Abstract
It is very important to measure growth of root for analyzing its biological physiology and growth mechanism. Then there are some reports about measurment of root growth, but it is very difficult to detect the root system in the ground. One method of them is the Glass Faced Profile Wall Method that detects it in sight, and their method are difficult to measure automatically.
Then it is tried to measure the root system by electric method which uses conductivity meter. The conductivity meter which uses the four electrodes method are developed for measurment of the root system as it does not exert influence on the seepage flow of water in the soil. The four conductivity meter that use four hundle-type electrodes are set up in the direction of depth and are able to measure of root growth in the same direction.
