1. Averaging water content and electrical conductivity of a layered soil using time domain reflectmetry Hiroyuki Ochiai, and Kosuke Noborio School of Agriculture, Meiji University, Japan People use TDR probes vertically and horizontally installed. However there is a little of research on vertical TDR probes taking an average of and EC) with layers. In this study, averaging EC is shown. People use TDR probes vertically and horizontally installed. However there is a little of research on vertical TDR probes taking an average of water content (  ) and electrical conductivity (EC) with layers. In this study, averaging EC is shown. Objective ・ Topp et al. (1980, 1982) developed the Time Domain Reflectmetry (TDR) method for measuring soil water content (  ). ・ Topp and Davis (1984) studied measuring q at the field by TDR. ・ Kachanoski et al. (1990) were using TDR probes by vertically insert. ・ Nadler et al. (1991) studied measuring electrical conductivity by TDR method. Background Material TDR probe for vertical(80mm) 80mm Column with TDR probe i.d.=76.5mmh=20mm Research Type1. Same water content and different concentration in each columns Type2. Different water content and same concentration in each columns Type3. Different water content and different concentration in each columns Results and Discussion Type1 1. Similar concentration in 3yayers vertical = horizontal vertical = horizontal 2. Highest concentration in the highest column vertical > horizontal vertical > horizontal 3. Highest concentration in the lowest column vertical > horizontal vertical > horizontal 4. Lowest concentration in the middle column vertical > horizontal vertical > horizontal 5. Highest concentration in the middle column vertical < horizontal vertical < horizontal Type2 6. Similar  in 3yayers vertical = horizontal vertical = horizontal 7. Highest  in the middle column vertical < horizontal vertical < horizontal 8. Highest  in the highest column and middle is the lowest vertical < horizontal vertical < horizontal 9. Highest  in the lowest column and middle is the lowest vertical < horizontal vertical < horizontal 10. higher  in the higher column vertical > horizontal vertical > horizontal Type1 Type2 Type3 11. Highest concentration in the highest column and the highest  in the middle column vertical > horizontal vertical > horizontal 12. Highest concentration in the highest column and the highest  in the lowest column vertical < horizontal vertical < horizontal 13. Highest concentration in the lowest column and the highest  in the highest column vertical > horizontal vertical > horizontal 14. Highest concentration in the lowest column and the lowest  in the highest column vertical > horizontal vertical > horizontal 15. Highest concentration in the lowest column and the lowest  in the middle column vertical > horizontal vertical > horizontal 16. Highest concentration in the middle column and the lowest  in the lowest column vertical < horizontal vertical < horizontal 17. Highest concentration in the middle column and the lowest  in the middle column vertical < horizontal vertical < horizontal Conclusions Average data of vertical probes Average data of horizontal probes = ・ When mass of KCl in the top or bottom column is the highest, Average data of vertical probes Average data of horizontal probes > Average data of vertical probes Average data of horizontal probes > ・ When mass of KCl in the middle column is the lowest, ・ When mass of KCl in the middle column is the highest, ・ When mass of KCl in 3 columns is the same, Average data of vertical probes Average data of horizontal probes < Note Win TDR sometimes did not work because the form between t1 and t2 is wavy. Therefore, it did not proceed to obtain an EC value. t1t2 ・ Ratio differences of mass KCl in each columns effect on increasing differences of average data between vertically and horizontally. acknowledgement This study is carried out as a part of “Ground – based Research Announcement for Space Utilization” promoted by Japan Space Forum