Dynamic general equilibrium analysis of improved weed management in Australia's winter cropping systems*

A recent analysis indicated that the direct financial cost of weeds to Australia's winter grain sector was approximately $A1.2bn in 1998–1999. Costs of this magnitude represent a large recurring productivity loss in an agricultural sector that is sufficient to impact significantly on regional economies. Using a multi‐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 eliminated, with a diminishing benefit in succeeding years. At the national level, there is a welfare increase of $700m in discounted net present value terms. The regions with relatively high concentrations of winter crops experience small temporary macroeconomic gains.     

Empirical investigation of investment behaviour in Australia's pastoral region*

Optimal intertemporal investment behaviour of Australian pastoralists is modelled using panel data for the period 1979–1993. Results indicate that quasi‐fixity of inputs of labour, capital, sheep numbers and cattle numbers is characteristic of production in the pastoral region. It takes about two years for labour, four years for capital and a little over two years for both sheep numbers and cattle numbers to adjust towards long‐run optimal levels. Results also indicate that, after accounting for adjustment costs, own‐price product supply and input demand responses are inelastic in both the short and long run.     

Economic contribution of French serradella (Ornithopus sativus Brot.) pasture to integrated weed management in Western Australian mixed‐farming systems: an application of compressed annealing*

Sowing phases of French serradella (Ornithopus sativus Brot.) pasture between extended cropping sequences in the Western Australian wheatbelt can sustain grain production through restoring soil fertility and reducing selective herbicide use. The objective of this article is to investigate the profitability of rotations involving this pasture under a variety of weed management scenarios to obtain greater insight into its value for mixed farming systems in this region. A stochastic search procedure, compressed annealing, is used to identify profitable sets of weed management strategies in a simulation model representing a large number of potential combinations of chemical and non‐chemical forms of weed control. In contrast to a continuous‐cropping sequence, the inclusion of a serradella phase in a rotation is profitable at high weed densities and with increasing levels of herbicide resistance. A single year of pasture in the rotation is optimal if resistance to Group A selective herbicides is present at the beginning of the planning horizon, but a three‐year phase is required if resistance to multiple herbicide groups is observed. Sowing a serradella pasture twice over a two‐year phase is also shown to be economically attractive given benefits of successive high weed kills.     

The distribution of benefits from public international germplasm banks: the case of beans in Latin America

The unrestricted international flow of genetic resources from international genebank collections is the source of perhaps one of the greatest impacts of international agricultural research. This paper examines the distribution across countries in Latin America of benefits generated from bean genetic resources held by the International Center for Tropical Agriculture (CIAT). The genealogies of commercial bean cultivars released since 1976, containing materials from the collection, are analysed to calculate for each country the source of the genetic resources used. All countries in the region are shown to be heavily dependent on imported genetic resources for their commercial cultivars. From the available information on the economic impact of these improved bean varieties, the share of economic productivity benefits associated with imported germplasm by country of origin is calculated. The benefits received by each country from improved bean germplasm are compared with the contribution of that country's germplasm to other countries. Some of the patterns in the flow and use of genetic resources are analysed.     

Piloting a systematic framework for public investment in regional natural resource management: Dryland salinity in Australia

The Salinity Investment Framework (SIF3) is designed to help environmental managers make better policy decisions about protecting key assets under threat of dryland salinity, a major degradation problem in Australia. This study reports results from applying SIF3 in partnership with two regional organizations (in the states of Victoria and Western Australia) with contrasting institutional powers and structures. We also engaged relevant policy makers with a view to influencing national policy. Available knowledge, science, and data were used to develop region-specific recommendations for public investment in salinity management. SIF3 proved easy to apply, requiring minimal changes from its original version. Establishing trust and credibility with stakeholders was extremely important. More time was required to be spent on communicating what SIF3 was and what it would mean for stakeholders than in applying it in the catchments. In both regions, recommendations included making a clear distinction between localized assets (such as a particular wetland) and dispersed assets (such as agricultural land as a whole); more targeted investment in spatially identified localized assets; using a broader range of policy tools; basing recommendations on the levels of public and private net benefits; anticipating the adoptability of sustainable land-management practices; and formally integrating relevant scientific, economic and social information with community values. The differences between current action and recommendations were significant in both regions, particularly in Victoria. As a result of our work both regions have decided to implementing a similar asset-based approach covering various environmental threats in addition to dryland salinity. The research indicates that it is feasible to use decision frameworks such as SIF3 to improve the rigour of decision making by community-based environmental management organizations. A broader range of policy tools are needed for dryland salinity, with less reliance on extension and small grants, and more emphasis on intervention around key assets and investment in technology development. We have influenced policy makers to some extent at state level and nationally through discussion of SIF3 in a national inquiry, preparation of a policy paper for peak multi-government policy committees, briefings and provision of advice on policy design. Despite this, achieving significant policy change at the state and national levels remains difficult for a number of reasons. Governments give limited signals to environmental managers to achieve environmental outcomes, being more concerned with community participation objectives and political considerations. We hope for significant policy change with increased scrutiny about sound decision making and public accountability.     

The external costs of pasture weed spread: an economic assessment of serrated tussock control

The external cost associated with the spread of pasture weeds such as serrated tussock (Nassella trichotoma) is an important economic problem. This problem is complicated in many parts of south‐eastern Australia where low rainfall and low soil fertility prevent the economic viability of control of this weed through pasture improvement. A consequence of serrated tussock spread in this region has been calls for increased public intervention in its control. However, because there have been no attempts to measure the external costs of serrated tussock spread, one of the major economic grounds on which this activity might be justified has not been quantified. The purpose of this paper is to provide this information. A stochastic simulation model is developed to determine the size of the external cost associated with the spread of serrated tussock and to evaluate the economic benefits of a range of control scenarios. It is concluded that on low rainfall‐low soil fertility country the socially optimal control option for serrated tussock is to retire land from agriculture and re‐vegetate it with trees.     

The importance of seasonal variability and tactical responses to risk on estimating the economic benefits of integrated weed management

Seasonal variability is an important source of risk faced by farmers and, regardless of an individual's attitude to risk, there are options to tactically adjust production strategies as the outcomes of risk become known. The objective of this article is to measure the economic benefits of alternative approaches to managing weeds, one of the most serious production problems in Australian cropping systems. A bioeconomic model that combines weed biology, crop growth and economics is developed to value the effects of seasonal variability and the role of tactical responses and sequential decision making in determining an optimal integrated weed management strategy. This shows that there are substantial differences in the measured long‐term benefits from deterministic and stochastic simulations. It is concluded that, for research evaluation of technologies that involve complex biological and dynamic systems, ignoring the impacts of seasonal variability, responses to risk and sequential decision making can lead to an incorrect estimate of the economic benefits of a technology. In this case study of optimal weed management strategies in Australia, the size of the error is high.     

Risk management in public land development projects: Comparative case study in Finland,and the Netherlands

Public land development is an approach where the public authority acquires land for development, services the land with public infrastructure, and transfers the serviced building plots to private building developers or self-developing end-users. Motivations to use public land development can be divided to planning goal related motivations and financial motivations. In this paper, we study management of public risks related to the use of public land development by analysing case studies located in Finland and the Netherlands, countries known to have strong tradition in public land development. Our findings indicate that, whereas public land development has efficiencies in managing the risks related to the achievement of public planning goals, the management of the financial risks related to the public land development approach can be remarkably difficult even in countries with wide experience in public land development.     

Evaluating combined land conservation benefits from perennial pasture: lucerne (Medicago sativa L.) for management of dryland salinity and herbicide resistance in Western Australia*

The inclusion of perennial pasture phases in cropping rotations has been widely promoted throughout Australia for reducing the incidence of dryland salinity. To a lesser extent, they have also been promoted to enhance the management of herbicide‐resistant weeds. No previous economic analysis of perennial pasture has considered both of these benefits. This study combines a dynamic linear programming model to estimate the magnitude of salinity‐related benefits and a complex simulation model to assess the economics of herbicide‐resistance management. We present a case study of the perennial pasture lucerne (Medicago sativa L.) in the Wheatbelt of Western Australia, where the weed annual ryegrass (Lolium rigidum Gaudin) is resistant to multiple herbicide groups. Sequences incorporating lucerne are the most profitable land use at the standard set of parameter values if (i) annual ryegrass is resistant to all selective herbicides, (ii) the water table is so shallow (approximately < 3.5 m deep) that frequent rotation with perennials is required to avert soil salinisation, (iii) sheep production is highly profitable, or (iv) there is a combination of less extreme cases. The value of perennial pasture is sufficient under these circumstances to overcome its high establishment cost and the displacement of multiple years of crop. Consideration of dryland salinity and herbicide resistance are about equally important in evaluating the economics of lucerne; neither should be neglected.     

Land tenure and farm management efficiency: the case of paddy and cinnamon production in customary land areas of Sumatra

This study attempts to identify the impacts of land tenure institutions on the efficiency of farm management based on a case study of lowland paddy (rice) and upland cinnamon production in customary land areas of Sumatra. While the traditional joint-family ownership system is found to exist in paddy land, more individualised ownership systems are widely observed in upland areas. Yet, we found no statistical evidence that residual profit per unit of land is affected by land tenure institutions in either the lowlands or uplands, indicating that the prevailing land tenure institutions are equally conducive to efficient farm management.     

Facilitating collaboration in forest management: Assessing the benefits of collaborative policy innovations

Collaborative governance and landscape approaches have become a more prevalent in public land management in the United States in the face of increasing ecological and societal complexity and decreasing government resources and capacity. In this era of devolution and social-ecological change, there is a growing need for policy approaches that facilitate partnerships and participatory approaches to land management. One unique policy that emphasizes collaboration and large-landscape restoration on US federal forestlands is the Collaborative Forest Landscape Restoration Program (CFLRP), established in 2009 to accelerate the pace and scale of forest restoration. The policy included novel characteristics such as a decade-long commitment to landscapes and formal requirements for collaboration. This program presented an opportunity to assess how this policy affected collaboration and the factors that led to differential policy implementation. We conducted 89 interviews across all 23 CFLRP projects with internal agency staff and external collaborators on each project. We found that the CFLRP generated a variety of benefits related to collaboration, including increased trust and stronger relationships, increased collaborative partner influence, decreased litigation and conflict, and increased capacity to accomplish work; however, there were also challenges associated with the program, including thetime-intensive nature of collaboration and the lack of industry or contractors. Various local factors affected collaborative outcomes under the policy, including staff turnover and capacity, local leadership, and collaborative history. Successful collaborative outcomes were widespread under the CFLRP, and from this, we draw implications for the broader environmental governance literature about the policy characteristics that facilitate collaboration and the other institutional variables that may require attention in this context.     

Optimal management of a flammable forest providing timber and carbon sequestration benefits: an Australian case study*

In deciding to keep or fell a forest stand given its age, the risk of loss of timber through wildfire is an important consideration. If trees also have value from sequestration of carbon, another effect of fire is the unplanned loss of stored carbon. Factors affecting the decision to keep or fell trees, and how much to spend on fire protection, are investigated using stochastic dynamic programming, using carbon sequestration in stands of mountain ash in Victoria as a case study. The effect of treating sawlogs as a permanent carbon sink after harvesting is explored.     

The economic benefits of rabbit control in Australian temperate pastures by the introduction of rabbit haemorrhagic disease

The European rabbit is present in most Australian environments and causes economic loss in agricultural systems by reducing production and imposing control costs on producers and governments. Research into rabbit control has recognised the need for reliable benefit‐cost analysis to justify inputs into rabbit management. This paper provides estimates of the costs of rabbits in Australian temperate pasture systems and of the long‐term benefits of reducing rabbits by the introduction of rabbit haemorrhagic disease (RHD). Rabbits impose annual costs on wool producers in the temperate pasture areas of between 7.1 and 38.7 million Australian dollars (mA$) depending on their density. Controlling rabbits by RHD has the potential to generate substantial long‐term economic benefits by reducing grazing competition with sheep. Reducing rabbit costs by 25% generated 15‐year net present values (NPVs) between 18.4 and 97.3 mA$ at various pre‐RHD rabbit densities. A 50% reduction in rabbit costs increased the total NPVs between 36.9 and 202.4 mA$, virtually all of which was captured by temperate area wool producers. The corresponding benefit‐cost ratios were between 2.9:1 and 16.2:1 for a 25% rabbit reduction and 5.9:1 and32.4:l for a 50% reduction, where the total costs of the RHD program in the temperate pasture areas were incurred by the wool industry. The analysis provides guidelines for the economic evaluation of other pest problems in agricultural production systems.     

适应公共财政体制要求的水利投资对策

公共财政是与市场经济相适应的一种财政模式。国家公共财政框架体系的初步建立,为加大水利基础设施的投入和水利投资体制改革提供了历史性的机遇,广泛吸引各方投资,就可能形成公益性极强的产业组织,建立市场大规模投入水利基础设施的良性运行机制,并形成中央财政转移支付的重要通道。     

User fees, equity and the benefits of public outdoor recreation services

The paper addresses the question of who benefits from public recreation areas. Employing a set of survey data from users and nonusers of state-owned recreation and conservation areas in Finland, we derive two measures for distributional analysis. The first, the income elasticity of willingness to pay for recreation services, indicates that public provision of recreation benefits lower-income groups more than higher-income groups. The second, a welfare measure including efficiency loss, reveals ambiguous impacts depending on the level of the fee implemented. Low fee levels decrease recreation visits among lower-income users, whereas high fees reduce the welfare level of higher-income users in particular.     

Feeding management of dairy cattle affect grassland dynamics in an alpine pasture

The effect of different supplementary feeding rates for grazing cattle on high-altitude pastures dynamics was evaluated. A field experiment was carried out during three years in a subalpine pasture area of the Eastern Alps. The investigated pasture area was 40?ha, located between 1820 and 2230?m?a.s.l. Two paddocks were chosen in the experiment and two herds of 12 cattle each were kept in the two enclosures for 5 weeks. For the first herd (HS), the supplementary feeding rate was 4.8?kg?OM?head^?1 per day, while for the second herd (LS), the rate was 1.6?kg?OM?head^?1 per day. The amount of herbage consumed by each cattle was determined using the n-alkane technique. To monitor the pasture vegetation dynamics, eight metal exclusion cages were placed in each paddock to determine herbage growth, utilization rates, vegetation composition and animal grazing selectivity. Grazing behaviour of dairy cattle, in terms of herbage intake and species selection was affected by the different feeding rates. Cattle grazing Paddock HS consumed 1.9?kg?OM?day^?1 of herbage less than Paddock LS. In the LS paddock, cattle grazed higher phytomass rates. When the animals were fed by higher concentrate rates, a more selective grazing seemed to significantly increase the pasture necromass component. The lower grazing selectivity favoured the development of species as Nardus stricta and Deschampsia caespitosa, which are well known for their low palatability. Distinct vegetation dynamic patterns were observed, with a reduction of hair grass and an increase of legumes in the Paddock LS.     

The political economy of public research investment and commodity policies in agriculture: an empirical study

The paper tests a political economy theory of simultaneous government decision‐making on income redistribution through commodity policies and on public research investment in agriculture. We use data from 37 countries on agricultural protection and public agricultural research expenditures (PARI). The empirical results are consistent with the political economy hypotheses. The analysis suggest that structural changes in the economy have important effects on the political incentives for governments not only to subsidize or tax farmers, but also to invest in public agricultural research. Furthermore, the analysis supports the hypotheses that the impact of such structural changes on government decision‐making on PARI is non‐linear and conditional on other factors. Regarding the impact of political institutions, the results suggest that more democracy neither leads to more distortionary transfers (agricultural protection), nor to lower investment in public goods (PARI). ©2000 Elsevier Science B.V. All rights reserved.