100 research outputs found

    PHOSPHORUS-BASED NUTRIENT MANAGEMENT PLANNING ON DAIRY/POULTRY FARMS: IMPLICATIONS FOR ECONOMIC AND ENVIRONMENTAL RISKS

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    The effects of phosphorus (P)-based nutrient management plans on economic and environmental risks of dairy and dairy-poultry farms in Virginia were evaluated. Phosphorus-based nutrient management plans can greatly reduce P runoff risk but also reduce farmers' returns. P-based plans cause greater reductions in returns and P runoff on the dairy-poultry farm than on the dairy only farm.nutrient runoff, cost, mathematical programming, simulation, watershed, Environmental Economics and Policy, Livestock Production/Industries,

    The Expanding Dairy Industry: Impact on Ground Water Quality and Quantity with Emphasis on Waste Management System Evaluation for Open Lot Dairies

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    Major expansion of the dairy industry has occurred in the last 12 years in North Central Texas, especially in Erath County. For several decades, this area has been the location of small dairy farms with sufficient land to maintain low animal densities on pastures except during milking operations. Today, however, new dairy operations are typically much larger (500-1,000 or more head) and maintain milking and dry cattle in open lots or corrals on small areas relative to the number of cows, in a manner that is similar to practices in the desert Southwest. Typical animal spacings in open lots are 56 m2 (600 square feet) pa cow. Large amounts of water are used for manure removal and milk sanitation, resulting in significant volumes of process-generated wastewater. Concern has increased regarding the potential for ground and surface water quality degradation due to the increasing number and size of open lot dairies, particularly in the Upper North Bosque River watershed (Erath and Hamilton Counties, Texas). The outcropping of the Paluxy Formation within the watershed, which acts as a recharge zone for the Trinity Aquifer group, has led to concern about the quality of ground water in the watershed. The Upper North Bosque River (stream segment 1226) flows through the center of Erath County and eventually enters a municipal water supply reservoir before entering the Brazos River at Waco. This stream segment has been characterized as the state's major "known problem" for agricultural nonpoint source water quality pursuant to 1988 and 1990 assessments under Section 319 of the Federal Clean Water Act (TWC, 1988). Animal confinement operations, specifically dairy operations, were identified as primary contributors to the problem. A number of interagency research and demonstration projects have been initiated since 1988 in response to the concerns about water quality degradation due to open lot dairies. A common goal of these projects is to obtain and disseminate data and information related to the design and evaluation of dairy waste management practices. The results of these studies will aid producers, engineers, planners, and regulatory officials in the refinement and adoption of appropriate practices for water quality protection

    Effectiveness of Native Species Buffer Zones for Nonstructural Treatment of Urban Runoff

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    A field study was conducted to determine the influences of vegetation composition, buffer width, and infiltration rate on the effectiveness of native vegetation buffer zones as nonstructural treatments of urban runoff with respect to increasing water quality. The field site was in Austin, Texas with runoff originating in a parking lot with a drainage area of approximately one hectare. The soil was a shallow, well-drained clay overlying limestone. Twelve constituents were measured; fecal streptococci, fecal coliforms, dissolved nitrate, total nitrate, dissolved total phosphorus, total phosphorus, dissolved ammonia, total ammonia, dissolved total Kjeldahl nitrogen, total Kjeldahl nitrogen, total lead, and total suspended solids. Four different vegetation compositions were used as treatments; wooded areas, wooded areas cleared, native grasses mowed, and native grasses unmowed. The vegetation in the mowed and unmowed areas was primarily composed of Johnson grass (Sorghum halepense), Bermuda grass (Cynodon dactylon) and mixed legumes. The wooded area was dominated by common red cedar (Juniperus virginiana) with scattered live oak (Quercus virginiana) and Ashe juniper (Juniperus ashei). The ground cover was juniper litter and scattered Texas wintergrass (Stipa leucotricha). Only total suspended solids, total lead, total Kjeldahl nitrogen, total nitrate, total phosphorus, dissolved nitrate, and dissolved total phosphorus were influenced at the 0.10 significance level by vegetation composition and buffer width. For pollutants affected by vegetation composition, the wooded areas had the highest mean concentrations of pollutants. The mowed and unmowed areas generally had the lowest concentrations of pollutants. For this application of buffer strips, it was found that as buffer width increased, the pollutant concentration also increased. Other researchers have reported decreasing pollutant concentrations. One explanation is that this is caused by excess transport capacity associated with the runoff entering the buffer strip. As the runoff moved though the buffer strip, pollutants were detached and transported through the buffer strip. If the buffer strip is sufficiently wide, an equilibrium between detachment and transport capacity may be reached and a decrease in pollutant concentration may be seen subsequently. A physically-based model was developed to simulate sediment yield through the buffer strips studied. The model has a stochastic pollutant concentration input generator. Transport capacity is computed using the Yalin equation. Detachment and deposition are computed using a modified version of the Universal Soil Loss Equation. The model was used to simulate this field study. The model did not simulate individual rainfall events well. The model predicted the long-term average results of this field study with concentrations increasing with buffer width. The coefficient of determination for observed concentrations compared to average predicted concentrations was 0.90

    African linguistics on the prairie: Selected papers from the 45th Annual Conference on African Linguistics

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    African Linguistics on the Prairie features select revised peer-reviewed papers from the 45th Annual Conference on African Linguistics, held at the University of Kansas. The articles in this volume reflect the enormous diversity of African languages, as they focus on languages from all of the major African language phyla.  The articles here also reflect the many different research perspectives that frame the work of linguists in the Association for Contemporary African Linguistics. The diversity of views presented in this volume are thus indicative of the vitality of current African linguistics research. The work presented in this volume represents both descriptive and theoretical methodologies and covers fields ranging from phonetics, phonology, morphology, typology, syntax, and semantics to sociolinguistics, discourse analysis, language acquisition, computational linguistics and beyond.  This broad scope and the quality of the articles contained within holds out the promise of continued advancement in linguistic research on African languages

    African linguistics on the prairie: Selected papers from the 45th Annual Conference on African Linguistics

    Get PDF
    African Linguistics on the Prairie features select revised peer-reviewed papers from the 45th Annual Conference on African Linguistics, held at the University of Kansas. The articles in this volume reflect the enormous diversity of African languages, as they focus on languages from all of the major African language phyla.  The articles here also reflect the many different research perspectives that frame the work of linguists in the Association for Contemporary African Linguistics. The diversity of views presented in this volume are thus indicative of the vitality of current African linguistics research. The work presented in this volume represents both descriptive and theoretical methodologies and covers fields ranging from phonetics, phonology, morphology, typology, syntax, and semantics to sociolinguistics, discourse analysis, language acquisition, computational linguistics and beyond.  This broad scope and the quality of the articles contained within holds out the promise of continued advancement in linguistic research on African languages

    African linguistics on the prairie: Selected papers from the 45th Annual Conference on African Linguistics

    Get PDF
    African Linguistics on the Prairie features select revised peer-reviewed papers from the 45th Annual Conference on African Linguistics, held at the University of Kansas. The articles in this volume reflect the enormous diversity of African languages, as they focus on languages from all of the major African language phyla.  The articles here also reflect the many different research perspectives that frame the work of linguists in the Association for Contemporary African Linguistics. The diversity of views presented in this volume are thus indicative of the vitality of current African linguistics research. The work presented in this volume represents both descriptive and theoretical methodologies and covers fields ranging from phonetics, phonology, morphology, typology, syntax, and semantics to sociolinguistics, discourse analysis, language acquisition, computational linguistics and beyond.  This broad scope and the quality of the articles contained within holds out the promise of continued advancement in linguistic research on African languages

    African linguistics on the prairie: Selected papers from the 45th Annual Conference on African Linguistics

    Get PDF
    African Linguistics on the Prairie features select revised peer-reviewed papers from the 45th Annual Conference on African Linguistics, held at the University of Kansas. The articles in this volume reflect the enormous diversity of African languages, as they focus on languages from all of the major African language phyla.  The articles here also reflect the many different research perspectives that frame the work of linguists in the Association for Contemporary African Linguistics. The diversity of views presented in this volume are thus indicative of the vitality of current African linguistics research. The work presented in this volume represents both descriptive and theoretical methodologies and covers fields ranging from phonetics, phonology, morphology, typology, syntax, and semantics to sociolinguistics, discourse analysis, language acquisition, computational linguistics and beyond.  This broad scope and the quality of the articles contained within holds out the promise of continued advancement in linguistic research on African languages

    African linguistics on the prairie: Selected papers from the 45th Annual Conference on African Linguistics

    Get PDF
    African Linguistics on the Prairie features select revised peer-reviewed papers from the 45th Annual Conference on African Linguistics, held at the University of Kansas. The articles in this volume reflect the enormous diversity of African languages, as they focus on languages from all of the major African language phyla.  The articles here also reflect the many different research perspectives that frame the work of linguists in the Association for Contemporary African Linguistics. The diversity of views presented in this volume are thus indicative of the vitality of current African linguistics research. The work presented in this volume represents both descriptive and theoretical methodologies and covers fields ranging from phonetics, phonology, morphology, typology, syntax, and semantics to sociolinguistics, discourse analysis, language acquisition, computational linguistics and beyond.  This broad scope and the quality of the articles contained within holds out the promise of continued advancement in linguistic research on African languages

    African linguistics on the prairie: Selected papers from the 45th Annual Conference on African Linguistics

    Get PDF
    African Linguistics on the Prairie features select revised peer-reviewed papers from the 45th Annual Conference on African Linguistics, held at the University of Kansas. The articles in this volume reflect the enormous diversity of African languages, as they focus on languages from all of the major African language phyla.  The articles here also reflect the many different research perspectives that frame the work of linguists in the Association for Contemporary African Linguistics. The diversity of views presented in this volume are thus indicative of the vitality of current African linguistics research. The work presented in this volume represents both descriptive and theoretical methodologies and covers fields ranging from phonetics, phonology, morphology, typology, syntax, and semantics to sociolinguistics, discourse analysis, language acquisition, computational linguistics and beyond.  This broad scope and the quality of the articles contained within holds out the promise of continued advancement in linguistic research on African languages

    African linguistics on the prairie: Selected papers from the 45th Annual Conference on African Linguistics

    Get PDF
    African Linguistics on the Prairie features select revised peer-reviewed papers from the 45th Annual Conference on African Linguistics, held at the University of Kansas. The articles in this volume reflect the enormous diversity of African languages, as they focus on languages from all of the major African language phyla.  The articles here also reflect the many different research perspectives that frame the work of linguists in the Association for Contemporary African Linguistics. The diversity of views presented in this volume are thus indicative of the vitality of current African linguistics research. The work presented in this volume represents both descriptive and theoretical methodologies and covers fields ranging from phonetics, phonology, morphology, typology, syntax, and semantics to sociolinguistics, discourse analysis, language acquisition, computational linguistics and beyond.  This broad scope and the quality of the articles contained within holds out the promise of continued advancement in linguistic research on African languages
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