Seasonal Water Table and Temperature Relationships in Glaciomarine Soils of Eastern Maine

Abstract

Water table depths, soil temperature, and dissolved O2 content (DOC) in “free water” were monitored for three to seven growing seasons in four frigid, fine, very deep, glaciomarine pedons in Machias, ME. Three of the pedons are somewhat poorly drained Aquepts, while the other is an eroded, moderately well drained Udept. Hydrologic data from each pedon during the growing season supported the aquic moisture regime and somewhat poor drainage class, even in the eroded Udept. Very brief durations of saturation were observed at the depth to redoximorphic features in each pedon, features attributed to the capillary fringe in these fine‐textured soils. A reasonable correlation (R2 = 0.59) was observed between length of frost‐free season and soil temperatures above biological zero, while annual and seasonal precipitation did not correspond well with water table depths. Frost‐free season was considerably shorter, and ended 5 to 6 wk sooner in autumn relative to soil temperature. Autumn water table depths were shallower than spring, but aquic conditions prevailed in the fall due to warmer soil temperatures and much lower DOC. Soil temperature at 20 inches was similar between sites and could be predicted by calendar date with a relatively high degree of confidence (R2 = 0.885). Soil temperature at 6 inches was more variable relative to the 20‐inch depth and was higher in spring, lower in fall, and approximately equal in mid to late September. Dissolved O2 content was much lower for water tables in the silty clay substratums than in the silty clay loam or silt loam sola.