Reynolds Creek Experimental Watershed, Idaho (Lysimeter)

Lysimeters are instruments that measure water and/or solute movement in soils. The primary purpose for these lysimeters was to measure evapotranspiration (ET); these data describe changes in soil water during the snow-free season. In addition to measuring changes in total soil water, soil water content profiles and soil temperature profiles were measured within or adjacent to the lysimeters and are reported. Two pairs of soil lysimeters were installed in the RCEW in 1967, one pair at the Lower Sheep Creek climate station (designated the east and west lysimeters), separated, center to center, by 3.6 m, and the other pair at the Reynolds Mountain climate station (designated north and south), separated by 4.7 m. These lysimeters were hydraulic weighing lysimeters in which an inner cylindrical tank containing soil is set within a slightly larger outer cylinder. The inner cylinder rests on a coil of 0.05 m diameter butyl tubing filled with liquid (different low-freezing point liquids were used). The inner cylinder was 1.22 m deep and 1.47 m in diameter. The butyl tubing was hydraulically connected underground to a pressure transducer or manometer. The soil in each lysimeter was extracted from near the lysimeter sites. A soil core was taken by repeatedly excavating a soil cylinder of slightly larger diameter than the lysimeter and forcing the lysimeter sleeve over the soil to the depth of the sleeve (1.22 m). A metal plate was then forced across the cylinder bottom and welded to it in place. The inner cylinder, thus filled with soil, was then transported to the previously excavated outer cylinder via crane and set on the butyl tubing. A neutron probe access tube was installed in the center of each lysimeter to monitor soil water content changes with depth, and two 1.2 m ceramic suction "candles" were placed at the bottom of the lysimeters through a separate entrance. This operation resulted in an undisturbed soil monolith with extant vegetation in place. This is critical for two reasons: (1) Growing native vegetation under natural conditions is problematic in this environment, and plant development is slow. (2) The soil horizonation, particularly the argillic and calcic horizons which are both strongly embedded in coarse fragments, would be essentially impossible to reproduce artificially.

• Resource Title: Soil Moisture.

  File Name: soilmoisture.zip

  Resource Description: Data for Reynolds Creek Experimental Watershed, Idaho (Lysimeter)