SEKI Katsutoshi

J-GLOBAL         Last updated: Sep 30, 2019 at 00:42
SEKI Katsutoshi
Toyo University
Natural Science Laboratory
Job title
Ph.D.(The University of Tokyo)
Research funding number
Twitter ID


My research focuses on physical processes in the unsaturated (vadose) zone, in the basic theory of flow and application of the theory to environmental problems. Hydraulic parameters are important for the modeling of water flow in soil, and I made a simple web interface, SWRC Fit (, for determining the parameters from laboratory experiment. As determination of hydraulic parameters in laboratory is not very easy, I am trying to establish a method for estimating hydraulic parameters directly from field monitored water content.

I am also interested in biological processes in soil associated with physical properties. I have numbers of publications in the topic of biological clogging, or bioclogging, of soil pores by microbes, and these publications are frequently cited (

I have a broad interest in environmental topics as a scientist. At Toyo University, I am teaching an introductory course of "Environmental Science" to attract interest to environmental problems for students of various field of major. I published several papers related to environmental problems in soil. The topics include alkalinization of soil, contamination of soil by fallout radiocesium and strontium, physical and chemical properties of soil affected by forest fire, and remediation of soil with biobarrier technique.

Research Areas


Academic & Professional Experience

Apr 1998
Nov 1998
Researcher, The University of Tokyo
Dec 1998
Mar 2007
Research Associate, Graduate School of Agricultural and Life Sciences, The University of Tokyo
Aug 2002
May 2003
Visiting Scholar, Department of Crop and Soil Sciences, Cornell University (USA)
Apr 2007
Mar 2008
Assistant Professor, Graduate School of Agricultural and Life Sciences, The University of Tokyo
Apr 2008
Mar 2015
Associate Professor, Faculty of Business Administration, Toyo University
Apr 2013
Mar 2014
Invited Professor, Laboratory of Hydrology and Geochemistry, University of Strasbourg (France)
Apr 2015
Professor, Faculty of Business Administration, Toyo University


Apr 1989
Mar 1993
Faculty of Agriculture, The University of Tokyo (Received B.S.)
Apr 1993
Mar 1995
Graduate School of Agricultural and Life Sciences, The University of Tokyo, Master course (Received M.S.)
Apr 1995
Mar 1998
Graduate School of Agricultural and Life Sciences, The University of Tokyo, Doctor course (Received Ph.D.)

Committee Memberships

Apr 1999
Mar 2001
Journal of Japanese Society of Soil Physics  Editorial board
Jun 2004
May 2006
Journal of the Agricultural Engineering Society, Japan  Editorial board
Oct 2019
Geosciences  Editorial board

Awards & Honors

Jul 2018
Outstanding reviewer award (Geoderma), Elsevier

Published Papers

Seki, K., T. Miyamoto and Y. Iwata
International Agrophysics   33(1) 113-119   Feb 2019   [Refereed]
In order to establish sustainable agricultural practices and to avoid excess fertiliser application, it appears important to understand the process of water and solute transport. With a view to analysing transport through the soil, based on the da...
Seki, K., P. Ackerer and F. Lehmann
Geoderma   247 117-128   Jun 2015   [Refereed]
Field-scale estimation of soil hydraulic parameters is important for describing water movement in vadose zones. The importance of soil water measurements has been acknowledged with increasing soil water measurements becoming available; thus, the e...
Seki, K.
Open Journal of Soil Science   3(3) 148-152   Jul 2013   [Refereed]
Increased microbial activity leads to biological clogging (or bioclogging), i.e., the pore space is clogged by microbes and saturated hydraulic conductivity of porous media decreases. A series of column experiments were carried out to study the bi...
Kajiura, M., T. Tokida and K. Seki
Geoderma   181-182 30-35   Jul 2012   [Refereed]
Potential water repellency (PWR) is a common index to indicate the degree to which soils repel water. Soil organic matter (SOM) is a requisite substance for the water repellency but many studies have shown that SOM content alone could not fully ac...
T. Nishimura, Y. Ishihama, K. Seki, H. Imoto, M. Mizoguchi, T. Miyazaki
Transactions of The Japanese Society of Irrigation, Drainage and Rural Engineering   279 35-44   Jun 2012   [Refereed]
Katsutoshi Seki
Journal of Business Administraion, Toyo University   78 13-26   Nov 2011
Due to the Fukushima Daiichi nuclear plant accident in Japan, huge amount of radionuclides were emitted to the environment. Remediation of soil contaminated with radionuclides is urgent and important. Several remediation techniques are reviewed, e...
Dumale, W. A. Jr., T. Miyazaki, T. Nishimura and K. Seki
E-International Scientific Research Journal   3(2) 128-144   Jun 2011
In a 110-day constant temperature experiment (20°C), we determined the effect of fresh organic matters (FOM): 0 (control); 1.81 g leaf litter (LL) carbon kg-1; and 2.12 g chicken manure (CM) carbon kg-1 in the stable soil organic carbon [mineral-a...
Seki, K., K. Suzuki, T. Nishimura, M. Mizoguchi, H. Imoto, T. Miyazaki
Journal of Tropical Forest Science   22(4) 414-424   Oct 2010   [Refereed]
The ecological recovery of Dipterocarpaceae forest in East Kalimantan, Indonesia, after the forest fire in 1997–1998 was studied. Soil physical and chemical properties of the plots—heavily damaged by forest fire (HD), lightly damaged by fire (LD) ...
Sadao Eguchi, Noriko Yamaguchi, Hideshi Fujiwara, Taijiro Fukuyama, Yasushi Mori, Katsutoshi Seki, Katsuhiko Suzuki, and Kazuhide Adachi
Proceedings of 19th World Congress of Soil Science   (paper 0826) 1-3   Aug 2010
The atmospherically-derived cosmogenic (7-Be), anthropogenic (137-Cs), and airborne radionuclides (210-Pb_xs) were used to investigate the origin and travel time of the mobile soil particles discharged from the tile drain in a heavy clay soil. The...
Seki, K.
Journal of the Toyo University Natural science   54 1-14   Mar 2010
Volcanic ash soils have excellent soil hydrological properties, as high water retentivity and high water permeability compared with other clayey soils. They contain abundant allophane and organic matter. Having well developed aggregated structures...
Hamamoto, S., K. Seki and T. Miyazaki
Journal of Hazardous Materials   166(1) 207-212   Jul 2009   [Refereed]
The understanding of the gaseous adsorption process and the parameters of volatile organic compounds such as organic solvents or fuels onto soils is very important in the analysis of the transport or fate of these chemicals in soils. Batch adsorpt...
Wang L., Seki K., Miyazaki T., Ishihama Y.
Paddy and Water Environment   7 259-270   Jun 2009   [Refereed]
The causes of soil alkalinization in the Songnen Plain of Northeast China were mainly analyzed from two aspects, natural and anthropogenic. Natural factors of alkalinization are parent materials, topographic positions, freeze-thaw action, wind con...
Saito, H., K. Seki, J. Simunek
Hydrol. Earth Syst. Sci.   13 453-465   Apr 2009   [Refereed]
There are two approaches available for mapping water retention parameters over the study area using a spatial interpolation method. (1) Retention models can be first fitted to retention curves available at sampling locations prior to interpolating...
Dumale, W. A., T. Miyazaki, T. Nishimura and K. Seki
Geophysical Research Letters   36 L01301   Jan 2009   [Refereed]
The organic carbon of particle size <53 μm is mineral-associated organic carbon (MAOC), the measurable fraction of passive soil organic matter pool described in CENTURY model. We studied the effect of fresh organic matters (FOMs): no OM (control);...
Wang, L., Y. Ishihama, K. Seki and T. Miyazaki
Pratacultural Science   2007(10)    Oct 2007   [Refereed]
Seki, K.
Journal of Japanese Society of Soil Physics   105 67-78   Mar 2007   [Refereed]
The soil hydraulic parameters for analyzing soil water movement can be determined by fitting a soil water retention curve to a certain function, i.e., a soil hydraulic model. For this purpose, a program which performs nonlinear fitting of soil wat...
Seki, K.
Hydrol. Earth Syst. Sci. Discuss.   4(1) 407-437   Feb 2007   [Refereed]
The soil hydraulic parameters for analyzing soil water movement can be determined by fitting a soil water retention curve to a certain function, i.e., a soil hydraulic model. For this purpose, the program "SWRC Fit," which performs nonlinear fitti...
Yamaguchi, N., K. Seki, M. Komamura, K. Kurishima
Science of the Total Environment   372(41673) 595-604   Jan 2007   [Refereed]
In this study, we evaluated the mobility of 90Sr in ploughed upland soil, which affects the residual amount in the soil and plant uptake on the basis of long-term monitoring data. Paired samples of soil and wheat grain were taken annually from 196...
Khalil, M., K. Seki, T. Miyazaki, M. Mizoguchi, M. Sakai
Transactions of Japanese Society of Irrigation, Drainage and Reclamation Engineering, Vol. 246 (2006), pp. 33-40, doi:10.11408/jsidre1965.2006.841 Key: citeulike:1114169   246 33-40   Dec 2006   [Refereed]
Zero Flux plane (ZFP) is defined as a plane, which separates two zones of upward and downward movement of water in soil with upward and downward flow occurring simultaneously. In this study, the analysis of the ZFP movements was carried out by two...
Seki, K., M. Thullner, J. Hanada, T. Miyazaki
Ground Water Monitoring and Remediation   26(3) 68-76   Jun 2006   [Refereed]
Permeable reactive barriers (PRBs) are an alternative technique for the biological in situ remediation of ground water contaminants. Nutrient supply via injection well galleries is supposed to support a high microbial activity in these barriers bu...
Deb, S. K., T. Miyazaki, M. Mizoguchi and K. Seki
Transactions of Japanese Society of Irrigation, Drainage and Reclamation Engineering   241 1-11   Feb 2006   [Refereed]
Two-dimensional soil water movement under the rainfall infiltration has been demonstrated using the model slope layered with traffic pan. The experimental runs of the 8-degree and 12-degree model slopes under the prolonged steady rainfalls of 80, ...
Seki, K., J. Kamiya and T. Miyazaki
Transactions of Japanese Society of Irrigation, Drainage and Reclamation Engineering   237 13-19   Jun 2005   [Refereed]
Decrease in hydraulic conductivity due to microbial biomass accumulation in soil pore, i.e., biological clogging or bioclogging, was studied in laboratory repacked sand columns, and temperature dependence of the bioclogging was observed. Glucose s...
Tokida, T., T. Miyazaki, M. Mizoguchi, and K. Seki.
56 389-395   Jan 2005   [Refereed]
Natural wetlands are a significant source of atmospheric methane, an important greenhouse gas. Compared with numerous papers on measurements of methane emission from natural wetland surfaces, there are few reports on methane configuration and dist...
Seki, K., T. Miyazaki, M. Mizoguchi, H. Imoto, K. Nakaya, H. Miyazawa
Journal of Japanese Society of Soil Physics   97 25-30   Jul 2004   [Refereed]
This study evaluated the performance of a rainwater utilization system. Excess rainwater is drained from rooftops into an underground container from which the water infiltrates from the base and sides into the surrounding soil of a vadose zone. Th...
Seki, K., M. Thullner, P. Baveye
Annals of Microbiology   54(2) 181-188   Apr 2004   [Refereed]
In practical situations where direct observation of the morphology and biomass distribution of filamentous microorganisms is not feasible, there is at present some uncertainty concerning the appropriate mathematical model to use to describe the su...
Seki, K., T. Suko and T. Miyazaki
Transactions of World Congress of Soil Science   1244-1-1244-8   Aug 2002   [Refereed]
We analyzed biological clogging of glass beads in laboratory column experiments. Glucose solution of 50 g/m3 was percolated in columns packed with glass beads of 0.2-mm and 0.05-mm in diameters, and change in hydraulic conductivity was measured co...
Seki, K. and T. Miyazaki
Water Resources Research   37(12) 2995-2999   Dec 2001   [Refereed]
We develop a theory that explains the decrease in saturated hydraulic conductivity Ks due to biological clogging of porous media. Experiments show that discontinuous microcolonies in fine-textured soils decrease Ks more severely than biofilms do. ...
Fujikawa, T., T. Miyazaki, K. Seki and H. Imoto
Transactions of Japanese Society of Irrigation, Drainage and Reclamation Engineering, Vol. 208 (2000), pp. 443-452, doi:10.11408/jsidre1965.2000.443 Key: fujikawa2000   208 443-452   Aug 2000   [Refereed]
Concentrations of soil gases differ from those of atmosphere, because soil animals respire and gases diffuse through soil pores in proportion to the gradation of their concentrations. The objective of this paper is to make clear the correlation be...
Seki, K., T. Miyazaki, M. Nakano
European Journal of Soil Science   49(2) 231-236   Jun 1998   [Refereed]
Microorganisms can clog pores in soils and decrease hydraulic conductivity and infiltration. We did three column experiments to clarify the effects. In all three columns, glucose solution of 50 μg cm−3 was percolated for 120 days, and both the sat...
Seki, K., T. Miyazaki, M. Nakano
Transactions of Japanese Society of Irrigation, Drainage and Reclamation Engineering   181 137-144   Feb 1996   [Refereed]
A series of column experiments were carried out to elucidate the effects of microorganisms on reduction in the saturated hydraulic conductivity, Ks, of paddy field soil. The Ks of surface 1 cm layer decreased 2 orders of magnitude during 118 day p...

Books etc

T. Miyazaki, K. Seki (Part:Joint Work)
CRC Press   Jul 2005   ISBN:0824753259

Conference Activities & Talks

Seki, K., T. Miyamoto, Y. Iwata
Annual Meeting of Japanese Society of Irrigation, Drainage and Rural Engineering   4 Sep 2019   
Seki, K.
The 51st Japan National Conference on Geotechnical Engineering   15 Sep 2016   
Seki, K.
Soil moisture workshop   29 Nov 2014   
Seki, K.
Annual Meeting of Japanese Society of Irrigation, Drainage and Rural Engineering   27 Aug 2014   
Seki, K.
Joint Conference of JSPS and Maison Universitaire France Japon   25 Nov 2013   
A program for fitting soil water retention curves with 5 models including a new bimodal lognormal pore-size distribution model
Seki, K.
Japan Geoscience Union Meeting   May 2007   
Soil hydrological properties of Andisols in Japan in relation to the dispersion-coagulation behavior
Seki, K. T. Miyazaki, H. Imoto and M. Mizoguchi
18th World Congress of Soil Science   15 Jul 2006   
Seki, K., J. Hanada, T. Miyazaki
American Geophysical Union Fall Meeting   Dec 2004   
Gaseous methane dynamics in a waterlogged peat soil
Tokida, T.. K. Seki and T. Miyazaki
Soil Science Society of America   Nov 2004   
Hanada, J., K. Seki and T. Miyazaki
American Geophysical Union Sprint Meeting   May 2002   
Seki, K., J. Hanada and T. Miyazaki
American Geophysical Union Spring Meeting   May 2002   
A Prototype of Japanese Soil Database on Internet
Seki, K., K. NodaM. MizoguchiT. Miyazaki
Annual Meetings of American Society of Agronomy, Crop Science Society of America and Soil Science Society of America   Nov 2001   
Effect of microorganisms on hydraulic conductivity decrease
Seki, K. and T. Miyazaki
Annual Meetings of American Society of Agronomy, Crop Science Society of America and Soil Science Society of America   Nov 2000   


SEKI Katsutoshi   Web Service   
SEKI Katsutoshi   Web Service   
The soil hydraulic parameters for analyzing water movement in variably saturated soil can be determined by fittig soil hydraulic model to a soil water retention curve. SWRC Fit performs nonlinear fitting of 5 soil hydraulic models to measured soil...


Reviewers of:
Archives of Agronomy and Soil Science
Environmental Progress & Sustainable Energy
Environmental Technology
Hydrogeology Journal
Hydrological Processes
International Journal of Environmental Research and Public Health
Irrigation, Drainage and Rural Engineering Journal
Journal of Contaminant Hydrology
Journal of Hydrologic Engineering
Journal of the Japanese Society of Soil Physics
Journal of Water Supply
Open Journal of Soil Science
Soil Research
Soil Science and Plant Nutrition
Soil Science Society of America Journal
Water, Land and Environmental Engineering
Water Resources Research