Sustainability, Externalities and Economics: The Case of Temperate Perennial Grazing Systems in NSW

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 grass composition in terms of net income from grazing, and the impact upon the externalities.perennial pasture, sustainability, externalities, bioeconomic modelling, dynamic programming, Research and Development/Tech Change/Emerging Technologies, 160,

A Dynamic Optimisation Model of Weed Control

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 maximum principle, the conditions for optimal input use (ie weed control) are compared for static and dynamic situations. It is shown that a higher level of input use for a given weed population is optimal using a dynamic framework than would be derived under a static framework. The analysis is further extended by the incorporation of uncertainty and shows that the optimal level of weed control is also affected by uncertainty in herbicide efficacy and the survival of weed seeds produced. A case study of the optimal long-term management under deterministic and stochastic conditions of an annual cropping weed, Avena fatua, is presented.weed control, resource economics, optimal control, dynamic programming, wild oats, Farm Management,

A bioeconomic model for determining the optimal response to a new weed incursion in Australian cropping systems

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.weeds, incursion, bioeconomic model, Crop Production/Industries, Research Methods/ Statistical Methods,

An Economic Evaluation of a Pest Management Control Program: "Outfox the Fox"

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 landholders at least twice a year, undertake baiting during periods when the fox is most susceptible, regularly check and replace baits, and continue until the bait take declines. A stochastic economic surplus and benefit-cost analysis model was developed to evaluate this program. The change in annual economic surplus due to the ‘Outfox the Fox’ program was $3.4m. The benefit-cost analysis showed that the project provided a significant return on public investment with a mean net present value of$9.8m and a mean benefit-cost ratio of 13.0:1. The stochastic analysis indicated that there was a very low probability of this program providing a negative economic return.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,

Tax reform in Korea

노트 : A publication of the Korea Economic Institute and the Korea Institute for International Economic Polic

Book reviews

Teaching/Communication/Extension/Profession,

An Economic Evaluation of Research into the Improved Management of the Annual Grass Weed Vulpia in Temperate Pastures in South-Eastern Australia

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 economic returns from the project (the with-research scenario) and those that would have resulted if the project had not been initiated (the without-research scenario). The results indicated high levels of economic benefits from the vulpia project. The annual net project benefit had a mean value of $58 million. The benefit-cost analysis generated a mean NPV of$196.9 million and a mean BCR of 22.2. These results demonstrate that research by NSW Agriculture into the improved management of vulpia has the potential to generate substantial long-term economic benefits. Other socio-economic aspects of the results showed that wool producers outside the New South Wales temperate areas lost economic surplus (from a mean -$21.7 million to -$47.8 million) because they were unable to adopt the cost-reducing technology and faced a reduced wool price. All wool consumers gained from vulpia research because of expanded wool production and lower wool prices. Improved vulpia management is also considered to produce important environmental benefits by encouraging a greater use of deep-rooted perennial grasses and the beneficial effects of these on mitigating soil problems and reducing water table discharges.benefit cost analysis, research evaluation, annual grass weeds, vulpia, Research and Development/Tech Change/Emerging Technologies, Q160,

A Liquefaction Potential Map for Cache Valley, Utah

The identification of liquefaction susceptible soil deposits in Cache Valley, Utah and the relative potential that these deposits have for liquefaction were the two main purposes of this study. A liquefaction susceptibility map was developed to outline areas where liquefaction might occur during an earthquake. The susceptibility map was combined with a liquefaction opportunity map to produce a liquefaction potential map for Cache Valley, Utah. The opportunity map for Cache Valley was developed in a companion study, Greenwood (1978). The development of the susceptibility map and the opportunity map and combining them to form a liquefaction potential map for Cache Valley was based on a procedure developed by Youd and Perkins (1977). The liquefaction potential map is a general location map and will be a useful tool for preliminary planning by governmental agencies, planners, developers, and contractors. The use of the liquefaction potential map by these various groups will aid them in avoiding possible problem areas for project locations. It will also be a guide for further analysis of specific sites where liquefaction is probable

Randall S. Jones in a Senior Voice Recital

This is the program for the senior voice recital of baritone Randall S. Jones. Pianist Susan Crosby assisted the performance. The recital took place on February 23, 1989, in the Mabee Fine Arts Recital Hall