MOISTURE WETTING PATTERNS IN SURFACE AND SUBSURFACE DRIP IRRIGATION SYSTEMS

Abstract

Soil moisture patterns from emitters are important for the design and management of drip irrigation systems. The soil moisture distribution pattern around an emitter depends on depth of lateral placement, emitter spacing, duration and frequency of water application, soil physical and hydraulic properties. This experiment was carried out at Agricultural Research Station, Bhavanisagar. Soil moisture measurements were carried out using soil moisture meter after irrigation at different horizontal and vertical distance (0, 15, 30 and 45 cm). The results indicated that the soil moisture distribution within the soil profile under subsurface drip was to great extent affected by the distance between drippers and variations in discharge. It was also found that, soil moisture distribution varied with variation of lateral location from the soil surface. Soil moisture movement was found to be higher at lower depth of laterals placed at 15 and 30 cm depth.The gradual increment in the moisture content around the dripper was found at the surface layer and vertical layer with increasing the measuring time up to 2 hr at 15 and 30 cm lateral depth. The measurements of soil water content at 2hr indicated that the lower soil layer was the one with higher moisture content at 30 cm depth of placement of lateral irrespective of discharge. Dripper spacing of 30 cm with dripper discharge of 2LPH at 30 cm depth of placement of lateral was found to be higher in soil moisture content of more than 27.2 per cent than of that under 15 cm.