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1
Eyles, Alieta, Garth Coghlan, Marcus Hardie, Mark Hovenden, and Kerry Bridle. "Soil carbon sequestration in cool-temperate dryland pastures: mechanisms and management options." Soil Research 53, no. 4 (2015): 349. http://dx.doi.org/10.1071/sr14062.
Повний текст джерелаАнотація:
Permanent pastures, which include sown, native and naturalised pastures, account for 4.3 Mha (56%) of the national land use in Australia. Given their extent, pastures are of great interest with respect to their potential to influence national carbon (C) budgets and CO2 mitigation. Increasing soil organic C (SOC) mitigates greenhouse gases while providing other benefits such as pasture productivity, soil health and ecosystem services. Several management approaches have been recommended to increase C sequestration in pasture-based systems; however, results have proved variable and often contradictory between sites and years. Here, we present an overview of the processes and mechanisms responsible for C sequestration in permanent pastures. In addition, we discuss the merits of traditional and emerging pasture-management practices for increasing SOC in pastures, with a focus on dryland pasture systems of south-eastern Australia. We conclude by summarising the knowledge gaps and research priorities for soil C-sequestration research in dryland pastures. Our review confirms that soils under a range of pasture types have considerable potential for sequestration of atmospheric CO2 in Australia, and that the magnitude of this potential can be greatly modified by pasture-management practices. Although the shortage of long-term studies under Australian conditions limits our ability to predict the potential of various management approaches to sequester soil C, our review indicates that prevention of erosion through maintenance of groundcover and adoption of options that promote deep C sequestration are likely to confer broad-scale maintenance or increases in SOC in pasture soils over a decade or longer. We acknowledge that the evidence is limited; therefore, confidence in the recommended practices in different locations and climates is largely unknown.
2
Mitchell, M. L., M. R. McCaskill, and R. D. Armstrong. "Phosphorus fertiliser management for pastures based on native grasses in south-eastern Australia." Crop and Pasture Science 70, no. 12 (2019): 1044. http://dx.doi.org/10.1071/cp19217.
Повний текст джерелаАнотація:
Approximately 3.1 Mha (22%) of the agricultural area of south-eastern Australia can be classified as native pasture. There is the assumption that, owing to the widespread occurrence of low-fertility soils in Australia, native grass species do not respond to increased phosphorus (P) fertility. Currently, there are no industry recommendations of target soil-test P values for native-grass-based pastures. This paper reviews the responses of perennial native pasture species endemic to south-eastern Australia to P application in controlled environments, surveys, replicated experiments and paired-paddock trials. Eighty-seven site-years of trial data where different levels of P were applied, conducted over the last two decades, on native-based pastures in south-eastern Australia are reviewed. Data indicate that application of P fertilisers to native grass pastures can increase dry matter (DM) production and maintain pasture stability. However, minimum targets for herbage mass (800 kg DM/ha) and groundcover (80%) are required to ensure persistence of perennial native grasses. Stocking rates also need to match carrying capacity of the pasture. Based on previous research, we recommend target soil-test (Olsen; 0–10 cm) P levels for fertility-tolerant native grass pastures, based on Microlaena stipoides, Rytidosperma caespitosum, R. fulvum, R. richardsonii, R. duttonianum and R. racemosum, of 10–13 mg/kg, whereas for pastures based on fertility-intolerant species such as Themeda triandra, lower levels of <6 mg/kg are required to ensure botanical stability.
3
Ward, P. R., R. A. Lawes, and D. Ferris. "Soil-water dynamics in a pasture-cropping system." Crop and Pasture Science 65, no. 10 (2014): 1016. http://dx.doi.org/10.1071/cp14046.
Повний текст джерелаАнотація:
Pasture cropping is a farming system in which annual crops are sown into established perennial pastures. It may provide environmental benefits such as increased groundcover and reduced deep drainage, while allowing traditional crop production in the Mediterranean-style climate of south-western Australia. In this research, we investigated deep drainage and the temporal patterns of water use by a subtropical perennial grass, annual crops, and a pasture-cropping system over a 4-year period. Both the pasture and pasture-cropped treatments reduced deep drainage significantly, by ~50 mm compared with the crop treatment. Competition between the pasture and crop components altered patterns of average daily water use, the pasture-cropped treatment having the highest water use for July, August and September. Consequently, water-use efficiency for grain production was lower in the pasture-cropped plots. This was offset by pasture production, so that over a full 12-month period, water-use efficiency for biomass production was generally greater for the pasture-cropped plots than for either the pasture or crop monocultures. Pasture cropping may be a viable way of generating sustainable economic returns from both crop and pasture production on sandy soils of south-western Australia.
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Kemp, D. R., and P. M. Dowling. "Towards sustainable temperate perennial pastures." Australian Journal of Experimental Agriculture 40, no. 2 (2000): 125. http://dx.doi.org/10.1071/ea98003.
Повний текст джерелаАнотація:
Naturalised pastures across the higher rainfall (>600 mm) perennial pasture zone of south-eastern Australia are less productive than they were, while sown pastures fail to maintain their initial levels of production. Several factors have contributed to this, including lack of knowledge of suitable grazing practices, weed invasion, increasing acid soils, rising water tables and poor management practices during droughts. A key issue in each case is the decline in perennial grass species which is both a cause and effect of the decline in productivity and sustainability of these ecosystems. This paper introduces a volume devoted to the largest collaborative study done to evaluate tactics for better grazing management and to improve the sustainability of perennial pasture ecosystems. Grazing practices to manage the composition of pastures have been largely neglected in pasture research, but are an important first step in improving pasture sustainability. This paper also outlines a new, open communal grazing experimental design which was developed and used across 24 sites on farms in New South Wales, Victoria, Tasmania and South Australia, to evaluate tactics for grazing management. The general aim across these experiments was to maintain (if adequate) or enhance (if degraded), the proportion of desirable perennial grasses in the sward to achieve more sustainable pastures. The results will provide the basis for building more sustainable grazing systems.
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McCormick, Jeff I., Richard C. Hayes, Guangdi D. Li, and Mark R. Norton. "A review of pasture establishment by undersowing with special reference to the mixed farming zone of south-eastern Australia." Crop and Pasture Science 65, no. 10 (2014): 956. http://dx.doi.org/10.1071/cp14049.
Повний текст джерелаАнотація:
Pastures continue to provide essential functions for the mixed-farming zone in south-eastern Australia, where crop and livestock production are integral parts of most farms. Establishment of pastures in this zone needs to be low-cost and preferably with minimal risk. Pastures are typically sown either directly or in combination with a cover-crop (also called undersowing; the practice of sowing pasture seed simultaneously with a crop that is intended for grain production in the first year), so that the establishment cost is offset by income from the sale of grain. The purposes of this review are to: (i) draw together the literature on undersowing pastures, including studies conducted since the previous review in 1965; (ii) understand why there is a discrepancy between research results that generally do not support the practice of undersowing pastures, whereas farmer preference appears to establish pastures under a cover-crop; and (iii) identify critical needs for further research to aid in making decisions about pasture establishment on-farm. Published and unpublished data from the Australian wheatbelt on establishing pastures by undersowing was examined from the 1920s to the present and included seven publications for perennial species from 26 different experiments. Eight publications addressing establishment of annual species were available from 30 experiments. Many trials appear to have been conducted without being analysed or published. A further 16 international publications were reviewed. Generally, cover-crops reduced annual pasture seedset and perennial density even though the pastures established under the cover-cropping were commonly deemed ‘satisfactory’ by the authors. Pasture establishment was improved by reducing the sowing rate of the cover-crop and/or sowing on alternate rows. Technological change during the past 25 years has led to different configurations of seeding machinery, increased use of herbicides and longer cropping phases. Conclusions previously reached may therefore need to be re-assessed. No data published quantified the risks associated with undersowing on a seasonal and regional basis to determine the probability of success, and there are insufficient data to model the complex physiological interactions between crop and pasture, with most experiments focused on basic agronomic parameters. Furthermore, long-term effects of establishment method on total pasture biomass production and subsequent effects on following crops have rarely been demonstrated, because of the short time-frames in which most experiments have been conducted. Farmers in the mixed-farming zone still prefer to establish pastures under a cover-crop because of perceived financial benefit of the practice. This review identifies substantial research gaps to be addressed to improve pasture-establishment decisions.
6
Jones, Roger A. C. "Virus diseases of perennial pasture legumes in Australia: incidences, losses, epidemiology, and management." Crop and Pasture Science 64, no. 3 (2013): 199. http://dx.doi.org/10.1071/cp13108.
Повний текст джерелаАнотація:
This article reviews current knowledge for Australia over the occurrence, losses caused, epidemiology, and management of virus diseases of perennial pasture legumes. Currently, 24 viruses have been found infecting perennial pasture legumes, and one or more viruses have been detected in 21 of these species. These viruses are transmitted by insect vectors, non-persistently or persistently, by contact or via seed. Their modes of transmission are critical factors determining their incidences within pastures in different climatic zones. Large-scale national or state surveys of lucerne (alfalfa) (Medicago sativa) and white clover (Trifolium repens) pastures revealed that some viruses reach high incidences. Infection with Alfalfa mosaic virus (AMV) was very widespread in lucerne stands, and with AMV and White clover mosaic virus (WClMV) in white clover pastures. Several other viruses are potentially important in pastures in these and other perennial temperate/Mediterranean pasture species. Data demonstrating herbage yield losses, diminished pasture persistence, and impaired nitrogen fixation/nodule function are available for AMV in lucerne, and AMV, WClMV, and Clover yellow vein virus in white clover. Integrated Disease Management approaches involving phytosanitary, cultural, chemical, and host resistance control measures are available to minimise virus infection in lucerne and white clover. Research on virus diseases of perennial tropical–subtropical pasture legumes has focussed almost entirely on virus identification, and information on their incidences in pastures, the losses they cause, and how to control them is lacking. Overall, viruses of perennial pasture legumes are least studied in South Australia and the Northern Territory. These and other critical research and development gaps that need addressing are identified.
7
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.
Повний текст джерелаАнотація:
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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Moore, G. A., P. Sanford, P. J. Dolling, and D. Real. "The challenges of developing resilient perennial pastures for a Mediterranean environment – a review for Western Australia." Crop and Pasture Science 72, no. 9 (2021): 613. http://dx.doi.org/10.1071/cp20304.
Повний текст джерелаАнотація:
Perennial pastures are the dominant feedbase in many regions of the world, and offer several advantages when compared with an annual pasture system. In Western Australia (WA) there has been a concerted effort over seven decades to develop new perennial pasture options and expand the adoption of suitable species. The agricultural region of WA (i.e. south-western Australia) is characterised by a Mediterranean climate where the 5–7 month summer drought has proved a considerable challenge with only a small number of the many promising species being adopted commercially. Research, development, and extension have covered a wide range of herbaceous perennial legumes, leguminous and native shrubs, herbs, and temperate and warm season grasses. This paper reviews the literature to determine whether a perennial pasture must satisfy the following criteria to be successful and widely adopted in south-western Australia: (i) sourced from a similar Mediterranean environment and adapted to the target soils; (ii) have a relative advantage over the annual-based system it replaces; (iii) a robust management package; and (iv) a viable seed supply. The findings of this review highlight that perennial pastures must indeed satisfy multiple criteria to be commercially successful. Notably, the requirement for the source of the germplasm to have a good match between climate and soils is less clear because some of the commercially successful species come from diverse environments. We conclude with some key learnings for future perennial pasture development as climate change intensifies the research challenge and the drive for producers to adapt.
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Michalk, D. L., P. M. Dowling, D. R. Kemp, W. McG King, I. J. Packer, P. J. Holst, R. E. Jones, et al. "Sustainable grazing systems for the Central Tablelands, New South Wales." Australian Journal of Experimental Agriculture 43, no. 8 (2003): 861. http://dx.doi.org/10.1071/ea02180.
Повний текст джерелаАнотація:
Pasture degradation is a major issue in the high rainfall zone (>600 mm) of temperate Australia. Characterised by a decline in the perennial grass component, this degradation is responsible for reduced livestock production and implicated in environmental problems, such as dryland salinity, through changed water-use patterns. This paper reports on a multi-disciplinary research program conducted at Carcoar in central New South Wales, one of 6 sites that comprised the Sustainable Grazing Systems National Experiment. The aim of the experiment was to develop more profitable and sustainable pasture systems by evaluating the impact of changes in the perennial grass component on animal production and water-use patterns. Tactical management strategies were evaluated on naturalised and sown perennial grass pastures and on chicory (Cichorium intybus), using a Merino ewe-based first cross lamb enterprise. Data presented showed that grazing deferment over summer, combined with reduced stocking rate, increased perenniality and reduced annual grass weeds compared with continuous grazing. Livestock performance, however, did not always follow trends in available perennial herbage mass. Naturalised and sown pastures were suitable for raising prime lambs, but only chicory had the capacity to finish lambs to market specification without supplementation. With respect to water-use patterns, sown perennial pastures were more successful than naturalised pastures in reducing leakage of water from the root zone, although this seemed to be related mostly to the abundance of the perennial grass in the pasture. From a sustainability perspective, continuously grazed pastures generated higher net cash flows, but had negative environmental impacts, whereas tactically grazed pastures had positive on- and off-farm impacts but lower net cash flows. The implications of these findings for incorporation into future management strategies for sustainable production in high rainfall environments are discussed.
10
Waller, R. A., and P. W. G. Sale. "Persistence and productivity of perennial ryegrass in sheep pastures in south-western Victoria: a review." Australian Journal of Experimental Agriculture 41, no. 1 (2001): 117. http://dx.doi.org/10.1071/ea00049.
Повний текст джерелаАнотація:
Loss of perennial ryegrass (Lolium perenne L.) from the pasture within several years of sowing is a common problem in the higher rainfall (550–750 mm annual rainfall), summer-dry regions of south-eastern Australia. This pasture grass came to Australia from northern Europe, where it mostly grows from spring to autumn under mild climatic conditions. In contrast, the summers are generally much drier and hotter in this region of south-eastern Australia. This ‘mismatch’ between genotype and environment may be the fundamental reason for the poor persistence. There is hope that the recently released cultivars, Fitzroy and Avalon, selected and developed from naturalised ryegrass pastures in south-eastern Australia for improved winter growth and persistence will improve the performance of perennial ryegrass in the region. Soon-to-be released cultivars, developed from Mediterranean germplasm, may also bridge the climatic gap between where perennial ryegrass originated and where it is grown in south-eastern Australia. Other factors that influence perennial ryegrass persistence and productivity can be managed to some extent by the landholder. Nutrient status of the soil is important since perennial ryegrass performance improves relative to many other pasture species with increasing nitrogen and phosphorus supply. It appears that high soil exchangeable aluminium levels are also reducing ryegrass performance in parts of the region. The use of lime may resolve problems with high aluminium levels. Weeds that compete with perennial ryegrass become prevalent where bare patches occur in the pasture; they have the opportunity to invade pastures at the opening rains each year. Maintaining some herbage cover over summer and autumn should reduce weed establishment. Diseases of ryegrass are best managed by using resistant cultivars. Insect pests may be best managed by understanding and monitoring their biology to ensure timely application of pesticides and by manipulating herbage mass to alter feed sources and habitat. Grazing management has potential to improve perennial ryegrass performance as frequency and intensity of defoliation affect dry matter production and have been linked to ryegrass persistence, particularly under moisture deficit and high temperature stress. There is some disagreement as to the merit of rotational stocking with sheep, since the results of grazing experiments vary markedly depending on the rotational strategy used, climate, timing of the opening rains, stock class and supplementary feeding policy. We conclude that flexibility of grazing management strategies is important. These strategies should be able to be varied during the year depending on climatic conditions, herbage mass, and plant physiology and stock requirements. Two grazing strategies that show potential are a short rest from grazing the pasture at the opening rains until the pasture has gained some leaf area, in years when the opening rains are late. The second strategy is to allow ryegrass to flower late in the season, preventing new vegetative growth, and perhaps allowing for tiller buds to be preserved in a dormant state over the summer. An extension of this strategy would be to delay grazing until after the ryegrass seed heads have matured and seed has shed from the inflorescences. This has the potential to increase ryegrass density in the following growing season from seedling recruitment. A number of research opportunities have been identified from this review for improving ryegrass persistence. One area would be to investigate the potential for using grazing management to allow late development of ryegrass seed heads to preserve tiller buds in a dormant state over the summer. Another option is to investigate the potential, and subsequently develop grazing procedures, to allow seed maturation and recruitment of ryegrass seedlings after the autumn rains.
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Thomas, Dean T., Roger A. Lawes, Katrien Descheemaeker, and Andrew D. Moore. "Selection of crop cultivars suited to the location combined with astute management can reduce crop yield penalties in pasture cropping systems." Crop and Pasture Science 65, no. 10 (2014): 1022. http://dx.doi.org/10.1071/cp13436.
Повний текст джерелаАнотація:
Pasture cropping is an emerging farming-systems practice of southern Australia, in which winter grain crops are sown into an established stand of a winter-dormant, summer-growing perennial pasture. There is a pressing need to define times, locations and climates that are suitable for pasture cropping. To evaluate effects of management interventions, agro-environment, and possible interactions on crop and pasture productivity associated with pasture cropping, an AusFarm® simulation model was built to describe a pasture-cropping system based on annual crop and subtropical grass. The model was parameterised using data from field research on pasture cropping with barley cv. Buloke and a C4 subtropical grass, Gatton panic (Panicum maximum cv. Gatton), conducted at Moora, Western Australia. The simulation was run over 50 years using the historical climate data of five southern Australian locations (Cunderdin, Jerdacuttup, Mingenew, and Moora in Western Australia, and Karoonda in South Australia). Two wheat cultivars and one barley crop were considered for each location, to examine the impact of crop phenology on this farming system. Jerdacuttup and Moora favoured pasture cropping, with average barley-yield penalties of 10 and 12%. These locations were characterised by colder growing seasons, more plant-available water at anthesis, and more winter–spring rain. The cereal crops did not rely on stored soil moisture, growing instead on incident rain. The winter–spring growth of the Gatton panic pasture was highest at Mingenew. This generated a high yield penalty, 38% loss under pasture cropping, compared with the other locations. Changing the efficacy of a herbicide application to the pasture when the crop was sown had a strong effect on yield. Yield penalties at Moora and Mingenew reduced to 7 and 29%, respectively, when the proportion of live biomass killed by the herbicide was doubled. Utilisation of soil moisture by the Gatton panic pasture during summer and early autumn had little effect on subsequent grain yield, whereas reduced pasture growth during the winter–spring growing period had a substantial effect on crop yield. Pasture cropping can therefore succeed in agro-climatic regions where crops can be grown on incident rain and pasture growth is suppressed through low temperature or herbicide. Perennial pasture growth should be minimised during the crop growing period through the management of crop sowing date, nitrogen fertiliser application and C4 grass suppression to minimise the effect on stored soil water at crop anthesis.
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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.
Повний текст джерелаАнотація:
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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Doran-Browne, Natalie A., John Ive, Phillip Graham, and Richard J. Eckard. "Carbon-neutral wool farming in south-eastern Australia." Animal Production Science 56, no. 3 (2016): 417. http://dx.doi.org/10.1071/an15541.
Повний текст джерелаАнотація:
Ruminant livestock production generates higher levels of greenhouse gas emissions (GHGE) compared with other types of farming. Therefore, it is desirable to reduce or offset those emissions where possible. Although mitigation options exist that reduce ruminant GHGE through the use of feed management, flock structure or breeding management, these options only reduce the existing emissions by up to 30% whereas planting trees and subsequent carbon sequestration in trees and soil has the potential for livestock emissions to be offset in their entirety. Trees can introduce additional co-benefits that may increase production such as reduced salinity and therefore increased pasture production, shelter for animals or reduced erosion. Trees will also use more water and compete with pastures for water and light. Therefore, careful planning is required to locate trees where the co-benefits can be maximised instead of any negative trade-offs. This study analysed the carbon balance of a wool case study farm, Talaheni, in south-eastern Australia to determine if the farm was carbon neutral. The Australian National Greenhouse Gas Inventory was used to calculate GHGE and carbon stocks, with national emissions factors used where available, and otherwise figures from the IPCC methodology being used. Sources of GHGE were from livestock, energy and fuel, and carbon stocks were present in the trees and soil. The results showed that from when the farm was purchased in 1980–2012 the farm had sequestered 11 times more carbon dioxide equivalents (CO2e) in trees and soil than was produced by livestock and energy. Between 1980 and 2012 a total of 31 100 t CO2e were sequestered with 19 300 and 11 800 t CO2e in trees and soil, respectively, whereas farm emissions totalled 2800 t CO2e. There was a sufficient increase in soil carbon stocks alone to offset all GHGE at the study site. This study demonstrated that there are substantial gains to be made in soil carbon stocks where initial soils are eroded and degraded and there is the opportunity to increase soil carbon either through planting trees or introducing perennial pastures to store more carbon under pastures. Further research would be beneficial on the carbon-neutral potential of farms in more fertile, high-rainfall areas. These areas typically have higher stocking rates than the present study and would require higher levels of carbon stocks for the farm to be carbon neutral.
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Bolland, M. D. A., J. S. Yeates, and M. F. Clarke. "Single and coastal superphosphates are equally effective as sulfur fertilisers for subterranean clover on very sandy soils in high rainfall areas of south-western Australia." Australian Journal of Experimental Agriculture 43, no. 9 (2003): 1117. http://dx.doi.org/10.1071/ea02168.
Повний текст джерелаАнотація:
To reduce leaching of phosphorus (P) from fertilised pastures to shallow estuaries in the high rainfall (>800 mm annual average) areas of south-western Australia, and to supply extra sulfur (S) for subterranean clover (Trifolium subterraneum L.) in pasture, 'coastal superphosphate' was developed as a possible alternative P and S fertiliser to single superphosphate. Coastal superphosphate is made by adding phosphate rock and elemental S to single superphosphate as it comes out of the den before granulation. It has about 3 times more sulfur (S) and one-third the water-soluble P content than single superphosphate. Four long-term (5-year) field experiments were conducted in south-western Australia to compare the effectiveness of single and coastal superphosphate as S fertilisers for subterranean clover pasture grown on very sandy soils that are frequently S deficient after July each year due to leaching of S from soil. Seven different amounts of S were applied as fertiliser annually. Fertiliser effectiveness was assessed from clover herbage yield and S concentration in dried herbage. Fertiliser nitrogen was not applied in these experiments as this was the normal practice for pastures in the region when the research was conducted.Both coastal and single superphosphates were equally effective per unit of applied S for producing dried clover herbage and increasing S concentration in herbage. Previous research on very sandy soils in the region had shown that coastal superphosphate was equally or more effective per unit of applied P for production of subterranean clover herbage. It is, therefore, concluded that coastal superphosphate is a suitable alternative S and P fertiliser for clover pastures on very sandy soils in the region. The concentration of S in dried clover herbage that was related to 90% of the maximum yield (critical S) was about 0.20–0.35% S during August (before flowering) and 0.15–0.20% S during October (after flowering).
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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.
Повний текст джерелаАнотація:
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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Grace, PR, JM Oades, H. Keith, and TW Hancock. "Trends in wheat yields and soil organic carbon in the Permanent Rotation Trial at the Waite Agricultural Research Institute, South Australia." Australian Journal of Experimental Agriculture 35, no. 7 (1995): 857. http://dx.doi.org/10.1071/ea9950857.
Повний текст джерелаАнотація:
The Permanent Rotation Trial at the Waite Agricultural Research Institute in South Australia was established on a red-brown earth in 1925, with predominately cereal-long fallow rotations on 34 adjacent plots. The trial was upgraded in 1948 to include a greater proportion of pasture leys in the rotations and currently contains 11 treatments. The trial is unreplicated; however, each phase of a sequence is represented each year. Seven of the original rotations have remained in an unbroken sequence since 1925: continuous wheat (W), wheat-fallow (WF), wheat-peas (WPe), wheat-pasture-fallow (WPaF), wheatoats- fallow (WOF), wheat-barley-peas (WBPe), wheat-oats-pasture-fallow (WOPaF). For the 11 rotations, soil organic carbon (SOC) in the top 10 cm declined from 2.75% in 1925 to a mean value of 1.56% in 1993. One plot, which had reverted to permanent pasture in 1950, showed the smallest decline with an SOC content of 2.46% in 1993. The greatest declines in SOC were in the 4 original rotations that included fallow phases in the sequence (mean value of 1.22%). In the WF rotation the SOC content had declined from 2.75 to 1.04% during 68 years of cropping. Associated yield decreases showed that the treatment could not sustain production. Soil organic C declined linearly with increasing frequency of fallows and decreasing frequency of pasture in the rotations. Average grain yields (1925-93) in the 7 original sequences ranged from 2.64 t/ha in WOPaF to 0.89 t/ha in the continuous W plot. The linear decline in yields for WBPe, WPaF, WPe, and WOF treatments indicate a convergence in the 1990s under current management, with an average yield of 1.54 t/ha in 1993 and average SOC in the top 10 cm of 1.32%. We hypothesise that the gradual increase in grain yields from the continuous W plot since the 1960s is the result of a gradual build-up of light fraction organic material, which assists in the maintainence of structure and nutrient availability.
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Moore, Andrew D. "Opportunities and trade-offs in dual-purpose cereals across the southern Australian mixed-farming zone: a modelling study." Animal Production Science 49, no. 10 (2009): 759. http://dx.doi.org/10.1071/an09006.
Повний текст джерелаАнотація:
Dual-purpose cereals are employed in the high-rainfall zone of southern Australia to provide additional winter forage. Recently there has been interest in applying this technology in the drier environments of South and Western Australia. It would therefore be useful to gain an understanding of the trade-offs and risks associated with grazing wheat crops in different locations. In this study the APSIM (Agricultural Production Systems Simulator) crop and soil simulation models were linked to the GRAZPLAN pasture and livestock models and used to examine the benefits and costs of grazing cereal crops at 21 locations spanning seven of the regions participating in the Grain & Graze research, development and extension program. A self-contained part of a mixed farm (an annual pasture–wheat rotation plus permanent pastures) supporting a breeding ewe enterprise was simulated. At each location the consequences were examined of: (i) replacing a spring wheat cultivar with a dual-purpose cultivar (cv. Wedgetail or Tennant) in 1 year of the rotation; and (ii) either grazing that crop in winter, or leaving it ungrazed. The frequency of early sowing opportunities enabling the use of a dual-purpose cultivar was high. When left ungrazed the dual-purpose cultivars yielded less grain on average (by 0.1–0.9 t/ha) than spring cultivars in Western Australia and the Eyre Peninsula but more (by 0.25–0.8 t/ha) in south-eastern Australia. Stocking rate and hence animal production per ha could be increased proportionately more when a dual-purpose cultivar was used for grazing; because of the adjustments to stocking rates, grazing of the wheat had little effect on lamb sale weights. Across locations, the relative reduction in wheat yield caused by grazing the wheats was proportional to the grazing pressure upon them. Any economic advantage of moving to a dual-purpose system is likely to arise mainly from the benefit to livestock production in Western Australia, but primarily from grain production in south-eastern Australia (including the Mallee region). Between years, the relationship between increased livestock production and decreased grain yield from grazing crops shifts widely; it may therefore be possible to identify flexible grazing rules that optimise this trade-off.
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Mason, W. K., and G. Kay. "Temperate Pasture Sustainability Key Program: an overview." Australian Journal of Experimental Agriculture 40, no. 2 (2000): 121. http://dx.doi.org/10.1071/ea98002.
Повний текст джерелаАнотація:
This special edition of the Australian Journal of Experimental Agriculture presents papers from work undertaken as part of the Temperate Pasture Sustainability Key Program (TPSKP; see Fig. 1), and presented at a workshop in Sydney in November 1997. TPSKP was initiated by Meat and Livestock Australia (MLA). The Land and Water Resources Research and Development Corporation, the International Wool Secretariat and the Murray Darling Basin Commission were joint funders of some of the individual projects. Most projects were carried out on private properties, and many had producer groups associated with the sites to provide input into treatment selections as well as management guidance and support. This substantial producer input was provided free to the program. The success of TPSKP relied heavily on physical and financial support from State departments of agriculture and conservation, CSIRO and universities, and also on the enthusiasm of these groups to work collaboratively across the 4 south-eastern states. One of the key results of this cooperation was the development of a set of experimental protocols so that measurements taken anywhere in TPSKP could be directly compared. TPSKP aimed to develop the principles for manipulating pasture composition to make grazing systems more productive and sustainable. The program priorities were to: (i) determine by survey the attitudes of producers to grazing management and identify the characteristics of those producers most likely to adopt the program results; (ii) demonstrate by June 1996 that potentially responsive perennial grass-based pastures could be upgraded using grazing management to become a ‘desirable’ pasture for animal production and sustainability; (iii) demonstrate by June 1996 that newly sown perennial grass-based pastures could be maintained in a desirable condition using grazing management; (iv) determine the critical factors responsible for the capacity of perennial grasses to persist, respond to drought, and ameliorate land degradation; (v) develop producers’ skills in pasture species identification, pasture and animal assessment, and feed budgeting, both to enhance their existing management, and to ‘prime’ them for the outputs from TPSKP; (vi) to demonstrate (in phase 2) that improvements in pasture composition and grazing management can have both economic and environmental benefits.
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Jones, R. E., P. M. Dowling, D. L. Michalk, and W. McG King. "Sustainable grazing systems for the Central Tablelands of New South Wales. 5. A bioeconomic framework for assessing the long-term economic benefits of grazing management tactics and implications for sustainability." Australian Journal of Experimental Agriculture 46, no. 4 (2006): 495. http://dx.doi.org/10.1071/ea04196.
Повний текст джерелаАнотація:
There have been significant declines in the perennial grass (PG) content in native and sown pastures across temperate Australia. Not only has this reduced agricultural productivity, it has contributed to more serious degradation, such as loss of soil and biodiversity, decreasing water quality, and dryland salinity caused by rising watertables. Results from the Sustainable Grazing Systems Key Program (SGS) research undertaken at Carcoar on the Central Tablelands of New South Wales were reported by Michalk et al. (2003). This research indicated that grazing management tactics can be used to manipulate pasture composition, thereby changing animal production and water-use patterns. The main grazing tactic investigated was termed a summer grazing rest, where resting was imposed in late spring if PG composition was <50%. Reported in this present paper is an economic framework for valuing the long-term benefits of grazing management tactics. The framework involves the development of a bioeconomic modelling system that links a dynamic programming model with biophysical models for water and environmental processes, soil fertility, pasture growth, livestock energy requirements and the change in pasture species composition. The study concludes that long-term economic returns are improved by strategies, e.g. a summer rest, that lead to an increase in PG composition over time. The study also determined that environmental factors, such as deep drainage, runoff and soil loss, are reduced as perenniality is increased.
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Moore, A. D., P. J. Vickery, M. J. Hill, J. R. Donnelly, and G. E. Donald. "Combining satellite data with a simulation model to describe spatial variability in pasture growth at a farm scale." Australian Journal of Experimental Agriculture 39, no. 3 (1999): 285. http://dx.doi.org/10.1071/ea98109.
Повний текст джерелаАнотація:
Practical application of simulation modelling as a decision aid for grazing system management usually involves an assumption of uniformity of model inputs over a farm paddock or property. In reality, paddocks and farms display high spatial variability in model inputs. There is considerable interest in assessing the significance of this spatial variablity for anmal production and enterprise profitability. This study seeks to demonstrate the use of spatial data with the GRAZPLAN pasture model to provide estimates of annual net primary production from pastures at a farm scale on the Northern Tablelands of New South Wales, Australia. The GRAZPLAN pasture model was validated against data from 2 separate field experiments for a typical improved pasture based on Phalaris aquatica from 1968 to 1972. A spatial coverage, classifying paddocks into 9 pasture types based on a botanical survey, was used to define the pasture parameter sets used in simulations. A Landsat TM satellite image classified to give 3 pasture growth status classes was used to define within-paddock levels of a fertility index used in the simulation model. Simulations over 1975–94 were conducted for all combinations of pasture types and fertility scalar values using climate data for the CSIRO Pastoral Research Laboratory near Armidale. Simulation output was written to a lookup table and imported into a PC-based geographic information system. The spatial data layers were combined to form a display template representing spatial variation in pasture type, pasture condition and fertility. The spatial template was reclassified using the lookup tables to create maps of annual net primary production from pastures. Spatial variability in simulated annual net primary production was greater for the paddocks with diverse mixtures of sown and native species than for the more uniform highly improved or pure native pastures. The difference in response to rainfall of simulated net primary production was greater between different pastures types than between different levels of the fertility index. The resulting maps provide a demonstration of the way in which satellite imagery and other data can be interfaced with a decision support system to provide information for use in precision management of grazing systems. Implementation of such methods as a management tool will depend on development of quantitative spatial data layers which provide accurate and repeatable initial conditions and parameter values for simulation models.
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Pembleton, K. G., R. P. Rawnsley, J. L. Jacobs, F. J. Mickan, G. N. O'Brien, B. R. Cullen, and T. Ramilan. "Evaluating the accuracy of the Agricultural Production Systems Simulator (APSIM) simulating growth, development, and herbage nutritive characteristics of forage crops grown in the south-eastern dairy regions of Australia." Crop and Pasture Science 64, no. 2 (2013): 147. http://dx.doi.org/10.1071/cp12372.
Повний текст джерелаАнотація:
Pasture-based dairy farms are a complex system involving interactions between soils, pastures, forage crops, and livestock as well as the economic and social aspects of the business. Consequently, biophysical and farm systems models are becoming important tools to study pasture-based dairy systems. However, there is currently a paucity of modelling tools available for the simulation of one key component of the system—forage crops. This study evaluated the accuracy of the Agricultural Production Systems Simulator (APSIM) in simulating dry matter (DM) yield, phenology, and herbage nutritive characteristics of forage crops grown in the dairy regions of south-eastern Australia. Simulation results were compared with data for forage wheat (Triticum aestivum L.), oats (Avena sativa L.), forage rape (Brassica napus L.), forage sorghum (Sorghum bicolor (L.) Moench), and maize (Zea mays L.) collated from previous field research and demonstration activities undertaken across the dairy regions of south-eastern Australia. This study showed that APSIM adequately predicted the DM yield of forage crops, as evidenced by the range of values for the coefficient of determination (0.58–0.95), correlation coefficient (0.76–0.94), and bias correction factor (0.97–1.00). Crop phenology for maize, forage wheat, and oats was predicted with similar accuracy to forage crop DM yield, whereas the phenology of forage rape and forage sorghum was poorly predicted (R2 values 0.38 and 0.80, correlation coefficient 0.62 and –0.90, and bias correction factors 0.67 and 0.28, respectively). Herbage nutritive characteristics for all crop species were poorly predicted. While the selection of a model to explore an aspect of agricultural production will depend on the specific problem being addressed, the performance of APSIM in simulating forage crop DM yield and, in many cases, crop phenology, coupled with its ease of use, open access, and science-based mechanistic methods of simulating agricultural and crop processes, makes it an ideal model for exploring the influence of management and environment on forage crops grown on dairy farms in south-eastern Australia. Potential future model developments and improvements are discussed in the context of the results of this validation analysis.
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Schwenke, G. D., M. K. McLeod, S. R. Murphy, S. Harden, A. L. Cowie, and V. E. Lonergan. "The potential for sown tropical perennial grass pastures to improve soil organic carbon in the North-West Slopes and Plains of New South Wales." Soil Research 51, no. 8 (2013): 726. http://dx.doi.org/10.1071/sr13200.
Повний текст джерелаАнотація:
Sown tropical perennial grass pastures may be a means to restore soil organic carbon (C) lost by cropping with conventional tillage to the levels originally present in native grass pastures. To assess this, total organic carbon and related soil properties were measured under sown tropical pastures, conventionally cultivated cropping, and native pastures on 75 Chromosols and 70 Vertosols to 0.3 m depth in the New South Wales North-West Slopes and Plains region of Australia. The impact of several perennial pasture species on soil organic carbon was also assessed in a 6-year-old, sown pasture experiment on a previously cropped Chromosol. Soil cores in 0.1-m segments to 0.3 m were analysed for total organic carbon, total nitrogen (N), pH, and phosphorus (Colwell-P). Mid-infrared scans were used to predict the particulate, humus, and resistant fractions of the total organic carbon. Bulk density was used to calculate stocks of C, N, and C fractions. In Chromosols, total organic carbon in the surface 0–0.1 m was greater under sown tropical pastures (23.1 Mg ha–1) than conventional tillage cropping (17.7 Mg ha–1), but still less than under native pastures (26.3 Mg ha–1). Similar land-use differences were seen for particulate and resistant organic C, and total N. The proportional differences between land uses were much greater for particulate organic C than other measures, and were also significant at 0.1–0.2 and 0.2–0.3 m. Subsurface bulk density (0.1–0.2 m) was lower under sown tropical pastures (1.42 Mg m–3) than conventionally tilled cropping (1.52 Mg m–3). For Vertosols, total organic carbon in the surface 0–0.1 m was greater under sown tropical pastures (19.0 Mg ha–1) and native pastures (20.5 Mg ha–1) than conventional tillage cropping (14.0 Mg ha–1). Similar land-use effects were seen for the particulate and humus organic C fractions, and total N. In the sown pasture species experiment, there was no significant difference in total N, total organic carbon, or any C fraction between soils under a native-grass species mixture, two improved tropical grass species, or a perennial pasture legume. Regular monitoring is required to better discern whether gradual changes are being masked by spatial and temporal variation. The survey results support previous research on Vertosols within the New South Wales North-West Slopes and Plains that show sown tropical grass pastures can improve total organic carbon. Improvements in total organic carbon on Chromosols have not previously been documented, so further targeted soil monitoring and experimentation is warranted for the region.
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Pullman, AL, I. Beveridge, and RR Martin. "Epidemiology of nematode infections of weaner sheep in the cereal zone of South Australia." Australian Journal of Agricultural Research 39, no. 4 (1988): 691. http://dx.doi.org/10.1071/ar9880691.
Повний текст джерелаАнотація:
Trichostrongyloid nematode infections of weaner sheep were investigated at the Turretfield and Minnipa Research Centres in the cereal zone of South Australia over a three-year period (1982-1985). Acquisition of nematode larvae from pasture occurred over a limited period each year, principally during the winter months, and coincided with the elimination of, or a reduction in the numbers of adult nematodes; sheep subsequently resisted challenge by infective larvae. Faecal egg counts were elevated during the summer, but declined to negligible levels during the winter months when larval challenge was at its maximum. Scouring, which was common in untreated sheep during winter at Turretfield, did not occur in regularly treated sheep, but no adverse effects were noted at Minnipa.
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Lewis, D. C., M. D. A. Bolland, R. J. Gilkes, and L. J. Hamilton. "Review of Australian phosphate rock research." Australian Journal of Experimental Agriculture 37, no. 8 (1997): 845. http://dx.doi.org/10.1071/ea96103.
Повний текст джерелаАнотація:
Summary. Most of the research on the effectiveness of phosphorus (P) fertilisers in Australia has involved comparing phosphate rock (PR) or partially acidulated PR (PAPR) with superphosphate (SP) or other water-soluble P fertilisers. There are many estimates of effectiveness (current relative effectiveness or CRE) which compared freshly-applied (current) PR and freshly-applied (current) SP. The CRE values for PR range from <0.1 to 2.5, with a mean value for apatite PR of 0.26 and 0.43 for calcined calcium iron aluminium PR (Calciphos). As measured in field experiments in the years after application, and using current SP as a basis for comparison, the residual effectiveness of PR (residual value or RV) is low and constant for up to 11 years after application. Phosphate rock is 5–30% as effective as current SP. The average value of RV for SP declines by about 40% in the first year after application, followed by a further 15% in the second year, and a further 30% over the remaining 6 years. Values of relative effectiveness and RV, and the rate of decline in RV differ substantially between sites and sometimes between plant species. Laboratory studies of reactions between PR and soil have shown that the poor effectiveness of PR is primarily due to the limited extent and rate of dissolution of these fertilisers compared with the almost complete and rapid dissolution of water-soluble P fertilisers. Many Australian soils are only moderately acid (pH in water >5.5) with low pH buffering capacities and they cannot quickly contribute a large supply of hydrogen ions to promote rapid dissolution of PR. Soils are commonly sandy and have low water-holding capacities; in the strongly seasonal Mediterranean climate of south-western and southern Australia, the fertilised surface soil rapidly dries between rains thereby restricting PR dissolution. This restricted dissolution contributes to the poor agronomic effectiveness of PR fertilisers. Studies in Western Australia have shown that the effectiveness of current and residual PR relative to current SP generally decreases with increasing level of application. Therefore, relative to current SP, PR fertilisers become less effective per unit of PR as more is applied to the soil. Consequently, PR fertilisers frequently cannot support the same maximum yield as current SP. Published work indicates that PR fertilisers cannot be regarded as economic substitutes for SP for most agricultural applications in Australia. However, much Australian research has used low reactive PRs in conditions that are not likely to favour even highly reactive PRs. The soils dry out between rains during the growing season and have insufficient hydrogen ions to cause rapid, extensive dissolution of even reactive PR. Research elsewhere has suggested that reactive apatite PRs can be as effective as SP for suitable soils and environments. These are soils that remain wet for the whole growing season and which contain sufficient hydrogen ions to cause rapid dissolution of reactive PR. Laboratory studies, in which there is no P leaching, on 254 different soils collected from throughout south-western Australia showed that 29 soils, all collected from >800 mm average annual rainfall areas, dissolved >40% highly reactive North Carolina PR, suggesting that in the field these soils could be suitable for highly reactive PRs. Insufficient research has been conducted in the high rainfall areas of Australia, where the environment is more likely to favour highly reactive PR, and PAPR made from highly reactive PR. Therefore, a national program was undertaken in 6 Australian states to identify circumstances under which PRs, including reactive PR and PAPR made from reactive PR, may be economic fertilisers for acidic soils in the high rainfall areas of Australia where agricultural production is largely based on pasture production.
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Badgery, W. B., and D. L. Michalk. "Synthesis of system outcomes for a grazing-management experiment in temperate native pastures." Animal Production Science 57, no. 9 (2017): 1869. http://dx.doi.org/10.1071/an16599.
Повний текст джерелаАнотація:
Increasing the intensity of grazing management from continuous grazing or set-stocking to intensive rotational grazing has been proposed as a way of improving the profitability and environmental outcomes for native pasture-based grazing systems in the high-rainfall zone (HRZ) of southern Australia. The present paper synthesised the results and outcomes of eight papers covering different aspects of a grazing-system study investigating the intensity of grazing management at Panuara (33°27ʹS, 148°56ʹE), 25 km south-west of Orange, New South Wales. The systems analysis covered soils and soil water, pastures, animal production, profitability and business risk by using a combination of field experiments and biophysical modelling. The experimental approach, engagement with stakeholders and the potential impact of the research outcomes are discussed; as are the future directions for grazing system research. Increasing the intensity of grazing management from a 1- to a 20-paddock system resulted in a 21% higher pasture growth, 22% higher stocking rate and 20% higher lamb production per hectare. However, modelling demonstrated that seasonal variability had a greater impact on profitability than did the management system, and whole-farm profitability of the 20-paddock system was lower than that of the 1- and 4-paddock systems due to higher infrastructure costs. Pasture stability was associated with a high perennial grass content (>70%), and a stocking rate of 4.2 ewes/ha for continuous grazing or 5.3 ewes/ha for intensive rotational grazing limited the potential for degradation events. Advantages were identified in fencing and managing production zones, with different production potential within a farm, to improve utilisation across the landscape and efficiency of fertiliser use. The farming-system approach successfully integrated field research with pre- and post-experimental modelling, and with strategic input from an advisory group containing farmers, researchers and advisors, to develop a full understanding of the impact, at a system level, of increasing the intensity of grazing management in the HRZ.
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GÉNIER, FRANÇOIS, and ADRIAN L. V. DAVIS. "Digitonthophagus gazella auctorum: an unfortunate case of mistaken identity for a widely introduced species (Coleoptera: Scarabaeidae: Scarabaeinae: Onthophagini)." Zootaxa 4221, no. 4 (January 19, 2017): 497. http://dx.doi.org/10.11646/zootaxa.4221.4.8.
Повний текст джерелаАнотація:
At risk of committing entomological heresy, we question the identity of a dung-burying beetle species that originates from Africa and has been introduced first into Hawaii and subsequently to Australasia, North America, and South America (Fincher 1986; Edwards 2007; Noriega et al. 2010) for pasture improvement and biological control of dung-breeding flies (Waterhouse 1974; Bornemissza 1979). Under the name Onthophagus gazella (Fabricius 1787), it was the first species selected for introduction into Australia by the CSIRO Dung Beetle Project (Bornemissza 1976; Edwards 2007). Firstly, in 1968, a "tropical strain" was introduced from Hawaii where it had become established after introduction from Zimbabwe in 1957 (Markin & Yoshioka 1998). Later, after establishment of the CSIRO Dung Beetle Research Unit in Pretoria in 1970, a "cold" or "even rainfall strain" was introduced into Australia directly from South Africa (Bornemissza 1976) (even rainfall region = south coast of Eastern Cape). The species was subsequently introduced into the southern continental United States of America (Victoria County, Texas) from Hawaii (Montes de Oca & Halffter 1998) then elsewhere into southeastern and southwestern states from Hawaii and breeding colonies from Australia (Anderson & Loomis 1978). It has since expanded its range through Mexico, Central America, and the Caribbean to coastal Colombia (Kohlmann 1994; Noriega 2002; Noriega et al. 2006, 2011). Expansion of its range within central southern South America (Noriega et al. 2010) has been assisted by introductions into Brazil from the United States of America since the 1980s (Bianchin et al. 1998), and others into Venezuela and Chile (Vidaurre et al. 2008). More recently, it has been introduced into quarantine and field trials in New Zealand (Forgie et al. 2013) using individuals originating from the south coast of the Eastern Cape and Northwest Province of South Africa (S. Forgie, personal communication).
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Pullman, AL, I. Beveridge, and RR Martin. "Corrigendum - Epidemiology of nematode infections of weaner sheep in the cereal zone of South Australia." Australian Journal of Agricultural Research 39, no. 4 (1988): 691. http://dx.doi.org/10.1071/ar9880691c.
Повний текст джерелаАнотація:
Trichostrongyloid nematode infections of weaner sheep were investigated at the Turretfield and Minnipa Research Centres in the cereal zone of South Australia over a three-year period (1982-1985). Acquisition of nematode larvae from pasture occurred over a limited period each year, principally during the winter months, and coincided with the elimination of, or a reduction in the numbers of adult nematodes; sheep subsequently resisted challenge by infective larvae. Faecal egg counts were elevated during the summer, but declined to negligible levels during the winter months when larval challenge was at its maximum. Scouring, which was common in untreated sheep during winter at Turretfield, did not occur in regularly treated sheep, but no adverse effects were noted at Minnipa.
28
Douglas, M. L., M. J. Auldist, J. L. Jacobs, M. C. Hannah, S. C. Garcia, and W. J. Wales. "Quantifying the ruminal degradation of nutrients in three cultivars of perennial ryegrass (Lolium perenne L.) sampled during early spring and summer." Animal Production Science 60, no. 3 (2020): 370. http://dx.doi.org/10.1071/an19002.
Повний текст джерелаАнотація:
Context The Australian dairy industry is characterised by pasture-based feeding systems, where grazed pasture is commonly supplemented with cereal grain to increase milk production of dairy cows. Perennial ryegrass (PRG; Lolium perenne L.) is the most commonly used pasture species, with a wide range of cultivars available. However, the nutritive characteristics and the degradation of nutrients in individual PRG cultivars grown in different environments in Australia are unknown, and significant variation between cultivars may impact on supplementary nutrient requirements. Aims The objective of this experiment was to quantify the extent of ruminal degradation of nutrients in three contrasting PRG cultivars (Bealey NEA2, Trojan NEA2 and Victorian SE) harvested during early spring and summer from Gippsland, northern Victoria and south-west Victoria in Victoria, Australia. Methods Degradation parameters were determined by in situ incubation in the rumens of non-lactating, rumen-fistulated Holstein–Friesian cows for 72 h using a nylon bag technique. Key results During both seasons, Bealey NEA2 had the greatest effective degradability of crude protein and neutral detergent fibre compared with Trojan NEA2 and Victorian SE. Cultivars harvested during early spring had greater effective degradability of crude protein and neutral detergent fibre, and a greater amount of rumen degradable protein compared with cultivars harvested during summer. Cultivars harvested from Gippsland had greater crude protein and neutral detergent fibre effective degradability, as well as a greater amount of rumen degradable protein, whereas cultivars harvested from northern Victoria had a greater amount of undegraded dietary protein. Conclusions These results demonstrate that the ruminal degradation of PRG cultivars declines with increasing maturity, and that there are differences between cultivars and regions; however, differences between seasons are of a greater magnitude and are more important to consider when formulating optimal supplementary grain rations. Implications This research has positive implications for farmers who will be able to understand the degradation of nutrients in PRG, and the amounts of rumen degradable protein and undegraded dietary protein available from pasture during each season. Farmers will be able to use this information to formulate supplementary grain rations that complement the nutrients from pasture and optimise milk production.
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Guy, P. L. "Viruses of New Zealand pasture grasses and legumes: a review." Crop and Pasture Science 65, no. 9 (2014): 841. http://dx.doi.org/10.1071/cp14017.
Повний текст джерелаАнотація:
This article reviews knowledge of 23 plant viruses infecting pasture grasses and legumes in New Zealand. The incidence, ecology and impact of each virus and prospects for control using natural or artificial resistance genes or by vector control is discussed. The most prevalent viruses are Alfalfa mosaic virus and White clover mosaic virus in pasture legumes and Cocksfoot mottle virus, Ryegrass mosaic virus and Barley yellow dwarf virus in pasture grasses. Lucerne Australian latent virus is restricted to the North Island and Red clover necrotic mosaic virus is largely restricted to the South Island. These patterns are likely to be dynamic with ongoing changes in weather patterns, land use, the spread of insect vectors and the continuing introduction of viruses and vectors. The existing and potential threats to 12 pasture species are tabulated and the knowledge gaps for each species highlighted. Control of vectors including aphids, eriophyid mites and soil-borne fungi is probably not economic per se but could be an additional benefit of integrated pest management in pasture and cropping systems. The most cost-effective and practical preventative measures are likely to be the use of virus-tested seed to establish new pastures and the incorporation of resistance genes by conventional breeding or by genetic engineering. Finally, recommendations are made for future research for New Zealand, which is also relevant to other temperate regions of the world.
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Guppy, C. N., C. Edwards, G. J. Blair, and J. M. Scott. "Whole-farm management of soil nutrients drives productive grazing systems: the Cicerone farmlet experiment confirms earlier research." Animal Production Science 53, no. 8 (2013): 649. http://dx.doi.org/10.1071/an12147.
Повний текст джерелаАнотація:
The Cicerone Project included a study of three 53-ha farmlets, each subjected to a different management system. The systems varied first in their input of fertilisers and sown pastures and second in their grazing management. Farmlet A undertook a high level of pasture renovation and had soil fertility targets of 60 mg/kg Colwell phosphorus (P) and 10 mg/kg KCl-40 sulfur (S), while farmlets B and C both had a low rate of pasture renovation and targets of 20 mg/kg P and 6.5 mg/kg S. In addition, both farmlets A and B adopted a flexible rotational grazing regime over the eight paddocks of each farmlet, whereas farmlet C, which had 37 paddocks, adopted intensive rotational grazing. This paper first reviews the literature relating to soil fertility research in the summer-dominant rainfall region of the Northern Tablelands of New South Wales, Australia. It then examines whether the soil fertility targets set for the farmlets were attained and how the consequences of fertiliser management measured in this trial related to earlier research findings. Fertiliser applications, comprising both capital and maintenance rates, were based on soil test results but at times were constrained by the availability of finance. Soil tests over 5 years indicated that only nitrogen (N), P and S varied with time within the farmlets while the other indices of soil fertility remained similar. Phosphorus and S levels increased in response to fertiliser applications whereas N levels responded to increases in legume composition, which was stimulated by the higher P and S levels. Multivariate statistical analyses demonstrated that farmlet productivity was driven by P and S fertility and thus the two farmlets with lower P and S fertility (farmlets B and C) had similar but lower levels of farmlet productivity compared with farmlet A. Significant increases in several measured pasture productivity parameters were observed in response to the higher P and S fertility on farmlet A, especially when climatic conditions were favourable. The results of the Cicerone farmlet experiment confirm the findings of earlier research on the Northern Tablelands, and elsewhere in the high rainfall zone, that has demonstrated that higher soil fertility levels and pasture renovation enhance the productivity of grazing enterprises more than grazing management, without imposing significant risks to the environment.
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Li, Guangdi D., Richard C. Hayes, Jeff I. McCormick, Matthew J. Gardner, Graeme A. Sandral, and Brian S. Dear. "Time of sowing and the presence of a cover-crop determine the productivity and persistence of perennial pastures in mixed farming systems." Crop and Pasture Science 65, no. 10 (2014): 988. http://dx.doi.org/10.1071/cp13447.
Повний текст джерелаАнотація:
Incorporation of perennial pastures into cropping rotations can improve whole-farm productivity, profitability and sustainability of mixed farming systems in southern Australia. However, success in establishing perennial pastures depends on choice of species, time of sowing, method of establishment, seasonal conditions, and whether sowing is under a cover-crop. Field experiments were sown from 2008 to 2010 to determine effects of sowing time and the presence of a cover-crop on the performance of four perennial pasture species, lucerne (Medicago sativa L.), chicory (Cichorium intybus L.), phalaris (Phalaris aquatica L.) and cocksfoot (Dactylis glomerata L.), at Yerong Creek, New South Wales (NSW). Results showed that lucerne was the most productive pasture, followed by chicory and phalaris, with cocksfoot being the poorest performer. Under favourable seasonal conditions, lucerne and chicory pastures produced 29.3 and 25.0 t ha–1 of total dry matter (DM), comprising 71% and 52%, respectively, of sown perennial species in the sward in their second growing season, when sown in autumn. Spring-sown pastures produced 24.6 and 18.3 t ha–1 of total DM in the second season, with 55% and 47% of sown species in the sward being lucerne and chicory, respectively. However, spring-sown pastures contained a very low proportion of subterranean clover (Trifolium subterraneum L.) in the sward in the first 2 years, despite efforts to broadcast seeds at the break of season in the following year. It is recommended that non-legume perennial species, such as chicory and phalaris, be sown in autumn with companion annual legumes until methods are developed and tested to establish annual legumes reliably in spring. However, lucerne can be established in autumn or spring because it can fix its own nitrogen and is not reliant on a companion legume. Cocksfoot cv. Kasbah, in general, appears less suitable than the other perennial species for this medium-rainfall environment in southern NSW. Our study showed that pastures sown without a cover-crop had the most reliable establishment, whereas pastures sown with a cover-crop in a dry year had poor establishment or total failure, as well as a significant reduction of grain yield from the cover-crop. In a wet year, pastures established satisfactorily under a cover-crop; however, growth of the cover-crop still suppressed pasture DM production in subsequent years. Research is under way to model our data to determine the likely financial implications of establishing perennial pastures under cover-crops.
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Sprague, S. J., J. A. Kirkegaard, H. Dove, J. M. Graham, S. E. McDonald, and W. M. Kelman. "Integrating dual-purpose wheat and canola into high-rainfall livestock systems in south-eastern Australia. 1. Crop forage and grain yield." Crop and Pasture Science 66, no. 4 (2015): 365. http://dx.doi.org/10.1071/cp14200.
Повний текст джерелаАнотація:
The development of guidelines for successful dual-purpose (graze and grain) use of wheat and canola in Australia’s high-rainfall zones (HRZ) has mostly emerged from separate wheat- and canola-focused research. Less attention has been placed on the benefits of integrating dual-purpose wheat and canola into pasture-based grazing enterprises. We conducted a farming systems experiment during 2010–11 to evaluate the benefits of integrating wheat and canola as dual-purpose crops into a pasture-based grazing system in Australia’s south-eastern tablelands. We compared forage production and grain yield in three separate crop–livestock systems in which the sheep grazed long-season wheat, winter canola or a combination of these. Initial growth rates were higher in early-autumn-sown canola than wheat in 2010, but were much lower although similar in both crops in 2011. Significant forage was available from both canola (3.1–3.4 t ha–1) and wheat (2.3–2.4 t ha–1) at the onset of grazing, but winter growth rates of wheat were higher than those of canola, leading to increased sheep grazing days (SGD). In the favourable 2010 season, dual-purpose wheat and canola separately provided 2393 and 2095 SGD ha–1, and yielded 5.0 and 1.9 t ha–1 grain, respectively, with an apparent nitrogen limitation in canola. In the drier season of 2011, grazing was reduced to 1455 and 735 SGD ha–1 in wheat and canola, respectively. Wheat yield was reduced from 5.9 to 5.4 t ha–1 grain by grazing, whereas canola yield was unaffected (3.6 t ha–1). In both years, grazing did not affect harvest index or oil content of canola, but harvest index was higher in grazed wheat crops. The yield of wheat and canola crops grazed in sequence did not differ from yield in treatments where animals grazed only a single crop, but the total overall grazing window when crops were grazed sequentially increased by 1054 and 618 SGD ha–1 in wheat, and by 1352 and 1338 SGD ha–1 in canola in 2010 and 2011, respectively. The major benefits of including crops that can be grazed sequentially were the widening of the grazing window and other operational windows (sowing, harvest), along with the rotational benefits for wheat by including canola in the system. Additional benefits to pastures may include eliminating the need to re-sow, because a more productive pasture composition is maintained under lower grazing pressure while stock are on crops, and reduced weed invasion. The commercial availability of new, herbicide-tolerant winter canola varieties provides significant opportunities to underpin the performance of dual-purpose crop sequences on mixed farms in the high-rainfall zone.
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Waters, C., B. Dear, B. Hackney, P. Jessop, and G. Melville. "Trangie wallaby grass [Austrodanthonia caespitosa (Gaudich.) H.P. Linder]." Australian Journal of Experimental Agriculture 48, no. 4 (2008): 575. http://dx.doi.org/10.1071/ea07151.
Повний текст джерелаАнотація:
Trangie wallaby grass, Austrodanthonia caespitosa (Dc1), is a composite of wild ecotypes collected from western New South Wales. A. caespitosa is a widespread native grass adapted to a broad range of environmental conditions but is particularly suited to low rainfall (300–450 mm) areas of south-eastern Australia. In this region, this cultivar has a demonstrated superior persistence to its close relative A. richardsonii (Cashmore) H.P. Linder cv. Taranna and the widely used pasture species, phalaris (Phalaris aquatica cv. Sirolan) and cocksfoot (Dactylis glomerata cv. Currie). This superior persistence was apparent in its ability to recruit new seedlings, even under summer drought conditions. Trangie wallaby grass was maintained under seed increase for 5 years at Trangie Agricultural Research Centre and subsequently at Dareton Agricultural and Advisory Station for 3 years.
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Nordblom, T. L., T. R. Hutchings, R. C. Hayes, G. D. Li, and J. D. Finlayson. "Does establishing lucerne under a cover crop increase farm financial risk?" Crop and Pasture Science 68, no. 12 (2017): 1149. http://dx.doi.org/10.1071/cp16379.
Повний текст джерелаАнотація:
Rainfed farms in south-eastern Australia often combine annual cropping and perennial pasture phases with grazing sheep enterprises. Such diversity serves in managing diseases, pests and plant nutrition while stabilising income in the face of wide, uncorrelated variations in international commodity prices and local weather over time. We use an actuarial accounting approach to capture the above contexts to render financial risk profiles in the form of distributions of decadal cash balances for a representative 1000-ha farm at Coolamon (34°50ʹS, 147°12ʹE) in New South Wales, Australia. For the soil and weather conditions at this location we pose the question of which approach is better when establishing the perennial pasture lucerne (Medicago sativa L.): sowing with the final crop of the cropping phase, or sowing alone following the final crop? It is less expensive to sow lucerne with the final crop, which can provide useful income from the sale of grain, but this practice can reduce pasture quantity and quality in poorer years. Although many years of field research have confirmed that sowing lucerne alone is the most reliable way to establish a pasture in this area, and years of extension messages to this effect have gone out to farmers, they often persist in sowing lucerne with their final cereal crops. For this region, counting all costs, we show that sowing lucerne alone can reduce farm financial risk (i.e. probability of negative decadal cash balances) at stocking rates >10 dry sheep equivalents (DSE)/ha, compared with the practice of sowing lucerne with a cover crop. Establishing lucerne alone allows the farmer the option to profitably run higher stocking rates for higher median decadal cash margins without additional financial risk. At low stocking rates (i.e. 5 DSE/ha), there appears to be no financial advantage of either establishment approach. We consider the level of equity, background farm debt and overhead costs to demonstrate how these also affect risk-profile positions of the two sowing options. For a farm that is deeply in debt, we cannot suggest either approach to establishing lucerne will lead to substantially better financial outcomes.
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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.
Повний текст джерелаАнотація:
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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Li, Guangdi D., Zhongnan Nie, Amanda Bonython, Suzanne P. Boschma, Richard C. Hayes, Andrew D. Craig, Greg M. Lodge, et al. "Evaluation of chicory cultivars and accessions for forage in south-eastern Australia." Crop and Pasture Science 61, no. 7 (2010): 554. http://dx.doi.org/10.1071/cp10011.
Повний текст джерелаАнотація:
The comparative herbage production and persistence of 7 chicory cultivars and 14 accessions collected from diverse regions of the world were evaluated over 3 years in 5 agro-ecological environments across New South Wales (NSW), Victoria (Vic.) and South Australia (SA). Results showed that all cultivars had higher herbage yields than the accessions, but varied greatly among sites. Averaged across all cultivars, total herbage yields were up to 24.6 t DM/ha over 3 years at the Hamilton, Vic. site, but as low as 6.9 and 5.7 t DM/ha at the Wagga Wagga and Bookham, NSW sites, respectively, where chicory only persisted for 2 years. In contrast, the average herbage yield of all accessions was only one-half of that produced by the cultivars at the Hamilton site and about one-third of that at the other 4 sites. All cultivars and accessions persisted well under the favourable climate conditions experienced at the Hamilton site. In contrast, severe drought in 2006 resulted in the death of chicory swards at the Wagga Wagga and Bookham sites, and substantial declines in persistence at the Manilla, NSW and Willalooka, SA sites. Nevertheless, accessions collected from Australia and Asia were more persistent than some of the cultivars and may provide opportunities to select genotypes better adapted to intermittently dry mixed farming systems in south-eastern Australia. Our findings indicated that the current cultivars were best suited to sites similar to the Hamilton site in the winter-dominant, higher rainfall zone of south-eastern Australia. Under these conditions chicory was likely to be productive and persistent for 4 years or longer. In the drier mixed farming zone, chicory may be more suitable in shorter (2–3-year) pasture phases. Further research is required to identify those factors contributing to poor persistence.
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Andrew, M. H., and G. M. Lodge. "The Sustainable Grazing Systems National Experiment. 1. Introduction and methods." Australian Journal of Experimental Agriculture 43, no. 8 (2003): 695. http://dx.doi.org/10.1071/ea02183.
Повний текст джерелаАнотація:
This paper outlines the development and design of the Sustainable Grazing Systems (SGS) National Experiment from the initial call for expressions of interest, through several workshop processes to the final selection and implementation of its 6 component sites, and the general methodology used at each. Sites were located in Western Australia, western Victoria, north-east Victoria, and on the Central Tablelands, North West Slopes, and the eastern Riverina of New South Wales. Sites in Western Australia, north-east Victoria, the North West Slopes, and the eastern Riverina also had subsites. Methods for the sites and subsites (data collection for pastures, livestock, weather, soils and site characterisation) are presented to provide a central reference, and to save duplication in subsequent papers. Descriptions are provided of the location, average annual rainfall, major pasture, soil and stock types, design and number of treatments, and initial soil levels (0–10 cm) of phosphorus, electrical conductivity, and pH for sites and subsites. Also outlined is the major focus of the research undertaken at each site. While sites studied regionally relevant issues, they operated under a common protocol for data collection with a minimum data set being specified for each of 5 unifying themes: pastures, animal production, water, nutrients, and biodiversity. Economic analyses were also undertaken at the macro- and micro-level, and a procedural tool developed for appraising the on- and off-farm impacts of different systems. To give effect to the themes, common database and modelling tools were developed specifically for the national experiment, so that collectively sites comprised a single experiment.
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Turner, NC. "Crop production on duplex soils: an introduction." Australian Journal of Experimental Agriculture 32, no. 7 (1992): 797. http://dx.doi.org/10.1071/ea9920797.
Повний текст джерелаАнотація:
Duplex or texture-contrast soils occur over about 60% of the agricultural areas of south-west Western Australia. Annual crops of wheat, barley, oats, and lupins predominate on these soils, grown in rotation with annual pastures. The climate is characterised by cool, wet winters and hot, dry summers. Crop production is restricted to the winter and spring and is limited by waterlogging in the wet winter months and by water shortage during grain filling in spring. Research on crop production on duplex soils has been undertaken for the past 8 years by a collaborative team from the CSIRO Dryland Crops andyoils Program and the Western Australian Department of Agriculture. This research has been focussed on 3 sites at which processes limiting crop production on duplex soils have been highlighted. This special issue was initiated to summarise that research and to put it in its regional and national perspective. Additionally, opportunity was taken to compare and contrast experiences both within Western Australia and throughout Australia, and to draw out management options for crop production on duplex soils.
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Sudmeyer, R. A., T. Daniels, H. Jones, and D. Huxtable. "The extent and cost of mallee - crop competition in unharvested carbon sequestration and harvested mallee biomass agroforestry systems." Crop and Pasture Science 63, no. 6 (2012): 555. http://dx.doi.org/10.1071/cp12129.
Повний текст джерелаАнотація:
Mallee-based agroforestry has potential to provide farmers with new income sources derived from biofuels, biofeedstocks, and carbon sequestration. Although mallees are planted on >12 700 ha across the south-west of Western Australia, very little commercial harvesting of mallee has occurred to date. The development of biomass processing industries is constrained by lack of robust information regarding the productivity of integrated mallee and agricultural systems. This study addresses this constraint by quantifying the productivity and economics of agricultural crops and pastures growing in the competition zone adjacent to mallee belts at 15 sites across the Western Australian wheatbelt. The sites covered a range of climate and edaphic conditions, three mallee species (Eucalyptus polybractea R Baker, E. loxophleba ssp. lissophloia LAS Johnson and KD Hill, or E. kochii ssp. plenissima (CA Gardner) Brooker), various crop and pasture rotations, and various mallee harvest-management treatments. Mallee–crop competition was negatively correlated with rainfall and positively correlated with mallee age and size, and greater for crops than pasture. Consequently, extent and magnitude of competition were highly variable across sites and years. On average, mallee–crop competition extended 11.3 m from unharvested belts and reduced crop and pasture yields by 36% within 2–20 m of the mallee belts relative to open paddock yields. This is similar to what has been reported for taller tree species. Harvesting mallees reduced competition such that crop and pasture yield was reduced by 22 or 27% relative to open paddock yields for mallees harvested at 3- or 6+-year intervals, respectively. The economic cost of mallee–crop competition on agricultural enterprises was also highly variable between sites, and between years within individual sites. Averaged across all site-years, the opportunity cost of competition was equivalent to forgoing agricultural production for 14.4 m on each side of unharvested mallee belts, or 9–10 m on each side of harvested belts. Farmers with mallee agroforestry systems will need to manage the economic impacts of competition by reducing agricultural input costs in the competition zone, timing crop-grazing rotations with mallee harvests, ensuring that the width of alleys is at least 25 times the height of the mature trees, and possibly root-pruning mallees in unharvested or long harvest interval systems. This research has shown that mallee–crop competition presents a significant cost to farmers and must be considered when designing mallee agroforestry systems. The findings have relevance for the development of appropriate biomass and carbon sequestration pricing benchmarks for mallee plantings.
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Leddin, Clare, Khageswor Giri, and Kevin Smith. "Variation in the Nutritive Characteristics of Modern Perennial Ryegrass Cultivars in South-Eastern Australian Dairy Environments and Prospects for Inclusion in the Australian Forage Value Index (FVI)." Agronomy 12, no. 1 (January 6, 2022): 136. http://dx.doi.org/10.3390/agronomy12010136.
Повний текст джерелаАнотація:
Perennial ryegrass (PRG) is an important forage grown on dairy farms in temperate regions globally, including south-eastern Australia. A forage value index (FVI) providing information on the seasonal production of commercially available PRG cultivars is currently available. Despite the importance of the nutritive value of pasture in dairy farm systems, the nutritive characteristics of PRG cultivars are not currently included in the FVI as they are not routinely measured in cultivar evaluation trials. This study investigated differences between cultivar functional groups (diploid and tetraploid). It also examined differences between individual cultivars within seasons at four locations in south-eastern Australia and examined how trial location affects cultivar ranking. Samples were collected from existing cultivar evaluation trials over a 3-year period and analysed for nutritive characteristics. There were differences (p < 0.05) between diploids and tetraploids for metabolisable energy (ME) and neutral detergent fibre (NDF) in each season at each location with a few exceptions in summer and autumn. Crude protein (CP) differed between functional groups in some seasons at some sites. Spearman rank correlations within season were strong for ME between trial locations (r = 0.78–0.96), moderate to high for NDF (0.51–0.86) and variable for CP (−0.69–0.56). These findings provide guidance on methods for implementing nutritive value testing in cultivar evaluation trials and support the imminent inclusion of ME in the Australian FVI. The ranking of cultivars for ME was more consistent across trial sites compared to NDF and CP, suggesting the latter two traits, in particular CP, are more sensitive to environmental influences. Based on these results, we do not recommend the inclusion of CP as an individual trait in the Australian FVI. A significantly larger dataset and further research on the genotype by environment interactions would be needed to reconsider this. The addition of ME in the Australian FVI will lead to better cultivar choices by farmers and could lead to more targeted perennial ryegrass breeding programs.
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Donald, G. E., J. M. Scott, and P. J. Vickery. "Satellite derived evidence of whole farmlet and paddock responses to management and climate." Animal Production Science 53, no. 8 (2013): 699. http://dx.doi.org/10.1071/an11179.
Повний текст джерелаАнотація:
Satellite imagery was used to assess differences between three treatments in a grazing enterprise systems study of three 53-ha farmlets on the Northern Tablelands of New South Wales, Australia. The study involved a comparison between a typical control farmlet (B) with one with higher levels of sown pasture and soil fertility (A) and one employing intensive rotational grazing (C). Landsat thematic mapper data were used to derive normalised difference vegetation index (NDVI) and spectral class images for eight dates from before the commencement of the farmlet trial (June 2000) to annual spring measurements in September–October of each year from 2000 to 2006 across all paddocks of each farmlet. The Landsat imagery taken before the commencement of the farmlet treatments (June 2000) showed only small differences between the three farmlets, confirming that the allocation of land to the farmlets had been without bias. The assessments using Landsat NDVI in spring over 7 years showed differences in green herbage resulting from the variation in rainfall received over different years as well as differences between the farmlets. The Landsat NDVI images showed increasing and significant differences in pasture greenness over time, especially between Farmlet A and Farmlets B and C. In addition, there were significant differences in pasture spectral classes between Farmlet A and Farmlets B and C, with a significant correlation with higher levels of sown perennial and annual grasses and legumes on Farmlet A. Using different statistical tools, several relationships were found between NDVI and spectral class data and explanatory variables of farmlet, paddock, sowing phase, modelled soil moisture and recent grazing activity. The moderate resolution Landsat data across the entire area of each farmlet proved to be especially useful for assessing pastures within every paddock used in this farmlet study. In addition, moderate resolution imaging spectro radiometer NDVI satellite data were collated for weekly intervals from September 2003 to December 2006 in order to assess seasonal pasture growth patterns on each of the farmlets. These patterns were significantly correlated with a growth index calculated from temperature and available soil moisture, and showed that the growth on the three farmlets was closer to a highly productive reference paddock than a low input, unsown pasture in another reference paddock. The satellite data facilitated the detection of significant differences in pasture botanical composition, soil fertility, grazing management, climate and season. The ready availability of quality remote sensed imagery, combined with the significance of the relationships established, confirms that the technology is a valuable objective tool for both farming systems research and for managing entire farms.
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Behrendt, K., J. M. Scott, D. F. Mackay, and R. Murison. "Comparing the climate experienced during the Cicerone farmlet experiment against the climatic record." Animal Production Science 53, no. 8 (2013): 658. http://dx.doi.org/10.1071/an12300.
Повний текст джерелаАнотація:
Farming systems research conducted under dryland conditions is subject to the vagaries of the climate during the experimental period. Whether such an experiment experiences a representative series of climatic years must be examined in relation to the longer term climatic record. The Cicerone Project’s farmlet experiment was conducted on the Northern Tablelands of New South Wales, Australia, to investigate the profitability and sustainability of three different management systems: one managed under typical, moderate-input conditions (farmlet B); a second which employed a higher level of pasture inputs and soil fertility (farmlet A); and a third which focussed on the use of moderate inputs and intensive rotational grazing (farmlet C). The climate experienced during the 6.5-year experimental period was compared with the 118-year climatic record, using a biophysical simulation model of grazed systems. The model utilised the long-term daily climate data as inputs and provided outputs that allowed comparison of parameters known to affect grazed pastures. Modelled soil-available water, the number of soil moisture stress days (SMSDs) limiting pasture growth, and growth indices over the experimental period (2000–06) were compared with data over the climatic record from 1890 to 2007. SMSDs were defined as when the modelled available soil moisture to a depth of 300 mm was <17% of water-holding capacity. In addition, minimum temperatures and, in particular, the frequency of frosts, were compared with medium-term (1981–2011) temperature records. Wavelet transforms of rainfall and modelled available soil water data were used to separate profile features of these parameters from the noise components of the data. Over the experimental period, both rainfall and available soil water were more commonly significantly below than above the 95% confidence intervals of both parameters. In addition, there was an increased frequency of severe frosting during the dry winters experienced over the 6.5-year period. These dry and cold conditions were likely to have limited the responses to the pasture and grazing management treatments imposed on the three farmlets. In particular, lower than average levels of available soil water were likely to have constrained pasture production, threatened pasture persistence, and reduced the response of the pasture to available soil nutrients and, as a consequence, livestock production and economic outcomes. Ideally, dryland field experimentation should be conducted over a representative range of climatic conditions, including soil moisture conditions both drier and wetter than average. The drier than average conditions, combined with a higher than normal frequency of severe frosts, mean that the results from the Cicerone Project’s farmlet experiment need to be viewed in the context of the climate experienced over this 6.5-year period.
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Yates, Colin J., and Richard J. Hobbs. "Temperate Eucalypt Woodlands: a Review of Their Status, Processes Threatening Their Persistence and Techniques for Restoration." Australian Journal of Botany 45, no. 6 (1997): 949. http://dx.doi.org/10.1071/bt96091.
Повний текст джерелаАнотація:
Temperate eucalypt woodlands were once widespread throughout southern Australia and Tasmania. Following European settlement, woodlands were cleared for agriculture, or grazed and converted to pasture. In the wheatbelts of south-western and south-eastern Australia, woodlands have been almost completely eliminated from the landscape with as little as 3% of some woodland types remaining. As a consequence, some temperate eucalypt woodland communities are amongst the most poorly conserved ecosystems in Australia. The main effect of widespread clearing and grazing has been the loss of habitat. This has had a devastating impact on the woodland flora and fauna. A number of species have become extinct and many are threatened; many others have undergone regional and local population declines. Woodlands now occur throughout much of their former range as remnants of varying size, quality and isolation. Many of these are under threat from further clearing, rising saline water tables and increased inundation, livestock grazing, nutrient enrichment, soil structural decline, altered fire regimes and the invasion of exotic weeds. The degradation and loss of biodiversity in temperate eucalypt woodlands will continue unless clearing stops and the management of remnants changes; this will invariably involve ecological restoration both at the patch and landscape level. The review discusses approaches to restoration and reveals that there are few data in the published literature describing techniques for reversing degrading processes and restoring diversity structure and function in remnant woodlands. This information is urgently needed. Past research on temperate eucalypt woodlands has focused on identifying the processes of degradation and these are now relatively well documented. There is a need to shift the focus of research to developing solutions for these problems.
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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.
Повний текст джерелаАнотація:
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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Dowling, P. M., D. R. Kemp, P. D. Ball, C. M. Langford, D. L. Michalk, G. D. Millar, P. C. Simpson, and R. P. Thompson. "Effect of continuous and time-control grazing on grassland components in south-eastern Australia." Australian Journal of Experimental Agriculture 45, no. 4 (2005): 369. http://dx.doi.org/10.1071/ea03104.
Повний текст джерелаАнотація:
Declining grassland productivity is a major concern in southern temperate Australia. Continuous grazing is thought to be a primary contributor to this decline, which is associated with the loss of perennial grasses. Landholders are evaluating grazing management strategies that might curb the loss of perennials and increase long-term productivity. This study reports on a comparison between continuous grazing and time-control grazing with sheep and cattle using a paired-paddock design at 5 locations in south-eastern Australia (lat. 30–42°S) over 6 years (1994–99). Pasture herbage mass, grassland species composition and basal cover of perennial grasses were assessed at 6-monthly intervals. Species abundance data were analysed by ANOVA, ordination (multi-dimensional scaling) and splining procedures to assess comparative trends between the 2 management treatments at each site. Species were categorised into major functional groups for analysis. Over all 5 sites there were few consistent differences between management treatments (continuous grazing v. time-control grazing). Basal cover was greater on the time-control grazing management compared with continuous grazing for most of the experimental period at 3 sites, but the initial values were also greater, resulting in a non-significant management × time interaction. Based on this study, we conclude that there was no apparent medium-term benefit of a multi-paddock rotational (time-control grazing) grazing system over continuous grazing for encouraging and maintaining a favourable botanical composition. The benefits for land managers from employing systems such as time-control grazing may accrue through other mechanisms. The study also highlights some of the difficulties with conducting on-farm paired-paddock research.
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Birrell, H. A., and R. L. Thompson. "Effect of environmental factors on the growth of grazed pasture in south-western Victoria." Australian Journal of Experimental Agriculture 46, no. 4 (2006): 545. http://dx.doi.org/10.1071/ea03048.
Повний текст джерелаАнотація:
This paper presents work from several studies on pasture production that were conducted in south-west Victoria at the Pastoral Research Institute, Hamilton. The frequency with which pasture growth commenced for each week of autumn in the years from 1965 to 1991 was assessed. The median period for the commencement of growth was in the third week of March (although the average date was March 27). Autumn data from several trials conducted over 3 decades were collated and analysed. A relationship between the grazed pasture yield (average of stocking rates plots) at the end of autumn and the rainfall showed that 200 mm of rainfall in the 3 months to the end of May was optimal while higher rainfall depressed the growth. The average daily growth rates of introduced pasture (perennial rye grass, Lolium perenne L. cv. Victorian, phalaris, Phalaris aquatica L. cv. Australian, subterranean clover Trifolium subterranneum L. and volunteer species) were measured in 2- and 4-week growth periods (G 2 and G 4, kg DM/ha.day) for the seasonal growth cycles over 4 years (1980–84 except 1983) when grazed by Merino wether sheep at stocking rates of 10, 13 or 18 sheep/ha. The rainfall throughout the study was lower than normal. Although differences in the animal performance between the stocking rates were only small, at the low stocking rate capeweed (Arctotheca calendula L.) in patches became the major component of the sward. Greater variation in G 2 than in G 4 indicated that growth responded quickly to current environmental conditions. A nonlinear regression accounted for 74% of the variance in G 2 when related to the 3 climatic factors of daylength, soil temperature at 10 cm depth and the soil moisture to a depth of 10 cm, and a plant factor of green herbage yield. The 26 % of unaccounted variance appears to be associated with an effect of stocking rate, possibly botanical composition. The botanical composition was not continuously monitored hence the only sward character included in the investigation was herbage yield. Comparison of the patterns of pasture growth from different latitudes indicated that while the growth pattern in south-western Victoria is erratic, it is intermediary between Mediterranean and temperate pasture types. Understanding this aspect has implications for improving the efficiency of animal production in this environment.
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Ryan, WJ, D. Pratchett, and BL McIntyre. "Alternative turnoff strategies for Kimberley beef cattle. 1. Live animal performance and carcass characteristics." Rangeland Journal 9, no. 2 (1987): 61. http://dx.doi.org/10.1071/rj9870061.
Повний текст джерелаАнотація:
In June 1980, 190 Kimberley Shorthorn steers from five properties in the Kimberley were divided into three age categories. Half were sent to Chapman Research Station (CRS) in the agricultural area of Western Australia and the remainder stayed at Ord Regeneration Research Station (ORRS) in the Kimberley. Animals in both locations grazed for either one or two pasture growing seasons and a third group was fed a concentrate ration based on grain after the first growing season. Cattle lost between 20-30 kg in handling and transport south which, together with the reduced initial grazing season, led to gains of only 50 kg while those in the north gained around 100 kg. In the second grazing season at both locations animals gained around 140 kg. Animals at ORRS laid down more fat than those at CRS. Animals fed on concentrate rations in the agricultural area grew significantly faster, but had poorer food conversion and were leaner compared with those fed in the Kimberley.
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Bolland, M. D. A., and W. K. Russell. "Changes in chemical properties of 48 intensively grazed, rain-fed dairy paddocks on sandy soils over 11 years of liming in south-western Australia." Soil Research 48, no. 8 (2010): 682. http://dx.doi.org/10.1071/sr09199.
Повний текст джерелаАнотація:
Soil testing was conducted during 1999–2009 to determine lime and fertiliser phosphorus (P), potassium (K), and sulfur (S) requirements of intensively grazed, rain-fed, ryegrass dairy pastures in 48 paddocks on sand to sandy loam soils in the Mediterranean-type climate of south-western Australia. The study demonstrated that tissue testing was required in conjunction with soil testing to confirm decisions based on soil testing, and to assess management decisions for elements not covered by soil testing. Soil testing for pH was reliable for indicating paddocks requiring lime to ameliorate soil acidity, and to monitor progress of liming. Soil P testing proved reliable for indicating when P fertiliser applications were required, with no P being required when soil-test P was above the critical value for that soil, and when no P was applied, tissue testing indicated that P remained adequate for ryegrass production. Soil testing could not be used to determine paddocks requiring fertiliser K and S, because both elements can leach below the root-zone, with rainfall determining the extent of leaching and magnitude of the decrease in pasture production resulting from deficiency, which cannot be predicted. The solution is to apply fertiliser K and S each year, and use tissue testing to improve fertiliser K and S management. Research has shown that, for dairy and other grazing industries in the region, laboratories need measure and report every year soil pH and soil-test P only, together with measuring every 3–5 years the P-buffering index (estimating P sorption of soil), organic carbon content, and electrical conductivity.
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Fleming, P. J. S., J. D. Croft, and H. I. Nicol. "The impact of rabbits on a grazing system in eastern New South Wales. 2. Sheep production." Australian Journal of Experimental Agriculture 42, no. 7 (2002): 917. http://dx.doi.org/10.1071/ea01107.
Повний текст джерелаАнотація:
Much research, time and money have been invested in the control of rabbits in Australia, yet the relationship between rabbit density and livestock production losses has not been quantified. We experimentally investigated the variations in sheep production parameters caused by 4 densities of rabbits, 0, 24, 48 and 72 rabbits/ha. Medium to strong wool merino wethers were run at a constant stocking rate in replicated plots with rabbits at 4� different densities. Sheep liveweight and body condition and wool production variables were measured over 3�years. Low to medium densities of rabbits were not found to reduce liveweights of wethers, whereas wethers run with the high density of rabbits were significantly lighter. The presence of rabbits reduced the body condition of sympatric sheep with the lowest body condition recorded at the high rabbit density. Mean greasy fleece weights, wool yields and clean-fleece weights were significantly different between densities of rabbits. Wethers run with the high rabbit density grew less wool than the wethers run with the other 3 densities of rabbits. The cumulative gross return per ha from wool production was highest for the medium rabbit density and lowest at high rabbit density. At the conclusion of this short-term experiment, the presence of some rabbits enhanced returns from wool production because of lower fibre diameter and comparable clean-fleece weights of fleeces grown at low and medium rabbit densities. These production characteristics might have been caused by synergistic effects on pasture growth or a sheep stocking rate that was too conservative for the prevailing seasonal conditions. At high rabbit density, competition for pasture between rabbits and sheep overrode possible synergistic and understocking effects. The economic implications of the presence of rabbits on merino sheep production are discussed.
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Robertson, M. J., D. Gaydon, D. J. M. Hall, A. Hills, and S. Penny. "Production risks and water use benefits of summer crop production on the south coast of Western Australia." Australian Journal of Agricultural Research 56, no. 6 (2005): 597. http://dx.doi.org/10.1071/ar04249.
Повний текст джерелаАнотація:
Summer crops grown during the summer fallow in a Mediterranean-type climate have the potential to produce out-of-season biomass and grain, increase water use, and reduce deep drainage. The potential effects of growing grain sorghum on components of the water balance, sorghum biomass and grain production, and yield of subsequent wheat crops were investigated by simulation using APSIM and long-term climate data from the Esperance district. Sorghum was simulated as part of 3 systems: (1) as an opportunity crop following wheat harvest, (2) as a fallow replacement after pasture removal and before entering a cropping phase, or (3) as a fallow replacement after a failed or waterlogged winter crop. Simulations were conducted for the period 1957–2003 at Myrup (mean annual rainfall 576 mm), Scaddan (408 mm), and Salmon Gums (346 mm). Sorghum was assumed to have a similar rooting depth to wheat. In order to gain confidence in using APSIM for these investigations, tests were initially conducted against field data involving summer and winter crops in sequence and measurements of soil water dynamics. Data sets also varied in summer rainfall, species (forage sorghum, grain sorghum, Japanese millet), and soil type (deep sand, and medium and shallow duplex). Overall, the simulations showed that incorporation of a sorghum crop increased transpiration by 10–30 mm/year, made the soil profile drier by a similar amount at wheat sowing, and consequently reduced deep drainage by 3–25 mm/year, depending upon cropping system and location. Long-term average drainage results were dominated by large episodes in wet years. The increased transpiration from the summer crop, although reducing drainage in wet years, could not eliminate drainage. Following wheat yields were reduced by an average of 200–400 kg/ha, corresponding to a reduction of 10% at wetter and 30% at drier locations. In the 2 fallow replacement systems, sorghum biomass was produced in nearly every simulated season. However, averaged over all seasons, sorghum grain production was much less reliable comprising only 10–20% of biomass. In the opportunity system, sorghum produced biomass in only 1 in 3 seasons at Salmon Gums and Scaddan and 1 in 2 at Myrup. Grain was produced in 1 in 5 seasons at all 3 locations, underlining the riskiness of this opportunity niche for summer crops in the Esperance district. Although summer cropping was shown to result in modest reductions in deep drainage, it also comes at a cost to wheat production. The largest effects on drainage and most reliable biomass production were seen in the systems where the summer crop was grown following pasture removal or a failed (waterlogged) winter crop. This research has also shown that recent farmer and researcher experiences of summer cropping are likely to be more favourably biased towards prospects for summer cropping than indicated by long-term simulations because of their longer-term perspective.