EFFECTIVENESS OF GRANULAR MATRIX SENSORS IN DIFFERENT IRRIGATION TREATMENTS AND INSTALLATION DEPTHS

Continuous monitoring of soil moisture content plays a key role in irrigation scheduling and yield formation. This study was conducted to derive the technique and efficiency of application of granular matrix sensors (GMSs) in a sprinkler irrigation system of maize (Zea mays L.). Two irrigation (a2 = 60%– 100% of field capacity (FC), a3 = 80%–100% of FC) treatments were imposed during two growing seasons (2010, 2012) and compared with rainfed control plots (a1). GMSs are used as an indirect method for monitoring soil water status at two depths (b1 = 15 cm and b2 = 30 cm) in order to make a decision on when to irrigate. The sensors used in this study were calibrated using a mass-based gravimetric method. In both growing seasons, irrigation treatment and installation depths have a significant influence (P 0.01) on soil water content. Sensors have shown a satisfactory response to wetting and drying periods in irrigation scheduling at 30-cm depth. Yet, due to variability of weather conditions, a slow response to wetting and drying was recorded in periods with intensive rainfall events (2010) and drought conditions with frequent irrigation intervals (2012).