Variation of advance power function coefficients and water advance time in alternate furrow irrigation management

Advance time is one of the most important factors, especially for determining irrigation timing. This project has been conducted for determining and evaluation of furrow advance time in two irrigation management including conventional and alternative furrow irrigation. Four different inflow rates within two periods of Maize growth stages for two furrow irrigation management were considered. Results showed, the water advance time in conventional furrow irrigation in two growth stages with inflow rate as 0.15, 0.28, 0.35 and 0.46 l/s were 1.8, 2.4, 1.6 and 1.6 times respectively comparative to alternative furrow irrigation. Also results in end of season revealed that with increasing inflow rate the advance time in conventional furrow irrigation were 1.3, 1.6, 1.4 and 1.5 times as comparatives to a conventional furrow irrigation. Soil surface moisture variation showed that the soil moisture content in alternative furrow irrigation decreased about 28% in comparison with the conventional furrow irrigation. With increasing furrow inflow rate the coefficients of advance power function (r & p) increased about 4 and 56% for conventional and 12 and 26% respectively alternative furrow irrigation.