Intensive cultivation of Walla Walla silt loams (coarse silty,
mixed, mesic, typic Haploxeroll) in eastern Oregon and Washington
during the past 50 years, has decreased internal soil drainage in
the 15 to 40 cm layer. However, no measurements have been made to
determine the causes and corrective management for this...
Riparian ecosystems, through their unique positions in the agricultural landscape, have the potential to mitigate nutrient loading to streams. This study was conducted to gain a better understanding of N cycling in a poorly drained Grass Riparian Zone (GRZ) and adjacent Perennial Ryegrass seed Field (PRF) in the Willamette Valley,...
A study was conducted on German velvetgrass (Holcus mollis L.), a weedy, rhizomateous perennial grass introduced in the
United States in relatively recent years, The purpose of this study
was to learn more about its distribution, growth habits, and control
under conditions found in Western Oregon. German velvetgrass infestations of...
Reed canarygrass (Phalaris arundinacea L.) is a desirable pasture
grass on wet areas in the Northern United States and Southern Canada,
but it is a serious and troublesome ditchbank weed in the Pacific Northwest
and Rocky Mountain States. The purpose of this study was to learn
more about the development,...
A new method for determining ion exchange equilibrium
data by liquid scintillation counting of the equilibrated solution
phase is described. This method has been applied to determine
equilibria between Dowex 50W X8, a commercial strong cation exchange
resin, and binary and ternary solution containing the varying combinations
of H⁺¹, Cs⁺¹,...
This thesis is composed of four parts: i) system
description, ii) model development, iii) parameter
estimation, and iv) validation. The natural system used
here is an aspect of the immune system, namely, the
distribution of recirculating lymphocytes in various
organs throughout the body. This distribution gains
importance because: i) it...