Relay strip-cropping combines two vegetation management tactics, under-sowing
and strip-management. In this study conducted from 1994 though 1997, a
cover crop seed-mixture containing oats (Avena sativa L. var. "Monida"), common
vetch (Vicia sativa L.), red clover (Trifolium pratense L.), annual ryegrass (Lolium
multflorum Lam.), and buckwheat (Fagopyrum esculentum Moench) was...
Development in China over the last thirty years has emphasized infrastructural and economic advancement. Despite enormous gains in living standards in the industrialized eastern provinces, much of China's interior and western provinces remain relatively underdeveloped. Populated mostly by ethnic minorities, the southwest province of Yunnan (meaning south of the clouds)...
This dissertation uses argon geochronology and cosmogenic nuclide surface exposure dating methods to address three research questions. The first question concerns a geomagnetic instability recorded in lava flows on the island of Floreana in the Galapagos Archipelago. Changes in the Earth’s magnetic field (intensity and orientation) occur frequently throughout geologic...
This thesis explores open questions regarding molecular forms and interactions of natural and synthetic aromatic compounds present in soils and sediments.
Plant biomass-derived black carbon (biochar) generated through incomplete natural and anthropogenic combustion processes is a major source of aromaticity in terrestrial ecosystems. Chapter one represents a detailed account of...
Intimate associations with reactive metal species permanently protect soil organic matter (SOM) from microbial access and oxidation, contributing to the build-up of organic carbon (C) stocks in soils. It is increasingly recognized, however, that such associations can be reversible and that reactive metal species might even facilitate the oxidation of...
Women, Gender, and Sexuality Studies (WGSS) is an interdisciplinary academic field that addresses gender, sexuality, and social justice issues. The research objective of this project was to examine the attitudes of self-identified male students in introductory Women, Gender, and Sexuality Studies for winter term 2016 at Oregon State University. This...
Millions of U.S. households experienced hunger in 2005 and millions more experienced food insecurity. Previous research indicates that low-wage work and little social support contribute to food insecurity. Research also suggests that individuals cope by finding alternate food sources and drawing on social support. Further, researchers have found that rural...
The Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), is the most devastating foliage-feeding pest of potatoes in the United States. Potential biological control agents include the nematodes Heterorhabditis marelatus Liu & Berry and Steinernema riobrave Cabanillas, Poinar & Raulston, which provided nearly 100% CPB control in previous laboratory trials. In...
The biology and behavior of the codling moth, Cydia pomonella (L.), was studied to
determine factors responsible for differences in susceptibility to moth damage among apple
and pear cultivars.
In release experiments, codling moth adults were intercepted in significantly greater
numbers in host (apple, pear) than in non-host (maple) trees,...