Tillage of forest soils compacted by ground-based logging systems is a practice that is becoming widely accepted in the Pacific Northwest. However, past research has failed to adequately define the conditions and specifications that particular tillage operations should meet in order to produce the maximum growth response from planted seedlings....
The effects of five tillage treatments on soil bulk density and
mechanical impedance were examined on Newburg sandy loam soil in the
Willamette Valley, Oregon, in 1987. Subsequent effects on seedling
emergence and yield of carrots (Daucus carota L., cvs. Orlando Gold
and Royal Chantenay) were also measured. Mechanical impedance...
Implements for tilling compacted forest soils were
tested on sites logged with ground-based machines in
Oregon. The sites covered a variety of soil conditions
ranging from a clay loam to a rock7 2C2 iplemeflts
tested included disk harrows (four aies), brusa blades
(three sites), standard subsoiler tines (two sites), wing.-...
Shovel logging is a relatively new ground-based method of yarding tinther. It involves moving logs from stump to landing by successive swinging with a hydraulic excavator modified into a log loader by replacing the shovel bucket with a grapple. Loaders used in shovel yarding can weigh in excess of 100,000...
Although previous research in central Oregon has shown soil compaction can lead to a decline in site productivity, the subject is not understood well enough to predict the growth changes resulting from a given level of soil compaction. A study was initiated to relate the basal area, height and volume...
An experiment was established in 1992 in the central Sierra Nevada Mountains of California to assess the effects of high levels of surface organic residues, severely compacted soil, and shrub competition on the development of mixed conifer plantations. This study was conducted in 1997 to determine if selected combinations of...
Forest soils contain a substantial portion of global terrestrial carbon stores. Forest management can influence the soil carbon pool and how soil organic matter functions. The long-term productivity of forests is an ongoing goal where land managers utilize biomass and timber. A site-specific understanding of intensively managed forests can ensure...
Leaf elongation is a major indicator of plant growth. It is
controlled by complex interactions of many factors including light
intensity, photoperiod, water availability, atmospheric conditions,
and plant water stress. In this study, the response of leaf elongation
to length of photoperiod and to plant water stress as indicated by...
A study, consisting of two sequential greenhouse experiments, was
designed to determine the effects of soil liming upon the fungal
partner in a mycorrhizal association. A Willamette Valley foothill
soil, of the Jory series, was limed in increments to achieve a range
of acidity and alkalinity. The P-deficiency and P-fixing...