Entity

Time filter

Source Type


McDowell R.W.,Invermay Agricultural Center | Nash D.,Future Farming Systems Research Division
Journal of Environmental Quality | Year: 2012

The loss of phosphorus (P) from land to water is detrimental to surface water quality in many parts of New Zealand and Australia. Farming, especially pasture-based dairying, can be a source of P loss, but preventing it requires a range of fully costed strategies because little or no subsidies are available and the effectiveness of mitigation strategies varies with different farm management systems, topography, stream density, and climate. This paper reviews the cost-effectiveness of mitigation strategies for New Zealand and Australian dairy farms, grouping strategies into (i) management (e.g., decreasing soil test P, fencing streams off from stock, or applying low-water-soluble P fertilizers), (ii) amendments (e.g., alum or red mud [Bauxite residue]), and (iii) edge-of-field mitigations (e.g., naturalor constructed wetlands). In general, onfarm management strategies were the most cost-effective way of mitigating P exports (cost range, $ 0 to $ 200 per kg P conserved). Amendments, added to tile drains or directly to surface soil, were often constrained by supply or were labor intensive. Of the amendments examined, red mud was cost effective where cost was offset by improved soil physical properties. Edge-of-field strategies, which remove P from runoff (i.e., wetlands) or prevent runoff (i.e., irrigation runoff recycling systems), were generally the least cost effective, but their benefits in terms of improved overall resource efficiency, especially in times of drought, or their effect on other contaminants like N need to be considered. By presenting a wide range of fully costed strategies, and understanding their mechanisms, a farmer or farm advisor is able to choose those that suit their farm and maintain profitability. Further work should examine the potential for targeting strategies to areas that lose the most P in time and space to maximize the cost-effectiveness of mitigation strategies, quantify the benefits of multiple strategies, and identify changes to land use that optimize overall dairy production, but minimize catchment scale, as versus farm scale, nutrient exports. © 2012 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. Source


Trenerry V.C.,Future Farming Systems Research Division | Plozza T.,Future Farming Systems Research Division | Caridi D.,Victoria University of Melbourne | Murphy S.,Victoria University of Melbourne
Food Chemistry | Year: 2011

A renewed international interest in vitamin D status has revealed significant deficiencies in several populations, including Australia. Vitamin D exists in two forms, cholcalciferol (D3) and ergocalciferol (D2). The main source of vitamin D3 is from exposure of 7-dehydrocholesterol present in the skin to UV irradiation. However, there is an absolute requirement for vitamin D through proper dietary intake if humans live in the absence of sunlight or exclusively indoors. Bovine milk is considered to be a good dietary source of vitamin D3, even though the levels are quite low. This paper describes robust methods using liquid chromatography-linear ion trap mass spectrometry (LC-MSn) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) to measure the levels of vitamin D3 in fresh bovine milk (0.05μg/100ml), commercial (natural and fortified) milk samples (0.01-2μg/100ml) and a dairy based infant formula (8μg/100g), without the need for extensive clean-up procedures. The limits of quantification (LOQ) are 0.01μg/100ml and 0.02μg/100ml for LC-MSn and LC-MS/MS, respectively. Recoveries of vitamin D3 added to the samples prior to saponification were satisfactory (range 60-90%). 25-Hydroxyvitamin D3 was not present in any of the samples analysed (LOQ=0.01μg/100ml, recovery range 30-40%). © 2010. Source


Plozza T.,Future Farming Systems Research Division | Trenerry V.C.,Future Farming Systems Research Division | Zeglinski P.,University of Melbourne | Nguyen H.,Australian National Measurement Institute | Johnstone P.,Future Farming Systems Research Division
International Food Research Journal | Year: 2011

Aminoglycosides are a large class of antibiotics that are characterised by two or more amino sugars linked by glycosidic bonds to an aminocyclitol component. They are water soluble, highly polar thermally labile compounds with no chromophores or fluorophores and so difficult to assay using standard HPLC, GC or GC-MS instrumentation. This paper reports a robust method to confirm and quantify the levels of dihydrostreptomycin, streptomycin, apramycin, neomycin and gentamicin (C1a, C2 and C1a) present in animal tissue and dihydrostreptomycin, streptomycin, neomycin and gentamicin (C1, C2 and C1a) present in bovine milk using liquid chromatography-tandem mass spectrometry. The aminoglycosides were extracted from the samples with perchloric acid, EDTA, phosphate buffer solution, followed by centrifugation and cleanup using weak cation exchange solid phase chromatography. The compounds were separated with a 5 μm C18 HPLC column and a mobile phase consisting of a mixture of acetonitrile, water and 50 mM heptafluorobutyric acid. Matrix matched standards were used to achieve the best accuracy of the method. The Limits of Quantification (LOQ) (0.1-0.5 mg/kg for animal tissue and 0.01-0.1 mg/kg for milk) were based on the requirements of the Australian antibiotic residue monitoring programs. The method was used to measure the levels of aminoglycoside residues in samples submitted by the Australian Regulatory Authorities. Source


Abuzar M.,Australian Department of Primary Industries and Fisheries | Abuzar M.,Future Farming Systems Research Division | Whitfield D.,Australian Department of Primary Industries and Fisheries | Whitfield D.,Future Farming Systems Research Division | And 7 more authors.
International Geoscience and Remote Sensing Symposium (IGARSS) | Year: 2013

Irrigation has a significant impact on water resources. It is therefore important that objective assessments of the use of irrigation water are undertaken on a regular basis. Current affordable remote sensing technologies provide an opportunity to assess and monitor water use at farm and regional scales. This study demonstrates the use of satellite-based estimates of evapotranspiration (ET) and NDVI in irrigation performance indicators that relate crop water use to crop water requirement in an irrigation region of Australia. A modified energy balance algorithm was used to derive ET estimates using Landsat-7 ETM+ data. Results show a consistent trend of slightly over-supply of crop water as compared to actual requirement at both field and farm scales during the peak irrigation season in 2011-12. © 2013 IEEE. Source


Pettit C.J.,Future Farming Systems Research Division | Imhof M.,Future Farming Systems Research Division | Cox M.,Future Farming Systems Research Division | Lewis H.,Future Farming Systems Research Division | And 2 more authors.
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives | Year: 2010

The access to, and visualisation of, landscape information through online websites can effectively support natural resource management and decision making. Online repositories of information are a useful resource for community members and researchers to enhance their understanding of agricultural and natural landscapes past, present and future. In this paper we report on the development of an online geographical visualisation resource in Australia that provides access to scientific outputs created through a number of visualisation techniques. The Victorian Resources Online website (http://www.dpi.vic.gov.au/vro) is a collection of more than 7,500 pages of natural resource information and maps. A Geographical Visualisation Portal resides within the site that includes: (i) links to contemporary media, (ii) access to technical reports and publications, (iii) video clips depicting visualisation techniques applied for understanding real and fictitious geographies, (iv) downloadable interactive content such as KMZ files, (v) a virtual soil profile used as an educational aid to increase understanding of the complex dimensions and properties of soils and (vi) a 3D object library comprising trees, shrubs, animals, built structures and rural features. The online visualisation portal provides an alternative metaphorical interface for users to access content to better understand Victorian landscapes. Source

Discover hidden collaborations