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.
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.
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.
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.
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.
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.
Brendecke, Jeffrey Walter. (The University of Arizona., 1992)
This study measured the effects of four years of municipal, anaerobically digested sewage sludge application on long-term soil microbial activity in a Pima clay loam (Typic Torrifluvent) growing Upland cotton (Gossypium hirsutum L.). Treatments were one unfertilized control, sludge applied at optimum rates for plant growth (based on N requirements), and sludge applied at three times the optimum rates (a total of 8.01 and 24.2 Mg ha⁻¹ (dry weight over four years)). Soil microbial activity was measured by viable heterotrophic plate counts for bacteria, actinomycetes and fungi; acridine orange direct counts for bacteria; the dehydrogenase assay; and carbon dioxide evolution analysis. As the high sludge treatment significantly reduced cotton plant stand and significantly stimulated some parameters of microbial activity (dehydrogenase activity and CO₂ evolution), soil microbial activity may not serve as a reliable predictive index of plant response to sludge-applied pollutants.
Janat, Mussaddak,1953- (The University of Arizona., 1985)
The effect of phosphorus (P) fertilization on drip irrigated cotton (Gossypium hirsutum L.) was studied in 1984 on a Trix clay loam classified as fine-loamy, (calcareous), hyperthermic, Typic Torrifluevent. The objectives of this study were to relate P fertilization to the P concentration in plant tissues, P uptake and cotton yield under drip irrigated conditions. Growth analysis data and total phosphorus in plant tissues were obtained at specific sampling intervals from both P and non-P fertilization treatments in a replicated field study. Moreover, flowering pattern, flower abscission and boll production were studied. Fertilizer treatments were arranged in a Randomized Complete Block design with N, NP, NPK and NPKZn treatments. Rates of N, P, K and Zn fertilizers were 175.4, 44.8, 88.6 and 2.58 kg/ha, respectively. Application of P in this field experiment did not increase P content in plant tissues and did not increase dry matter production, P uptake, and cotton yield significantly, but there were consistant trends toward increased dry matter, P uptake, and cotton yield in the P treated plots. Soil test for P before application of P fertilizer showed enough phosphorus was available in that particular soil for cotton production.
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