DESIGN AND EVALUATION OF AUTOMATED SURFACE DRIP-IRRIGATION SYSTEM USING ARDUINO-OPERATED SOIL MOISTURE SENSOR

The study was conducted in the Agricultural and Biosystems Engineering Complex, Mindanao State University-General Santos City. The calibration of the sensor was done in the Soil and Water Laboratory of the College of Agriculture at the same university. Generally, the objective of the study was to design and calibrate an automated drip irrigation system using an Arduino-operated soil moisture sensor. Specifically, it aimed to calibrate and program the soil moisture sensor; to determine the level of accuracy of the reading of the calibrated Soil Moisture Sensor in terms of the difference in the moisture content obtained through oven-drying and the calibrated soil moisture sensor; to evaluate the performance of the soil moisture sensor in terms of the delay of switching on/off the water pump. The high accuracy of sensor reading was attained by making other variables of measurement constant. The compactness of the soil as observed affected readings from the sensor. The sensor was calibrated for sandy loam soil and was further tested for another two soil types. The data gathered showed that for the sandy loam type of soil, the determinant coefficient（R2) is 0. 9981, for the loam soil (R2) is 0.9959, and for the garden soil coefficient of determination is 0.9788. These values imply that the readings obtained from the soil moisture sensor and MC values computed from the oven-drying method have a high, positive, strong relationship. Therefore, SMS can be considered reliable. Time efficiency in terms of the time of delay of the system was determined. According to the analysis, from the time when the LCD displayed AMD was reached to the time the pump switched off, there were no significant differences among the three (3) treatments. Therefore, soil type did not affect the performance of the system from the three (3) time frames. However, there is a significant difference in the time from when the system started analyzing MC through the LCD to the time the first MC value was displayed. Therefore, the soil type affected the reading efficiency of the system. For this particular study, it is recommended that the sensor be further studied and calibrated to other soil types for the versatility of the system. In terms of the operation of the system, it must be shut down first before removing the sensor from the soil, every time. Since the probe is a high-conducting metal, it must be cleaned immediately after use, removing all soil particles.