Field experiments were established in 1982 and 1983 on a Woodburn silt loam soil (Aquultic Argixeroll) to examine the effect of S fertilizer on dinitrogen fixation and dry matter yield of 10 week-old seedling alfalfa (Medicago sativa L. cv. 'Apollo'). Six levels of S fertilizer (0 to 67.2 kg S/ha)...
Nitrogen fertilization of seedling legumes is a controversial practice intended to provide N to the plant during periods when seed N, soil N, and N₂ fixation may not meet plant requirements; eg. prenodulation, postharvest, or in the event of an inoculation failure. Field experiments were conducted in 3 consecutive years...
The usefulness of preplant nitrogen (N) in establishing
alfalfa in colder production areas has not been
well characterized. This study was conducted to determine
the effect of preplant N and soil temperature on
yield, percent N derived from biological nitrogen fixation
(PBNF), and shoot N concentration in alfalfa (Medicago
sativa...
Sampling error associated with estimates of species composition and age composition
of commercial groundfish landings in Oregon from 1989 to 1991 is documented to evaluate
the impact of variable landing data on fisheries management and monitoring programs. The
statistical reliability and bias associated with two multistage sampling designs are
investigated...
Twenty-three bottom-trawl fish assemblages were identified from the relative biomass of
33 dominant species that occurred in the National Marine Fisheries Services' triennial
trawl surveys over the continental shelf and upper slope off California, Oregon, and
Washington from 1977 to 1992. The assemblages accounted for about 70% of the total...
The spawning habitat associated with fall chinook salmon (Oncorhynchus
tshawytscha) redd clusters was investigated in the Hanford Reach of the Columbia River.
A conceptual spawning habitat model is proposed that describes how geomorphic
features of river channels create hydraulic processes, including hyporheic flows, that
influence where salmon spawn in unconstrained...
Co-management is considered an alternative approach to fisheries management,
however, not all co-managed fisheries have been successful. Most studies discussing the
success and failure of co-management have emphasized economic and social attributes of
success and failure, such as fishery rights and institutional arrangements. The effect on
co-management of biological characteristics,...
Stock assessments for many U.S. Pacific coast groundfish stocks are developed using the catch-at-age method known as Stock Synthesis. In this work a simulation package was developed and used to evaluate the sensitivity of the Stock Synthesis program. More specifically, the evaluation focused on the impacts of input data errors...