Optimization of Depth of Placement of Lateral for Sandy Loam Soil in Western Zone of Tamil Nadu, India

Abstract

Soil moisture patterns from emitters are important for the design and management of drip irrigation systems. The soil moisture distribution pattern around a emitter depends on depth of lateral placement, emitter spacing, duration and frequency of water application, soil physical and hydraulic properties. These patterns can be obtained by direct measurements of wetting in the field, which is site specific, or by simulations using some models. Simulation of water movement in soil is very useful for optimum management of water use. Hence, the study was conducted to optimize the depth of placement of lateral in drip irrigation. Laterals were placed at 0, 15 and 30 cm below the ground level with constant lateral spacing of 1.50 m with the combination of emitter spacing of 30 and 60 cm with 2.2 and 4 LPH dripper discharge. Soil moisture distribution pattern was studied by using gravimetric method. The study revealed that wetting front in the horizontal direction started overlapping after 6 hours in lateral spaced at 15cm depth with 4 lph dripper @60 cm apart. So the layout 15 cm depth of lateral placement and60 cm @4 lph was found better than other layouts since the losses due to evaporation and percolation were minimized.