The erosion process was characterized on two small agricultural watersheds in Piedmont Virginia. Rainfall and runoff were measured for all storms at both watersheds over a two year monitoring period. Although the data base was relatively short, the data covered a wide range of rainfall and runoff conditions. Runoff samples were collected, analyzed, and used to compute loading rates of sediment, nitrate N, ammonium N, TKN, orthophosphate P, and total P on an event basis. Yields from missed storms were estimated from log-log linear least squares regression rating curves. Seasonal and annual totals of loading rates were computed by summing the yields for all storms. Existing estimation techniques were used to calculate rainfall energy, rainfall energy contributing to rainfall, the runoff/rainfall ratio, gross erosion and delivery ratios. USLE C-factors for each field were evaluated for changes in crop and cover conditions. Enrichment ratios for available P, nitrate N, and TKN were estimated on an annual basis. Clay enrichment and particle size distributions of the surface soil and the sediment in runoff from each watershed were also determined. These erosion characteristics were contrasted between the two watersheds whose land management practices differed. A comparison between years was also made on the conservation watershed, where part of the conservation plan was abandoned the second year. The use of conservation practices resulted in smaller estimates of gross erosion, smaller sediment and sediment-bound nutrient yields, and less runoff. / M.S.

This questionnaire study was an attempt to determine the practices teachers follow in planning and conducting a program of vocational education in agriculture in Virginia high schools. The study revealed that the thinking of the regular teachers of vocational and the assistant teachers of vocational agriculture in charge of veterans was comparable as indicated by the nearly equal percentage of teachers from both groups who checked the practices on the questionnaire as “Commonly practiced" or "Recommended". Many practices were not carried out by a majority of the teachers; however, the additional recommendations to these practices indicates that the majority of all teachers favored the use of most of those practices in the instructional program of vocational agriculture. The responses to some practices were not complete, particularly by the assistant teachers of vocational agriculture in charge of veterans who failed to provide information on the practices dealing with the FFA program. The number of teachers who failed to recommend these practices were in a small minority and only one practice was checked as not recommended by a majority of the regular teachers of vocational agriculture. On the whole, most practices were favored by all teachers. The large majority of teachers who carried out these practices or recommended that they be carried out would tend to indicate that they favor using these practices in the program of vocational education in agriculture in Virginia high schools. / M.S.

The teaching and research programs at the Virginia Polytechnic Institute have been hampered for many years by the lack of adequate library facilities. Even though books are available through gift and exchange sources, the lack of a library building precludes the effective expansion of the book collection. The use of the present collection, which numbers a.bout 150,000 volumes, is difficult because the present facilities are overcrowded and unattractive. It is the purpose of this thesis to analyze the library situation at V. P. I., and to present a design study for a library building to effectuate an adequate library program for V. P. I. The success of the thesis is considered to be inherent in its usefulness to those who must ultimately plan a library for the college. / M.S.

M.S.

An examination of a proposed state self-insurance fund to replace commercial fire insurance on public properties. / Master of Science

Bouguer gravity anomalies at 1870 locations on the central Piedmont of Virginia from 37° 37' N to 37° 52' N and 77° 44' W to 78° 23' W display patterns of variation produced by upper crustal density contrasts and thickening of the crust in a WNW direction. No other deep sources are evident. Upper crustal density contrasts are associated with rock units known from geologic mapping. ‘The subsurface distribution of these rock units interpreted from seismic reflection data was confirmed by measured variations in gravity. A two-dimensional model analysis indicates the following average in situ density values for the principal formations: Arvonia Formation-2.77 gm/cc, Columbia Granitoid-2.75 gm/cc (tonalite) and 2.73 gm/cc (pegmatite), Chopawamsic Volcanics- 2.77 gm/cc (felsic units), and 2.79 gm/cc (mafic units}, Catoctin/ Lynchburg-2.815 gm/cc, Maidens Gneiss-2.775 gm/cc, Grenville Basement- 2.71 gm/cc. Gravity and seismic data are consistent with the existence of a major thrust fault at depths between 9 km and 16 km that separates Grenville Basement rocks from younger Catoctin/Lynchburg rocks. The slight eastward dip of this thrust fault beneath the western part of the area increases significantly east of 78° 05' W. Gravity anomalies suggest the existence of several mafic inclusions within the Columbia Granitoid that were not identified by geologic mapping. / Master of Science

Interviews with the Farm Game Cooperators in Game Conservation Districts II, V and VI disclosed that individual landowners were interested in improving habitats for farm game species. In order of preference of wildlife planting materials cooperators chose annual seeds, <u>L. bicolor</u> seeds, <u>L. bicolor</u> plants and <u>L. sericea</u>. (Pp.25-35) The data on cultural practices indicate that the Farm Game Program cooperators need to follow instructions of the Virginia Commission of Game and Inland Fisheries for planting, fertilizing and cultivating wildlife materials in order to receive maximum benefits from the objectives of the Farm Game Program. (pp. 38-52) Cooperators considered the wildlife plantings of intrinsic value in that they were using the plantings for erosion control, food and cover for wildlife, field-woods borders and turn rows for farm machinery. (Pp. 55-56) It was observed that farm game species were utilizing wildlife food plantings established in 1950-51. The perennial plantings were immature yet in many instances they attracted quail, rabbits, turkey and deer. The data on food availability as determined by ground quadrant samples taken from wildlife food plantings on the three specific areas indicate that adequate food is be:ing produced on one-eighth acre plots, which have been maintained according to recommended cultural practices. A hundred percent increase was noted in quail populations on the Hawfield Game Demonstration Area during 1950. (Pp. 70-75) / Master of Science

Conversion of natural forest to loblolly pine plantations has become a common practice on commercial forest land in the central Piedmont of Virginia. To gain insight as to bow habitat conditions for wildlife vary over time, vegetation composition and structure were quantified in 21 converted stands at two state forests. The stands represented three replications of seven developmental stages ranging in age from 1 to 22 years. Six natural forest stands Which typify sites presently being converted were selected for comparison. The seral process can be exemplified by comparing vegetative changes in species richness, evenness, and vegetative coverage in the ground stratum (<1m). Richness and vegetative coverage showed the same trends: high values in stands 1 to 5 years of age followed by a decline from 5 to 15 years, at Which point canopy closure was complete and these variables were relatively stable for the next seven years. Evenness over time was fairly constant, except for three-rear-old stands where a decline occurred due to predominance by <u>Andropogon virginicus</u>. Trends in richness and evenness differed from the old-field successional model due to a diverse reservoir of propagative units at the initiation of succession and the rapid closure of the canopy by co-developing pines and sprout hardwoods. From an analysis of habitat variables, it appeared that one-year-old stands satisfied requirements of bobwhite quail and wild turkey; stands aged three years were deficient in food plants and probably too densely vegetated. Nine-year-old stands still provided browse for white-tailed deer. Post-canopy closure stands (15 to 22 yrs) were of little value to wildlife. In native forest stands (72 yrs), understory forage production was comparable to the post-canopy closure stands, while mast production, as estimated by Oak basal area and density, was more than adequate for good deer and turkey habitat. The present value of converted stands to wildlife depends on their size and interspersion with native forest and other cover types. Their future value could vary significantly depending on the silvicultural treatments applied. / Master of Science

Field mapping, structural analysis, and mineral equilibria of rocks between Fries and Galax, Virginia provide information on the tectonic and metamorphic history of the Ashe Formation, a series of late Precambrian gneisses, pelitic schists and amphibolites, and the underlying Cranberry Gneiss. The dominant penetrative foliation of the rocks is composed of an early S₁ foliation that is crenulated and transposed by a later S₂ foliation which strikes N 50° E and dips SE. Metamorphic porphyroblast growth of biotite, garnet, staurolite, and kyanite followed penetrative foliation development, with metamorphic grade increasing stratigraphically upward to form inverted isograds. Thrust faulting along the Fries Fault caused extensive mylonitization of the Cranberry Gneiss and offset of the metamorphic isograds. Textural evidence indicates that mylonitization is the greatest in rocks at the Fries Fault trace, and decreases upward through the Cranberry-Ashe contact. No textural evidence of an additional episode of faulting at the AsheCranberry contact was observed, based on lack of a second episode of mylonite, relatively good preservation of sedimentary clasts in the Ashe, and similarity of metamorphic grade. Mineral equilibria show systematic trends from chlorite-biotite grade to staurolite-kyanite grade. Muscovite compositions show an increase in paragonite component and decrease in celadonite component. Chlorite, biotite, garnet, and staurolite show a systematic increase in Mg/(Mg+ Fe) toward higher grade. AFM topologies indicate that these compositional trends may be explained a series of continuous reactions ( chl + mu=bi + q + V followed by chl + mu + q=gt + bi + V) and discontinuous reactions (gt + chl + mu= st + bi + V followed by st + chl + mu= ky + bi + V). Temperatures inferred from garnet-biotite equilibria are approximately 550 to 600° C in the staurolite zone, with pressures estimated from various equilibria to be between 4.5-7 kb. The inversion of the isograds is interpreted as resulting from overthrusting of the Ashe metasediments during the Paleozoic. The above information can also be applied to the deformation of the Gossan Lead massive sulfide. Structural data from the Bumbarger mine pit indicates that the massive sulfide underwent the same sequence of structural events as the surrounding rocks. During D₂, shearing of gneisses and schists in a matrix of ductile pyrrhotite caused isoclinal folding, fracture, and rotation of the metasediments while preserving the gross sedimentary layering. This information confirms synsedimentary models of the formation of the Gossan Lead. / Ph. D.

The Virginia oyster industry changed markedly in the period between 1950 and the present. This change has been the result of a variety of forces which can be conveniently classified as economic, biological and institutional. In general, biological forces initiated a series of changes in the fishery which have had economic impacts and impacts on the institutional structure of the fishery. The biological forces have had a much more severe impact on the seed-planting, or private grounds, sector than on the public grounds sector. The dependence of the seed planting sector on public seed beds and the different regulatory regimes applicable to the public and private grounds makes it difficult to draw firm conclusions on the relative merits of alternative tenure structures. The magnitudes of economic, biological and public policy forces as contributing factors to the decline of the oyster fishery are estimated and it is concluded that the biological forces have played the dominant role in the decline of the Virginia oyster fishery. It is suggested that attention be focused on the physical and management inputs to the production of oysters and on methods for bringing forth an appropriate resource mix. It is argued that either a predominantly private grounds fishery, a predominantly public grounds ‘' fishery, with appropriate institutional modifications to allow efficient harvest technologies to be used without threatening the viability of the resource base, or a mixed tenure system could be used and with appropriate management could result in substantial revitalization of the Virginia oyster industry. However, because of the biological changes which have occurred, management, whether public or private, takes on a much more important role in determining the future of the Virginia oyster fishery. / Ph. D. / incomplete_metadata