A variety of soil properties have been proposed and tested as potential
indicators of soil quality. This study was conducted in an effort to produce a
standardized soil quality index for systems in Oregon. Soils in both forested and
agricultural systems were sampled in a wide variety of locations, climates,...
Soil response and function were investigated following the adoption of an integrated reduced-tillage and cover-cropped vegetable system in the Willamette Valley of Western Oregon. The experiment was conducted over three cropping seasons (2002-2004) at the Oregon State University Vegetable Research Farm (Corvallis, OR). The design was a randomized complete-block with...
This paper defends a reading of Hennan Melville's Moby-Dick that elevates Ishmael's status from mere narrator of Ahab's tragedy to that of protagonist of his own story, a novel of epistemological seafaring. As a metaphysical quester, Ishmael provides the novel's only reliable and complex vision of the condition of man...
The purpose of this article is to explore student reasoning with regard to problems in logic, particularly those related to the Principle of Mathematical Induction (PMI). The five case studies presented build off of work done by other researchers, most notably Dubinsky and Harel, who both looked at how students'...
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Thomas P. Dick
The purpose of this article is to explore student reasoning with regard to
Increasing regulation and costs of soil fumigation to manage diseases such as
Verticillium wilt caused by soil-borne pathogens have prompted a search for
management alternatives. Single-year microplot experiments were conducted in 2002
and 2003 in central Oregon to evaluate the effects of Austrian winter pea, broccoli,
and Sudan grass green...
The Oregon Long-Term Soil Quality Project was initiated to identify soil
properties that respond rapidly to alternative management practices. Such practices
included winter cover cropping, which was implemented at two experimental research
stations and several grower fields throughout the Willamette Valley. The goal of this
thesis was to identify the...
Two native shrub species (Piliostigma reticulatum and Guiera senegalensis) are prominent vegetation components in farmers’ fields in Senegal. However, their role in nutrient cycling and ecosystem function has largely been overlooked. A study including both laboratory and field experiments was conducted to evaluate potential biophysical interactions of the two shrub...
Nitrogen availability in agricultural soils from fertilizer, plant residue inputs, and soil organic matter has important implications beyond crop yield. Legume winter cover crops and one fourth the recommended N rate on sweet corn resulted in yields equivalent to those at the recommended rate in the Willamette Valley of western...
Common root rot is a major disease of commercially grown snap bean (Phaseolus vulgaris L.) on the irrigated sandy soils of central Wisconsin. The objective of this study was to determine the relationships between soil properties and suppressiveness to common root rot of snap bean (causal agent Aphanomyces euteiches) in...