Researcher Profile and Settings

Affiliation

• Research Faculty of Agriculture　Fundamental AgriScience Research　Bioscience and Chemistry

Job Title

• Lecturer

Degree

• Master of agriculture（Hokkaido University）

J-Global ID

• 200901071849399198

Research Areas

• Life sciences / Plant nutrition, soil science
• Environmental science/Agricultural science / Environmental policy and society
• Environmental science/Agricultural science / Environmental impact assessment

Educational Organization

•  Bachelor's degree program　School of Agriculture
•  Master's degree program　Graduate School of Agriculture
•  Doctoral (PhD) degree program　Graduate School of Agriculture

Association Memberships

• 農業土木学会   日本ペドロジー学会   土壌物理研究会   日本土壌肥料学会   

Research Activities

Books etc

• 非特定発生源による水質汚濁の評価

  北海道の農業と土壌肥料1999北農会 1999
• 畑土壌における水・物質移動の不均一性

  北海道の農業と土壌肥料1999北農会 1999
• Elucidation of water pollution by nonpoint sources

  Soil Science and Plant Nutrition in Hokkaido Agriculture, 1999 1999
• Unhomogeneous of mater and solute movement under field condition

  Soil Science and Plant Nutrition in Hokkaido Agriculture, 1999 1999

Works

• 低生産性圃場の土地改良に関する研究

  1999
• Research on Land Improvement of Low Production field

  1999
• 同位体元素を用いた水循環の研究

  1992
• Study on Water cycle using stable isotopes

  1992

MISC

• 圃場条件下での溶質移動

  北海道土壌肥料研究通信  45-  41  -54  2000  [Not refereed][Not invited]
  
• Transter of Solute under field condition

  45-  41  -54  2000  [Not refereed][Not invited]
  
• 窒素負荷源解析へのS¹⁵N値の利用

  水環境保全のための農業環境モニタリングマニュアル  (]G0005[)-2,1-9  1999  [Not refereed][Not invited]
  
• Effects of Microtopography on Fruit Production of Strawberry, Fragaria chiloensis Duch, var, ananassa Bailey

  Kuramochi Kanta, Haraguchi Akira, Nagata Osamu, Hatano Ryusuke  Journal of The Faculty of Agriculture Hokkaido University  69-  (1)  17  -25  1999  [Not refereed][Not invited]
  
• 草地酪農地域の水質への草地負荷寄与率の推定

  土・水研究会資料  15-  36  -47  1998  [Not refereed][Not invited]
  
• 草地酪農が河川水質に及ぼす影響

  圃場と土壌  (316・317)  6  -13  1995  [Not refereed][Not invited]
  
• The effect of a dairy faming on the river water chemistry

  (316・317)  6  -13  1995  [Not refereed][Not invited]
  
• 草地酪農地域における地下水と草地排水の窒素およびリンによる汚染 -根釧台地における事例研究I-

  日本土壌肥料学雑誌  65-  (5)  522  -528  1994  [Not refereed][Not invited]
  
• Nitrogen and Phosphorus Contamination of Ground Water and Drainage Water in Grassland Area - A Case Study in Konsen Upland I -

  Japanese Journal of Soil Science and Plant Nutrition  65-  (5)  522  -528  1994  [Not refereed][Not invited]
  
• Abundance of Deuterium Water In Natural Waters In Hokkaido

  SAKUMA Toshio, MASUYA Yukio, KURAMOCHI Kanta  Japanese Journal of Soil Science and Plant Nutrition  60,203-209-  (3)  203  -209  1989  [Not refereed][Not invited]
   

  To obtain basic information on the natural abundance of deuterium water, water samples in Hokkaido were collected and analyzed. The average and range of δ_D values of rain (snow) water samples in the suburbs of Sapporo were -60.6 and -140~1.5‰, and the daily fluctuation seemed to be significant. The values of coastal sea waters around Hokkaido were slightly lower than those of the standard sea water (-20~-10‰) ; especially in Ishikari Bay, the natural abundance of deuterium water was lower than that of other coastal regions. This may be attributable to the isotope dilution by big-river water. The δ_D values of big-river waters, e.g. Ishikari River, were in the range from -95~-75‰, and their variation was not remarkable. The low, consistent δ_D values of big-river waters would be due to the dilution by discharges form inland tributaries. The natural abundance of deuterium water in lake waters and related river waters, e.g. Lake Shikotu and Chitose River, were higher compared with those of the big-river waters. This is probably caused by the sampling strategy of the present study. Small tributaries and lakes in inland areas should be included to obtain limnologically unbiased results. The natural abundance of deuterium water in the greater numbers of soil samples was -116.3‰ in average and its variation was in the range of -150~-60‰. In general, both the average and the range of the natural abundance were greater in surface soils than those in subsurface soils and the values of subsurface soils were around -120‰. The influence of D supply by preceding rains was usually held in the profiles of δ_D values in soils and the behavior of water in soils could be studied by tracing their change with time. Some correction on the amount of deuterium water that is supplied by rains in the duration of the experiments is indispensable, especially in the long-term field experiments. This means that the determination of D/H has to be performed in a low D/H range near the natural abundance. Precise analysis managements, therefore, are required to perform this by using TCD-gas chromatography. Frequent calibrations together with the reduction of background by using low D/H hydrogen carrier gas are recommended to maintain high accuracy and good reproducibility of the laboratory analysis as described previously.
• Studies on the Methods for Tracing D_2O in Soils. : Precision of Analysis and Methods for Sample Preparation

  SAKUMA Toshio, KURAMOCHI Kanta, SAITO Hideki, MASUYA Yukio, MOCHIZUKI Michiyo, MORISHITA Taizo  Japanese Journal of Soil Science and Plant Nutrition  60,197-202-  (3)  197  -202  1989  [Not refereed][Not invited]
   

  A series of experiments were conducted to ascertain the accuracy of D/H determination by applying a TCD-gas chromatography and to improve the methods of sample preparation for the determination. The sensitivity, repeatability, and reproducibility of D/H determination by the TCD-gas chromatography was significantly improved when low D/H hydrogen (LDH), which is supplied from a hydrogen generator fed by water of low deuterium content, was used as the carrier gas . The calibration curve was fitted very well by a straight line in the range of D/H from 100 to 1000 ppm and the least significant difference at confidence level of 0.05 was less than 3 ppm and 8 ppm in the cases of more than 40 and 5 replications, respectively. The reproducibility of D/H determination was also satisfactory, especially in the cases of low D/H samples near natural abundance. When commercial high-quality hydrogen was used as the carrier gas, the linearity of the calibration curve was satisfactory, but both repeatability and reproducibility were somewhat inferior compared with those obtained by using LDH. In the direct distillation of soil samples to prepare water sample for the analysis, the efficiency of vacuum distillation apparatuses, which were proposed previously, was not satisfactory. The efficiency was improved significantly by using a larger distillation flask of more than 30 mm in inner diameter and the accuracy of determination was not influenced by the alteration. A tension lysimeter system was devised and tested to extract soil solution in the field experiments. It was concluded that the system was suitable when the soil water suction was less than about 0.3 bar. The isotope effect together with the extraction was not so significant, but some correction was recommended to compensate the reduction of D/H caused by the isotope effect. In field experiments, tracer solution is diluted rapidly by soil water. The determinations, therefore, have to be performed in the low range of D/H from natural abundance to about 300 ppm and, moreover, high reproducibility is required to evaluate the time series of D/H change in soils. The reduction of background by using LDH as the carrier gas and frequent calibration (two standard samples for a lot of determinations) were recommended to maintain a satisfactory accuracy and reproducibility.
• 傾斜地畑土壌における浸潤・再分配過程

  日本土壌肥料学雑誌  60-  1989  [Not refereed][Not invited]
  
• Abundance of Deuterium Water in Natural Waters in Hokkaido

  SAKUMA Toshio, MASUYA Yukio, KURAMOCHI Kanta  Japanese Journal of Soil Science and Plant Nutrition  60,203-209-  (3)  203  -209  1989  [Not refereed][Not invited]
   

  To obtain basic information on the natural abundance of deuterium water, water samples in Hokkaido were collected and analyzed. The average and range of δ_D values of rain (snow) water samples in the suburbs of Sapporo were -60.6 and -140~1.5‰, and the daily fluctuation seemed to be significant. The values of coastal sea waters around Hokkaido were slightly lower than those of the standard sea water (-20~-10‰) ; especially in Ishikari Bay, the natural abundance of deuterium water was lower than that of other coastal regions. This may be attributable to the isotope dilution by big-river water. The δ_D values of big-river waters, e.g. Ishikari River, were in the range from -95~-75‰, and their variation was not remarkable. The low, consistent δ_D values of big-river waters would be due to the dilution by discharges form inland tributaries. The natural abundance of deuterium water in lake waters and related river waters, e.g. Lake Shikotu and Chitose River, were higher compared with those of the big-river waters. This is probably caused by the sampling strategy of the present study. Small tributaries and lakes in inland areas should be included to obtain limnologically unbiased results. The natural abundance of deuterium water in the greater numbers of soil samples was -116.3‰ in average and its variation was in the range of -150~-60‰. In general, both the average and the range of the natural abundance were greater in surface soils than those in subsurface soils and the values of subsurface soils were around -120‰. The influence of D supply by preceding rains was usually held in the profiles of δ_D values in soils and the behavior of water in soils could be studied by tracing their change with time. Some correction on the amount of deuterium water that is supplied by rains in the duration of the experiments is indispensable, especially in the long-term field experiments. This means that the determination of D/H has to be performed in a low D/H range near the natural abundance. Precise analysis managements, therefore, are required to perform this by using TCD-gas chromatography. Frequent calibrations together with the reduction of background by using low D/H hydrogen carrier gas are recommended to maintain high accuracy and good reproducibility of the laboratory analysis as described previously.
• Studies on the Methods for Tracing D₂O in Soils

  SAKUMA Toshio, KURAMOCHI Kanta, SAITO Hideki, MASUYA Yukio, MOCHIZUKI Michiyo, MORISHITA Taizo  Japanese Journal of Soil Science and Plant Nutrition  60,197-202-  (3)  197  -202  1989  [Not refereed][Not invited]
   

  A series of experiments were conducted to ascertain the accuracy of D/H determination by applying a TCD-gas chromatography and to improve the methods of sample preparation for the determination. The sensitivity, repeatability, and reproducibility of D/H determination by the TCD-gas chromatography was significantly improved when low D/H hydrogen (LDH), which is supplied from a hydrogen generator fed by water of low deuterium content, was used as the carrier gas . The calibration curve was fitted very well by a straight line in the range of D/H from 100 to 1000 ppm and the least significant difference at confidence level of 0.05 was less than 3 ppm and 8 ppm in the cases of more than 40 and 5 replications, respectively. The reproducibility of D/H determination was also satisfactory, especially in the cases of low D/H samples near natural abundance. When commercial high-quality hydrogen was used as the carrier gas, the linearity of the calibration curve was satisfactory, but both repeatability and reproducibility were somewhat inferior compared with those obtained by using LDH. In the direct distillation of soil samples to prepare water sample for the analysis, the efficiency of vacuum distillation apparatuses, which were proposed previously, was not satisfactory. The efficiency was improved significantly by using a larger distillation flask of more than 30 mm in inner diameter and the accuracy of determination was not influenced by the alteration. A tension lysimeter system was devised and tested to extract soil solution in the field experiments. It was concluded that the system was suitable when the soil water suction was less than about 0.3 bar. The isotope effect together with the extraction was not so significant, but some correction was recommended to compensate the reduction of D/H caused by the isotope effect. In field experiments, tracer solution is diluted rapidly by soil water. The determinations, therefore, have to be performed in the low range of D/H from natural abundance to about 300 ppm and, moreover, high reproducibility is required to evaluate the time series of D/H change in soils. The reduction of background by using LDH as the carrier gas and frequent calibration (two standard samples for a lot of determinations) were recommended to maintain a satisfactory accuracy and reproducibility.
• Water Movement during the Stage of Infiltration and Redistribution in Field Soils on a Hill Slope

  KURAMOCHI Kanta, SAKUMA Toshio  Japanese Journal of Soil Science and Plant Nutrition  60-  (4)  298  -306  1989  [Not refereed][Not invited]
   

  In an attempt to grasp the role of macropores on the water movement during infiltration and redistribution in soils of sloped uplands, field experiments using deuterium water (D_2O) as a tracer were conducted in a hilly area of central Hokkaido. Experimental plots (depth=0.7 m ×width=1m×length=5m) isolated by a polyvinyl sheet were made on an upper slope (Plot I, Typic Dystrochrepts) and on a lower slope (Plot II, Typic Haplumbrepts). After the application of D_2O solution, the plots were treated by an artificial rainfall and the distribution of D_2O abundance was traced for 11 days. 1) During the stage of infiltration (t<1 day after rainfall), water flow was not homogeneous, but the uneven distribution of tracer D_2O was observed in both plots, especially in the subsurface horizons. The macropore system in the subsurface soil horizons of the Plot I was characterized by very coarse root channels of more than 10 mm in diameter and, on the contrary, that of Plot Ii consisted mainly of fine or medium, but continuous, interstitial macropores. The very fast percolation and uneven distribution of tracer D_2O can be attributed to the by-pass effect of the macropores. This was ascertained for Plot I by means of a dye-injection method. Only very coarse root channels, 8-10 mm or greater in diameter, were effective as the by-passing routes, since many of the finer macropores (d<5 mm) were clogged up by entrapped air and/or solid debris during the early stage of infiltration. The frequency of very coarse root channels (d>10 mm) in the subsurface horizons of soils in Plot I was about 3 (channels/1 m^2). 2) The distribution of tracer D_2O and its change during the stage of redistribution (1 < t ≤ 11 days) were also dependent on the characteristics of the macropore system. In Plot I, a homogeneous slow seepage through soil matrix was predominant throughout the stage. Because the root channels dominated vertically and were independent, lateral flows in the subsurface horizons were not significant and water accumulated at the bottom of root channels by the by-pass flow was diffused slowly into the surrounding soil matrix. In the Plot II, however, the uneven distribution of tracer D_2O was prolonged and the fast lateral flow through the deeper part of B horizon continued for a longer period than that in Plot I. These are owing mainly to the continuous nature of interstitial macropores among subangular blocky peds in the B horizon and very low permeability of the underlying Cg horizon.

Research Grants & Projects

• 物質循環研究における安定同位体の利用
• 非特定発生源による水質汚濁機構の解明
• Research on Nutrient cycling using stable isotope
• Research on Nutrient cycling using stable isotopes
• Elucidation of water pollution mechanism by nonpoint sources.

Educational Activities

Teaching Experience