Your question is the best practical way for measuring infiltration rate under field condition?
please, identify the irrigation condition is that surface or sprinkler any way!
Under surface irrigation (border or basin) , you can use duple ring set as a best measuring method.
under surface irrigation (farrow) , you can apply the method of water balanced by using tow cut through flume or tow Parshall flume, one measures the inflow water in the farrow and the other measures the outflow water for the farrow. then the difference is the the water intake by the soil.