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1
Collins, David J., and Ian D. Rae. "R. W. E. MacIvor: Late-nineteenth-century Advocate for Scientific Agriculture in South-eastern Australia." Historical Records of Australian Science 19, no. 2 (2008): 125. http://dx.doi.org/10.1071/hr08007.
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Ralph Waldo Emerson MacIvor, a Scottish chemist, was brought to Victoria in 1876 by the prominent landowner W. J. Clarke to lecture to farmers on scientific agriculture. MacIvor lectured frequently over the next few years, joining in agricultural politics and supporting the establishment of agricultural colleges. He also lectured in South Australia and New Zealand. His lectures were fully reported in the press and in 1879 he incorporated their content in a book, The Chemistry of Agriculture. He was one of the unsuccessful applicants for the University of Melbourne's chair of chemistry to which David Orme Masson was appointed in 1886. In 1884, MacIvor was appointed by the new Sydney Technical College to lecture in country districts on scientific agriculture, but served for less than a year. He returned to Britain where he practised in London as a consulting analytical chemist. MacIvor came with experience in original chemical research, but he was not brought to Australia to conduct research in agricultural chemistry. His role was to act as instructor and advocate for scientific agriculture.
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Bolan, NS, RE White, and MJ Hedley. "A review of the use of phosphate rocks as fertilizers for direct application in Australia and New Zealand." Australian Journal of Experimental Agriculture 30, no. 2 (1990): 297. http://dx.doi.org/10.1071/ea9900297.
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Field trials in New Zealand have shown that reactive phosphate rocks (RPRs) can be as effective as soluble P fertilisers, per kg of P applied, on permanent pastures that have a soil pH<6.0 (in water) and a mean annual rainfall >800 mm. Whereas RPRs such as North Carolina, Sechura, Gafsa and Chatham Rise have been evaluated on permanent pastures in New Zealand, most Australian field trials have examined unreactive PRs such as Christmas Island A and C grade, Nauru and Duchess, using annual plant species. Only in recent experiments has an RPR, North Carolina, been examined. Except on the highly leached sands in southern and south-western Australia, both reactive and unreactive PRs have shown a low effectiveness relative to superphosphate. In addition to chemical reactivity, other factors may contribute to the difference in the observed agronomic effectiveness of PRs in Australia and New Zealand. Generally, PRs have been evaluated on soils of lower pH, higher pH buffering capacity (as measured by titratable acidity) and higher P status in New Zealand than in Australia. Rainfall is more evenly distributed throughout the year on New Zealand pastures than in Australia where the soil surface dries out between rainfall events. Dry conditions reduce the rate at which soil acid diffuses to a PR granule and dissolution products diffuse away. Even when pH and soil moisture are favourable, the release of P from PR is slow and more suited to permanent pasture (i.e. the conditions usually used to evaluate PRs in New Zealand) than to the annual pastures or crops used in most Australian trials. Based on the criteria of soil pH<6.0 and mean annual rainfall >800 mm, it is estimated that the potentially suitable area for RPRs on pasture in New Zealand is about 8 million ha. Extending this analysis to Australia, but excluding the seasonal rainfall areas of northern and south-western Australia, the potentially suitable area is about 13 million ha. In New Zealand, many of the soils in the North and South Islands satisfy both the pH and rainfall criteria. However, suitable areas in Australia are confined mainly to the coastal and tableland areas of New South Wales and eastern Victoria, and within these areas the actual effectiveness of RPR will depend markedly on soil management and the distribution of annual rainfall. Further research on RPR use should be focused on these areas.
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Seymour, M. "Response of narrow-leafed lupin (Lupinus angustifolius L.) to foliar application of growth regulators in Western Australia." Australian Journal of Experimental Agriculture 36, no. 4 (1996): 473. http://dx.doi.org/10.1071/ea9960473.
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Four experiments were conducted during 1991-93 in the south coastal and lakes regions of Western Australia, to test the hypothesis that foliar application of a range of growth regulators will improve the pod set and seed yield of narrow-leafed lupins (Lupinus angustifolius L.). The chemicals tested (not all in any 1 year) were: Cultar (250 g paclobutrazol/L), Pursuit (240 g imazethapyr/L), Cytokinin (21 g 6-benzyladenine/L), Legumex (400 g 2,4-DB/L), Cytolin (20 g gibberellins A4 and A7/L and 20 g 6-benzyladenine/L), Bladex (500 g cyanizine/L), Diuron 500F (500 g diuron/L), Lexone (750 g Metribuzin/kg), NAA (40 g 1-napthalene acetic acid/L), Pix (38 g mepiquat chloride/L), Gesatop 500 (500 g simazine/L), High Yield (unknown active ingredient), Lontrel (300 g clopyralid/L), a Cultar-Lontrel mix, and a Lexone-Brodal(500 g diflufenicad) mix. Chemicals were applied from as early as 6 weeks before flowering on the main stem to as late as flowering on the 1st-order branches. Any gross physical effects were visually assessed. Canopy height and components of yield were measured at some of the experimental sites. In 2 experiments, no chemical had any significant effect on seed yield (P>0.05). At the 2 remaining sites, Cultar, Lontrel, and the Lexone-Brodal mix increased seed yield of lupins by 230-250 kg/ha. Seed yield increases were related to improvements in pod set. No chemical had any significant effect (P>0.05) on dry weight production. Timing of application was critical, with application 6 weeks before flowering giving the most consistent positive responses.
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Hoffmann, Ary A., Andrew R. Weeks, Michael A. Nash, G. Peter Mangano, and Paul A. Umina. "The changing status of invertebrate pests and the future of pest management in the Australian grains industry." Australian Journal of Experimental Agriculture 48, no. 12 (2008): 1481. http://dx.doi.org/10.1071/ea08185.
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The Australian grains industry is dealing with a shifting complex of invertebrate pests due to evolving management practices and climate change as indicated by an assessment of pest reports over the last 20–30 years. A comparison of pest outbreak reports from the early 1980s to 2006–07 from south-eastern Australia highlights a decrease in the importance of pea weevils and armyworms, while the lucerne flea, Balaustium mites, blue oat mites and Bryobia mites have increased in prominence. In Western Australia, where detailed outbreak records are available from the mid 1990s, the relative incidence of armyworms, aphids and vegetable weevils has recently decreased, while the incidence of pasture cockchafers, Balaustium mites, blue oat mites, redlegged earth mites, the lucerne flea and snails has increased. These changes are the result of several possible drivers. Patterns of pesticide use, farm management responses and changing cropping patterns are likely to have contributed to these shifts. Drier conditions, exacerbated by climate change, have potentially reduced the build-up of migratory species from inland Australia and increased the adoption rate of minimum and no-tillage systems in order to retain soil moisture. The latter has been accompanied by increased pesticide use, accelerating selection pressures for resistance. Other control options will become available once there is an understanding of interactions between pests and beneficial species within a landscape context and a wider choice of ‘softer’ chemicals. Future climate change will directly and indirectly influence pest distributions and outbreaks as well as the potential effectiveness of endemic natural enemies. Genetically modified crops provide new options for control but also present challenges as new pest species are likely to emerge.
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Cox, J. W., D. J. Chittleborough, H. J. Brown, A. Pitman, and J. C. R. Varcoe. "Seasonal changes in hydrochemistry along a toposequence of texture-contrast soils." Soil Research 40, no. 4 (2002): 581. http://dx.doi.org/10.1071/sr01042.
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Ameliorative strategies are urgently required in some agricultural catchments in southern Australia to reduce the loss of potential contaminants to streams. However, a better understanding of where the contaminants are generated on hillslopes, their forms, and the pathways through which they are transported were required. Thus, seasonal changes in the quantities and forms of several chemical species were measured in both vertical and lateral flow pathways at 4 sites along a toposequence in the Mt Lofty Ranges, South Australia. Instrumentation was installed to measure and quantify overland flow and throughflow, and porous-wick samplers were installed at 2 depths to study the chemistry of leachate. Neutron moisture meter access tubes were installed to measure seasonal changes in soil water content with depth as this influences chemical concentrations and mobility. In years of average to below average annual rainfall, throughflow was the most important transport pathway for contaminants. However, it was expected that overland flow will be the dominant transport pathway when annual rainfall is above about 550 mm. Changes in water content of the texture-contrast soils was caused by seasonal rainfall causing periodic saturation, by waterlogging, groundwater, or both. This affected the type and form of contaminant. For example, Na and Cl concentrations were generally only large (800 and 1500 mg/L, respectively) on the lower slopes but in the wettest seasons their concentrations increased at depth on mid-slopes due to the influence of shallow saline groundwater. These chemicals then leached when groundwater levels subsided. The results suggest that ameliorative strategies to reduce agricultural contaminants should target the transport pathways specific to each chemical species, at the point (or points) in the landscape where they are generated.
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Dillard, HR, TJ Wicks, and B. Philp. "A grower survey of diseases, invertebrate pests, and pesticide use on potatoes grown in South Australia." Australian Journal of Experimental Agriculture 33, no. 5 (1993): 653. http://dx.doi.org/10.1071/ea9930653.
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In 1991, a survey was distributed to 251 potato growers in South Australia to determine major diseases, insect and other invertebrate pests, and chemicals used to control them. The overall response rate was 48%, but of these, 24 individuals were no longer growing potatoes. The results were summarised for the State and by district (Adelaide Hills, Adelaide Plains, Murray Lands, South East). The most prevalent diseases encountered by respondents in all districts were target spot caused by Alternaria solani, and rhizoctonia canker caused by Rhizoctonia solani. Other diseases of concern to growers included late blight caused by Phytophthora infestans, seed piece decay caused by various pathogenic and saprophytic microorganisms, common scab caused by Streptomyces scabies, and leaf roll caused by potato leaf roll virus. The most commonly used fungicides for disease control were chlorothalonil (33-42% of respondents), mancozeb (30%), and cupric hydroxide (11-13%). The most commonly used seed treatments for control of seed piece decay were mancozeb (51 % of respondents), tolclofos methyl (24%), and lime (20%). Green peach aphid (Myzus persicae), potato aphid (Macrosiphum euphorbiae), potato moth (Phthorimaea operculella), and jassids and leafhoppers (Jassidae, Cicadellidae) were the pests of greatest concern to the growers. Others included Rutherglen bug (Nysius vinitor), redlegged earth mite (Halotydeus destructor), and thrips (Thripidae). The most commonly used insecticides were ethamidophos (40% of respondents), monocrotophos (22-28%), and dimethoate (7-13%).
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Choct, M., R. J. Hughes, and G. Annison. "Apparent metabolisable energy and chemical composition of Australian wheat in relation to environmental factors." Australian Journal of Agricultural Research 50, no. 4 (1999): 447. http://dx.doi.org/10.1071/a98155.
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A total of 81 wheats collected from New South Wales, Victoria, South Australia, Queensland, and Western Australia over 3 harvests were assayed for apparent metabolisable energy (AME) in broiler chickens. The non-starch polysaccharides (soluble and insoluble) and their individual sugar components, starch, and protein were also determined. The nutritive quality of wheat varied significantly (P < 0.01), especially at time of harvest, with approximately 40% having an average AME value <13 MJ/kg dry matter. The low-AME wheats usually caused copious quantities of watery and sticky droppings. The occurrence of low-AME wheats was associated more with climatic conditions during growth than with geographical region.
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Kleemann, DO, RW Ponzoni, JE Stafford, and RJ Grimson. "Carcass composition of the South Australian Merino and its crosses with the Booroola and Trangie Fertility Merino." Australian Journal of Experimental Agriculture 28, no. 2 (1988): 167. http://dx.doi.org/10.1071/ea9880167.
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South Australian medium-wool (M), non- Peppin medium-wool Booroola (B) and Peppin medium-wool Trangie Fertility (TF) Merino rams were joined to M ewes at Turretfield Research Centre, South Australia, in 2 years. Carcass composition was assessed in the ewe and wether progeny at 2 mean slaughter liveweights, viz. 24 and 38 kg. When adjusted to the same carcass weight, B x M had 13% more carcass chemical fat, 15% more subcutaneous fat, 6% less bone and the same lean tissue as M. The same result was observed for TF x M in relation to M in year 2. However, TF x M had more lean and the same amount of subcutaneous and chemical fat as M in year 1. Within the Booroola strain, there were no differences between offspring from 3 sires with genotype FF and the 1 sire with + + for any of 5 variables analysed. We conclude that crossing the Booroola with the South Australian Merino produces carcasses with the same amount of lean tissue, less bone and more fat when compared at the same carcass weight. The rank of TF x M with the other strains for the major carcass components remains obscure owing to a strain x year interaction.
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Adcock, D., A. M. McNeill, G. K. McDonald, and R. D. Armstrong. "Subsoil constraints to crop production on neutral and alkaline soils in south-eastern Australia: a review of current knowledge and management strategies." Australian Journal of Experimental Agriculture 47, no. 11 (2007): 1245. http://dx.doi.org/10.1071/ea06250.
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Crop yield variability and productivity below potential yield on neutral and alkaline soils in the semiarid Mediterranean-type environments of south-eastern Australia have been attributed, in part, to variable rooting depth and incomplete soil water extraction caused by physical and chemical characteristics of soil horizons below the surface. In this review these characteristics are referred to as subsoil constraints. This document reviews current information concerning subsoil constraints typical of neutral and alkaline soils in south-eastern Australia, principally salinity, sodicity, dense soils with high penetration resistance, waterlogging, nutrient deficiencies and ion toxicities. The review focuses on information from Australia (published and unpublished), using overseas data only where no suitable Australian data is available. An assessment of the effectiveness of current management options to address subsoil constraints is provided. These options are broadly grouped into three categories: (i) amelioration strategies, such as deep ripping, gypsum application or the use of polyacrylamides to reduce sodicity and/or bulk density, deep placement of nutrients or organic matter to overcome subsoil nutrient deficiencies or the growing of ‘primer’ crops to naturally ameliorate the soil; (ii) breeding initiatives for increased crop tolerance to toxicities such as salt and boron; and (iii) avoidance through appropriate agronomic or agro-engineering solutions. The review highlights difficulties associated with identifying the impact of any single subsoil constraint to crop production on neutral and alkaline soils in south-eastern Australia, given that multiple constraints may be present. Difficulty in clearly ranking the relative effect of particular subsoil constraints on crop production (either between constraints or in relation to other edaphic and biological factors) limits current ability to develop targeted solutions designed to overcome these constraints. Furthermore, it is recognised that the task is complicated by spatial and temporal variability of soil physicochemical properties and nutrient availability, as well as other factors such as disease and drought stress. Nevertheless, knowledge of the relative importance of particular subsoil constraints to crop production, and an assessment of impact on crop productivity, are deemed critical to the development of potential management solutions for these neutral to alkaline soils.
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Huett, D. O., A. P. George, J. M. Slack, and S. C. Morris. "Diagnostic leaf nutrient standards for low-chill peaches in subtropical Australia." Australian Journal of Experimental Agriculture 37, no. 1 (1997): 119. http://dx.doi.org/10.1071/ea96040.
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Summary. A leaf nutrient survey was conducted of the low-chill peach cultivars, Flordaprince (October maturing) and Flordagold (mid November–early December maturing) at 3 commercial sites in both northern New South Wales and southern Queensland. Recently mature leaves from the middle third of a current season’s fruiting lateral (spring flush) were sampled at stone hardening and 2-weeks postharvest and of a non-fruiting lateral at maturity of the summer flush (after summer pruning) during the 1992–93 and 1993–94 seasons. At an additional site in New South Wales (Alstonville), leaf nutrient concentrations were also determined on cv. Flordagem (early November maturing) at 2-week intervals during both seasons. Soil (0–30 cm) chemical determinations were conducted at all sites at 2-weeks postharvest Seasonal trends in leaf nutrient composition were associated with a leaf age–maturity effect. As flush leaves matured during spring, and as mature leaves aged after hardening of the summer flush, nitrogen (N) concentration declined and calcium (Ca) concentration increased. Nitrogen and Ca concentrations increased when young leaves produced from the summer flush were sampled. Time of sampling produced the most consistently significant (P<0.05) main effects on leaf nutrient concentration. The 2-week postharvest period was selected as a convenient time to sample—when leaves were of a consistent age and maturity, and the effect of crop load on tree nutrient reserves was still present. Paclobutrazol, which reduces vegetative growth in stonefruit, was applied to all Queensland sites and, as a consequence, mid lateral leaves contained higher (P<0.05) Ca, magnesium (Mg) and chloride (Cl) and lower (P<0.05) N and phosphorus (P) concentrations than leaves from New South Wales sites. State effects can therefore be interpreted as paclobutrazol effects. Cultivar effects (P<0.05) occurred for many leaf nutrients, however, at the 2-week postharvest sampling, concentrations were sufficiently similar to combine as a narrow adequate concentration range for both cultivars. The diagnostic adequate leaf nutrient concentrations were within the range developed for high-chill peaches (Leece et al. 1971) with the exception of lower Ca, lower Mg for New South Wales (both cultivars), lower iron for Flordaprince (both states), higher P for Flordaprince in New South Wales and higher manganese values for Queensland (both cultivars). Regression analyses were conducted between leaf and fruit nutrient concentrations and soil chemical properties. The only consistent result demonstrated that as the soil Ca : Mg ratio increased, leaf Mg concentration decreased exponentially (P<0.001), indicating that the practice of heavy annual agricultural limestone or gypsum applications in the absence of Mg fertiliser, which had been adopted by several growers in the survey, is associated with lower leaf Mg concentrations.
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Dunn, B. W., G. D. Batten, H. G. Beecher, and S. Ciavarella. "The potential of near-infrared reflectance spectroscopy for soil analysis — a case study from the Riverine Plain of south-eastern Australia." Australian Journal of Experimental Agriculture 42, no. 5 (2002): 607. http://dx.doi.org/10.1071/ea01172.
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Environmental management in agricultural systems must be maintained while controlling costs and increasing productivity. To obtain a better response from inputs in agriculture, cost-effective soil analysis is needed to enable site-specific applications. Near-infrared reflectance spectroscopy (NIRS) technology has the potential to provide a rapid, low-cost analysis enabling within field variability to be identified. NIRS was evaluated for its ability to predict a range of soil properties in the Riverine Plain soils of southern New South Wales. Over 550 topsoil (0-10�cm) and 300 subsoil (40-50 cm) samples from a range of soil types were air dried and ground before scanning with a NIRSystems model 6500 scanning spectrophotometer. The Partial Least Squares (PLS) regression procedure was used to determine the best correlation (i.e. calibration) between the chemical reference data and spectral data for both topsoil and subsoil samples. A validation set of samples was used to test the predictive ability of NIRS for a number of soil properties. The results demonstrated that NIRS can successfully determine some soil properties in both the topsoil and subsoil. In the topsoil, cation exchange capacity (CEC), exchangeable Ca and Mg, pH and Ca : Mg ratio were predicted with a high level of accuracy and organic carbon and exchangeable sodium percentage (ESP) with an acceptable level of accuracy. In the subsoil, CEC, exchangeable Na, Ca, Mg, ESP, pH and Ca : Mg ratio were all predicted with a high degree of accuracy. The predictive ability of NIRS for many soil constituents may make it suitable for use in agricultural soil assessment for site-specific agriculture in the Riverine Plain soils of southern New South Wales.
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Tennant, D., G. Scholz, J. Dixon, and B. Purdie. "Physical and chemical characteristics of duplex soils and their distribution in the south-west of Western Australia." Australian Journal of Experimental Agriculture 32, no. 7 (1992): 827. http://dx.doi.org/10.1071/ea9920827.
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Duplex soils are widespread in Western Australia and occupy about 60% of the south-west agricultural area. The physical and chemical properties of these soils reflect their origin as erosional surfaces of old laterite profiles and the predominance of underlying, quartz-rich, granitic materials. The resulting combination of high contents of quartz sand, kaolin clay, and iron and aluminium oxides has important consequences on water-holding capacity, fertility, nutrient leaching, phosphate fixation, anion and cation exchange capacity, and buffering capacity. These soils are generally held to have a number of physical and chemical problems. Among these, low fertility and low permeability of the clay B horizon have greatest effect. While data on the chemical properties of these soils are limited, significant data sets on the physical properties of duplex soils are available from several studies of catchment hydrology. These studies reflect concern with runoff, waterlogging, and the development of secondary salinisation. Depth to clay varies from 5 to >100 cm. The shallower depths (10-40 cm) predominate and, in medium and high rainfall areas, combine with low permeability in the clay to result in widespread waterlogging. Commonly, the sand surface can be hardsetting and can have high strength from structural decline, from the presence of cementing agents, and from traffic effects. Sodicity is widespread and has effects on hardsetting in the A horizon and on permeability of the B horizon. Management strategies are available to treat some of these problems, but generally, much has yet to be done to develop sustainable agricultural systems on these soils.
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Cooke, JW. "Effect of fallowing practices on runoff and soil erosion in south-eastern Australia." Australian Journal of Experimental Agriculture 25, no. 3 (1985): 628. http://dx.doi.org/10.1071/ea9850628.
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The effect on runoff and soil loss of four methods of preparation of fallow was investigated at each of three sites in north-central Victoria. There was a chemical fallow treatment (uncultivated) and three scarified treatments (smooth, medium and rough cultivation). When the results from the three sites were combined, there was 10.7 mm runoff from the uncultivated treatment, 5.1 mm from the smooth, 0.8 mm from the medium and 0.3 mm from the rough scarified treatments. Soil loss from the uncultivated treatment was 103 g/m2 compared with 87 g/m2 from the smooth, 22 g/m2 from the medium and 13 g/m2 from the rough treatment. The concentration of sediment in the runoff was negatively correlated (R2 = -0.56 to -0.98) with runoff. It ranged from 1.21% (w/w) for the uncultivated to 5.06% (w/w) for the rough scarified treatment. The results show that a regimen of minimum scarification to produce a rough surface, and then use of herbicides to control weeds, reduces soil loss compared with either an uncultivated or a smoothly cultivated soil surface.
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Holmes, Mike, Anu Kumar, Ali Shareef, Hai Doan, Richard Stuetz, and Rai Kookana. "Fate of indicator endocrine disrupting chemicals in sewage during treatment and polishing for non-potable reuse." Water Science and Technology 62, no. 6 (September 1, 2010): 1416–23. http://dx.doi.org/10.2166/wst.2010.436.
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The removal and fate of several indicator endocrine disrupting chemicals (EDCs) at two large municipal wastewater treatment plants (WWTPs) in Adelaide South Australia was investigated. Non-estrogens included the non-ionic surfactant breakdown compounds nonyl phenol mono- and di-ethoxylates, 4-t-octylphenol and 4-nonyl phenol; and, the plasticizer bisphenol A. Estrogens included 17β-estradiol; estrone; and, 17α-ethynylestradiol. Effluent from Bolivar WWTP is polished using stabilisation lagoons followed by coagulation, dissolved air flotation/filtration and chlorination for non-potable reuse. Biosolids from both plants is applied to agricultural land as a soil conditioner. Non-estrogen indicator EDCs were detected at the highest concentration in sewage, effluent and sludge but estrogen indicator EDCs contributed the greatest potential for estrogenicity. The fate of indicator EDCs at various treatment stages is complex and includes biochemical modification/transformation and/or partitioning to either solid or liquid phases. Activated sludge treatment was an important removal barrier achieving moderate—high removal of predicted and YES (a yeast screen assay) measured estrogen equivalent values (EEq). Combined polishing treatment achieved high removal of candidate EDCs (97%). Mass balance indicates that the largest source of estrogenicity discharged from both WWTPs investigated is digested sludge which accounts for 18 and 22% respectively of the combined predicted and YES measured EEq measured in sewage at the two WWTPs.
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Chan, K. Y., C. Dorahy, and S. Tyler. "Determining the agronomic value of composts produced from garden organics from metropolitan areas of New South Wales, Australia." Australian Journal of Experimental Agriculture 47, no. 11 (2007): 1377. http://dx.doi.org/10.1071/ea06128.
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About 0.3 million t/year of composted garden organics (CGO) including mulches and soil conditioners are produced annually in New South Wales, Australia, although only a small proportion of this material (<4%) is used in agriculture. A lack of information on product characteristics and agronomic performance has limited the development of agricultural markets for CGO products. These CGO products are the coarse and fine fractions separated by screening after composting. This paper presents the results of a survey of CGO mulches and soil conditioners (unblended or blended with a mixture of other organic materials including biosolids, animal manures and paper), which are commercially produced in the metropolitan areas of New South Wales and assesses their agronomic and soil amendment values in terms of chemical and biological properties. It also evaluates the short-term effects of applying increasing rates (0, 25, 50 and 100 t/ha) of selected composted soil conditioners on radish growth in a pot experiment. The mulch products had low nutrient concentrations but had high carbon (C) contents (mean C = 45%) and C/Nitrogen (N) ratios (mean C/N = 72) and are most suitable for use as surface mulch. The unblended soil conditioners were low in nutrients, particularly N (average total N = 1.0%, range 0.9–12%), and had lower and variable C contents. The pot trial results indicated lack of growth response of radish at application rates up to 100 t/ha of unblended soil conditioners from garden organics. The blended soil conditioners were more variable in quality and as confirmed by pot trial results produced highly variable plant responses. The high variability in product quality and performance of the soil conditioners, particularly the blended products might be related to the source and type of blending material as well as the composting conditions used in the manufacturing process. These results highlight the need to improve compost quality and consistency and the need for further research to advance understanding of the benefits using CGO in terms of improving soil quality, crop productivity and net economic returns to growers.
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Aryal, Rupak, Dheeraj Kandel, Durga Acharya, Meng Nan Chong, and Simon Beecham. "Unusual Sydney dust storm and its mineralogical and organic characteristics." Environmental Chemistry 9, no. 6 (2012): 537. http://dx.doi.org/10.1071/en12131.
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Environmental context In 2009, at the end of the longest drought period ever recorded in Australia, a major dust storm blanketed the cities of Sydney and Brisbane for more than 24 h. The source of the dust was inner New South Wales and South Australia, where large scale open-cut mining occurs together with agricultural practices. We report results of extensive mineralogical and chemical analyses of the dust, and discuss their significance in terms of the dust origins and potential human health risks. Abstract In a 24-h period from 23 to 24 September 2009, a dust storm passed over Sydney, Australia that produced a red sky and reduced the visibility to a few metres. It was Sydney’s worst dust storm since 1942. During this period, the PM10 (particles measuring 10 μm or less) value jumped from 50 to 11 800 µg m–3. The dust storm was sampled and its mineralogical and organic contents were analysed. Four major particle sizes (0.6, 4.5, 9.3 and 20 µm) were observed in the dust. A multimodal particle distribution indicated a long range of dust transport. Mineralogical analysis showed that the particles were mainly composed of crustal elemental oxides of Al and Si. The ratio of Al/Si was 0.39 and the organic content was 10.6 %, which was found to be enriched with humic-type substances. The high Al/Si ratio (>0.3) indicated that the dust originated from desert land whereas the high organic content indicated that the particles were also derived from eroded agricultural land. A fluorescence spectroscopic study on the organic matter at excitation and emission wavelengths of 245–265 and 330–350 nm indicated that biohazardous substances were unlikely to be present in the dust.
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Duong, Thi Tam, Tom D. Brewer, Jo Luck, and Kerstin K. Zander. "Farmers’ assessment of plant biosecurity risk management strategies and influencing factors: A study of smallholder farmers in Australia." Outlook on Agriculture 48, no. 1 (February 13, 2019): 48–57. http://dx.doi.org/10.1177/0030727019829754.
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Plant biosecurity threats such as pest, weeds and disease occurrences cause substantial economic damage to the agricultural sector, worldwide and in Australia. How smallholder farmers choose biosecurity management strategies remains poorly understood, particularly of smallholder cultural minority groups. In this study, we explore how Vietnamese smallholder farmers in Australia assess their biosecurity risk management strategies and the factors that explain their choice of different strategies. To do so, we conducted a survey of 101 Vietnamese farmers in the Northern Territory, South Australia and Western Australia. Based on the protection motivation theory, we assessed farmers’ perceived self-efficacy, response efficacy and response costs (all elements of their coping appraisal) using descriptive statistics, factor analysis and stepwise regression. Information sources related to biosecurity and farmers’ trust in public management explain how farmers assess their risk management strategies. Previous experience with biosecurity issues does not influence how farmers appraise their biosecurity risk coping capacity. Farmers use four types of biosecurity risk management strategies: chemical control, plant growth strategies, on-farm strategies and asset investment strategies. The first two are the most frequently used. We recommend tailoring relevant government policies to better support farmers’ adoption of risk management strategies based on their specific needs, more investment into biosecurity information dissemination and into trust building.
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Nadolny, Christopher. "Towards integrating farming and conservation: the role of native pastures." Pacific Conservation Biology 4, no. 1 (1998): 70. http://dx.doi.org/10.1071/pc980070.
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Agriculture has almost certainly contributed to the decline of native vegetation and wildlife in rural Australia. A prevalent culture supports agricultural systems that rely on the use of exotic plants and animals and greater use of chemicals and machinery. In general, these systems do not fully utilize or take account of the indigenous biota. The full implications of implementing such farming systems on a landscape scale are seldom considered. I use the grazing industry on the Northern Tablelands of New South Wales to illustrate two contrasting approaches: (1) "pasture improvement" involving replacement of native with exotic species versus (2) retention and management of existing native and naturalized pasture species. Pasture improvement has been refined by extensive agronomic research, plant selection and field testing of techniques. Nevertheless, the approach is losing support among farmers because of high inputs required to maintain "improved" pastures, the fragility of these pastures during droughts, low commodity prices, longterm declines in soil structure and increases in soil acidity. Other side-effects include tree decline, reduced diversity of indigenous herbaceous plant communities and loss of wildlife. Using native pastures may offer some solutions to these problems, but the level of understanding required to manage them effectively is limited. Exotic sown pastures have no clear advantage in areas with poor soils and irregular rainfall, and the environmental impacts of new developments involving large-scale pasture improvement can be unacceptable. I conclude that native and naturalised pastures are the best option for most of the region and sown pastures should be used strategically.
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Prober, Suzanne M., Ian D. Lunt, and Kevin R. Thiele. "Determining reference conditions for management and restoration of temperate grassy woodlands: relationships among trees, topsoils and understorey flora in little-grazed remnants." Australian Journal of Botany 50, no. 6 (2002): 687. http://dx.doi.org/10.1071/bt02043.
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Temperate grassy woodlands were once widespread and dominant in many agricultural regions of south-eastern Australia. Most are now highly degraded and fragmented and exist within a context of broadscale landscape degradation. Greater understanding of natural processes in these woodlands is needed to benchmark management and restoration efforts that are now critical for their ongoing survival. We studied physical and chemical properties of topsoils from rare, little-grazed remnants of grassy Eucalyptus albens Benth. and E. melliodora Cunn. ex Schauer woodlands in central New South Wales and examined natural patterns in topsoil properties and understorey flora in relation to trees and canopy gaps. Topsoils were generally low in available macronutrients (nitrogen, phosphorus and sulfur), but were favourable for plant growth in most other measured characteristics. Topsoils beneath trees were notably more fertile than in open areas, particularly in total carbon, total nitrogen, available phosphorus, available potassium and salinity. Higher nutrient concentrations, particularly of available phosphorus, may have contributed to patterns in understorey dominants, with Themeda australis (R.Br.) Stapf predominating in open areas and Poa sieberiana Spreng. beneath trees. Trees were also associated with a higher native-plant richness, possibly resulting from their influence on the competitive dynamics of the dominant grasses. We discuss the implications of these interactions for the use of burning, grazing and slashing in woodland management and re-establishment of native grasses and trees in restoration efforts.
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Hughes, JC, and RJ Gilkes. "Rock phosphate dissolution and bicarbonate-soluble-P in some soils from South-Western Australia." Soil Research 32, no. 4 (1994): 767. http://dx.doi.org/10.1071/sr9940767.
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Samples were collected from 228 soils from the main agricultural areas of Western Australia (W.A.) and their chemical and textural properties analysed. Soils were incubated for 7 days with North Carolina rock phosphate at a rate equivalent to 1022 �g Ca g(-1) and 383 �g P g(-1) soil. Subsequently, the amount of rock phosphate (RP) that had dissolved was determined by measuring the increase in extractable calcium (�Ca) and changes in plant-available P were estimated by a sodium bicarbonate extraction (�Bic-P). Only 29 soils dissolved more than 40% of the added RP and these occur in the wettest area of W.A., to the west of the 800 mm rainfall isohyet. They represent a variety of soil types including Vertisols, Spodosols, Alfisols and Ultisols. Simple and multiple regressions were carried out to investigate the soil properties responsible for RP dissolution and associated P availability. No single soil property adequately predicted RP dissolution or concomitant changes in bicarbonate-P. Titratable acidity and sand content together explained 61% of the variance in RP dissolution; titratable acidity was the most predictive single variable for bicarbonate-P but only explained 56% of the variance. Stepwise regression showed that titratable acidity and pH(CaCl2) together explained 79% of the variance in bicarbonate-P. The most suitable soils for RP application are sandy, humic or peaty podzols where much of the dissolved P remains available to plants. The other soils (mainly red and yellow earths and Vertisols) which dissolved much RP contain larger amounts of extractable aluminium (by dithionite or oxalate) which is the soil component largely responsible for P-sorption in these W.A. soils. These results indicate that RP fertilizers will be most effective on the humic, sandy podzols of the western and southern coastal plains of WA.
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Barnes, Phoebe, Brian R. Wilson, Chris Nadolny, and Ivor Growns. "The influence of individual native trees and grazing regime on soil properties and groundcover patterns in a temperate landscape of New South Wales, Australia." Rangeland Journal 31, no. 4 (2009): 405. http://dx.doi.org/10.1071/rj09017.
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Scattered native trees are a significant ecological resource across the agricultural landscape, yet their numbers are declining due to factors such as dieback, senescence and agricultural activity. This study examined the interactions among Eucalyptus melliodora (Cunn. ex Schauer) trees, vegetation composition and selected surface soil chemical properties in grazed and ungrazed paddocks on the Northern Tablelands of New South Wales, Australia. Four farms on granite soils were examined in grazed and ungrazed treatments. Vegetation composition was assessed, and soil samples were collected in plots beneath the canopy and in adjacent open areas in both north and south directions of the tree canopy. Native grasses dominated the vegetation in both beneath the canopy and open areas, at both grazed and ungrazed sites. However, their composition varied between farms. Several C3 and C4 grasses contributed to the groundcover of the canopy and open sites, but C3 grasses were generally more common under the canopy. Significant differences occurred in soil C, N, P and pH, and vegetation composition between canopy and open areas, and between grazed and ungrazed treatments. Soil P, C and N contents in grazed sites were typically similar to or higher than those in ungrazed sites, and soils were less acid in the ungrazed compared with grazed sites. All soil parameters measured were significantly higher under tree canopies, except P. The tree, soil and vegetation factors were strongly related. This study confirms that individual scattered trees create a distinct mosaic of localised soil improvement, and influence vegetation composition so that paddocks with trees are floristically more diverse than paddocks without trees. The results illustrate the potential benefits of retaining trees for both biodiversity values and livestock production in Australia.
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Cattle, Stephen R., and Damien J. Field. "A review of the soil science research legacy of the triumvirate of cotton CRC." Crop and Pasture Science 64, no. 12 (2013): 1076. http://dx.doi.org/10.1071/cp13223.
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For nearly two decades (1994–2012) a series of three consecutive Cooperative Research Centres (CRC) dealing with cotton production provided the impetus and financial support for a substantial body of soil science research in eastern and northern Australia. Focusing on the most commonly utilised soil for irrigated crop production, the Vertosol, CRC-affiliated soil researchers undertook detailed soil inventories of cotton-growing valleys in New South Wales, and tackled a range of applied soil research questions that faced the entire Australian cotton industry. Across the broad categories of soil mapping and characterisation, soil physical condition, salinity and sodicity, soil chemical fertility, and soil carbon and biota, some 120 CRC-affiliated research papers were published in peer-reviewed journals during the years of the CRC. Findings from this body of research were fed back to the industry through conferences, extension workshops and materials, and to a lesser extent, the peer-reviewed publications. In certain cases, underpinning basic research was carried out concurrently with the more applied research, meaning that the cotton CRC were effectively supporting advances in the discipline of soil science, as well as in sustainable cotton production. A feature of the soil research portfolio over the span of the three cotton CRC was that priorities shifted according to the interplay of three factors; the natural maturation of research topics and the concomitant evolution of cotton farming systems, the rising importance of environmental implications of agricultural land use, and the emergence of carbon as a national research priority. Furthermore, the commitment of the CRC to education resulted in the involvement of undergraduate and postgraduate university students in all aspects of the soil research effort. A legacy of the triumvirate of cotton CRC is a wide-ranging body of both applied and basic knowledge regarding the physical, chemical and biological attributes of Australian Vertosols used for irrigated agriculture.
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Davies, S. L., A. M. Storrie, A. S. Cook, R. A. Latta, A. D. Swan, and M. B. Peoples. "Factors influencing herbicide efficacy when removing lucerne prior to cropping." Australian Journal of Experimental Agriculture 46, no. 10 (2006): 1301. http://dx.doi.org/10.1071/ea05220.
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Farmers often experience inconsistent responses when using herbicides to terminate an established lucerne pasture prior to cropping. In an attempt to redress this problem, a series of field experiments were conducted between 1999 and 2002 at various locations in southern and northern New South Wales, the Australian Capital Territory, and south Western Australia that aimed to identify management guidelines that improved the efficacy of herbicide mixtures commonly used to remove lucerne. Collectively, these studies indicated that herbicides were generally less effective when applied either early (less than 2 weeks) or late (6 weeks or more) in the regrowth cycle of lucerne after defoliation. Herbicide efficacy tended to be greatest if applied to regrowth 3–5 weeks after defoliation, which corresponds to a time when the lucerne crown and root reserves are likely to be in the process of being replenished by photoassimilates transported from the shoot. The impact of timing of herbicide application in relation to season was compared at a number of locations. Across all the sites and years, spring herbicide applications were generally the most effective, removing on average 87% of the lucerne (range 53–100%) compared with 72% in summer (24–100%) and 60% in autumn (7–92%). Spring applications were also more consistent in their effect, removing >80% of the lucerne plants in 9 out of 12 experiments, whereas similar rates of removal occurred on 4 occasions in 9 summer applications and only twice in 8 autumn applications. Some of the seasonal variation could be explained by differences in the amount of rainfall prior to herbicide applications. It was assumed that the relationship between rainfall and herbicide efficacy reflected the stimulation of lucerne shoot and root growth by the additional soil moisture before herbicide treatment. Herbicide mixtures that contained ingredients such as picloram that retain residual activity in the soil tended to be more effective and were less influenced by lucerne growth and season than those herbicides with little or no residual activity. However, such chemicals could potentially restrict which crops can subsequently be grown after a lucerne pasture has been removed. It was concluded that >80% of lucerne plants were likely to be removed using herbicides provided that the herbicide treatment was applied to actively growing lucerne 3–5 weeks after defoliation, and when greater than 70–95 mm rain had fallen in the 6–8 weeks prior to application.
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Biswas, T. K., F. R. Higginson, and I. Shannon. "Effluent nutrient management and resource recovery in intensive rural industries for the protection of natural waters." Water Science and Technology 40, no. 2 (July 1, 1999): 19–27. http://dx.doi.org/10.2166/wst.1999.0076.
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Intensive rural industry is developing rapidly in parts of inland Australia. The usually nutrient and salt rich effluent from these sources has traditionally been disposed to both land and water bodies. Since direct water discharge is no longer permitted, a challenge now exists when applying effluent to land especially where the rate of application exceeds crop requirements. Effluent of high volume and concentration of nutrients and/or salts can easily contaminate land and water resources. Predicting the optimum rate of land application of effluent is complicated by the physical, chemical and biological properties of soils. This paper addresses the characteristics of effluents from various intensive rural industries and their potential environmental impacts when irrigated to agricultural land in New South Wales, Australia. To assess the environmental sustainability of effluent reuse in land application, a mathematical model (ERIM) has been developed based on a monthly water balance. ERIM includes historical rainfall and evaporation; the amount of nitrogen and phosphorus introduced; their yearly removal by plants to be grown; amount of applied organic matter; and water holding capacity of soil.
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Streeton, N. A., R. S. B. Greene, K. Marchiori, D. J. Tongway, and M. D. Carnegie. "Rehabilitation of an incised ephemeral stream in central New South Wales, Australia: identification of incision causes, rehabilitation techniques and channel response." Rangeland Journal 35, no. 1 (2013): 71. http://dx.doi.org/10.1071/rj12046.
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The degradation of semiarid agricultural rangelands in Australia can be traced back to the 19th century when Europeans expanded into these areas. That environmental degradation remains today and continues to harm agricultural productivity. The rehabilitation of a strongly incised ephemeral stream, ‘Spring Creek’, in central New South Wales, as an example of what can be achieved readily by landowners, is described. The causes of environmental degradation and the main environmental factors leading to the stream erosion were identified, rehabilitation began and the behaviour of the regime for 5 years within Spring Creek and the adjacent floodplain was monitored. It was found that intrinsically unstable sub-soils and sparse ground cover due to persistent grazing by domestic livestock were the major factors leading to incision. Several physical and chemical properties were found to be the primary causes of the soil’s instability. Rehabilitation focussed on stabilising the soils alongside the stream, promoting sedimentation and re-vegetation of the stream bed, with a longer-term objective of increasing the transfer of water, sediments and nutrients between the stream and its adjacent floodplain. The measures, implemented by local landowners, included the provision of in-stream porous rock weirs and the lowering of the grazing pressure on the stream bed and adjacent floodplain. Monitoring in 2007, 2009 and 2011 indicated that sedimentation was substantially faster above weirs than where there were no weirs. The rehabilitative measures resulted in the retention of fine sediment (<0.2 mm) along the stream bed behind weirs.
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Davy, M. C., and T. B. Koen. "Variations in soil organic carbon for two soil types and six land uses in the Murray Catchment, New South Wales, Australia." Soil Research 51, no. 8 (2013): 631. http://dx.doi.org/10.1071/sr12353.
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The aim of this study was to investigate variations in soil organic carbon (SOC) for two soil types and six common land uses in the New South Wales Murray Catchment and to explore the factors influencing those variations. Samples were collected from 100 sites on duplex soils (Ustalfs) of the Slopes region, and 100 sites on red-brown earths (Xeralfs) of the Plains region. Stocks of SOC (0–30 cm) across the study area ranged between 22.3 and 86.0 t ha–1, with means (± s.e.) of 42.0 ± 1.3 and 37.9 ± 0.8 t ha–1 for the Slopes and Plains regions, respectively. Higher SOC stocks were present in pasture-dominated land uses compared with mixed cropping in the Slopes region, with particularly high stocks found in pastures at positions on a slope of 7–10%. No significant differences in SOC stocks were identified between land-use groups (pastures or cropping) in the Plains region (<500-mm rainfall zone). Significant correlations were found between SOC and a range of climatic, topographical, and soil physico-chemical variables at both the catchment and sub-regional scale. Soil physico-chemical and topographical factors play an important role in explaining SOC variation and should be incorporated into models that aim to predict SOC sequestration across agricultural landscapes.
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Maier, NA. "Potassium nutrition of irrigated potatoes in South Australia. 2. Effect on chemical composition and the prediction of tuber yield by plant analysis." Australian Journal of Experimental Agriculture 26, no. 6 (1986): 727. http://dx.doi.org/10.1071/ea9860727.
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I compared the effects of potassium sulfate and potassium chloride fertiliser, at rates up to 1280 kg/ ha K, on the concentrations in petioles of the youngest fully expanded leaves and in harvested tubers of potassium, calcium (tubers only), magnesium, phosphorus, chloride and sulfur (petioles only) and on potassium: magnesium ratios in petioles. For the sites classified as deficient and marginal according to soil test potassium concentrations, increased application rates of potassium sulfate increased the potassium and sulfur concentrations and potassium: magnesium ratios in petioles and decreased magnesium, phosphorus and chloride concentrations. In tubers both potassium and magnesium concentrations increased as potassium sulfate rates increased, while calcium and phosphorus concentrations showed negative trends. Compared with potassium sulfate, potassium chloride resulted in higher potassium, calcium and chloride concentrations and lower sulfur concentrations. Chloride concentrations in petioles from many sites were much higher than those reported in other studies and were related to high chloride concentrations in irrigation waters. Significant correlations were obtained between bicarbonate- extractable potassium concentrations in the surface (0-1 5-cm) soils and potassium concentrations in petioles (r2 = 0.75***) and tubers (r2 = 0.84***). As bicarbonate-extractable potassium concentrations in the surface soils increased from 40 to 600 mg/kg, the potassium concentrations in tubers increased from 1.69 to 2.69% compared with an increase from 5.72 to 1376% in petioles. Significant correlations were obtained between relative yields ((mean treatment yields/maximum mean treatment yie1d)x 100) and potassium concentrations (dry weight basis) in petioles and tubers and potassium:magnesium ratios in petioles. The percentage of variance in relative yield accounted for by each regression was 67.9, 31.0 and 56.9% respectively. The potassium concentration in petioles was the most effective plant index to predict yield response to potassium. For petioles and tubers prognostic critical potassium concentrations of 11.30 k 0.26% and 2.19 � 0.11% respectively were established. Alternatively, a prognostic critical potassium:magnesium ratio of 14.8 � 0.8% was determined. The choice of the mathematical model used influenced the critical values obtained.
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Evans, C. M., and B. J. Scott. "Surface soil acidity and fertility in the central-western wheatbelt of New South Wales." Australian Journal of Experimental Agriculture 47, no. 2 (2007): 184. http://dx.doi.org/10.1071/ea04165.
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Documentation of the chemical fertility status of the soils is sparse for the western and central-western wheatbelt of New South Wales, Australia. We examined properties of the surface soils (0–10 cm) from central-western NSW by collating two published and nine unpublished datasets of soil analyses representing about 2800 soil samples. The emphasis was on the red soils used extensively for cropping. The surface soils of central-western NSW have low phosphorus (47% of soils) and sulfur (70% of soils <5 mg S/kg using KCl-40 analysis) status and commonly have organic carbon contents of about 1%. Surface soil acidity was a substantial problem with 56% of soils (0–10 cm) having a pHCa <5.0. Sodic and dispersive soils are also of concern in this area and these soils have received little attention or research. Approximately 5% of surface (0–10 cm) soils had an exchangeable sodium percentage of ≥6% (sodic). Salinity of surface soils was of minor significance compared with other soil problems in the area, although isolated areas occur. These results indicated that lime applications in this area are likely to benefit crop and pasture production. Additional use of phosphorus and sulfur fertilisers and agricultural practices which increase or maintain organic carbon will also need to be adopted to improve pasture and crop production. The use of gypsum and/or lime on sodic soils may also need to be addressed. As a priority, we suggest that the benefits of lime application to crop yield be examined. The application of lime to the 0–10 cm soil depth should ultimately arrest acidification of the subsurface soil (10–20 cm depth) through downward movement of the lime effect. Further examination of gypsum applications to dispersive sodic soils and the evaluation of sulfur deficiency in the field for pastures and canola are also priority areas of likely agricultural relevance.
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Conyers, Mark, Philip Newton, Jason Condon, Graeme Poile, Pauline Mele, and Gavin Ash. "Three long-term trials end with a quasi-equilibrium between soil C, N, and pH: an implication for C sequestration." Soil Research 50, no. 7 (2012): 527. http://dx.doi.org/10.1071/sr12185.
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The aim of this study was to assess the long-term changes in some key soil chemical properties at the completion of three long-term trials in south-eastern Australia and the relationship between those soil properties. From a soil organic matter perspective, the build-up of carbon (%C) requires an accumulation of nitrogen (%N), and the build-up of %C and %N fertility comes at the cost of soil acidity. Rotation, tillage, and stubble practices combine to alter the quantity, quality (C : N), and the depth distribution of organic matter in a soil, but the three soil chemical properties reported here seem to also be in quasi-equilibrium at the three long-term sites. The consequence is that if the build-up of soil organic matter leads to soil acidification, then the maintenance of agricultural production will require liming. The emission of CO2 when limestone reacts with soil acids, plus the C cost of limestone application, will negate a proportion of the gains from C sequestration as organic matter in soil. Such cautionary information was doubtless unforeseen when these three long-term trials were initiated.
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Reed, K. F. M. "Perennial pasture grasses—an historical review of their introduction, use and development for southern Australia." Crop and Pasture Science 65, no. 8 (2014): 691. http://dx.doi.org/10.1071/cp13284.
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The development and use of perennial ryegrass (Lolium perenne L.), cocksfoot (Dactylis glomerata L.), phalaris (Phalaris aquatica L.) and tall fescue (Lolium arundinaceum Darbysh.) in the high-rainfall zone and the wheat–sheep zone is reviewed through the pastoral era of extensive grazing (from European settlement to ~1930), the expansive era of pasture improvement (1930–80) and in the modern era. Their adoption, in conjunction with inoculated clover seed, rose steadily in specifically Australian systems of animal production, designed with an appreciation of the environment, and aided by technical developments such as single-disc and aerial spreaders for mineral fertiliser, chemical fallowing and direct-drilling. These species remain vital contributors to the competitive productivity of Australia’s cattle and sheep industries. Perennial ryegrass (~6 Mha by 1994) and cocksfoot emerged as the most important after a wide range of species was introduced through the 19th Century; many of these became naturalised. Regional strains of perennial ryegrass were subsequently selected for commercialisation in Victoria, New South Wales and Tasmania. In the modern era, persistent ecotypes were harnessed to breed persistent cultivars. Vision to both improve grass persistence and extend the area of adaptation encouraged the adoption of phalaris (~2.7 Mha by 2009) and, to a lesser extent, early-flowering types of cocksfoot and tall fescue, particularly for the marginal-rainfall, wheat–sheep zone. The sowing of grass and clover seed expanded after the wide adoption of superphosphate, which became recognised as essential for correcting the severe deficiency of soil phosphorus and nitrogen associated with ancient, intensely weathered soils. The initial and dramatic response of clover to superphosphate increased farm revenue, so fostering a phase in which perennial grasses could be successfully sown, due to having the benefit of (biologically fixed) nitrogen. The influence of European practice, agricultural societies, the Welsh Plant Breeding Station, CSIRO, universities, state Departments of Agriculture, collaborative arrangements and individuals that nurtured and managed pasture technology, plant breeding, cultivar registration and evaluation are outlined. Future considerations emerging from the review include monitoring the national pasture inventory, promotion of the great potential for increasing livestock carrying capacity, cultivar discrimination and information, relevance of models, and national coordination of collaborative research.
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Climstein, Mike, Brendan Doyle, Michael Stapelberg, Nedeljka Rosic, Isolde Hertess, James Furness, Vini Simas, and Joe Walsh. "Point prevalence of non-melanoma and melanoma skin cancers in Australian surfers and swimmers in Southeast Queensland and Northern New South Wales." PeerJ 10 (April 28, 2022): e13243. http://dx.doi.org/10.7717/peerj.13243.
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Background Surfing and swimming are two popular outdoor aquatic activities in Australia with an estimated 2.7 million surfers and three million swimmers; however, these activities are associated with intermittent exposure to ultraviolet radiation. Our aim was to determine the point prevalence of pre-skin cancer (actinic keratosis (PSC)), non-melanoma (NMSC) and melanoma skin cancers (MSC) in Australian surfers and swimmers. Methods This cross-sectional study involved Australian surfers who completed a survey that included physiological demographics, aquatic activity-specific demographics, history of skin cancer followed by screening. Results A total of 171 surfers (n = 116) and swimmers (n = 55) participated in the study. Both groups were identified as having a history of skin cancer (surfers 41.4%, swimmers 36.4%) and a family history of skin cancer (surfers 52.6%, swimmers 43.6%). The majority of both groups reported using a high percentage of a chemical or physical skin cancer prevention strategy (surfers 100%, Swimmers 92.7%, P = 0.003). Significantly more surfers were identified with a skin cancer of any type vs. swimmers (50% vs. 27.3%; OR 2.67; P = 0.005) with most the common skin cancer being PSC (44.7% vs. 11.3%, P = 0.076) followed by basal cell carcinoma (BCC) (24.2% vs. 7.6%, P = 0.068). There was a total of seven MSC identified in surfers and swimmers (4.6% vs. 0.8%, respectively, P = 0.137). Most skin cancers in surfers were located on the face (28.0%) followed by the arm and back (12.1% each), whereas in swimmers, the majority of skin cancers were identified on the face (17.3%), followed by the arm and lower leg (15.4% each). The highest number of melanomas were identified in surfers (n = 6) and mainly located on the face (n = 2) and back (n = 2). There was a single melanoma identified on the back in a swimmer. With the groups combined, the majority (42.9%) of melanomas were identified on the back in participants, followed by the face (28.6%). Rates per 100,000 of NMSC and MSC in surfers and swimmers (respectively) were BCC (11,206 vs. 14,545), squamous cell carcinoma (SCC) in situ (13,793 vs. 12,727), SCC (1,724 vs. 3,636) and MSC (5,172 vs. 1,818). When compared to the general Australian population, surfers and swimmers had higher odds ratios (OR), which included BCCs (OR 7.3 and 9.4, respectively), SCCs (OR 1.7 and 3.5, respectively) and MSC (OR 96.7 and 18.8, respectively). Conclusion Surfers and swimmers had consistently higher rates of PSC, NMSC and MSC than the general Australian population. Point prevalence of MSC (groups combined) was 76-fold higher than the general Australian population. These findings highlight the clinical importance of regular skin cancer screenings in individuals who surf or swim for early detection and treatment of skin cancer. Additionally, these aquatic enthusiasts should be advised of the benefits of sun protection strategies such as chemical and physical barriers to reduce the likelihood of developing skin cancer.
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Shi, Boyang, Olusegun O. Osunkoya, Aakansha Chadha, Singarayer K. Florentine, and Kunjithapatham Dhileepan. "Biology, Ecology and Management of the Invasive Navua Sedge (Cyperus aromaticus)—A Global Review." Plants 10, no. 9 (September 7, 2021): 1851. http://dx.doi.org/10.3390/plants10091851.
Full textAbstract:
Navua sedge (Cyperus aromaticus (Ridley) Mattf. & Kukenth) is an invasive perennial sedge, native to tropical Africa, which is threatening many natural ecosystems and agroecosystems, especially in northern Queensland, Australia. Crop and pasture production have been impacted by Navua sedge and it is also directly causing reductions in dairy and beef production in affected regions. This review documents the biology, ecology and potential management options to minimise the spread and impact of Navua sedge. The weed reproduces both sexually (seeds) and vegetatively (via underground rhizomes). Its tiny seeds can be spread easily via wind, water, vehicles, farm machinery and animals, whilst the rhizomes assist with establishment of dense stands. The CLIMEX model (which uses distribution and climate data in native and novel ranges) indicates that in Australia, Navua sedge has the potential to spread further within Queensland and into the Northern Territory, New South Wales and Victoria. Several management strategies, including mechanical, chemical and agronomic methods, and their integration will have to be used to minimise agricultural production losses caused by Navua sedge, but most of these methods are currently either ineffective or uneconomical when used alone. Other management approaches, including biological control and mycoherbicides, are currently being explored. We conclude that a better understanding of the interaction of its physiological processes, ecological patterns and genetic diversity across a range of conditions found in the invaded and native habitats will help to contribute to and provide more effective integrated management approaches for Navua sedge.
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Badgery, Warwick B., Aaron T. Simmons, Brian M. Murphy, Andrew Rawson, Karl O. Andersson, Vanessa E. Lonergan, and Remy van de Ven. "Relationship between environmental and land-use variables on soil carbon levels at the regional scale in central New South Wales, Australia." Soil Research 51, no. 8 (2013): 645. http://dx.doi.org/10.1071/sr12358.
Full textAbstract:
The potential to change agricultural land use to increase soil carbon stocks has been proposed as a mechanism to offset greenhouse gas emissions. To estimate the potential carbon storage in the soil from regional surveys it is important to understand the influence of environmental variables (climate, soil type, and landscape) before land management can be assessed. A survey was done of 354 sites to determine soil organic carbon stock (SOC stock; Mg C/ha) across the Lachlan and Macquarie catchments of New South Wales, Australia. The influences of climate, soil physical and chemical properties, landscape position, and 10 years of land management information were assessed. The environmental variables described most of the regional variation compared with management. The strongest influence on SOC stock at 0–10 cm was from climatic variables, particularly 30-year average annual rainfall. At a soil depth of 20–30 cm, the proportion of silica (SiO2) determined by mid-infrared spectra (SiMIR) had a negative relationship with SOC stock, and sand and clay measured by particle size analysis also showed strong relationships at sites where measured. Of the difference in SOC stock explained by land use, cropping had lower soil carbon than pasture in rotation or permanent pasture at 0–10 cm. This relationship was consistent across a rainfall gradient, but once soil carbon was standardised per mm of average annual rainfall, there was a greater difference between cropping and permanent pasture with increasing SiMIR in soils. Land use is also regulated by climate, topography, and soil type, and the effect on SOC stock is better assessed in smaller land-management units to remove some variability due to climate and soil.
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Wicks, TJ, B. Morgan, and B. Hall. "Influence of soil fumigation and seed tuber treatment on the control of Rhizoctonia solani on potatoes." Australian Journal of Experimental Agriculture 36, no. 3 (1996): 339. http://dx.doi.org/10.1071/ea9960339.
Full textAbstract:
Five field experiments were conducted in South Australia to determine the effect of soil fumigation (metham sodium) and chemical and biological seed tuber dressing on the severity of Rhizoctonia solani on potato stems and tubers. These experiments indicated that both soil- and tuber-borne inoculum must be considered in any program aimed at controlling R. solani. Tuber treatments of either a 20 min dip in 2% formaldehyde, sprays with pencycuron (0.15 mL a.i./10 kg seed), iprodione (2 mL a.i.110 kg seed) or a spore suspension of lo6 spores/ml of Verticillium biguttatum or a dust with tolclofos methyl (4 g a.i.110 kg seed) were most effective if planted in soil fumigated with 500 L/ha metham sodium or soil with low levels of R. solani. A commercial formulation of Trichoderma harziannum and T. koningii applied as a dust at 1.3 g110 kg seed was in most cases ineffective when treated seed was planted into either fumigated or unfumigated soil. The incidence of progeny tubers with sclerotia varied between sites and ranged from 85% in an unfumigated soil planted with infected tubers to 2% in a fumigated soil planted with pencycuron-treated tubers. Except for 1 experiment where tubers were harvested early, neither seed treatments nor fumigation improved total nor marketable yield.
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Thorn, CW, and MW Perry. "Effect of chemical removal of grasses from pasture leys on pasture and sheep production." Australian Journal of Experimental Agriculture 27, no. 3 (1987): 349. http://dx.doi.org/10.1071/ea9870349.
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Pasture production, pasture composition and quality, and liveweight, body condition and wool growth of Merino weaner wethers were monitored over 2 seasons and at 2 stocking rates (4 and 8 sheep/ha) on a mixed annual grass-legume pasture sprayed with propyzamide to control grasses. Propyzamide virtually eliminated annual grasses from the pasture (less than 5 kg/ha of grass dry matter in spring v. 403 kg/ha on untreated pasture in 1981) and this carried over into the second season (61 kg/ha v. 647 kg/ha in spring 1982). Propyzamide treated pastures had less total dry matter (P = 0.05) throughout 1981: however, except for a single sample date, there was no effect of propyzamide on total available pasture in the second season. Increased growth of clover and capeweed compensated for the absence of the grasses. The higher stocking rate reduced available clover, capeweed and total dry matter (P = 0.05) throughout both years. Sheep grazing grass-free pastures had lower liveweights during winter in both years, but made compensatory gains during late spring and summer consistent with the higher quality (1.6 v. 1.07% nitrogen when sampled in January) of propyzamide treated pastures. In 198 1, wool growth rates were reduced at the higher stocking rate and total clean wool production was reduced from 4.55 kg/sheep at 4/ha to 3.65 kg/sheep at 8/ha. Pasture treatment had no effect on wool production in either year. The implications of using selective herbicides to remove the annual grass component of legume-based annual pastures in south-western Australia are dis cussed in relation to pasture and sheep production.
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Jones, R., and R. Medd. "Economic analysis of integrated management of wild oats involving fallow, herbicide and crop rotational options." Australian Journal of Experimental Agriculture 37, no. 6 (1997): 683. http://dx.doi.org/10.1071/ea97036.
Full textAbstract:
Summary. The primary objective of this study was to estimate the economic benefits associated with an integrated weed management approach for wild oats (Avena fatua and A. ludoviciana) in northern New South Wales involving chemical and non-chemical controls. The paper presents a framework for assessing the population dynamics of wild oats and the economics of a range of control options over 15 years. Wild oats is a weed primarily of winter crops which, as a consequence of its persistence and its impact upon yields, leads to significant economic losses in the grain growing regions of Australia. In this study, a dynamic programming model is developed to examine the impact of a range of management strategies for the control of wild oats in wheat. The strategies evaluated include conventional herbicide control to reduce weed densities, the use of selective herbicides to reduce seed set of the weed, and summer crop and winter fallow rotational options which provide a break in the cereal cycle and allow accelerated control of wild oat populations. The hypothesis for the study, that strategies which involve measures that directly reduce seed production and minimise wild oats seed bank populations will yield the greatest economic benefit, is acceptable based on the findings of the study. The work also shows that a dynamic programming model provides a means of determining the optimal combination of strategies over time for various initial values of the seed bank. The methodology is considered to have general application as a framework for evaluating the economics of weed control problems in annual cropping systems.
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Noble, A. D., R. J. Jones, C. H. Thompson, and R. M. Jones. "The long-term impact of two pasture production systems on soil acidification in southern Queensland." Australian Journal of Experimental Agriculture 38, no. 4 (1998): 335. http://dx.doi.org/10.1071/ea98039.
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Summary. Soil samples to a depth of 90 cm were collected in 1996 from adjacent 1 ha paddocks which had either been established to a leucaena-based or nitrogen-fertilised and irrigated pasture system in 1960 at Samford, south-eastern Queensland, to assess the impact of these production systems on soil chemical properties. The chemical properties were compared with those of soil samples collected from the site in 1960. Soil pH under both the nitrogen-fertilised and leucaena-based systems have declined significantly to a depth of 40 cm against that of the soil samples collected in 1960. However, the extent of acidification was higher under the more intensively managed nitrogen-fertilised system compared with the leucaena-based system. The acidification rates for the nitrogen-fertilised and leucaena-based pasture systems over the 36-year period are 5.1 and 1.0 kmol H+/ha.year, respectively, and are similar to values observed under annual pasture systems of temperate southern Australia. Associated with the decline in pH there was a decline in exchangeable Ca2+ in the nitrogen-fertilised system and a corresponding increase in exchangeable acidity. The contribution of the nitrogen cycle to net acidification for the leucaena-based pasture system was estimated to account for 20% of the total net acid addition. This result is discussed in the light of a similar study undertaken in the semi-arid tropics where the contribution of the nitrogen cycle by a similar leucaena-based system was estimated to be 78% of the net acidification.
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Oram, R. N., V. Ferreira, R. A. Culvenor, A. A. Hopkins, and A. Stewart. "The first century of Phalaris aquatica L. cultivation and genetic improvement: a review." Crop and Pasture Science 60, no. 1 (2009): 1. http://dx.doi.org/10.1071/cp08170.
Full textAbstract:
2006 marked the centenary of the commercial propagation of phalaris (Phalaris aquatica L.) as a cultivated pasture plant, firstly in Australia, and soon after in New Zealand, South Africa, and North and South America. Small-scale evaluation of cv. Australian began in the Toowoomba Botanic Gardens, Queensland, in 1884. The first recorded large-scale production of seed was at the Glen Innes Research Farm of the NSW Department of Agriculture in February 1906. By 1908–15, several graziers in Australia and New Zealand sold seed widely within Australia, New Zealand, USA, Argentina, and South Africa. Factors affecting the utilisation of the original cultivar in Australia over the first half-century are reviewed. Thereafter, the need to extend the area of perennial pastures into regions unsuitable for cv. Australian led CSIRO and the US Department of Agriculture to collect germplasm widely in the Mediterranean region. Selection between and within Moroccan populations produced cvv. Sirocco and El Golea in Australia, and cv. Perla koleagrass in the USA. In Argentina, selection within cv. Australian produced the very successful, seed-retaining cv. Pergamino El Gaucho INTA, which was re-selected in Australia to produce cv. Seedmaster. The discovery of a single seed-retaining plant within a certified line of cv. Australian gave cv. Uneta, which had excellent seed retention because the rachillae of most seeds remained intact at maturity. In Australia, selection in populations derived from crosses between cv. Australian and Mediterranean ecotypes gave a succession of winter-active cultivars: Sirosa, Sirolan, Holdfast, Landmaster, Atlas PG, Advanced AT, and Holdfast GT. The latter 5 have Uneta-type seed retention, reduced tryptamine and tyramine alkaloids, and adaptation to different soil and climatic niches. Populations for the hotter, drier inland slopes of NSW are being field-tested. Also, a promising but unstable semi-dwarf line has been found: dwarfism appears to be caused by a transposable element. Breeding and selection programs in Argentina, several states of the USA, New Zealand, Israel, Tunisia, and Greece also produced cultivars with specific adaptations. Active breeding programs are continuing at Ardmore, OK, USA, and Pergamino, Argentina. A major remaining obstacle to the further improvement and utilisation of phalaris is the unknown chemical nature of the toxin(s) causing ‘sudden death’, which temporarily interfere with nitrogen metabolism in the brains of herbivores, especially ruminants.
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King, W. McG, P. M. Dowling, D. L. Michalk, D. R. Kemp, G. D. Millar, I. J. Packer, S. M. Priest, and J. A. Tarleton. "Sustainable grazing systems for the Central Tablelands of New South Wales. 1. Agronomic implications of vegetation - environment associations within a naturalised temperate perennial grassland." Australian Journal of Experimental Agriculture 46, no. 4 (2006): 439. http://dx.doi.org/10.1071/ea04039.
Full textAbstract:
Temperate perennial grass-based pastures dominate the high rainfall zone of south-eastern Australia and support a major livestock production industry. This area has experienced a recent change in overall pasture condition, however, typified by a reduction in the abundance of perennial grasses and an increasingly prominent winter-annual grass weed component. Improving the condition and productivity of these pastures can be achieved by improved management but this requires better knowledge of the interactions between management options and pasture species composition and of the interaction between pasture vegetation and the complex effects of a heterogeneous landscape. This paper reports the results of an intensive survey of a 60-ha paddock that was designed to identify the species present, determine their patterns of distribution and examine the relationships between pasture vegetation and the environment. The survey of species present in late summer was supplemented by the identification of seedlings that later emerged from extracted soil cores and by soil physical and chemical analyses. Data were analysed using ordination and interpreted with GIS software so that topographic features could be considered. The most frequently identified taxa were Hypochaeris radicata, Austrodanthonia spp. and Bothriochloa spp. (in late summer) and Vulpia spp., Bromus molliformis and Trifolium subterraneum (winter-annual species). Austrodanthonia spp. were commonly found on the drier ridges and more acid soils with lower phosphate levels. These were also the areas dominated in spring by Vulpia spp. and were generally lower in plant species richness overall. The most species-rich areas occurred downslope where soil fertility was higher and less moisture stress was presumably experienced. The measured environmental factors explained a substantial proportion of the variation in the vegetation dataset, which underlined the importance of considering landscape effects in the management of typical tablelands pastures.
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Roper, M. M., S. L. Davies, P. S. Blackwell, D. J. M. Hall, D. M. Bakker, R. Jongepier, and P. R. Ward. "Management options for water-repellent soils in Australian dryland agriculture." Soil Research 53, no. 7 (2015): 786. http://dx.doi.org/10.1071/sr14330.
Full textAbstract:
Water-repellent (‘non-wetting’) soils are a major constraint to agricultural production in southern and south-west Australia, affecting >10 Mha of arable sandy soils. The major symptom is dry patches of surface soil, even after substantial rainfall, directly affecting agricultural production through uneven crop and pasture germination, and reduced nutrient availability. In addition, staggered weed germination impedes effective weed control, and delayed crop and pasture germination increases the risk of wind erosion. Water repellency is caused by waxy organic compounds derived from the breakdown of organic matter mostly of plant origin. It is more prevalent in soils with a sandy surface texture; their low particle surface area : volume ratio means that a smaller amount of waxy organic compounds can effectively cover a greater proportion of the particle surface area than in a fine-textured soil. Water repellency commonly occurs in sandy duplex soils (Sodosols and Chromosols) and deep sandy soils (Tenosols) but can also occur in Calcarosols, Kurosols and Podosols that have a sandy surface texture. Severity of water repellency has intensified in some areas with the adoption of no-till farming, which leads to the accumulation of soil organic matter (and hence waxy compounds) at the soil surface. Growers have also noticed worsening repellency after ‘dry’ or early sowing when break-of-season rains have been unreliable. Management strategies for water repellency fall into three categories: (i) amelioration, the properties of surface soils are changed; (ii) mitigation, water repellency is managed to allow crop and pasture production; (iii) avoidance, severely affected or poorly producing areas are removed from annual production and sown to perennial forage. Amelioration techniques include claying, deep cultivation with tools such as rotary spaders, or one-off soil inversion with mouldboard ploughs. These techniques can be expensive, but produce substantial, long-lasting benefits. However, they carry significant environmental risks if not adopted correctly. Mitigation strategies include furrow-seeding, application of wetting agents (surfactants), no-till with stubble retention, on-row seeding, and stimulating natural microbial degradation of waxy compounds. These are much cheaper than amelioration strategies, but have smaller and sometimes inconsistent impacts on crop production. For any given farm, economic analysis suggests that small patches of water repellency might best be ameliorated, but large areas should be treated initially with mitigation strategies. Further research is required to determine the long-term impacts of cultivation treatments, seeding systems and chemical and biological amendments on the expression and management of water repellency in an agricultural context.
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Prober, Suzanne M., Kevin R. Thiele, and Ian D. Lunt. "Identifying ecological barriers to restoration in temperate grassy woodlands: soil changes associated with different degradation states." Australian Journal of Botany 50, no. 6 (2002): 699. http://dx.doi.org/10.1071/bt02052.
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Temperate grassy woodlands were once the dominant vegetation across many agricultural regions of south-eastern Australia, but most of these are now highly degraded and fragmented. Adequate conservation of these woodlands is dependent on successful ecological restoration; however, ecological barriers often limit ecosystem recovery once degrading processes are removed. To help identify these barriers, we used a state and transition framework to compare topsoils of little-disturbed (reference) and variously degraded remnants of grassy Eucalyptus albens Benth. and E. melliodora Cunn. ex Schauer woodlands. Topsoils of degraded remnants showed a repeated pattern, with the most compacted, most acidic and most depleted topsoils occurring in remnants dominated by Aristida ramosa R.Br. or Austrodanthonia H.P.Linder and Austrostipa scabra (Lindl.) S.W.L.Jacobs & J.Everett; the least compacted and most nutrient rich topsoils in remnants dominated by annual exotics; and generally intermediate topsoils in remnants dominated by Bothriochloa macra (Steud.) S.T.Blake or Austrostipa bigeniculata (Hughes) S.W.L.Jacobs & J.Everett. Surprisingly, topsoils beneath trees in reference sites (supporting Poa sieberiana Spreng.) were similar to topsoils supporting annual exotics for most soil properties. Chemical properties of topsoils from open areas of reference sites [supporting Themeda australis (R.Br.) Stapf] were usually intermediate and similar to Bothriochloa macra and Austrostipa bigeniculata topsoils. The most striking exception to these trends was for soil nitrate, which was extremely low in all reference topsoils and showed a high correlation with annual exotic abundance. We discuss the potential for positive feedbacks between soil nitrogen cycling and understorey composition and the need for intervention to assist possible nitrate-dependent transitions between annual and perennial understorey states. Dominant grasses, trees and annual weed abundance may be useful indicators of soil conditions and could inform selection of target sites, species and techniques for restoration projects.
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Novoa, Brundu, Day, Deltoro, Essl, Foxcroft, Fried, et al. "Global Actions for Managing Cactus Invasions." Plants 8, no. 10 (October 16, 2019): 421. http://dx.doi.org/10.3390/plants8100421.
Full textAbstract:
The family Cactaceae Juss. contains some of the most widespread and damaging invasive alien plant species in the world, with Australia (39 species), South Africa (35) and Spain (24) being the main hotspots of invasion. The Global Cactus Working Group (IOBC GCWG) was launched in 2015 to improve international collaboration and identify key actions that can be taken to limit the impacts caused by cactus invasions worldwide. Based on the results of an on-line survey, information collated from a review of the scientific and grey literature, expertise of the authors, and because invasiveness appears to vary predictably across the family, we (the IOBC GCWG): (1) recommend that invasive and potentially invasive cacti are regulated, and to assist with this propose five risk categories; (2) recommend that cactus invasions are treated physically or chemically before they become widespread; (3) advocate the use of biological control to manage widespread invasive species; and (4) encourage the development of public awareness and engagement initiatives to integrate all available knowledge and perspectives in the development and implementation of management actions, and address conflicts of interest, especially with the agricultural and ornamental sectors. Implementing these recommendations will require global co-operation. The IOBC GCWG aims to assist with this process though the dissemination of information and experience.
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Granger, AR, and DRC Traeger. "Effect of different rates and timing of soil applications of paclobutrazol on the growth of sweet cherries (Prunus avium L.)." Australian Journal of Experimental Agriculture 33, no. 2 (1993): 207. http://dx.doi.org/10.1071/ea9930207.
Full textAbstract:
The response of sweet cherry trees (butt circumference, canopy volume, yield) to different rates of the growth-inhibiting chemical paclobutrazol applied at various times during each year was studied on red podsolic soils in the Mount Lofty Ranges of South Australia Two experiments were conducted: one used a regression design with 16 rates of paclobutrazol; the other was a randomised block experiment with paclobutrazol treatments applied in spring, autumn, or half in autumn and half in spring. Butt circumference growth of the variety Sam grafted on Mahaleb rootstocks tended to reduce with inceased rates of paclobutrazol in the first year of application. The lowest rate of paclobutrazol to reduce butt growth sigdicantly below that of control trees was 1.2 g a.i./tree. Canopy growth showed a delayed response in measurable growth inhibition in the season after treatment; however, no significant differences were measured for rate of canopy growth in any year for any treatment in the regression experiment. Despite this, final canopy volumes of trees treated with 1.6 g paclobutrazol in spring were half those of control canopies. Variability in butt growth response to the range of rates applied was attributed largely to localised differences in soil properties which influenced paclobutrazol movement and uptake. This variability was gradually reduced over the 3-year period with continued paclobutrazol applications. In 1987, crop level ratings made before harvest showed significantly higher levels of fruit on trees treated with 1.6 g paclobutrazol in spring, indicating that fruit numbers could be increased by applications of paclobutrazol.
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Nasar-Abbas, Syed M., Julie A. Plummer, Peter White, Kadambot H. M. Siddique, Mario D'Antuono, David Harris, and Ken Dods. "Effect of site, harvesting stage, and genotype on environmental staining in faba bean (Vicia faba L.)." Australian Journal of Agricultural Research 59, no. 4 (2008): 365. http://dx.doi.org/10.1071/ar07150.
Full textAbstract:
Seed discoloration due to environmental staining in faba bean leads to poor quality and reduced market price. Environmental staining in faba bean is characterised by a dark brown, grey, or black discoloration of the seed coat at harvest. Its cause is unknown, but it does not appear to be caused by a pathogen. Environmental conditions during pod and seed formation and at maturity are thought to have a large effect on the degree of environmental staining. To test the hypothesis that seeds formed under stressful conditions will have a higher degree of staining, faba bean seeds were harvested at 2 different stages of maturity from trials located in a range of environmental conditions under a Mediterranean-type climate of south-western Australia over 2 seasons. Four faba bean varieties were studied (Fiord, Fiesta, Ascot, and Cairo). The majority of seeds had good colour but across the trials, 3–25% were stained up to an unacceptable level and this varied with location and variety. Seeds formed later in plant development (located on the upper nodes of the plant) had more staining than seeds formed earlier (located on the lower nodes). Seeds formed on small and weak plants had more staining than seeds formed on normal sized healthy plants. Fiord showed a greater amount of staining than Ascot, Fiesta, and Cairo when grown in the mild, southern environments. Early harvesting (at physiological maturity) did not reduce environmental seed staining compared with harvesting at full maturity. Chemical analysis of seed testa and cotyledons revealed that total phenolic contents of the testa and cotyledons increased with staining. An increase in Zn and Na and a decrease in K concentration in the testa were also associated with increased staining levels.
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Chadha, Aakansha, and Singarayer Florentine. "Biology, Ecology, Distribution and Control of the Invasive Weed, Lactuca serriola L. (Wild Lettuce): A Global Review." Plants 10, no. 10 (October 11, 2021): 2157. http://dx.doi.org/10.3390/plants10102157.
Full textAbstract:
Lactuca serriola L. (wild lettuce) is a highly invasive C3 weed in many countries, including Australia, Canada, and the USA. This weed is a severe threat to agricultural systems, especially in crops grown with reduced or no-tillage approaches, which commonly include wheat, cereals and pulses. Owing to the vertical orientation of its leaves in the north-south plane and its root architecture, L. serriola can maintain high water use efficiency under drought conditions, giving it the ability to expand its range under a drying climate. Each plant can produce up to 100,000 seeds which have no primary dormancy and form a short-term seedbank lasting up to three years. Most seedlings emerge in autumn and overwinter as a rosette, with a small flush of emergence in spring depicting staggered germination. Research into control methods for this weed has been performed, and these methods include chemical herbicides applied alone and in combination, the establishment of plant competition, tillage, mowing and bioherbicide. Herbicides can provide effective control when applied in the seedling or rosette stage; however, spring germination is difficult to control, as it skips the rosette stage. Some biotypes are now resistant to ALS inhibitor and synthetic auxins, causing concern regarding using herbicides. A dedicated integrated management plan for 3–4 years is recommended for the control of this troublesome species. This review will explore the biology, ecology, distribution, current control techniques and previous research on this weed, allowing us to make recommendations for its future research and management.
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Carlson, L. "Bibliography of the History of Australian Science, No. 22, 2001." Historical Records of Australian Science 14, no. 1 (2002): 119. http://dx.doi.org/10.1071/hr02007.
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Main sources for this bibliography were the 2001 editions of various databases such as the Australian Public Affairs Information Service (APAIS), Chemical Abstracts and Medline Express. In addition, issues of a number of Australian journals published in 2001 were scanned, and readers of the bibliography sent information about relevant items to the compiler. Most items included were published in 2001, but a number of earlier publications were also found which it was thought should be included. The scope of the bibliography is limited to material on the history of the natural sciences (mathematics, physical sciences, earth sciences and biological sciences), some of the applied sciences (including medical and health sciences, agriculture, manufacturing and engineering), and human sciences (psychology, anthropology and sociology). Biographical material on practitioners in these sciences is also of interest. The compiler would like to thank those people who sent items or information about items published during 2001 for inclusion in the bibliography. It would again be appreciated if he could be notified about other items dealing with the history of science in Australasia, the South West Pacific area and Antarctica published during 2001, but have been omitted. Readers are invited to alert the compiler to the publication of books, journal articles, conference papers, reports, Masters and PhD theses and reviews on the subject published during 2002 for inclusion in future bibliographies. Pertinent information should be sent to the compiler, C/- Deakin University Library, Geelong, Victoria 3217, Australia or by e-mail to laurie.carlson@austehc.unimelb.edu.au.
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Rossel, R. A. Viscarra, and A. B. McBratney. "Soil chemical analytical accuracy and costs: implications from precision agriculture." Australian Journal of Experimental Agriculture 38, no. 7 (1998): 765. http://dx.doi.org/10.1071/ea97158.
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Summary. This article reviews soil sampling and soil chemical analysis, discussing their implications from, and applications in, precision agriculture. The variability of a number of agriculturally important soil chemical properties was investigated and the ‘nugget’ variance or effect discussed in terms of its importance in determining the proportion of not only short-range spatial variation, but also sampling and measurement error. Comments were then made on the accuracy of laboratory methods. Analytical variances were compared with world-average and estimated nugget variances for a field in New South Wales, the comparison showing that analytical precision needs to be maintained or improved when developing or adapting analytical methods for precision agriculture. A simple cost-analysis showed that soil chemical analytical costs are much too large for economic use in precision agriculture, costs in Australia being higher than in the United States. The conclusion this paper draws is that, for large-scale implementation of precision agriculture, the development of field-deployed, ‘on-the-go’ proximal soil sensing systems and scanners is tremendously important. These sensing systems or scanners should aim to overcome current problems of high cost, labour, time and to some extent, imprecision of soil sampling and analysis to more efficiently and accurately represent the spatial variability of the measured properties.
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Woutersen, Amber, Phillip E. Jardine, Raul Giovanni Bogotá-Angel, Hong-Xiang Zhang, Daniele Silvestro, Alexandre Antonelli, Elena Gogna, et al. "A novel approach to study the morphology and chemistry of pollen in a phylogenetic context, applied to the halophytic taxon Nitraria L.(Nitrariaceae)." PeerJ 6 (July 19, 2018): e5055. http://dx.doi.org/10.7717/peerj.5055.
Full textAbstract:
Nitraria is a halophytic taxon (i.e., adapted to saline environments) that belongs to the plant family Nitrariaceae and is distributed from the Mediterranean, across Asia into the south-eastern tip of Australia. This taxon is thought to have originated in Asia during the Paleogene (66–23 Ma), alongside the proto-Paratethys epicontinental sea. The evolutionary history of Nitraria might hold important clues on the links between climatic and biotic evolution but limited taxonomic documentation of this taxon has thus far hindered this line of research. Here we investigate if the pollen morphology and the chemical composition of the pollen wall are informative of the evolutionary history of Nitraria and could explain if origination along the proto-Paratethys and dispersal to the Tibetan Plateau was simultaneous or a secondary process. To answer these questions, we applied a novel approach consisting of a combination of Fourier Transform Infrared spectroscopy (FTIR), to determine the chemical composition of the pollen wall, and pollen morphological analyses using Light Microscopy (LM) and Scanning Electron Microscopy (SEM). We analysed our data using ordinations (principal components analysis and non-metric multidimensional scaling), and directly mapped it on the Nitrariaceae phylogeny to produce a phylomorphospace and a phylochemospace. Our LM, SEM and FTIR analyses show clear morphological and chemical differences between the sister groups Peganum and Nitraria. Differences in the morphological and chemical characteristics of highland species (Nitraria schoberi, N. sphaerocarpa, N. sibirica and N. tangutorum) and lowland species (Nitraria billardierei and N. retusa) are very subtle, with phylogenetic history appearing to be a more important control on Nitraria pollen than local environmental conditions. Our approach shows a compelling consistency between the chemical and morphological characteristics of the eight studied Nitrariaceae species, and these traits are in agreement with the phylogenetic tree. Taken together, this demonstrates how novel methods for studying fossil pollen can facilitate the evolutionary investigation of living and extinct taxa, and the environments they represent.
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Barden, Graeme. "Regulation of Microbial Organisms in Australia – A Technical Overview." Phytoprotection 79, no. 4 (April 12, 2005): 14–21. http://dx.doi.org/10.7202/706150ar.
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The National Registration Authority for Agricultural and Veterinary Chemicals (NRA) is the regulatory body responsible for the coordinated registration, regulation and review of agricultural and veterinary (agvet) chemicals up to and including the point of retail sale. This role is defined by the Agvet Code, 1994. Each of Australia's eight states and territories retains its own jurisdictional controls over the use of agricultural and veterinary products. The NRA may issue permits to exercise control over research agricultural and veterinary (agvet) chemicals. Under defined emergency conditions, the NRA can also issue "emergency use" permits, and can approve the use of agvet chemicals for minor uses that do not normally appear on product labels, and would otherwise be illegal. The Existing Chemicals Review Program of the NRA reviews registered agvet chemical products to ensure that they meet contemporary standards for efficacy, safety and health, and pose no undue risk to the environment or trade. Recently reviewed chemicals include atrazine, metham sodium, endosulfan and ethylene dibromide, and certain changes to their registration and labelling are being implemented. Several other chemicals are currently under review. The Special Review Program allows the NRA to review registered agvet products if there are any special issues arising that may alter the terms of their original registration. Current challenges to the NRA include the management of insecticide and weed resistance, particularly in relation to the regulation of genes expressing insecticides and herbicide tolerance. Specific guidelines for the registration of microbiological products are currently being reviewed. Issues relating to the release of microbial organisms into existing agricultural Systems and environments require considered risk assessment prior to any approval. Macrobiological control agents are specifically excluded from regulation by the NRA. They may, however, be regulated under other pieces of legislation.
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Taylor, C. Robert, John B. Penson, Edward G. Smith, and Ronald D. Knutson. "Economic Impacts of Chemical Use Reduction on the South." Journal of Agricultural and Applied Economics 23, no. 1 (July 1991): 15–23. http://dx.doi.org/10.1017/s0081305200017763.
Full textAbstract:
A growing segment of society is concerned about a myriad of health and environmental issues related to the use of pesticides and other agricultural chemicals. Despite the leveling-off of agricultural chemical use in the 1980s, chemical use in agriculture has come to be seen as a two-edged sword. On the positive side, agricultural chemicals have become the engine for world-wide productivity gains. These chemicals have contributed to increased yields per acre and have reduced waste in storage and distribution. On the negative side, agricultural chemicals are perceived by many to present risks to the safety of the food we eat, to the quality of our drinking water, to the wildlife population, to applicators and to people who inadvertently come into point contact with them.