Standardization of lateral placement depths for subsurface drip irrigation with varying discharge rates of emitters in vertisols

Abstract

A study was conducted to optimize lateral placement depth of subsurface drip irrigation (SDI) in vertisols at ICAR-Central Institute of Agricultural Engineering, Bhopal, Madhya Pradesh, India. SDI laterals consisting of in-built emitter of discharge rates 1.3, 2, 2.3 and 3 Liter per hour (Lph) at 0.20, 0.30, 0.40, and 0.50 m spacing on lateral were placed at 0.05, 0.10, 0.15, 0.20 and 0.25 m depths below soil surface. Soil water content distribution in wetted zone was examined one day after water application for 0.5, 1, 2, and 3 hours through SDI. Placement depths were standardized based on higher availability and uniformity of soil water in wetted zone. Soil water content at 0.10-0.20 m depth close to emitter was found higher and uniform as compared to other depths. Similar trends in soil water content was observed at 0.15-0.25 m, and 0.15-0.20 m depth, respectively for 0.15 m and 0.30 m horizontal distance from emitter. Therefore, lateral placed at 0.10-0.15 m below soil surface might be recommended for SDI with emitter discharge rate 1.3 lph, and 0.15-0.20m depth for remaining laterals. SDI lateral placement depths for cultivating tomato revealed 7.47-12.64% significant increase in yield.