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Home > Tenured Faculties > Sugihara Soh

Tenured Faculties

Sugihara Soh

Affiliation Institute of Agriculture
Division Division of Biological Production
Research field Soil Science
Keyword(S) Nutirent dynamics, Sustainalbe land management, Soil fertility
Research experience

・2008-2010: JSPS research fellow (DC2)
・2010-2014: Postdoctoral researcher, Kyoto University, Japan
・2014-2015: Assistant Professor, Kyushu University, Japan
・2015-2015: Assistant Professor, Tokyo Metropolitan University, Japan
・2016-2020: Associate Professor, Tokyo University of Agriculture and Technology
・2021 - Present: Associate Professor(Tenured), Tokyo University of Agriculture and Technology

Educational background

・2004: BSc in Agriculture, Kyoto University, Japan
・2006: MSc in Agriculture, Kyoto University, Japan
・2010: PhD in Agriculture, Kyoto University, Japan


* The latest information is shown at the member's website.
(At Jan. 2016)
・2013: Excellent Poster award at the Japan Pedology conference

Selected papers and publications

* The latest information is shown at the member's website.
(At Jan. 2016)
・Sugihara S*, Tomita Y, Nishigaki T, Kilasara M, Wasaki J, Funakawa S. “Effects of different phosphorus- efficient legumes and soil texture on fractionated rhizosphere soil phosphorus of strongly weathered soils” Biology and Fertility of Soil, In press. (DOI 10.1007/s00374-015.1082-4)
・Sugihara S*., Funakawa S., Kadono A., Takata Y., Sawada K., Fujii K., Kosaki T. (2015) "In situ short-term dynamics of CO2 flux and microbial biomass after simulated rainfall in dry croplands in four tropical and continental ecosystems." Soil Science and Plant Nutrition, 61. 392-403.
・Sugihara S*, Shibata M, MVondo Ze A, Araki S, Funakawa S. (2015) “Effect of vegetation on soil microbial C, N and P dynamics in a tropical forest and savanna of Central Africa.” Applied Soil Ecology, 87. 91-98.
・Sugihara S*, Shibata M, MVondo Ze A, Araki S, Funakawa S. (2014) “Effect of vegetation on soil C, N, P and other minerals in Oxisols at the forest-savanna transition zone of central Africa.” Soil Science and Plant Nutrition, 60. 45-59.
・Sugihara S*, Funakawa S, Ikazaki K, Shinjo H, Kosaki T. “Rewetting of dry soil did not stimulate the carbon and nitrogen mineralization in croplands with plant residue removed in the Sahel, West Africa.” Tropical Agriculture and Development , 58 (2014), pp. 8-17.
・Sugihara S*, Funakawa S, Kilasara M, Kosaki T. “Effect of land management on soil microbial N supply to crop N uptake in a dry tropical cropland in Tanzania.” Agriculture Ecosystems and Environment, 146 (2012), pp. 209-219.
・Sugihara S*, Funakawa S, Kilasara M, Kosaki T. “Effects of land management on CO2 flux and soil C stock in two Tanzanian croplands with contrasting soil texture.” Soil Biology and Biochemistry, 46 (2012), pp. 1-9.
・Sugihara S*, Funakawa S, Kilasara M, Kosaki T. “Dynamics of fractionated P and P budget in soil under different land management in two Tanzanian croplands with contrasting soil textures.” Agriculture Ecosystems and Environment, 162 (2012), pp. 101-107.

Research Description

Soil play an important role for food production and natural environment. However, there had been limited attention for “Soil resources” for sustainable management. According to Millennium Ecosystem Assessment, soil provide the Supporting services for Food provisioning, Regulating the climate change, and Cultural aesthetic, and so on. To maintain the Ecosystems and Human well-being for the millennium, we must understand the soil itself more.
In this context, I studies the Soil Science, in order to conserve and utilize the soil resource more effectively, especially in Sub Saharan Africa (SSA). To solve the food shortage in Sub-Saharan Africa, I performed continuous cultivation experiments since 2006 in Tanzania, and the following results were obtained from the effect of land management on soil-plant nitrogen (N): 1) critical N leaching was occurred (ca. 60 kg N ha-1 yr-1), causing the low crop yields, 2) soil microbial biomass (SMB) contain much N as biomass at the early growth stage of crop and decreased at the late growth stage, and 3) reduced SMB contribute significantly to the crop growth stages as N source (ca. 20 kg N ha-1 yr-1). This study seeks to expand on these results. At the next step, I developed new technique of crop residue application to improve the N use efficiency as follows: 1) the application of plant residue before planting can increase SMB, resulting in much N, which is generally leached, is absorbed by SMB, 2) the increased SMB during the early crop growth period decreased the leached N, and also increased the N supply by SMB (ca. 200~250%) during the late crop growth period, and 3) it increased the crop growth (ca. 120 %) (Sugihara et al., 2010a, 2010b, 2012b). Furthermore, to utilize the recalcitrant soil P, which can not use for plant generally, I performed the new research and used White lupin (Lupinus albus), which can specially absorb recalcitrant soil P more than the other plants. At present, my result indicated that White Lupin can specially absorb the recalcitrant soil P associated with oxide Al/Fe in Tanzanian croplands, compared with other leguminous plants (Sugihara et al., In press).
As explained above, I mainly focus on nutrient dynamics in various agroecosystems (Tanzania, Cameroon, Thailand, India, Cambodia, and Japan), in relation to soil chemical characteristics, and suggest the sustainable land management.

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About TUAT's tenure-track program

This tenure-track program allows us to spend enough time on our own research, by reducing the coursework and some operations in university. Comparing with other coeval researcher in different institute or university, this program provide the special research environment, including room, fund, and human support. I really appreciate this position with warm encouragements and supports from mentors and other professors. Although the many task is there, but it must be solved with intensified effort for the fascinating research.

Future aspirations

All I have to do is “Research with good quality”. To achieve this object, it is necessary to create a good cycle; (1) facilitate the laboratory environment and get the research fund, (2) Study as usual (this is very easy), and (3) publish the results not only by journal papers but also by a service to society. To step the above cycle with fluency, the cooperation of laboratory staff and student must be necessary. Then, I would like to make the vigorous research team with some strict rule and deep affection.