Determination of infiltration rate from border irrigation advance and recession trajectories

Abstract

A volume-balance technique utilizing irrigation advance and recession functions, numerical integration, and an optimization procedure was developed to determine infiltration parameters. The procedure is simple yet rational and accounts for spatial variability of soil characteristics. The required data are flow rate, the coefficients and exponents of the advance and recession functions, and inflow shut-off time. In a field experiment on a clay loam soil (typical of southern Alberta) at the Lethbridge Research Centre, infiltration rates estimated by this technique were similar and in close agreement with those measured with a ring infiltrometer. Except for two border strips, there were no significant mean differences between simulated ( I s) and measured ( I m) infiltration rates. In the two non-conforming border strips, field measured infiltration rates were higher than those simulated with the volume balance approach, most likely due mainly to spatial variability of soil characteristics and partly to lateral flow which occasionally occurs when measuring infiltration with a ring infiltrometer.