Aldakheel, Yousef Yacoub,1957-(The University of Arizona., 1986)
This thesis evaluates the basic assumption of an infrared thermometry model to predict bare soil evaporation by infrared thermometry. Field data were obtained from the U.S. Water Conservation Laboratory, ARS-USDA at Phoenix, Arizona. Computationally, these field data validated that assumption. Secondly, a field experiment was conducted to study the thermal regime of air-dried soil inside metal and polyvinyl chloride (PVC) microlysimeters. A significant difference in soil heat flux was seen between metal and PVC microlysimeters, while no significant difference was observed between PVC microlysimeters and a reference soil. This study supports the findings from recent studies that inside metal microlysimeters, heat is conducted efficiently downward into the deeper soil depths, leaving the surface cooler than the surrounding soil.
Levine, Steven Joel.(The University of Arizona., 1985)
Two soils, both underlain by petrocalcic horizons at shallow depths, occur together on the same geomorphic surface, an old fan terrace located in the Avra Valley near Tucson, Arizona. Both soils have formed from similar parent materials and are assumed to be of the same age. One of the soils, a Petrocalcic Paleargid, occupies the broad, flat interfluvial areas of the fan surface. It contains an argillic horizon above the hardpan and is carbonate free in the upper part. The lower portion of the argillic horizon has been engulfed by the petrocalcic horizon. The other soil, a Typic Paleorthid, occurs above and adjacent to the narrow drainage ways that incise the fan terrace. This soil lacks an argillic horizon and is calcareous to the soil surface. Although no direct evidence of a former argillic horizon remains, it is believed that an argillic horizon was once present and then was truncated. Truncation was followed by brecciation of the exposed pan surface and subsequent recementation. The observed differences between the two soils: calcium carbonate content, particle size distribution, color, morphology and size of calcite crystals, and clay mineralogy are a result of the pedogenic processes of argillic horizon engulfment and truncation followed by brecciation and recementation.
Zhou, Maoqian, 1961-(The University of Arizona., 1989)
The growth and Nitrogen fixation by one low salt tolerant alfalfa (Medicago sativa L.) and two germination salt tolerant selections inoculated with were investigated at two salt levels (0, -0.6 Mpa) and two N rates (1, 5ppm) using a system which automatically recirculates a nutrient solution. The high level of salinity (-0.6 Mpa osmotic potential of culture solution) resulted in substantial reduction in the N fixation percentage and total fixed N. The effect of salinity was more pronounced for later cuttings than for the earlier cutting. The N fixation percentages were substantially decreased by increasing N level and the reduction was enhanced by time. The N treatment levels did not exhibit a significant effect on total fixed N. Cultivars did not differ in either growth or N fixation. However, the interaction of N and salinity significantly decreased the percentage and amount of N fixation.
Guilbault, Michael Roland, 1967-(The University of Arizona., 1993)
This study was conducted to determine emission rates of nitrous oxide (N₂O) gas from arid region locations. Fluxes were measured at an effluent-irrigated turfgrass location in Arizona, a Sonoran desert location, and a savannah location in Africa. Fluxes were measured by a closed chamber method at the Arizona locations on a weekly basis during the summer of 1991, and at the African location during two separate three day studies during the summer of 1992. Soils were sampled at each location during each sampling period and analyzed for water content, nitrate, pH, and total organic carbon content. Nitrous oxide fluxes in Arizona averaged approximately 13 and 0.7 kg N₂O-N ha⁻¹ yr⁻¹ for the turfgrass and desert locations respectively. The average fluxes from the African sites were 1.3, 1.6, and 1.3 kg N₂O-N ha⁻¹ yr⁻¹ for a millet field, fallow field, and "tigerbush" plateau, respectively. Diurnal and seasonal variability was observed.
Galioto, Thomas Robert.(The University of Arizona., 1985)
An elevational study of organic matter components was made of shallow soils of the Santa Catalina Mountains, Pima county, Arizona. At nineteen elevations (900 to 2700 m), total carbon, extractable organic carbon, humin carbon (tightly bound organic carbon), humic acid carbon, fulvic acid carbon, humic-fulvic acid ratios and E4/E6 ratios were determined. Parameters except the humic-fulvic acid ratios showed high correlations, R² at least .78, with elevation. Of these only the E4/E6 ratio was negatively correlated with elevation. Uncorrelated humic-fulvic acid ratios indicate no proprotional trend of the relative proportions of humic and fulvic acids. The E4/E6 ratio decrease with elevation agreed with all parameters. Humic acids are older, larger and contain higher concentrations of aromatics with increasing elevation. The humic-fulvic acid ratio, based on classical organic matter separation, does not produce a discriptively useful means for a range of climatically different soils. The E4/E6 ratio is more useful in evaluating soil genesis via composition.
Alfatesh, Ibrahim Yahya,1956-(The University of Arizona., 1986)
The purpose of this research was to study the effects of different types and amount of saline-sodic waters on the cation concentration changes in solution extracts, drainage waters, and on the exchange complex of two soils differing in their textures, exchange properties, and lime content. The composition of solution extracts, drainage waters and exchange phases of both soils was closely related to the cationic composition of the irrigation waters. Salt accumulation in the soils increased with increasing salinity of the applied water. Salts were distributed uniformally with depth after 8 and 11 applications. Exchangeable sodium was directly related to the SAR of the applied solutions. The SAR of soil leachates and solution extracts increased as the amount of salt and applied water increased. The two soils responded differently to the type and amount of the applied water. Both soils released some Ca and Mg to the soil solution from the dissolution of primary minerals and cation exchange reaction. Both soils were affected by the salinity and sodicity of the applied solution.
Nolin, Anne Walden, 1958-(The University of Arizona., 1987)
An airborne multispectral video system was used to collect soil spectral data over a four-square mile region in northeastern Arizona. Six multispectral video images were digitized. Using the red and blue bands of each image, an unsupervised classification was performed. Each was referenced to a digitized U.S. Soil Conservation Service map resulting in classification precisions ranging from 0-92.4 percent. Ground radiometric measurements were made to ascertain spectral separability of the soil samples. Soil color was determined to try to relate Munsell value to classification precision. Misclassification of soil map units was unrelated to soil brightness or areal extent of each soil. Rather, features such as slope, boundary complexity, and surface condition was responsible for misclassifications seen in this study. Best classification results occurred when soil mapping units were relatively homogeneous, possessed slight changes in slope, and had a regular surface with smooth and distinct boundaries.
Hayes, Alan Raymond,1956-(The University of Arizona., 1988)
This field experiment evaluated the use of secondary treated municipal wastewater for irrigation of turfgrasses. Common bermudagrass (Cvnodon dactvlon L. Pers.) was seeded to a gravelly sandy loam. In the Fall, perennial ryegrass (Lolium perenne L.) was overseeded to maintain an actively growing turf. Plots were irrigated identically with either effluent or potable water. Soil and water samples were collected periodically and analyzed for pH, salinity, major cations, nitrogen, phosphorus and potassium. Turf quality was assessed using a visual evaluation technique. Effluent irrigation produced significantly lower seed germination and resulted in increased salinity, sodium, nitrate and phosphorus concentrations in soils. Leachate waters contained greater salinity and higher concentrations of major cations than irrigation waters. Established effluent irrigated turf did not show signs of salt stress and produced turf quality as good as potable irrigated plots. High quality turf was grown using secondary sewage effluent for irrigation.
Turk, Colleen Mary, 1961-(The University of Arizona., 1995)
Organic matter amendments have long been known to improve native organic matter content, aggregation and structure of soils. In the laboratory, however, organic matter amendments to autoclaved soils have no such effect. This may explain the failure of many reclamation attempts on mine tailing wastes, which often proceed without regard for the microbiological processes necessary for soil formation and cycling of plant nutrients. In this study, incubation of tailing waste with soil microbes and a simple carbon source proved sufficient to increase the formation of water stable aggregates from tailing particles. Autoclaved control samples showed no change in aggregation. The incorporation of microbial cell mass into the mineral matrix of the tailing was observed using scanning electron microscopy. These results suggest that microbial activity is necessary in order to incorporate organic matter into the abiotic matrix of tailing, promoting aggregation and ultimately soil formation from this material.
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