Returns on investment in wild dog management-beef production in the South Australian Arid Lands

Beef cattle producers in Australia have reported an increase in calf losses as a result of wild dog attacks in recent years. However, while control measures may reduce calf losses from wild dog attacks, they may also reduce attacks on kangaroos. Thus, wild dog control measures may inadvertently increase kangaroo competition with cattle for grazing vegetation, which is potentially costly for graziers. In this study the net returns to beef production from investments in wild dog controls in a case study area—omitting the social and environmental effect of wild dogs—is assessed. The case study area for this study includes the natural resource management district groups of Marla–Oodnadatta and Marree–Innamincka, in the South Australian Arid Lands. A bioeconomic livestock model is developed to estimate the benefits of South Australian wild dog control programs to reduce calf losses. A decision to control wild dogs will depend on the magnitude of the benefits of wild dog management relative to the costs of increased kangaroo competition for grazing vegetation. Results indicate that the decision to implement wild dog control—based solely on the net benefits from beef production—will vary with changes in the rate of increase in calf deaths, the extent of kangaroo competition for grazing vegetation and the net value of livestock

Optimal Sustainable Agricultural Decisions: A Mixed Integer Approach

Soil is a capital asset and a renewable resource that requires continued maintenance to ensure the sustainability of agricultural output in the long-run. Growers are continually adjusting the soil's productivity by adding and extracting soil nutrients, and modifying the soil structure through cultivation. Accordingly, we approach sustainable agriculture in terms of capital assets and switching conditions. A theoretical model focusing on cover cropping and soil nitrates shows that profit maximizing farmers' cover cropping decision depend on the price of nitrogen, cost of chemical nitrogen, cost of cover crops and the farmer decision making horizon. In addition, we show that restriction on application of chemical nitrogen for environmental reasons will increase the value marginal product of cover crops. The results demonstrate the importance of analyzing sustainable agriculture as producing capital assets. We believe that the resulting conditions explain observed farm managers' behavior more accurately than static myopic approaches

Optimal Sustainable Agricultural Decisions: A Mixed Integer Approach

Soil is a capital asset and a renewable resource that requires continued maintenance to ensure the sustainability of agricultural output in the long-run. Growers are continually adjusting the soil's productivity by adding and extracting soil nutrients, and modifying the soil structure through cultivation. Accordingly, we approach sustainable agriculture in terms of capital assets and switching conditions. A theoretical model focusing on cover cropping and soil nitrates shows that profit maximizing farmers' cover cropping decision depend on the price of nitrogen, cost of chemical nitrogen, cost of cover crops and the farmer decision making horizon. In addition, we show that restriction on application of chemical nitrogen for environmental reasons will increase the value marginal product of cover crops. The results demonstrate the importance of analyzing sustainable agriculture as producing capital assets. We believe that the resulting conditions explain observed farm managers' behavior more accurately than static myopic approaches.Research Methods/ Statistical Methods,

A DYNAMIC ANALYSIS OF SUSTAINABLE FARMING SYSTEMS IN CALIFORNIA AGRICULTURE

The economic viability of alternative and more sustainable agriculture farming systems depend on the value of farm profits. These values may be estimated through short or long-run of profit maximization, but there is a difference in these methods. In short-run profit maximization the instantaneous marginal benefits are equated to the marginal costs of production. Where as in the long-run maximization of profits the capital value of soil resources are quantify in addition to the direct revenues and costs of each system over time. A long-run approach is fundamental to capture the value of capital improvements in soil resources. In this study we use short-run experimental data from SAFS's rotations to calibrate the crop simulation model EPIC, and obtain a time series cross-sectional data set for developing the dynamic bioeconomic models. With data from EPIC we are able to expand the existing short-run analysis, to estimate the long-run profitability and ecological benefits of alternative sustainable farming systems in comparison to conventional systems. Profit maximizing farmers who may not adopt sustainable methods based on short-run returns may well adopt them when long-run capital values are included. Finally, when environmental constraints are imposed on agricultural technology, for example to reduce non-point source pollution, results from our bioeconomic models are expected to show that sustainable technologies are more valuable

A DYNAMIC ANALYSIS OF SUSTAINABLE FARMING SYSTEMS IN CALIFORNIA AGRICULTURE

The economic viability of alternative and more sustainable agriculture farming systems depend on the value of farm profits. These values may be estimated through short or long-run of profit maximization, but there is a difference in these methods. In short-run profit maximization the instantaneous marginal benefits are equated to the marginal costs of production. Where as in the long-run maximization of profits the capital value of soil resources are quantify in addition to the direct revenues and costs of each system over time. A long-run approach is fundamental to capture the value of capital improvements in soil resources. In this study we use short-run experimental data from SAFS's rotations to calibrate the crop simulation model EPIC, and obtain a time series cross-sectional data set for developing the dynamic bioeconomic models. With data from EPIC we are able to expand the existing short-run analysis, to estimate the long-run profitability and ecological benefits of alternative sustainable farming systems in comparison to conventional systems. Profit maximizing farmers who may not adopt sustainable methods based on short-run returns may well adopt them when long-run capital values are included. Finally, when environmental constraints are imposed on agricultural technology, for example to reduce non-point source pollution, results from our bioeconomic models are expected to show that sustainable technologies are more valuable.Farm Management,

Decision support tools for crop plant germplasm maintenance in PNG

Papua New Guinea has major ex situ field collections of plant genetic material in its staple food crops (aibika, banana, cassava, sweet potato, taro, yams). With limited germplasm conservation resources available, difficult choices must be made as to which plants to maintain. The objective of this study is to provide a better basis for evaluating the efficient allocation of resources to plant germplasm conservation of food staples in PNG. Tools that could be employed to determine an efficient allocation include cost budgeting (through spreadsheets), and linear or dynamic programming. Cost budgets were developed to estimate the total cost of maintaining current sweet potato, taro, banana and aibika germplasm collections. Budgets are integrated through the key variables to produce a master spreadsheet. Key variables including (i) the number of accessions, (ii) the number of plants per accession, (iii) the planting density or (iv) the length of the reproduction cycle may be adjusted to investigate the effects on total costs of alternative strategies for maintaining collections. It is also planned to use linear and dynamic programming to identify the optimal allocation of resources subject to given constraints

Realistic payments could encourage farmers to adopt practices that sequester carbon

Carbon sequestration in agricultural land has been studied over the past few years to determine its potential for ameliorating climate change, Agricultural soils can be efficiently exploited as carbon sinks with a variety of techniques, such as reduced tillage, cover cropping and organic systems with better manure management. However, to fully understand the potential of carbon sequestration in agriculture, the economic costs of switching from conventional to conservation management must be estimated. Since carbon sequestration depends heavily on management, crop and soil type, we conducted a field-level survey of its economic aspects in Yolo County for the 2005 growing season. The survey showed that organic and conservation management can be more profitable for field crops than conventional management in Yolo County. Finall, we demonstrated how to combine the survey data with an agronomic process model to predict the rate of adoption for conservation techniques in response to carbon payments