Browsing by Subject "Soil chemistry"
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Item A comparison of physical and chemical properties of selected irrigated, dryland, and native range Texas High Plains soils(Texas Tech University, 1977-12) Bryant, Ray Baldwin,Not availableItem A comparison of the Neubauer, Cunninghamella, and Winogradsky methods for estimating the availability of soil nutrients of some typical High Plains soil(Texas Tech University, 1939-05) Whippo, Spencer PNot availableItem A study of mineral transformations and weathering processes occurring during the genesis of two soils developed from gneiss and schist in Llano County, Texas(Texas Tech University, 1965-05) Stahnke, Clyde RaymondLlano County is located in Central Texas and has an area of 942 square miles. In 1960 it had a population of 5,240. The altitude of Llano County ranges from 800 to 2000 feet. The average annual rainfall of the county is 27.59 inches. The mean average temperature is €6^ F.; the average temperature for January and S-olQf are respectively 47° F. and 85° F. Over 90% of the agricultural income is from cattle, sheep and goats, and hogs. Llano County belongs to the land resource area designated as the Central Basin (4l).Item Competition among blue grama and buffalograss ecotypes: effects of soil and past neighbor interactions(Texas Tech University, 2003-08) Moffet, Corey AllenNative plants are adapted to their environment. Typically, the abiotic component of the environment is given the greatest attention in rangeland revegetation projects. Past research has suggested that selection of plants for fitness to their biotic environment may deserve increased attention. The hypothesis that biotic adaptation is an important component of increased fitness suggests that, for example, sympatric buffalograss should be better fit (have greater productivity and fecundity) to grow in blue grama neighborhoods (especially sympatric blue grama) than allopatric buffalograss populations. The objectives of this study were to: (1) explore the relationships among plant responses and the abiotic and biotic components of the environment, and (2) determine if blue grama or buffalograss have evolved genetically-based adaptations specific to their biotic, abiotic, or combined biotic and abiotic environment. Two populations of buffalograss and two of blue grama were studied; populations included allopatric individuals (e.g., buffalograss plants collected from areas without blue grama) and sympatric individuals (e.g., buffalograss plants collected from areas with blue grama). Ramets of the 4 populations were collected and transplanted into rephcates of 5 different neighborhoods. The neighborhoods included no neighbors, allopatric blue grama, sympatric blue grama, allopatric buffalograss, and sympatric buffalograss. The sites from which these populations were sampled were characterized in terms of soil and vegetation properties. Growth and fecundity responses of these populations were measured; soil water content and temperature patterns were described. Results show that sympatric and allopatric populations responded the same to each of the neighborhood treatments; there were no central population-neighbor population interactions. Likewise, there was no suggestion that populations were more adapted to their site of origin than to other sites. Intraspecific competition was often greater than interspecific competition, although usually they were similar. Site had a significant effect on growth and fecundity for both species. Buffalograss and blue grama respond to their environment, but there are apparently no adaptations in these populations that make them better fit to their site or neighborhood of origin.Item Effect of the chemical composition of compaction water on the performance of soil subgrades and embankments(Texas Tech University, 2004-12) Ayenu-Prah, Albert YawsonThe Texas Department of Transportation (TxDOT) wants to employ the use of other water sources (alternative water) besides potable drinking water for those construction projects that use large amounts of water. This is due to increasing cost of drinking water treatment and, therefore, a consequent scarcity of potable water for construction purposes. The sometimes prohibitive cost of hauling water from remote areas to certain construction sites, and more importantly, issues related to performance are also part of the reason for this research effort. The research deals mainly with the investigation of the potential effects of the chemical composition of compaction water on the performance of soil subgrades and embankments, with an emphasis on the effects of sodium. Shaikh et al. (1988) indicate that the primary factor that influences the erodibility of unsaturated compacted clays is the soil pore-water chemistry. A comprehensive laboratory test program was carried out to ascertain the possible effects that the chemical composition of compaction water could have on engineered soils. Test results from the project would help in developing predictive models to serve as a framework for a preliminary feasibility evaluation, and selection of a particular alternative water source for use among candidate sources. Similarly, appropriate blending ratios could be determined for those water sources to meet design specifications. Varied results have been obtained that would lead to various conclusions. It was observed that even the worst sources of alternative water would have no significant effect on engineered soils.Item Mineralogy of the playa clays at the Pantex plant, Amarillo, Texas(Texas Tech University, 1996-08) Mars, Kenneth R.The Southem High Plains of Texas contains approximately 20,000 small ephemeral lake basins called playas. Recentiy, these playas have received considerable attention due to the realization that focused recharge to the Ogallala Aquifer can occur through these basins (Wood and Osterkamp, 1984, 1987; Scanlon et al., 1994; Wood et al., 1996). The Pantex Plant, located 16 miles northeast of Amarillo, Texas, in Carson County, has five playa lakes on property owned or leased by the Department of Energy. Potential contamination of the Ogallala Aquifer from Pantex has created much concern. Measurable contamination has been detected in the soils underlying the Plant (Laun, 1995). A sufficient knowledge of soil properties in playa basins is necessary to properly characterize the potential of contamination. Playa basins are a major focus of surface mnoff on the Southem High Plains. Playa basins have a distinctive surface soil, termed the Randall soil series (USDA-SCS unpublished material, 1978). Randall soils are defined as fine, montmorillonitic, thermic typic Halplustert. Playa basins collect mn-off from agricultural fields, roads, pavement and other man-made stmctures that can be sources of contamination. Mineralogy influences factors such as recharge and contaminant attenuation through these basins.Item Saline irrigation effects on some soil physical and chemical properties(Texas Tech University, 1979-05) Gichuru, Mwenja PNot availableItem Saline irrigation effects on some soil physical and chemical properties(Texas Tech University, 1979-12) Gichuru, Mwenja PNot available