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Registros recuperados: 22
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A bioeconomic model for determining the optimal response to a new weed incursion in Australian cropping systems AgEcon
Jayasuriya, Rohan T.; Jones, Randall E..
Invasions by non-indigenous plant species pose serious economic threats to Australian agricultural industries. When an invasion is discovered a decision has to be made as to whether to attempt to eradicate it, contain it or do nothing. These decisions should be based on long term benefits and costs. This paper describes a bioeconomic simulation framework with a mathematical model representing weed spread linked to a dynamic programming model to provide a means of determining the economically optimal weed management strategies over time. The modelling framework is used to evaluate case study invasive weed control problems in the Australian grains industry.
Tipo: Conference Paper or Presentation Palavras-chave: Weeds; Incursion; Bioeconomic model; Crop Production/Industries; Research Methods/ Statistical Methods.
Ano: 2008 URL: http://purl.umn.edu/6015
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A Dynamic Optimisation Model of Weed Control AgEcon
Jones, Randall E.; Cacho, Oscar J..
It is argued in this paper that static approaches to weed management, where the benefits and costs are only considered within a single season, are inappropriate for assessing the economic benefits of weed control technologies. There are carryover effects from weed management as weeds that escape control in one season may reproduce and replenish weed populations in following seasons. Consequently, it is appropriate to view weed control in the context of a resource management problem where the goal is to determine the optimal inter-temporal level of weed control that maximises economic benefits over some pre-determined period of time. A dynamic optimisation model for weed control is presented. Using the tools of comparative static analysis and Pontryagin's...
Tipo: Presentation Palavras-chave: Crop Production/Industries.
Ano: 2000 URL: http://purl.umn.edu/123685
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A Dynamic Optimisation Model of Weed Control AgEcon
Cacho, Oscar J.; Jones, Randall E..
It is argued in this paper that static approaches to weed management, where the benefits and costs are only considered within a single season, are inappropriate for assessing the economic benefits of weed control technologies. There are carryover effects from weed management as weeds that escape control in one season may reproduce and replenish weed populations in following seasons. Consequently, it is appropriate to view weed control in the context of a resource management problem where the goal is to determine the optimal inter-temporal level of weed control that maximises economic benefits over some pre-determined period of time. A dynamic optimisation model for weed control is presented. Using the tools of comparative static analysis and Pontryagin's...
Tipo: Working or Discussion Paper Palavras-chave: Weed control; Resource economics; Optimal control; Dynamic programming; Wild oats; Farm Management.
Ano: 2000 URL: http://purl.umn.edu/12902
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An Economic Evaluation of a Pest Management Control Program: "Outfox the Fox" AgEcon
Jones, Randall E.; Saunders, Glen; Balogh, Suzy.
Foxes are regarded as a serious pest of environmental and grazing systems in Australia. The fox is a recognised predator of native wildlife and has been a significant contributor to the population decline of many native mammal, bird and reptile species. There are also claims that foxes may account for up to 30% of lamb mortalities in some areas, while mortality due to predation of 2 to 5% is more likely in most regions. The ‘Outfox the Fox’ program was established by NSW Agriculture in conjunction with a number of Rural Land Protection Boards to achieve a more strategic and coordinated fox baiting program. This program relies on a community driven and integrated management approach to the problem. The main features are to synchronise baiting across...
Tipo: Report Palavras-chave: Benefit cost analysis; Research evaluation; Economic surplus; Fox; Farm Management; Land Economics/Use; Livestock Production/Industries; Production Economics; Research and Development/Tech Change/Emerging Technologies; Q160.
Ano: 2005 URL: http://purl.umn.edu/42653
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An Economic Evaluation of Research into the Improved Management of the Annual Grass Weed Vulpia in Temperate Pastures in South-Eastern Australia AgEcon
Vere, David T.; Jones, Randall E.; Dowling, Peter.
NSW Agriculture has a history of research investment in managing weed problems in the temperate pasture areas. One focus of that research has been on the development of improved management practices for the major annual grass weed vulpia. Recent surveys have found that weeds comprised up to 80% of pasture biomass in some temperate areas and that typical vulpia contents are between 30 and 40% of pasture biomass. Temperate pasture degradation is recognised as being a major contributor to the wider environmental problems of soil erosion, salinity and acidity. This evaluation related to a project (1996-2002) that focussed on the vulpia problem in the New South Wales temperate pasture areas. The benefits of that research were measured as the difference in the...
Tipo: Report Palavras-chave: Benefit cost analysis; Research evaluation; Annual grass weeds; Vulpia; Research and Development/Tech Change/Emerging Technologies; Q160.
Ano: 2004 URL: http://purl.umn.edu/42503
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Bioeconomic analysis of fertiliser input costs on pasture resource management under climatic uncertainty AgEcon
Behrendt, Karl; Cacho, Oscar J.; Scott, James M.; Jones, Randall E..
This paper has been withdrawn at the request of the authors.
Tipo: Conference Paper or Presentation Palavras-chave: Fertiliser input costs; Dynamic pasture resource model; Pasture persistence; Climatic uncertainty; Risk-efficient frontier; Crop Production/Industries.
Ano: 2009 URL: http://purl.umn.edu/47628
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Book reviews AgEcon
Jones, Randall E.; Windle, Jill; Culas, Richard J..
Tipo: Article Palavras-chave: Teaching/Communication/Extension/Profession.
Ano: 2005 URL: http://purl.umn.edu/118440
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Dynamic general equilibrium analysis of improved weed management in Australia's winter cropping systems AgEcon
Wittwer, Glyn; Vere, David T.; Jones, Randall E.; Griffith, Garry R..
A recent analysis indicated that the direct financial cost of weeds to Australia’s winter grain sectorwas approximately $A1.2bn in 1998–1999. Costs of thismagnitude represent a large recurring productivity loss in an agricultural sector that is sufficient to impact significantly on regional economies.Using amulti-regional dynamic computable general equilibrium model, we simulate the general equilibrium effects of a hypothetical successful campaign to reduce the economic costs of weeds. We assume that an additional $50m of R&D spread over five years is targeted at reducing the additional costs and reduced yields arising from weeds in various broadacre crops. Following this R&D effort, one-tenth of the losses arising from weeds is temporarily...
Tipo: Article Palavras-chave: CGE modelling; Dynamics; Weed management; Crop Production/Industries.
Ano: 2005 URL: http://purl.umn.edu/118584
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Economic benefits of public investment in weed management: the case of vulpia in south-eastern Australia’s temperate pasture areas AgEcon
Vere, David T.; Jones, Randall E.; Griffith, Garry R..
The present paper reports an economic evaluation of the long-term benefits to Australia of research by the Cooperative Research Centre for Weed Management Systems (CRC) into the improved management of vulpia , the major annual grass weed of temperate pastures in New South Wales and Victoria. Vulpia reduces livestock production by competition with more desirable pasture species, by the production of low quality feed at critical times of the grazing cycle, and by injury to animals. A 20-year stochastic benefit-cost analysis indicated that reducing the impacts of vulpia in these pastures produced a mean net present value of # A58.3 million and a mean benefit-cost ratio of 33:1. Temperate pasture zone wool producers would capture the largest shares of these...
Tipo: Journal Article Palavras-chave: Agricultural and Food Policy; Farm Management.
Ano: 2003 URL: http://purl.umn.edu/118162
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Economic cost of environmental flows in an unregulated river system AgEcon
Jones, Randall E.; Crean, Jason; Aluwihare, Parakrama B.; Letcher, Rebecca A..
This paper applies a stochastic dynamic programming framework, incorporating links to hydrological and biophysical models, to assess the economic costs of environmental flows in an unregulated river system in the Namoi Valley of northern New South Wales, Australia. Structural adjustment decisions are included in the model to account for farmer responses to changes in environmental flows through the introduction of a water sharing plan. The results of the analysis indicate that the proposed level of environmental flows reduces water extractions by around 6 per cent, and imposes an opportunity cost of less than 1 per cent in terms of reduced net income over a 20-year period.
Tipo: Journal Article Palavras-chave: Dynamic programming; Environmental flows; Irrigation; Resource /Energy Economics and Policy.
Ano: 2007 URL: http://purl.umn.edu/118334
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Economics of Integrated Catchment Management AgEcon
Marshall, Graham R.; Wall, Lisa M.; Jones, Randall E..
Integrated Catchment Management (ICM) can be viewed as an institutional instrument designed to ameliorate losses of economic efficiency that have arisen due to incomplete specification of the privileges and restrictions attached to property rights. If applied appropriately ICM can facilitate the emergence of a market in which parties disadvantaged by incomplete specification attempt to bribe those advantaged, with the aim of obtaining the latter's agreement to more complete specification. The instrument provides potential for transactions costs of bargaining to be reduced substantially by reducing the number of parties eligible to participate in, and installing the state as broker and arbiter of, the bargaining process. Participation by sub-catchment...
Tipo: Journal Article Palavras-chave: Resource /Energy Economics and Policy.
Ano: 1996 URL: http://purl.umn.edu/12415
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Farming Options for Ameliorating Acidifying Soils in South - Eastern Australia: An Economic Assessment. AgEcon
Islam, Q.; Mullen, John D.; Brennan, John P.; Li, G.D.; Helyar, K.R.; Jones, Randall E..
Acid and acidifying soils occur extensively in Australia. Currently, some 90 million hectares of agricultural land in Australia is considered to be acidic and around 35 million hectares are considered to be highly acidic which is both a serious agricultural and environmental problem. The nature, impact, and causes of soil acidification vary across Australia, as do farming systems and the institutional and socioeconomic issues relating to land management. In high-rainfall areas of south-eastern Australia, managing acid soils is particularly difficult in permanent pasture systems. In this paper, an economic analysis is made of the results of a long-term trial (MASTER – Managing Acid Soils Through Efficient Rotations) aimed at developing a sustainable...
Tipo: Presentation Palavras-chave: Soil acidity/pH/amelioration/farming/rotations/gross margin/stocking rates; Crop Production/Industries; Farm Management.
Ano: 1999 URL: http://purl.umn.edu/123818
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Land Salinisation, Waterlogging and the Agricultural Benefits of a Surface Drainage Scheme in Benerembah Irrigation District AgEcon
Jones, Randall E.; Marshall, Graham R..
Soil salinisation and waterlogging are significant problems in the Irrigation Areas and Districts of southern New South Wales. Various actions can be taken at either a regional or farm level to alleviate these problems. District surface drainage, sub-surface drainage, pumping from deep aquifers and changes to water pricing policies are regional options, while possible on-farm options include laser controlled landforming, pumping groundwater from shallow aquifers, recycling drainage water, changes to crops and rotations and the adoption of improved irrigation systems. The purpose of this study was to analyse the agricultural benefits of a surface drainage scheme proposed for an Irrigation District in the Murrumbidgee Valley. The objective of the analysis...
Tipo: Journal Article Palavras-chave: Land Economics/Use.
Ano: 1992 URL: http://purl.umn.edu/7423
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Modelling the Dynamics of Weed Management Technologies AgEcon
Jones, Randall E.; Cacho, Oscar J.; Sinden, Jack A..
An appropriate economic framework for valuing the benefits of weed management technologies is to treat weeds as a renewable resource stock problem. Consequently, the weed seed bank is defined as a renewable resource that changes through time due to management and seasonal conditions. The goal of decision-makers is to manage this (negative) resource so as to maximise returns over some pre-specified period of time. A modelling framework is presented for evaluating the biological and economic effects of weed management. The framework includes population dynamics, water balance, crop growth, pasture growth and crop/pasture rotation models for measuring the physical interactions between weeds and the environment. These models link in with numerical optimal...
Tipo: Conference Paper or Presentation Palavras-chave: Weeds; Modelling; Dynamic analysis.; Land Economics/Use.
Ano: 2003 URL: http://purl.umn.edu/57902
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On-farm Economics of Laser Landforming for Rice Farmers AgEcon
Marshall, Graham R.; Jones, Randall E..
The whole farm financial effects of laser land forming were analysed using a two stage modelling procedure. In the first stage, linear programming models of representative Murrumbidgee Irrigation Area (MIA) rice farms were used to predict the profit-maximising activity mixes with and without successive increments of land forming. In the second stage, the profit-maximising activity mixes with and without an increment became inputs into a spreadsheet model designed to undertake discounted cash flow analysis of investment in the increment. The transition over time of yields to the achievable levels for land formed layouts was accounted for in the spreadsheet model, as were the effects of taxation (including taxation concessions for land forming) and access to...
Tipo: Journal Article Palavras-chave: Farm Management.
Ano: 1993 URL: http://purl.umn.edu/10323
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Sheep CRC Renewal Proposal: Economic Evaluation of the Proposed Scientific Themes AgEcon
Griffith, Garry R.; Vere, David T.; Jones, Randall E..
The Australian sheep industry and its associated research and development agencies have developed a proposal for the CRC for Sheep Industry Innovation. “Top-down” and “bottomup” procedures were used to assess the expected economic benefits from this proposal. Formal “with-CRC” and “without-CRC” scenarios were defined for each product and each research theme. Relevant costs were similarly defined. The requested investment by the Commonwealth and the Australian sheep industry in the CRC is assessed relative to a scenario where an alternative, lower cost research program into this industry is implemented. These extra resources have a discounted value of about $34 million over the 25-year period of this evaluation. These resources are sufficient to allow some...
Tipo: Report Palavras-chave: Wool; Sheep meat; Research and development; Economic; Evaluation; Australia; Agribusiness; Livestock Production/Industries; Production Economics; Research and Development/Tech Change/Emerging Technologies; Q160.
Ano: 2006 URL: http://purl.umn.edu/42656
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Sustainability, Externalities and Economics: The Case of Temperate Perennial Grazing Systems in NSW AgEcon
Jones, Randall E.; Dowling, Peter.
The replacement of perennial grass species by undesirable annual grass weeds not only results in lower productivity but is also contributes to a range of external costs. In particular, shallow rooted annuals result in greater deep drainage and therefore a greater potential for salinity, and greater volumes of runoff of poor quality water to streams. In this paper an economic framework for examining the sustainability issues of a perennial grazing system on the NSW Central Tablelands is presented. This involves a combination of simulation and dynamic programming models, with the state of the system represented by variables for the perennial grass composition and soil fertility. The paper examines a range of management strategies that increase the perennial...
Tipo: Report Palavras-chave: Perennial pasture; Sustainability; Externalities; Bioeconomic modelling; Dynamic programming; Research and Development/Tech Change/Emerging Technologies; 160.
Ano: 2004 URL: http://purl.umn.edu/42504
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Tactical Opportunities, Risk Attitude and Choice of Farming Strategy: an Application of the Distribution Method AgEcon
Marshall, Graham R.; Jones, Randall E.; Wall, Lisa M..
When assessing farming strategies, it is important to account for the opportunities provided for tactically adjusting to outcomes of risk. The hypothesis that accounting for tactical adjustment is more important than accounting for risk attitude was supported in this study with regard to identifying the optimal drainage recirculation strategy for an irrigated dairy farm. Failing to account for tactical adjustment would lead to a sub‐optimal choice, costing the farmer about A$3 100 in present value terms. In contrast, failing to account for risk aversion would not affect the strategy chosen. The distribution method was found to be well suited to modelling tactical adjustment.
Tipo: Journal Article Palavras-chave: Research and Development/Tech Change/Emerging Technologies.
Ano: 1997 URL: http://purl.umn.edu/118064
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The economic cost of weeds in dryland cotton production systems of Australia AgEcon
Hoque, Ziaul; Farquharson, Robert J.; Taylor, Ian; Walker, Steve; Osten, Vikki; Jones, Randall E..
Economic losses and costs associated with weeds in dryland cotton production are important, both for growers and for industry bodies when making decisions about research priorities and research and development funding. A survey was conducted to provide information on weed types, control strategies and estimated costs to growers. We used information from the survey to estimate conventional financial losses due to weeds, and as a basis for evaluating aggregate economic (society) impacts. An economic surplus model was used to estimate the aggregate societal impact of weeds for three production regions in north-eastern Australia. The annual economic costs associated with weeds were estimated to be $41 million, and the on-farm financial costs were $25 million....
Tipo: Conference Paper or Presentation Palavras-chave: Weeds; Dryland Cotton; And Economics; Crop Production/Industries; Environmental Economics and Policy.
Ano: 2003 URL: http://purl.umn.edu/57893
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The on-farm impact of alternative grazing management options to improve sustainability in western Chinese grasslands AgEcon
Jones, Randall E.; Kemp, David R.; Michalk, David; Takahashi, Taro.
Chinese grasslands are suffering considerable pressures from human and livestock populations. It has been estimated that 90% of Chinese grasslands are suffering from light to heavy levels of degradation. Allied to this is the low household income of herders and farmers dependant upon livestock products for their livelihood. Although a range of reasons have been proposed for the high levels of grassland degradation, principal among these are the high stocking rates adopted by farmers. This not only results in high utilisation rates of the pasture biomass, leading to bare areas and soil erosion, but individual animal productivity rates also decline. This paper presents the results of a modelling study of a grassland system in Gansu Province and Inner...
Tipo: Conference Paper or Presentation Palavras-chave: Sustainable grazing; Bioeconomic model; China; Farm Management; Livestock Production/Industries; Resource /Energy Economics and Policy.
Ano: 2008 URL: http://purl.umn.edu/6019
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