414 research outputs found

    Economic Implications of Farmer Storage of Surface Irrigation Water in Federal Projects: El Paso County, Texas

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    The Bureau of Reclamation has approved a program for farmer storage of surface irrigation water in Elephant Butte Reservoir, New Mexico. This program would allow individual farmers to store part of their annual surface water allotment in the reservoir subject to evaporation loss to be drawn at a future date upon request. The purpose of this study is to ascertain the economic implications of such a program for farmers in the El Paso County Water Improvement District No. 1. The economic analysis was based on results from a linear programming model developed for crop production in E1 Paso County. The model was designed to maximize net farm revenue. Twelve crops were included in the analysis. The effects of soil type and salinity level of irrigation water on crop yields for all twelve crops were estimated. Input requirements by crop and yield level were identified. Input categories included seed, chemical, water, machinery, labor, harvest, other and fixed costs. Irrigation alternatives included both surface and ground sources. In addition, the water saving technology of laser leveling was incorporated into the model. The model was restricted by acreage of a soil group with a specified level of salinity in the underlying groundwater. Also, the quantity of surface irrigation water available was limited. This static linear programming model was applied for various surface irrigation water allocations ranging from zero to three acre feet per acre of cropland with groundwater assumed available. This procedure produced a schedule of net farm revenues for alternative surface irrigation water allocations for use in conjunction with groundwater. The procedure was repeated with groundwater availability limited to zero. These two schedules of net farm revenues were then used (1) to form the basis of two temporal linear programming models which maximized the real value in 1980 dollars of a stream of net farm revenues, and (23 to evaluate a specified annual surface irrigation water use scenario of two acre feet per acre per year. The temporal models maximized the 1980 real value of net farm revenues. This revenue stream was generated by optimal temporal use of the actual annual surface irrigation water allotments for 1963 to 1980. This optimal use includes the opportunity to store water in Elephant Butte Reservoir subject to evaporation. Results were obtained both with and without groundwater pumping over three surface water use scenarios (actual, optimal temporal and two acre feet per year). The results of this study indicated that, with the ability to store surface water, temporally optimizing surface water use would have increased the real value of net farm revenue 0.84peracreperyearor0.4percentabovetherealvalueofnetfarmreturnsimpliedbytheactualuseratesforthegroundwaterpumpingcase.Forthenogroundwaterpumpingcase,therealvalueofnetfarmreturnsincreasedby0.84 per acre per year or 0.4 percent above the real value of net farm returns implied by the actual use rates for the groundwater pumping case. For the no groundwater pumping case, the real value of net farm returns increased by 3.56 per acre per year or 2 percent above the net farm returns indicated by the actual use rates. Also, storing surface water for future use, or accumulation, tends to decrease the year to year variability of net farm revenues. Groundwater pumping is also known to decrease this variability. The target surface water allocation of the project administrators is three acre feet per year. The optimal temporal solutions tended to be between this three acre feet allocation and the two acre feet allocation as specified in the two acre feet per year scenario. An optimal temporal allotment of three acre feet appears too high while two acre feet appears too low. Without a system of farmer-held surface water storage, optimizing temporal use of surface irrigation water would not be possible. Thus, this water storage opportunity is an important irrigation management tool for individual farmers in the El Paso County Water Improvement District No. 1

    Economic Implications of New Crops, Row Damming and Land Clearing in the Texas Winter Garden

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    The chief sources of groundwater for the Texas Winter Garden are the Carrizo (Dimmit, Zavala, Frio, and LaSalle Counties) and Edwards (Uvalde County) Aquifers. The major user of groundwater in the region is irrigation. However, insufficient aquifer recharge relative to groundwater use has stimulated interest in alternatives to ease adjustments to diminished groundwater supplies. The impact on net revenue, groundwater utilization, and land use of new crops (guar, guayule, and short-season irrigated cotton), row damming, and conversion of range to cropland was evaluated using a regional linear programming model. Temporal analysis, 1981-2001, incorporated changes in groundwater availability, static groundwater levels, and corresponding fixed and variable costs. Introduction of guar and short-season irrigated cotton (base solution) was associated with increased groundwater pumpage from the Carrizo Aquifer, increased net revenue, and increased irrigated acreages. Edwards Aquifer pumpage remained constant at an upper limit. When guayule entered the base solution, net revenue rose by four million dollars and groundwater pumpage and irrigated acreages declined only in the Carrizo Aquifer. Land clearing without guayule added 17, 25.2, and 26.3 million dollars to net revenue for light; light and medium; and light, medium, and heavy brush clearing; respectively. Under light brush clearing about 480,000 acres were added to cropland and groundwater pumpage remained steady. Pumpage increased under the other land clearing activities. Land clearing with guayule almost doubled net revenue compared to land clearing without guayule. Row damming was the most effective alternative in reducing dependence on groundwater. Row damming in dryland grain sorghum and dryland cotton decreased groundwater pumpage and increased net returns above the base by 6.7 million dollars without land clearing and 18.6, 30.3, and 32.9 million dollars with the respective land clearing alternatives. Carrizo Aquifer groundwater pumpage was significantly reduced in each of the four alternatives and Edwards pumpage was reduced in all but the heavy brush clearing alternative. Under temporal and static analysis for projected (forecast) groundwater pumpage, net revenue, groundwater pumpage, and irrigated acres exceeded those of solutions with restricted (forced conservation) groundwater. Carrizo Aquifer groundwater pumpage was greater under restricted than in the projected groundwater scenarios

    Pricing and Conservation of Irrigation Water in Texas and New Mexico

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    Two possible policy alternatives for management of limited water supplies in arid portions of Texas and New Mexico were analyzed for economic feasibility. Detailed studies of the potential impact of a water accumulation policy for each of two irrigation districts (El Paso County Water Improvement District No. 1 in Texas, and the Elephant Butte Irrigation District in New Mexico) were undertaken using temporal linear programming techniques. Current cropping practices, soils, groundwater conditions, historical surface water allocations for Elephant Butte Reservoir and evaporation rates were incorporated within the analysis. Estimates of the benefits of accumulation of surplus portions of irrigation district member's annual surface water allocations, with subsequent use of the unevaporated portion in later years, were deemed insufficient to cover anticipated administrative costs of implementing the proposed policy. This suggests current allocations approximate a temporal optimum. Sensitivity analyses showed greater potential benefits, however, if current groundwater conditions worsen. Additional analysis of possible price-induced water conservation for the areas within the two states currently mining groundwater from the exhaustible Ogallala aquifer was also undertaken. The High Plains of Texas served as the representative region of study, with results assumed to be analogous for the portions of Eastern New Mexico relying on the Ogallala. Both static and temporal effects of a per unit tax on water pumpage and net returns were examined using a recursive linear programming model. Results indicated that imposition of a $20 per acre-foot tax on water pumped induced very little change in water use over a 40 year period, while reducing the present value of producer net returns from 9% to 27% depending upon initial groundwater conditions and the irrigation technology in use. These results imply that a price induced water conservation policy for the Ogallala is not economically justified

    The governance of co-operatives and mutual associations: a paradox perspective

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    This paper presents a new theoretical framework for understanding the governance of co-operative and mutual organisations. The theoretical literature on the governance of co-operatives is relatively undeveloped in comparison with that on corporate governance. The paper briefly reviews some of the main theoretical perspectives on corporate governance and discusses how they can be usefully extended to throw light on the governance of co-operatives and mutuals. However, taken individually these different theories are rather one dimensional, only illuminating a particular aspect of the board's role. This has lead to calls for a new conceptual framework that can help integrate the insights of these different theories. The paper argues that a paradox perspective offers a promising way forward. Contrasting the different theoretical perspectives highlights some of the important paradoxes, ambiguities and tensions that boards face

    Communitarian perspectives on social enterprise

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    Concepts of social enterprise have been debated repeatedly, and continue to cause confusion. In this paper, a meta-theoretical framework is developed through discussion of individualist and communitarian philosophy. Philosophers from both traditions build social theories that emphasise either consensus (a unitarist outlook) or diversity (a pluralist outlook). The various discourses in corporate governance reflect these assumptions and create four distinct approaches that impact on the relationship between capital and labour. In rejecting the traditional discourse of private enterprise, social enterprises have adopted other approaches to tackle social exclusion, each derived from different underlying beliefs about the purpose of enterprise and the nature of governance. The theoretical framework offers a way to understand the diversity found within the sector, including the newly constituted Community Interest Company (CIC).</p

    Why Social Enterprises Are Asking to Be Multi-stakeholder and Deliberative: An Explanation around the Costs of Exclusion.

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    The study of multi-stakeholdership (and multi-stakeholder social enterprises in particular) is only at the start. Entrepreneurial choices which have emerged spontaneously, as well as the first legal frameworks approved in this direction, lack an adequate theoretical support. The debate itself is underdeveloped, as the existing understanding of organisations and their aims resist an inclusive, public interest view of enterprise. Our contribution aims at enriching the thin theoretical reflections on multi-stakeholdership, in a context where they are already established, i.e. that of social and personal services. The aim is to provide an economic justification on why the governance structure and decision-making praxis of the firm needs to account for multiple stakeholders. In particular with our analysis we want: a) to consider production and the role of firms in the context of the “public interest” which may or may not coincide with the non-profit objective; b) to ground the explanation of firm governance and processes upon the nature of production and the interconnections between demand and supply side; c) to explain that the costs associated with multi-stakeholder governance and deliberation in decision-making can increase internal efficiency and be “productive” since they lower internal costs and utilise resources that otherwise would go astray. The key insight of this work is that, differently from major interpretations, property costs should be compared with a more comprehensive range of costs, such as the social costs that emerge when the supply of social and personal services is insufficient or when the identification of aims and means is not shared amongst stakeholders. Our model highlights that when social costs derived from exclusion are high, even an enterprise with costly decisional processes, such as the multistakeholder, can be the most efficient solution amongst other possible alternatives

    Cellular Radiosensitivity: How much better do we understand it?

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    Purpose: Ionizing radiation exposure gives rise to a variety of lesions in DNA that result in genetic instability and potentially tumorigenesis or cell death. Radiation extends its effects on DNA by direct interaction or by radiolysis of H2O that generates free radicals or aqueous electrons capable of interacting with and causing indirect damage to DNA. While the various lesions arising in DNA after radiation exposure can contribute to the mutagenising effects of this agent, the potentially most damaging lesion is the DNA double strand break (DSB) that contributes to genome instability and/or cell death. Thus in many cases failure to recognise and/or repair this lesion determines the radiosensitivity status of the cell. DNA repair mechanisms including homologous recombination (HR) and non-homologous end-joining (NHEJ) have evolved to protect cells against DNA DSB. Mutations in proteins that constitute these repair pathways are characterised by radiosensitivity and genome instability. Defects in a number of these proteins also give rise to genetic disorders that feature not only genetic instability but also immunodeficiency, cancer predisposition, neurodegeneration and other pathologies. Conclusions: In the past fifty years our understanding of the cellular response to radiation damage has advanced enormously with insight being gained from a wide range of approaches extending from more basic early studies to the sophisticated approaches used today. In this review we discuss our current understanding of the impact of radiation on the cell and the organism gained from the array of past and present studies and attempt to provide an explanation for what it is that determines the response to radiation
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