Positioning of soil moisture sensors for actual conditions of crop water requirement in the controlled drip irrigation system

Controlled drip irrigation systems are one of the most efficient irrigation systems. The soil moisture sensor has a problem with positioning in the soil which causes errors in reading the actual moisture levels and failure to meet the actual crop water requirements. This research aims to determine the optimum position of the soil moisture sensor that represents the actual condition of the root crop water requirements. Knowledge of soil wetted arising from the infiltration of an efficient controlled irrigation system, determines the position of the sensor. The experiment used 26 soil moisture sensor and approached the ratio comparison between the observation of the volume wetting and the volume of the wetting sensor moisture in each segment with an interval of 6 minutes. Indicated the sensor at that location represented actual wetted these occurred in a controlled drip irrigation system. The results showed, the sensors of soil moisture numbers 16, 17 and 18 have the best R² average value of 0.973, 0.953 and 0.931. These values showed that optimal position of the soil moisture sensor, which represents the actual condition of the crop water requirements. Thus, in the application of drip irrigation the position of the optimal soil moisture sensor is controlled at a depth of 10 cm at a radius of 5 cm from the emitter.