Effects of Dripper Discharge and Irrigation Amount on Soil-Water Dynamics under Subsurface Drip Irrigation

Abstract

Subsurface drip irrigation (SDI) that has a wide application prospect is one of the high efficiency water-saving irrigation techniques. Research on regulation of soil-water dynamics in irrigation design parameters of SDI has important points in improving its irrigation design and guiding its practical function. In this study, soil wetting patterns were investigated in laboratory experiments which were operated at three different dripper discharges (0.76, 1.15 and 1.25 l h-1) and two different irrigation amounts (4.6 and 9.2 l). The results showed that, (1) with the increase of dripper discharges from 0.76 l h-1 to 1.25 l h-1, water content around the emitter are increasing from 0.225 cm3 cm-3 to 0.300 cm3 cm-3, (2) increasing the dripper discharge and irrigation amount increased the size of the wetted zone, (3) upward distance of the wetting front is less than downward distance and horizontal distance of the wetting front presents symmetry distribution at the same the dripper discharges and irrigation amount, (4) with the increase of irrigation amounts from 4.6 l to 9.2 l, water contents of the vertical and horizontal direction are increasing 10% to 20%.