Abstract
A FieldRouter (FR) is equipment which wire-lessly connects a variety of sensors and dataloggers, col-lects measured data, and transfers the data to a webserver via mobile telephone communication. The FR has an ad-vantage of having a small power requirement so that it can work stably in harsh environments. The FR and adequate multiple soil moisture sensors work as a sensor network system to measure multipoint soil moisture in a small farm field. In this study, multipoint soil moisture in a cold up-land cabbage field during winter season were measured with a sensor network system using the FR that included eight dataloggers and thirty soil moisture sensors. The ef-fectiveness of the system was evaluated. Dynamic changes in soil moisture due to soil freezing and thawing, and dif-ferent trends of soil moisture at each point due to differ-ent freezing and thawing rates were observed with the sen-sor network system using FR. The overall data collection rate was 86 % since some data were lost because of power supply problem of the datalogger and the network adapter. The FR sensor network system was found to be enough ef-fective for multiple soil moisture monitoring, however, the improvement is in progress for precise water management in small scale farmlands.
