Effects of soil physical properties on irrigation quality of lateral in subsurface drip irrigation

Pressure head deviation rate and emitter flow deviation rate are two important indexes to evaluate irrigation quality of micro-irrigation system. The mathematical model for lateral hydraulic calculation in subsurface drip irrigation (SDI) was established. The model was used to study influences of soil physical properties upon hydraulic characteristics and irrigation quality of lateral in SDI. The results showed that pressure head deviation rate and flow deviation rate of lateral in SDI were lower than these two indexes in drip irrigation (DI) due to restrictive effects of soil physical properties on emitter discharges in SDI. The effects of soil texture, soil bulk density and initial soil moisture on irrigation quality of lateral in SDI were not significant. But the finer soil texture, higher soil bulk density, higher initial soil moisture was, the lower pressure head and flow deviation rates, and the better irrigation quality were. So irrigation quality of lateral in SDI was better than that of lateral in DI, and soil physical properties were advantageous to irrigation quality of laterals in SDI. These results can provide reference for studying hydraulic characteristics of field pipe network system in SDI and SDI technology application.