Abstract
We developed a wireless communication network system with Arduino, XBee, and TDT sensors to investigate soil moisture and salinity. The sensor network system was installed to monitor soil moisture ($\theta$) and bulk soil electrical conductivity (ECb) at three locations in a soybean field converted from a paddy field of tsunami-damaged farmland, Miyagi. Measured data was available to download through a Web server. Our sensor network system allowed us to collect all data without power supply and communication problems after using sleep power-saving mode. Our finding was local spatial variability of high salinity, influencing soybean growth at the field.
