This was copied from the abstract file in FS114 of the FSDB
3.2.3.
Soil Penetrometer Measurements.
Soil penetrometer measurements were taken along the transect center-line. The
instrument used was an ELE Soiltest CN-970 proving-ring cone penetrometer, equipped
with a LC-2B dial indicator and a 250 lb. proving ring. The values in the data
sheets represent deflection of the proving ring in ten-thousandths of an inch.
In a plot, measurements to a depth of 12" were taken at 12' intervals at five points along
the center-line: at 12',24',36',48', and 60'. Slope correction was applied as
necessary. Each penetrometer reading was assigned a road- location class as follows: A)
in an old skid trail, B) within five feet of an old skid trail, or C) more than five feet from
an old skid trail. In the data, the five readings for a plot are arranged vertically in the
order taken, i.e., the "12'" reading at the top, and the "60'" reading at the bottom.
Each reading in the penetrometer data represents the result of one attempt. The first
reading obtained with consistent, steady pressure was recorded. If a satisfactory reading
could not be obtained with 3-6 attempts, the sampling point was designated 'no reading'
(é), or impenetrable (impen). 'é' was used if mineral soil could not be reached at a
sampling point, due to obstacles such as stumps, logs or very deep duff; 'impen' was used
if the penetrometer could not be inserted to the specified 12" depth,
generally due to rocks or large roots.
Sampling points were located as closely as possible to the specified point on the
measuring tape; when necessary, sampling points were offset up to about 3 feet parallel
or perpendicular to the center-line. Early in the sampling (Oakridge and beginning at
Blue River) our tendency was toward offsetting if the sample point were obscured; later
in the sampling (ending at Blue River and at McKenzie) the incidence of offsetting was
reduced and obscured sample points were more often recorded as "no reading".
Four to six soil samples were taken during each day of sampling. Samples were weighed
and moisture contents calculated for use calibration of the penetrometer data. The
locations at which samples were taken were recorded on the data sheets. The samples
for the Oakridge sites were processed by David Murdough, Soil Scientist, Oakridge
Ranger District; samples for the Blue River
and McKenzie sites were processed by ---------.