55,283 research outputs found

    The Variable-Rate Input Application Decision for Multiple Inputs with Interactions

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    Research has evaluated the relative profitability of variable-rate (VRT) versus uniform-rate (URT) application of a single input in fields with multiple management zones. This study addresses map-based VRT decisions for multiple inputs in fields with multiple management zones. The decision-making framework is illustrated for nitrogen and water applied to irrigated cotton in fields with three management zones. Results suggest traditional methods of determining VRT application of a single input may by suboptimal if interactions exist among VRT inputs and URT inputs. Implications are that a systems approach to multiple-input VRT decisions can produce increased net returns to VRT.breakeven analysis, cotton, economic feasibility, multiple-inputs, precision farming, variable-rate technology, Crop Production/Industries,

    VARIABLE RATE NITROGEN APPLICATION ON CORN FIELDS: THE ROLE OF SPATIAL VARIABILITY AND WEATHER

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    Meta-response functions for corn yields and nitrogen losses were estimated from EPIC-generated data for three soil types and three weather scenarios. These metamodels were used to evaluate variable rate (VRT) versus uniform rate (URT) nitrogen application technologies for alternative weather scenarios and policy option. Except under very dry conditions, returns per acre for VRT were higher than for URT and the economic advantage of VRT increased as realized rainfall decreased from expected average rainfall. Nitrogen losses to the environment from VRT were lower for all situation examined, except on fields with little spatial variability.Corn, environment, meta-response functions, nitrogen restriction, precision farming, site-specific management, spatial variability, weather variability, Crop Production/Industries,

    Crop Production Using Variable Rate Technology for P&K in the United States Midwest: Evaluation of Profitability

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    This study evaluates profitability of crop production with variable rate technology (VRT) for P&K application relative to profitability of crop production with uniform rate technology (URT) using data from six fields with a corn-soybeans rotation situated in Indiana. The results suggest that crop production using VRT is more profitable than using URT in one of the six fields. In the case of the other five fields profitability of crop production using VRT relative to using URT falls in the range of 85 to 92%. Under the assumption of lower costs for field diagnostic services and variable rate fertilizer application profitability of crop production using VRT increases.Crop Production/Industries,

    ADOPTION AND ECONOMIC IMPACT OF SITE-SPECIFIC TECHNOLOGIES IN U.S. AGRICULTURE

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    A Heckman's two-stage method is used in conjunction with data from the 1998 Agricultural Resource Management Study to estimate the likelihood of adopting a variable rate application technology (VRT) and the impact of such adoption on the per-acre costs of fertilizers and lime in cash grain production. Results highlight the importance of operator's level of human capital and attitude toward risk, along with size and location of farm in impacting VRT adoption decisions. Results also indicate no significant cost-savings attributable to VRT adoption.Farm Management, Research and Development/Tech Change/Emerging Technologies,

    ASSESSING SPATIAL BREAK-EVEN VARIABILITY IN FIELDS WITH TWO OR MORE MANAGEMENT ZONES

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    Farmers are interested in knowing whether applying inputs at variable rates across a field is economically viable. The answer depends on the crop, the input, their prices, the cost of variable rate technology (VRT) versus uninform rate technology (URT), and the spatial and yield response variability within each field. Methods were investigated for determining the range of spatial variability over which the return to VRT covers its additional cost compared with URT in fields with multiple management zones. Models developed in this article, or variants thereof, could be used to help farmers make the VRT adoption decision.management zones, nitrogen, precision farming, site-specific management, spatial break-even variability proportions, spatial variability, variable rate technology, yield response variability, Farm Management,

    Economics of the Variable Rate Technology Investment Decision for Agricultural Sprayers

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    Producers lack information about the profitability of variable rate technology (VRT) for agricultural sprayers. An economic framework was developed to evaluate the returns required to pay for VRT investments. Payback variables included input savings, yield gains, and reduced application costs. We illustrate the framework with two example investment scenarios.capital budgeting, decision aid, farm management, precision agriculture, map-based, sensor-based, site-specific management, variable rate technology, Farm Management, Q10, Q16,

    Adoption of Variability Detection and Variable Rate Application Technologies by Cotton Farmers in Southern United States

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    A nested logit model was used to analyze the 2009 Southern Cotton Precision Farming Survey to study the impact of farmer and farm characteristics on the adoption of Variability Detection Technologies (VDT) and the adoption of Variability Rate application Technology (VRT) conditioned on the type of the VDT chosen. The results showed that the farm size and exposure to extension activities are important factors affecting the choice of VDTs. The farmers adopting both soil and plant based VDTs are more likely to adopt VRT. The probability of adoption of VRTs was lower for Texas cotton farmers irrespective of the type of VDT adopted. In general, younger, more educated farmers who use computers for farming operations are more likely to adopt VRT when they choose soil based or both soil and plant based VDT.Precision Agriculture, Technology Adoption, Cotton, Crop Production/Industries, Farm Management, Research and Development/Tech Change/Emerging Technologies, O33, Q16,

    SEQUENTIAL INVESTMENT IN SITE-SPECIFIC CROP MANAGEMENT UNDER OUTPUT PRICE UNCERTAINTY

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    An option-value model is developed to analyze the impacts of output price uncertainty, high sunk costs of adoption, and site-specific conditions on the optimal timing of adoption of two interrelated site-specific technologies, soil testing and variable rate technology (VRT). The model incorporates the potential for adopting these two technologies jointly or sequentially. The implications of the pattern of adoption for nitrogen pollution and for the design of a cost-share subsidy policy to accelerate the adoption of these technologies to reduce nitrogen pollution are also analyzed. Ignoring the potential for sequential adoption would tend to underpredict the adoption so soil testing and overpredict the adoption of VRT. Cost-share subsidies to induce accelerated adoption of VRT would be most effective at reducing nitrogen pollution if targeted toward fields with relatively high spatial variability in soil quality or soil fertility, and either low average soil quality or low average soil fertility.Demand and Price Analysis,

    Effectiveness of virtual reality-based vestibular rehabilitation in patients with peripheral vestibular hypofunction

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    Indexed keywords Metrics Abstract Background/aim: The rehabilitation of classical peripheral vestibular disorders is long and costly. Recently, interactive systems based on virtual reality (VR) technology have reduced the cost of vestibular rehabilitation therapy (VRT) and made the process more enjoyable. This study aims to investigate the effects of VR-based VRT in patients diagnosed with peripheral vestibular hypofunction (PVH). Materials and methods: In this study, a VR-based VRT program that utilized Sony Playstation®4 VR Head Mounted Display was applied to 25 patients (between 18–60) diagnosed with PVH. PVH was diagnosed by evaluating the patients’ clinical histories, the findings in the “Micromedical Technologies VisualEyes Spectrum” videonystagmography (VNG) and the “Micromedical Aqua Stim” model bithermal water caloric tests. VR-based VRT program was applied to the patients for 4 weeks, 2 sessions per week, 8 sessions in total. Each session lasted around 30 to 40 min. All patients underwent the Dizziness Handicap Inventory (DHI), Sensory Organization Test (SOT), Adaptation Test (ADT), Limits of Stability (LOS), and Rhythmic Weight Shift (RWS) before, after, and 8-week follow-up of the VRT program. In addition, the Cybersickness Survey was applied to the patients at the end of the VR-based VRT session every week. Results: The DHI mean scores of the patients were 54.60, 19.20, and 16.84, respectively, before, just after, and at the 8-week follow-up VRT (p < 0.001). The mean SOT composite score of the patients was obtained as 58.08 before VRT; 77.16 after VRT and 76.40 at 8-week after VRT (p < 0.000). On the other hand, the values in the ‘movement velocity’ and “direction control” parameters of the patients in LOS and RWS showed a significant improvement after VRT compared to before VRT (p < 0.000). From before VRT to 8 weeks after VRT, the patient’s oscillation averages in the ‘toes up’ and ‘toes down’ positions in ADT reduced progressively (p < 0.000). Conclusion: This study demonstrates that implementing a VR-based VRT protocol may be an efficient option to improve posture stability and the quality of life in patients with PVH. In addition, VR-based vestibular rehabilitation therapy has shown to be effective for PVH patients in the mid-term

    MOVING FROM UNIFORM TO VARIABLE FERTILIZER RATES ON IOWA CORN: EFFECTS ON RATES AND RETURNS

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    This study develops a model based on the yield potential of various soil types in 12 Iowa counties to estimate the potential value of switching from uniform to variable fertilizer rates. Results indicate modest increases in the gross returns over fertilizer costs, ranging from 7.43to7.43 to 1.52 per acre. The net profitability of variable-rate technology (VRT) is sensitive to the per acre costs of moving to a VRT program. Under the assumptions of the model, applying variable rates would increase yield by 0.05 to 0.5 bushels per acre, and would reduce fertilizer costs by 1.19to1.19 to 6.83 per acre.Crop Production/Industries,
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