【Author】LI Jiusheng; YANG Fengyan; LIU Yuchun; LI Yanfeng

【Abstract】Laboratory experiments were conducted using a plexiglass box to investigate the effects of soil layering on discharge performance of a buried emitter. A special SDI emitter with nominal discharge of 1.1 L/h at 10 m pressure was used. Two layered soils, a sandy-over-sandy loam (SL) and a sandy loam-sandy-sandy loam (LSL), and two uniform soils, a sandy loam (L) and a sandy soil (S) were tested. For the SL soil, the thickness of the top layer was 20 cm, and the LSL soil consisted of an upper 20 cm layer of sandy loam soil,a middle 10 cm layer of sandy soil, and a lower 50 cmlayer of sandy loam soil (referred to as LSL). The buried depth for emitters for the L, S, SL soils was 15 cm, while three buried depths of 15,25,and 35 cm were tested for the LSL soil to investigate the effects of the relative positions of emitters to the interface between soil textures on emitter performance. Four inlet pressure heads of 2, 3, 6, and 10m were tested.

【Key words】 subsurface drip irrigation; soil; texture; layered soils; discharge