Investigations were conducted to (1) determine the original
pattern of deposition and thickness of ash in the Ochoco and Blue
Mountain areas of Oregon, (2) determine if discontinuities exist in
the parent material of these soils, (3) determine the degree of mixing
of ash with other materials and evaluate reworking...
Snowbrush (Ceanothus velutinus), red alder (Alnus rubra), and
bitterbrush (Purshia tridentata) are three important nitrogen- fixing
nonleguminous species. They commonly grow in association with
commercially important conifers in western United States and conceivably
could be utilized to add nitrogen to forest ecosystems. Nitrogen
15 gas was used to study nitrogen...
One of many important physical properties that must be known
to understand transport phenomena in soils is pore size distribution.
Presently the pore size distributions of soils are most commonly
obtained from soil water characteristic curves. The soil water characteristic
curves are usually obtained by the pressure plate technique.
It...
Nine Gray Podzolic soils from different physiographic regions
of Thailand were studied to determine their characteristics and
genesis in relation to their parent materials, land form, pedogenic
environment, classification and management. The clay was characterized
by X-ray diffraction and standard chemical and physical
analyses were performed. Mineralogy of the light...
An investigation of Mn uptake by five-day-old excised barley
roots revealed that a metabolically-mediated process was involved.
In short-term experiments, the rate of Mn absorption was comparable
to that of the macronutrient cations. Like other metabolically
absorbed cations, the Mn absorption rate was a direct function of
the ambient concentration...
Experiments were conducted to study the effect of pore size
distribution on the diffusion of 2, 4-Dichlorophenoxyacetic acid (carbon-
14) through water saturated porous media. Eight size fractions of
glass beads were used representing the porous media. It was found
that as the average particle radius, and hence pore radius,...