Measured DOM Concentration (mg L-1) Horizons Soil Order Reference 22 23 O A Andisol Dawson et al. (1981) 36 22 10 O BA B Ultisol Dawson et al. (1981) 15–69 < 50 cm Spodosol Wallis et al. (1981) 2–13 B Ultisol Meyer and Tate (1983) 28.1 5.91 2.96 A Bs B Spodosol McDowell and Wood (1984) 10–53 2–12 A, B B, C Spodosol Cronan and Aiken (1985) 14 7.4 2.8 O B BC Spodosol Cronan et al. (1990) 13.7 2.1 0.78 O Bt C Ultisol Cronan et al. (1990) 32.5 32.5 O1 Oa Inceptisol Qualls et al. (1991)

Table 1: Measured dissolved organic matter (DOM) concentrations in various soils. Most of the soil solution was collected using tension lysimeters (modified from Herbert and Bertsch [1]).