies 21 ( 3 ) 129 - 134 2011.12
Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal)
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Soil erosion assessment using USLE in East Shewa, Ethiopia. Reviewed
Gara, A., Suzuki, S., Watanabe, F., Shimada, S., and Toyoda, H.
東京農業大学農学集報 56 ( 1 ) 1 - 8 2011.06
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)
エチオピア国東ショワゾーンの土壌侵食量を推定し，影響因子について考察した。
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Improvement and horizon of rain-fed agriculture in Africa from the point of view of water usage Invited
Journal of Arid Land Studies 20 ( 4 ) 219 - 226 2011.03
Language：Japanese Publishing type：Research paper (scientific journal)
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Measurement of soil heat flux and net radiation using a small data logger designed for measurement of thermocouples, and application of the system in central Ethiopia Reviewed
Journal of Arid Land Studies 20 ( 4 ) 201 - 206 2011.03
Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal)
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土壌凍結深や地温が融雪水の下方浸透に与える影響 Reviewed
岩田幸良，長谷川周一，鈴木伸治，根本学，廣田知良
土壌の物理性 ( 117 ) 11 - 21 2011.03
Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal)
土壌凍結層の発達が融雪期の下層への浸透量に与える影響を評価し，土壌凍結深が増加するほど融雪水の下層への浸透が抑制されるメカニズムをモデルにより説明した。
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New horizons of desert greening Invited Reviewed
Water Science 54 ( 6 ) 1 - 29 2011.02
Language：Japanese Publishing type：Research paper (scientific journal)
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Consecutive irrigation reservoir system in semi-arid area of East Africa Reviewed
Journal of the Japanese Society of Irrigation, Drainage and Rural Engineering 79 ( 2 ) 109 - 112 2011.02
Language：Japanese Publishing type：Research paper (scientific journal)
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Verification study on water collecting characteristic of water-harvesting technique in Ethiopia : Consecutive irrigation reservoir system with water-harvesting for NERICA in semi-arid area (2) Reviewed
Journal of Arid Land Studies 20 ( 3 ) 151 - 158 2010.12
Language：Japanese Publishing type：Research paper (scientific journal)
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Consecutive irrigation reservoir system with water-harvesting in Ethiopia
Journal of Arid Land Studies 20 ( 2 ) 127 - 131 2010.09
Language：Japanese Publishing type：Research paper (scientific journal)
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Effects of snow cover on soil freezing, water movement, and snowmelt infiltration: A paired plot experiment. Reviewed
Iwata, Y., Hayashi, M., Suzuki, S., Hirota, T., and Hasegawa, S.
Water Resources Research 46 ( 9 ) 2010.09
Language：English Publishing type：Research paper (scientific journal)
近年の気候変動に伴う土壌凍結深の減少傾向について取り上げ，積雪が多い場合と少ない場合の土壌の凍結の様子や土壌水分量の変化，および土壌水分フラックスの違いについて現地での実際の観測データに考察した。
DOI： 10.1029/2009WR008070
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Effects of frozen soil and snow cover on cold-season soil water dynamics in Tokachi, Japan. Reviewed
Iwata,Y., Hirota, T., Hayashi, M., Suzuki, S., and Hasegawa, S.
Hydrological Processes ( 24 ) 1755 - 1765 2010.06
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)
我が国の寒冷地において，土壌凍結が融雪水の浸透や下層の土壌水分に及ぼす影響について，5年に及ぶ観測結果から検討し，凍結が発達する年と発達しない年で明瞭な違いがあることを明らかにした。
DOI： 10.1002/hyp.7621
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Water usage and greening technology in arid region Invited
Journal of Arid Land Studies 20 ( 1 ) 55 - 61 2010.06
Language：Japanese Publishing type：Research paper (scientific journal)
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Salinity Tolerance of the Salt Grass (Distichlis spicata) in the Western Australia State Invited
Takahashi, S., Watanabe, F., Suzuki, S., and Takahashi, S.
Journal of Arid Land Studies 19 ( 3 ) 507 - 511 2009.12
Language：Japanese Publishing type：Research paper (scientific journal)
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Poverty alleviation through NERICA introduction into semiarid Sub-Saharan Africa Reviewed
Kitanaka, M., Nishimaki, R., Tsuboi, T., Suzuki, S., and Takahashi, S.
沙漠研究 19 ( 1 ) 77 - 80 2009.07
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)
東アフリカ半乾燥地帯におけるネリカ栽培の利点について述べた。
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Long-term-discharge analysis using the EPA method for the Tana River in Kenya Reviewed
Okazawa, H., Toyoda, H., Suzuki, S., Shimada, S., and Nishimaki, R.
沙漠研究 19 ( 1 ) 57 - 60 2009.07
Language：English Publishing type：Research paper (scientific journal)
ケニア国タナ川について，近年の気候変動に伴う流出特性の変化について調べた。
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Conveyance and drainage system in spate irrigation -A case of Boro Dodota spate irrigation- Reviewed
Geleta, Y., Edessa, C., Inada, K., Otubo, Y., Suzuki, S., and Toyoda, H.
沙漠研究 19 ( 1 ) 69 - 72 2009.07
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)
エチオピア国中央部において実施されているスペイト灌漑の実態について調べた。
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Trials on hydro meteorological analysis for spate irrigation development in Oromia, Ethiopia Reviewed
Negussie, G., Aman, H., Inada, K., Suzuki, S. and Toyoda, H.
沙漠研究 19 ( 1 ) 241 - 244 2009.07
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)
エチオピア国中央部で実施されているスペイト灌漑の計画・設計に必要な気象・水文解析の展望について述べた。
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Trial on water saving irrigation farming technology in semi-arid area of Ethiopia Reviewed
Inada, K., Lemma, G.., Oya, T., Kebebew, B., Suzuki, S., and Takahashi, S.
沙漠研究 19 ( 1 ) 245 - 248 2009.07
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)
エチオピア国中央部の畑地を対象に，適切な節水灌漑の方法について調べた。
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Approaches of agroforestry management in the Central Ethiopia. Reviewed
Deressa, M., Shiratori, K., Matsumoto, I., Jabessa, B. S., Suzuki, S., Kobayashi, Y., et al.
沙漠研究 19 ( 1 ) 351 - 354 2009.07
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)
エチオピア国中央部で実施されているアグロフォレストリの活動を紹介し，適切な樹種やアグロフォレストリが内外の気温や相対湿度，日射に与える影響について調べた。
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Meteorological and soil characteristics in the Central Ethiopia. Reviewed
Suzuki, S., Deressa, M., Watanabe, F., Shiratori, K., Matsumoto, I., Jabessa, B. S., et al.
沙漠研究 19 ( 1 ) 295 - 298 2009.07
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)
エチオピア国中央部の畑地において，気温，相対湿度，日射，風速の特徴を明らかにし，灌漑や降雨に伴う土壌の浸潤特性について基礎的な観測を行った。その結果，乾季や雨季の直前など，土壌が非常に乾燥した状態では，灌漑水や降雨が土壌の下層まで十分に届かないことが明らかになった。
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Relationship between vegetation and topography for an erosion management in Ethiopia Reviewed
Gara, A., Shimada, S., Toyoda, H., Okazawa, H., Suzuki, S., and Ghrabi, A.
沙漠研究 19 ( 1 ) 257 - 260 2009.07
Language：English Publishing type：Research paper (scientific journal)
チオピア国における土壌侵食の被害と植生の関係について明らかにした。
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Consecutive irrigation reservoir system with water-harvesting for NERICA in semi-arid area: Verification study in Ethiopia by irrigation water balance simulation Reviewed
Journal of Arid Land Studies 18 ( 3 ) 81 - 89 2008.12
Language：Japanese Publishing type：Research paper (scientific journal)
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Relationship between agricultural land use and nitrogen/phosphorus concentration of river water in Abashiri river basin in Hokkaido, Japan Reviewed
Transactions of the Japanese Society of Irrigation, Drainage and Rural Engineering ( 258 ) 45 - 50 2008.12
Language：Japanese Publishing type：Research paper (scientific journal)
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Rehabilitation of degraded sandy soils in Northeast Thailand Invited
Suzuki, S.
Journal of arid land studies 18 ( 3 ) 115 - 120 2008.12
Language：Japanese Publishing type：Research paper (scientific journal)
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Development and field testing of agricultural snowmelting agents made from recycled bio-waste materials Reviewed
Journal of the Agricultural Meteorology 64 ( 4 ) 271 - 279 2008.12
Language：Japanese Publishing type：Research paper (scientific journal)
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Rural engineering approaches for revitalization of marginal farming settlements Reviewed
Journal of the Japanese Society of Irrigation, Drainage and Rural Engineering 76 ( 12 ) 15 - 18 2008.12
Language：Japanese Publishing type：Research paper (scientific journal)
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Development of the water collection method by condensing air in Djibouti Invited
Tajima, K., Nakayama, N., Suzuki, S., Watanabe, F., Sekiyama, T., and Satoru, T.
Journal of Arid Land Studies 18 ( 1 ) 35 - 38 2008.06
Language：Japanese Publishing type：Research paper (scientific journal)
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Rainfall usage technology for agriculture in semi-arid region : Collect, store, and use Invited
Journal of arid land studies 17 ( 4 ) 193 - 197 2008.03
Language：Japanese Publishing type：Research paper (scientific journal)
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Soil acidification and carbon storage in fertilized pastures of Northeast Thailand. Reviewed
Noble, A. D., Suzuki, S., Soda, W., Ruaysoongnern, S., and Berthelsen, S.
Geoderma 144 ( 1-2 ) 248 - 255 2008.03
Language：English Publishing type：Research paper (scientific journal)
土壌荒廃によって強い酸性を示す東北タイの砂質畑圃場において，深根性の植物であるGamba grass (Andropogon gayanus)を用い，酸性の改良と土壌有機物の蓄積に成功した。
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Temperature trends at the national Agricultural Research Center for Hokkaido Region in the 40 years from 1966 to 2005. Reviewed
Sameshima, R., Hirota, T., hamasaki, T., and Suzuki, S.
Journal of Agricultural Meteorology 63 ( 2 ) 95 - 102 2007.06
Language：English Publishing type：Research paper (scientific journal)
北海道農業研究センターにおける過去40年の気象観測値を調べ，北海道内のいくつかの気象官署と比較したところ，都市化影響の僅少な農業地帯における過去の気温上昇程度は，一般に言われる値(1.0℃/y)よりも小さい可能性が示された。
DOI： 10.2480/agrmet.63.95
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Improvement in water-holding capacity and structural stability of a sandy soil in Northeast Thailand Reviewed
Suzuki, S., Noble, A. D., Ruaysoongnern, S., and Chinabut, N
Arid Land Research and Management 21 ( 1 ) 37 - 49 2007.01
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)
東北タイにおける荒廃土壌について，保水性の改善と土壌構造の安定化を図るために，地域で入手可能な改良資材を用いて現地実証を行った。
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Co-composting of acid waste bentonites and their effects on soil properties and crop biomass. Reviewed
Soda, W., Noble, A.D., Suzuki, S., Simmons, R., Sindhusen, L., and Bhuthorndharaj, S.
Journal of Environmental Quality 35 ( 6 ) 2293 - 2301 2006.11
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)
タイ国ではヤシや大豆を原料とした植物油の生産が盛んであり，その精製にベントナイトが用いられ，大量に廃棄されている。本研究では廃棄ベントナイトを鶏糞や籾殻とともにコンポスト化することによって，土壌の酸性や保肥力，および保水性が改良され，作物の乾物重量が顕著に増大することを明らかにした。
DOI： 10.2134/jeq2005.0455
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Decreasing soil-frost depth and its relation to climate change in Tokachi, Hokkaido, Japan. Reviewed
Hirota, T., Iwata, Y., Hayashi, M., Suzuki, S., Hamasaki, T., Sameshima, R., and Takayabu, I.
Journal of the Meteorological Society of Japan 84 ( 4 ) 821 - 833 2006.08
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal)
北海道・十勝地方では，1980年代中頃から積雪の早期化によって土壌凍結深が顕著に減少していることを明らかにした。この現象は，東アジア地域の冬季モンスーン勢力の減衰と一致していた。
DOI： 10.2151/jmsj.84.821
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Improving the productivity of degraded cropping systems in Northeast Thailand: Improving farmer practices with innovative approaches.
Noble, A. D. and Suzuki, S.
Proceedings of the International Conference on Research Highlights and Vanguard Technology on Environmental Engineering in Agricultural Systems 371 - 380 2005.09
Authorship：Lead author Language：English Publishing type：Research paper (international conference proceedings)
東北タイの土壌荒廃の現状や原因を明らかにし，現地で適用可能な改良技術として，ベントナイトを用いた保肥力と保水性の改良や，深根性の植物と硝酸態肥料を用いた土壌酸性の改良手法を提案した。
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Verification of freezing point depression method for measuring matric potential of soil water. Reviewed
Suzuki, S.
Soil Science and Plant Nutrition 50 ( 8 ) 1277 - 1280 2004.12
Language：English Publishing type：Research paper (scientific journal)
土壌の凝固点降下度がマトリックポテンシャルと比例関係にあることを用いて，凝固点降下度法が，土壌の生長阻害水分点から永久シオレ点近傍の水分特性曲線を求めるために有効であることを明らかにした。
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Dependence of unfrozen water content in unsaturated frozen clay soil on initial soil moisture content. Reviewed
Suzuki, S.
Soil Science and Plant Nutrition 50 ( 4 ) 603 - 606 2004.08
Language：English Publishing type：Research paper (scientific journal)
従来，凍土の不凍水量は初期水分量に依存しないと考えられてきたが，本研究では不凍水量が初期水分量の増加にともなって直線的に増大することをTDR法とNMR法を用いて明らかにした。
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野外土壌の透水性の簡易測定 Reviewed
中川進平，長谷川周一，柏木淳一，鈴木伸治
日本土壌肥料学雑誌 73 ( 6 ) 783 - 786 2002.12
Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal)
負圧浸入計を用いて野外で測定した土壌の不飽和透水係数について，室内実験で求めた値と比較し，土壌の孔隙構造の影響について検討した。
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Soil water movement under micro-irrigation using a perforated tube Reviewed
Nakagawa, S., Soma, K., Kashiwagi, J., and Suzuki, S.
Journal of Japanese Society of Soil Physics ( 91 ) 39 - 47 2002.07
Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal)
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Mechanism of hysteresis in thermal conductivity of frozen soils between freezing and thawing processes Reviewed
Suzuki, S., Kashiwagi, J., Nakagawa, S., and Soma, K.
( 218 ) 97 - 105 2002.04
Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal)
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Structure and thermal conductivity of pumice soils deposited in central Hokkaido Reviewed
Suzuki, S., Soma, K., Kashiwagi, J., and Nakagawa, S.
Transactions of The Japanese Society of Irrigation, Drainage ( 213 ) 83 - 92 2001.06
Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal)