643 research outputs found
EverFarmÂŽ - Climate adapted perennial-based farming systems for dryland agriculture in southern Australia
AbstractAustralian dryland agriculture will be affected by climate change in a number of ways. First, higher temperatures and changes to rainfall are likely to create greater variability of crop yields and livestock productivity. Second, government policies introduced to mitigate greenhouse gas emissions are likely to influence production costs and commodity prices. Third, global trade patterns are likely to alter as populations increase, and as climate change continues to affect producers and consumers worldwide. This will create both challenges and opportunities for Australian agriculture.Farmers will have to respond to the additional challenge of climate change even when it is compounded by existing long term stresses associated with declining terms of trade, climate variability and existing environmental issues. Investing in new land-use options to combat climate change, with their associated risks, is made more difficult by being set against a backdrop of declining profitability. The opportunity to create transformational change in farming enterprises was tested by combining the multiple components of the potential future perennialâbased dryland farming systems and assessing their expected contribution to climate change adaptation. This project has found that adopting perennial pastures for livestock grazing and tree crops for biomass production, when planted on appropriate soils, can improve profitability when compared to the existing land uses facing a changing climate. In some farming systems increased cropping is likely to result in improved future farm profits.This work demonstrated that Mallees as a biomass tree crop can be cohesively integrated into existing farming systems with minimal interruption to normal operations of livestock and cropping enterprises. A woody biomass crop can be profitable and diversify revenue risk by enabling farmers to supply biomass and sequester carbon to relevant markets. This work demonstrates suitable designs of a mallee belt planting layout that minimizes costs and maximizes benefits when planted in appropriate agroâclimatic zones and where there are adequate soil conditions. Knowledge developed from this work will help build farmers capacity about climate change adaptation and assist in achieving positive social, environmental and economic outcomes.Please cite this report as:Farquharson, R, Abadi, A, Finlayson, J, Ramilan, T, Liu, DL, Muhaddin, A, Clark, S, Robertson, S, Mendham, D, Thomas, Q, McGrath, J 2013 EverFarmÂŽ â Climate adapted perennial-based farming systems for dryland agriculture in southern Australia, National Climate Change Adaptation Research Facility, Gold Coast, pp. 159.AbstractAustralian dryland agriculture will be affected by climate change in a number of ways. First, higher temperatures and changes to rainfall are likely to create greater variability of crop yields and livestock productivity. Second, government policies introduced to mitigate greenhouse gas emissions are likely to influence production costs and commodity prices. Third, global trade patterns are likely to alter as populations increase, and as climate change continues to affect producers and consumers worldwide. This will create both challenges and opportunities for Australian agriculture.Farmers will have to respond to the additional challenge of climate change even when it is compounded by existing long term stresses associated with declining terms of trade, climate variability and existing environmental issues. Investing in new land-use options to combat climate change, with their associated risks, is made more difficult by being set against a backdrop of declining profitability. The opportunity to create transformational change in farming enterprises was tested by combining the multiple components of the potential future perennialâbased dryland farming systems and assessing their expected contribution to climate change adaptation. This project has found that adopting perennial pastures for livestock grazing and tree crops for biomass production, when planted on appropriate soils, can improve profitability when compared to the existing land uses facing a changing climate. In some farming systems increased cropping is likely to result in improved future farm profits.This work demonstrated that Mallees as a biomass tree crop can be cohesively integrated into existing farming systems with minimal interruption to normal operations of livestock and cropping enterprises. A woody biomass crop can be profitable and diversify revenue risk by enabling farmers to supply biomass and sequester carbon to relevant markets. This work demonstrates suitable designs of a mallee belt planting layout that minimizes costs and maximizes benefits when planted in appropriate agroâclimatic zones and where there are adequate soil conditions. Knowledge developed from this work will help build farmers capacity about climate change adaptation and assist in achieving positive social, environmental and economic outcomes
A linear programming study of the effects of climatic change on Scottish agriculture
Although there is considerable uncertainty in the literature about the effects of greenhouse gases on the climate there is little doubt that the composition of the atmosphere has changed in recent times. As a result of human activities the concentration of C02 is likely to double from pre-industrial levels by the middle of next century and as a consequence global temperatures are likely to rise. The potential importance of a change in the climate for the environment and agriculture and the complexity of the issues that are involved means that it is important to develop analytical tools to study this problem. The principle aim of the study is to evaluate the possible effects of a change in climate on the pattern, structure and viability of agriculture in Scotland. To address this objective it was necessary to evaluate the effects of climate change at a range of different levels of resolution.A linear programming model was developed that includes a large amount of biological, physical and economic detail. The models of crop growth (grass, grass /clover, swedes, potatoes, barley, vining peas, oilseed rape and wheat) account for variations in weather conditions, soil types, weeds, applications of nitrogen and pesticides, different planting dates and cropping rotations. The livestock operations that are modelled include sheep, dairy and beef fattening enterprises. In addition a considerable amount of effort was devoted to modelling variations in machinery requirements (and the sensitivity of these operations to climate), labour, buildings and finance. The inclusion of this information has allowed the types of adjustments that farmers may implement to be considered.The model is structured as a series of linked sub-problems where the most basic units are farms. In turn the interactions between farmers in terms of flows of intermediate goods, land, and labour are considered at the regional and national level. While further developments to the model would allow the status of Scottish agriculture to be more accurately modelled, in its current stage of development, the model has allowed a realistic evaluation of the effects of climate change. The results of this study suggest that climate change will have a detrimental effect on Scottish agriculture, however, the effects of climate are likely to vary between the different farm types and regions. In general, cropping farms are likely to benefit from a change in climate while the profitability of livestock farms, and sheep in particular, will decline
Disposition of precipitation: Supply and Demand for Water Use by New Tree Plantations
As the greatest rainwater users among all vegetative land covers, tree plantations have been employed strategically to mitigate salinity and water-logging problems. However, large-scale commercial tree plantations in high rainfall areas reduce fresh water inflows to river systems supporting downstream communities, agricultural industries and wetland environmental assets. A bio-economic model was used to estimate economic demand for water by future upstream plantations in a sub-catchment (the 2.8 million ha Macquarie valley in NSW) of the Murray-Darling Basin, Australia. Given four tree-product values, impacts were simulated under two settings: without and with the requirement that permanent water entitlements be purchased from downstream entitlement holders before establishing a tree plantation. Without this requirement, gains in economic surplus from expanding tree plantations exceeded economic losses by downstream irrigators, and stock and domestic water users, but resulted in reductions of up to 154 GL (gigalitres) in annual flows to wetland environments. With this requirement, smaller gains in upstream economic surplus, added to downstream gains, could total $330 million while preserving environmental flows. Extending downstream water markets to new upstream tree plantations, to equilibrate marginal values across water uses, helps ensure water entitlements are not diminished without compensation. Outcomes include better economic-efficiency, social-equity and environmental-sustainability.Environmental Economics and Policy, forest, environmental services, catchment, water sources, interception, entitlement, supply, demand, market, economic surplus, evapo-transpiration, urban water, irrigation, wetlands.,
Low cost 3D-printing used in an undergraduate project:an integrating sphere for measurement of photoluminescence quantum yield
Low cost 3D-printing used in an undergraduate project:an integrating sphere for measurement of photoluminescence quantum yield
Bio-economic evaluation of pasture-cropping, a novel system of integrating perennial pastures and crops on crop-livestock farms
Pasture-cropping is a novel approach to increase the area of perennial crops in mixed sheep and cropping systems. It involves planting annual cereals directly into a living perennial pasture. There is interest in subtropical grasses as they are winter dormant and their growth profile is potentially well suited to pasture-cropping. However, a wide range of factors can affect the uptake of such systems. This paper assesses the relative importance of factors that can influence decisions to introduce pasture-cropping. In this paper the research question is: what factors predispose a farm to take up a new technology such as (1) subtropical grass and (2) subtropical grass that is pasture-cropped. The analysis uses the MIDAS model of a central wheatbelt farm in Western Australia. The results suggest the adoption of subtropical grasses is likely to be strongly influenced by soil mix; feed quality; and whether the farm is predominantly grazing or cropping and by the presence of meat versus wool producing animals. The same factors are relevant for subtropical grass that is pasture-cropped but in addition yield penalties due to competition between the host perennial and the companion cereal become important. The results suggest the level of forage production by subtropical grass is less important but this factor is likely to become more important if feed quality can be improved.Environmental Economics and Policy,
Spectroscopic Ellipsometry and Optical Modelling of Structurally Colored Opaline Thin-Films
The method of spectroscopic ellipsometry is applied to complex periodic nanomaterials, consisting of shear-ordered polymeric nanosphere composites, with intense resonant structural color. A corresponding multilayer optical quasi-model of the system, parametrizing the inherent degree of sample disorder and encompassing key properties of effective refractive-index and index-contrast, is developed to elucidate the correlation between the â and Ψ ellipsometric parameters and the shear-induced opaline crystallinity. These approaches offer reliable means of in-line tracking of the sample quality of such âpolymer opalsâ in large scale processing and applications
Experiments with regulations & markets linking upstream tree plantations with downstream water users
Land-use change in upper catchments impact downstream water flows. As trees use large amounts of water the expansion of upstream plantations can substantially reduce water availability to downstream users. There can also be impacts on downstream salinity due to reduced dilution flows. In some jurisdictions afforestation requires the purchase of water rights from downstream holders, while in others it does not, effectively handing the water rights to the upstream landholders. We consider the economic efficiency and equity (profitability and distributional) consequences of upstream land use change in the presence of a water market under alternate property rights regimes and different salinity scenarios.experimental-economics, tree-plantations, environmental-services, urban, irrigation, stock & domestic, water use, land use,
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