2,740 research outputs found

    Spatial and Temporal Analysis of the Morphological and Land use Characteristics of the Buffalo River Watershed

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    The Buffalo River was established by Congress iQ. 1972 as the first National River in the United States. The Buffalo River, which originates in the higher elevations of the Boston Mountains in Newton County, is one of the few remaining free-flowing streams in Arkansas. It is considered to be one of Arkansas\u27 greatest natural treasures, and thus, there is strong interest in protecting it from anthropogenic influences. An initial characterization of the soil taxonomic units, watershed boundaries, topography and physiographic units in the Buffalo River Watershed was presented by Scott and Smith (1994). The spatial distribution of the geologic units in the watershed was presented by Hofer et al. (1995)

    Movement of Pesticides in the Soil Water Fertilizer System

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    A theoretical and experimental study of the transport of pesticides was conducted in several Arkansas soils with metribuzin, a herbicide. In a field study, chloride and metribuzin were applied to a Captina silt loam under maximum leaching conditions and their redistribution was compared with that of soil water. Metribuzin was found in significantly detectable quantities to a depth of 61 cm; the largest concentrations were detected in the surface 23 cm and particularly in the 0-5 cm increment. Two days after application 72.6 and 33.6% could be detected in the vegetation and no-vegetation plots. The metribuzin half life was 7.88 and 5.13 days in the no-vegetation and vegetation plots, respectively. Chloride was found throughout the profile. Metribuzin and chloride generally were observed to move in the same direction as soil water, but at a considerably slower rate. Persistence of metribuzin within the soil was influenced greatly by microbial degradation. The laboratory studies centered on further quantifying the transport and adsorption-desorption parameters of metribuzin under controlled environmental conditions. Diffusion coefficients of 14C - metribuzin, 36CI, and 3HOH were shown to be influenced by soil type, soil water content, and soil temperature. The magnitude of the diffusivities were in the order 3HOH\u3e^^Cl\u3e^^C-metribuzin; however, the ratios varied. The rates of adsorption of metribuzin were found to be dependent on shaking time and soil type. For the most part linear adsorption isotherms were observed. Desorption rates were found to be influenced by solution concentration, shaking time and soil type. It was concluded from these studies that the potential polluting effects of metribuzin leaching through the soil and subsequently moving into the water table or underground streams are minimal. Metribuzin will redistribute within the soil profile, but will be degraded by microorganisms before it becomes a potential pollution hazard

    Vulnerability and use of Ground and Surface Waters in the Southern Mississippi Valley Region

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    There is a concern in the Southern Mississippi River Valley of the United States over non-point source pollution of ground and surface waters resulting from activities associated with agricultural production. This agriculturally intensive region consists of two major land resource areas (MLRAs): Southern Mississippi Valley Silty Uplands (MLRA 134) and the Southern Mississippi Valley Alluvium (MLRA 131). Both MLRAs have level to undulating and rolling topography, relatively fertile soils and a climate particularly conducive for row crop production

    Spatial Distribution of the Surface Geology and 1992 Land Use of the Buffalo River Watershed

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    The Buffalo River was established by Congress in 1972 as the first National River in the United States and is one of the few remaining free-flowing streams in Arkansas . The Buffalo River flows through the three major physiographic provinces of northern Arkansas, originating in the higher elevations of the Boston Mountains, and flowing generally northeastward to cut through the Springfield and Salem Plateaus. It drops from approximately 2000 feet in the headwaters to around 500 feet above sea level at its confluence with the White River in Marion County. The Buffalo River is considered to be one of Arkansas\u27 greatest natural treasures; thus there is strong interest in protecting it from undue anthropogenic influences. A general description of the area within the Buffalo River Watershed was given by Smith (1967)

    Animal Waste and the Land-Water Interface

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    This book presents abstracts of research studies conducted on animal wastes and the interface between application of animal waste to land. The abstracts were divided into sections which tend to organize summaries of research studies conducted on similar topics. These topics range from characteristics of animal waste to the effects of animal wastes on streams, lakes, wetlands, and watersheds, development of best management practices, nutrient management, edge of field losses and alternative uses. The posters will be available for viewing from 10:00 a.m. Monday, July 17, until 12:00 noon on Wednesday, July 19, 1995

    Landuse and Landcover Classification for Independence, Union, Bradley and Cleveland Counties of Arkansas

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    Landuse/landcover (LULC} is a function of natural factors such as soils, climate and water and of anthropogenic factors such as predominant use. In Arkansas, the primary use of the land varies depending on the physiographic region. For example, in the Mississippi Delta region of eastern Arkansas row crop agriculture predominates, whereas in the Gulf Coastal Plains forestry dominates. In both regions LULC is spatially and temporally . variable. Knowledge of LULC can be used in estimating the potential for agricultural production, locations of critical ecological areas, siting of homes, small businesses, industries, roads and landfills as well as source areas of pollution

    Spatial and Temporal Analyses of the Morphological and Land Use Characteristics of the Buffalo River Watershed

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    The Buffalo River was established by Congress it11972 as the first National River in the United States. The Buffalo River, which originates in the higher elevations of the Boston Mountains in Newton County, is one of the few remaining free-flowing streams in Arkansas. It is considered to be one of Arkansas\u27 greatest natural treasures, and thus, there is strong interest in protecting it from anthropogenic influences. An initial characterization of the soil taxonomic units, watershed boundaries, topography and physiographic units in the Buffalo River Watershed was presented by Scott and Smith (1994). The spatial distribution of the geologic units in the watershed was presented by Hofer et al. (1995)

    Ground Water Monitoring Project for Arkansas, Phase III

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    This report is composed of two parts. The first part is an interpretation of the pesticide and nitrate data collected in Woodruff County based on samples collected during 1994. Because there is an indication that there were hydrological differences between 1994 and 1995, and because most of the pesticide data is from 1994, this interpretive portion is restricted to 1994 data. Six wells initially sampled in 1994 that contained pesticides had continuing contamination in re-sampling in 1994 and 1995. Part II lists a seventh well in Woodruff County that contained pesticides in February and May of 199

    Simulation of Runoff Transport of Animal Manure Constituents

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    Runoff losses of land-applied animal manure constituents can adversely affect the quality of downstream waters. Reliable mathematical simulation models can help estimate runoff losses of animal manure constituents and identify management measures to reduce these losses. The objective of this study was to develop and calibrate an event-based simulation model to describe the runoff transport of solids (soil and manure particles) and nutrients (nitrogen and phosphorus) from areas treated with animal manure. The resulting model, consisting of linked hydrology, soil/manure transport, and nutrient transport components, is process-oriented and uses measurable parameters to the greatest degree possible. The three components of the model were calibrated sequentially (hydrology, soil/manure transport, and nutrient transport, in order) using data from plot-scale field experiments involving grassed plots treated with poultry litter. The calibrated parameter values were generally consistent with previously published values. Transport of total suspended solids, ammonia-nitrogen, dissolved phosphorus, and total phosphorus was well-predicted by the model. Transport of nitrate-nitrogen, however, was overpredicted by approximately an order of magnitude, while total Kjeldahl nitrogen transport was underpredicted by approximately an order of magnitude. Improvements in model structure (e.g., using different equations to describe the release of nitrate from the litter to the soil and assuming a significant proportion of organic nitrogen to be soluble) and parameter selection appear warranted to improve prediction of nitrate and total Kjeldahl nitrogen losses

    Agricultural Water Management in the Missippi Delta Region of Arkansas

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    Agriculture is the largest use of soil and water resources in eastern Arkansas. This bulletin summarized the recent historical use of soil and water by agriculture and the impact of irrigation on yields of rice, soybeans and cotton. The experiments conducted in the field to quantitatively schedule irrigations of crops are summarized. The results show the close relationship between the irrigation of crops and the extraction of water from the Alluvial Aquifer. The implications of this relationaship for the future are discussed
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