Approximately 3-4 month-old containerized Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings (seed zone 262 and 271) were subjected to 6 moisture stress treatments (65, 53, 41, 29, 17 and 7% soil water content by volume of dry soil) starting July 4 to September 22, 1991 at Forest Research Laboratory's greenhouse at...
Soil infiltration and wettability measurements during the first year following a broadcast burn in the Siskiyou Mountains of
southwest Oregon, have illustrated the magnitude of the effects of light-to-moderate intensity burning on hydrological soil
properties. A prescribed fire near White Creek in late spring significantly reduced soil infiltration for 4...
Published September 1960. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Soil moisture and temperature regimes during spring-summer 1996 were evaluated
in plots with compaction and organic residues treatments established in 1993 at three sites
in the Sierra National Forest after forest harvesting. The results indicate that the bare
condition (non-compacted soil with total removal of the harvesting residues and forest...
Roughstalk bluegrass (Poa trivialis L.) (RB) is a weed species that increased very quickly in grass seed production fields of the Willamette Valley. The invasion of RB in grass seed crops often occurs in waterlogged soils. In waterlogged areas, RB exhibited better competitiveness and had greater population densities than other...
Many miles of roads are built in the Pacific Northwest Forests to provide access for logging and fire protection. Logging roads often cross steep mountainous terrain. Logging roads and the associated cut and fill slopes represent a discontinuity in the natural stress state in the soil mantle. These conditions result...
The human health effects of acute exposure to high levels of ionizing radiation are well understood; however, when these irradiations occur at low levels, there is controversy as to their potential health threat (BEIR V, 1990). For individuals living in areas where the level of naturally occurring background radiation is...
Soft white winter wheat is grown in western Oregon and requires a spring application of nitrogen (N) fertilizer for optimum production. Determining the amount of N to apply has been a challenge for growers. Wheat obtains N from two sources: soil and fertilizer. Both available and mineralizable N can be...
Soft white winter wheat grown in western Oregon requires a spring application of nitrogen (N) fertilizer for optimum production. Determining the amount of N to apply has been a challenge for growers because wheat is produced in numerous rotations that provide varying amounts of N to the wheat crop. Inadequate...