| Summary: | Four methods were applied at four experimental sites following a two-factor completely randomized design for field soil infiltration measurements at the University of Arizona Maricopa Agricultural Center. The Cassel ring and the disc permeameter at a 2 cm positive head provided saturated measurements whereas the 10 cm and the 5 cm tension disc permeameters provided unsaturated measurements which excluded pores ^ 0.03 and 0.06 cm in diameter, respectively. Sorptivity, hydraulic conductivity and characteristic mean pore size were calculated by the method given by White, Sully and Perroux (1989). Both sorptivity and hydraulic conductivity showed dependence on the method applied. The high sorptivity and hydraulic conductivity values obtained by saturated measurements were associated with the unavoidable presence of root channels and cracks at field hence provided large variation and poor repeatability. On the contrary, the disc permeameter at 5 cm tension demonstrated reliable repeatability and reasonable results.
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