Journal articles on the topic 'Austrodanthonia'
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1
Jacobs, Surrey. "A new combination in Austrodanthonia (Gramineae)." Telopea 9, no. 3 (January 5, 2002): 741. http://dx.doi.org/10.7751/telopea20024011.
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Garden, D. L., N. J. S. Ellis, M. A. Rab, C. M. Langford, W. H. Johnston, C. Shields, T. Murphy, M. Holmberg, K. B. Dassanayake, and S. Harden. "Fertiliser and grazing effects on production and botanical composition ofnative grasslands in south-east Australia." Australian Journal of Experimental Agriculture 43, no. 8 (2003): 843. http://dx.doi.org/10.1071/ea02216.
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The effects of application of superphosphate and grazing on production and botanical composition of native grasslands were investigated at 3 locations in the high rainfall zone of south-east Australia. These studies were conducted as part of the Sustainable Grazing Systems Key Program, which investigated various aspects of grassland productivity and sustainability between 1996 and 2001. Grasslands in this study either had high contents of Themeda australis or Austrodanthonia spp., or were based on a degraded Austrodanthonia spp. grassland with a high content of annual and weedy species. All sites used increasing levels of superphosphate application (nil, low, medium and high) as treatments, with clover being added in some treatments at 1 site, and herbicide in 1 treatment at another site. Grazing (sheep) was continuous at 1 site (with stocking rates matched to pasture productivity) and intermittent at other sites, with grazing being dictated by available herbage between defined trigger points. Climate was monitored and changes in soil P, herbage mass, botanical composition, ground cover and sheep production recorded. Changes in composition resulting from the treatments varied between sites. At the continuously grazed Austrodanthonia spp. site, there was a decline in native perennial grasses throughout the experiment and an increase in exotic annual grasses in spring where superphosphate was applied. The grassland at the T. australis site remained relatively stable, which may have been due to the limited amount of grazing applied. The degraded Austrodanthonia�spp. grassland showed wide seasonal fluctuations in annual species. There were no clear effects of treatments at the latter 2 sites. Sheep production increased with increased superphosphate application at the continuously grazed Austrodanthonia spp. site, but there was little effect at the other 2 sites. Recommendations are made for sustainable management of native grasslands depending on their current botanical state.
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Thapa, R., D. R. Kemp, D. L. Michalk, W. B. Badgery, and A. T. Simmons. "Seedling recruitment of native perennial grasses within existing swards." Crop and Pasture Science 62, no. 7 (2011): 591. http://dx.doi.org/10.1071/cp10212.
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Two field experiments, one each on Austrodanthonia spp. and Bothriochloa macra, investigated the effects of biomass manipulation, seed level modification, site preparation and pasture composition on the recruitment of native perennial grass seedlings. The experiments coincided with drier than average years and although successful emergence of seedlings occurred, survival was extremely low. In the Austrodanthonia experiment, control treatments resulted in the emergence of only 1 seedling/m2, whereas there were 130/m2 in the best treatment which had biomass cut with plant material removed, seed added, and the soil surface scarified. Insecticide treatments increased emergence as seed-harvesting ants are common in these systems, but the benefits were small. Similarly, B. macra had no emergence in the control treatment compared with 73 seedlings/m2 in the best treatment, which was pasture cropped, and had seed added and herbicide applied. Availability of microsites may be a major constraint to B. macra emergence, as soil disturbance through pasture cropping substantially increased seedling numbers (279/m2). The effects of herbicide on emergence were small with the largest being related to bare ground and litter biomass. Austrodanthonia seedling numbers at emergence were related to bare ground, litter and green biomass. Survival of young Austrodanthonia plants 24 weeks after emergence was negatively related to plant cover, but only in treatments where plant material was cut and removed. The success of survival was determined at 52 weeks after emergence and the number of young plants that survived in both experiments seemed to have been influenced by the presence of competitive biomass of existing plants.
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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.
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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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Islam, M. Anowarul, Peter M. Dowling, Paul J. Milham, Lindsay C. Campbell, Brent C. Jacobs, and Denys L. Garden. "Ranking acidity tolerance and growth potential of Austrodanthonia accessions." Grassland Science 52, no. 3 (September 2006): 127–32. http://dx.doi.org/10.1111/j.1744-697x.2006.00057.x.
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Lodge, G. M. "Studies of seed production in two Austrodanthonia grass cultivars." Australian Journal of Agricultural Research 53, no. 11 (2002): 1197. http://dx.doi.org/10.1071/ar01173.
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Studies were conducted in 1993–94 on 2 native grass cultivars, Austrodanthonia richardsonii (Link) H.P.�Linder (syn. Danthonia richardsonii Cashmore) cv. Taranna and A. bipartita (Link) H.P. Linder (syn. D. linkii Kunth) cv. Bunderra, to quantify the important morphological factors affecting seed production (as measured by seed weight, g/plant). Experiments also examined the influence of nitrogen (N) application and investigated the effects of time and method of harvest on seed production and subsequent germination. For both cultivars, inflorescence and floret number accounted for the highest proportion of the variation in seed production per plant (R2 = 0.873 and 0.686 for Taranna and Bunderra, respectively). Although N applied (0, 25, and 50 kg/ha) at the late vegetative or early flowering stage, or split applications at both times, had no significant effect (P > 0.05) on the seed production per plant of Taranna and Bunderra, further studies of N effects are required. In 1993 and 1994, time of inflorescence harvest and method of harvest had no significant effect on inflorescence number and seed production of Taranna and Bunderra and no significant effect on the subsequent germination of Bunderra seed. However, in 1993, harvesting at an early stage of flowering (10% of florets white and fluffy) reduced Taranna seed production by 17% compared with the mean and decreased (P < 0.05) seed germination by about 10%. In 1994, harvesting at early flowering (5% florets white and fluffy) reduced Taranna seed production by a mean of around 55% compared with harvesting at 50% maturity, and subsequent seed germination was also lower (P < 0.05) for the early harvest time. Application of 1 L/ha of paraquat (a.i. 200 g/L of paraquat dichloride) at mid-flowering to desiccate the crop in 1993 had no significant effect on the germination of Taranna and Bunderra caryopses. The implications of these data for commercial seed production are discussed.
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Garden, D. L., G. M. Lodge, D. A. Friend, P. M. Dowling, and B. A. Orchard. "Effects of grazing management on botanical composition of native grass-based pastures in temperate south-east Australia." Australian Journal of Experimental Agriculture 40, no. 2 (2000): 225. http://dx.doi.org/10.1071/ea98010.
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Grazing management strategies to alter botanical composition of native pastures were investigated at 4 locations in the high rainfall zone of south-east Australia, including Tasmania. These studies were conducted as part of the Temperate Pasture Sustainability Key Program, which evaluated the effects of grazing management on a wide range of pasture types between 1993 and 1996. Pastures in this study were based on Aristida ramosa/Bothriochloa macra, Microlaena stipoides–Austrodanthonia spp. or Themeda triandra–Austrodanthonia spp. Seasonal rests, increased grazing pressure in spring, mob stocking and cutting for hay were compared to continuous grazing at all sites. In addition, specific local treatments were tested at individual sites. Changes in composition resulting from the treatments were minimal at most sites. This may have been due to a combination of the inherent stability of the pastures, the relatively short duration of the experiments, and the drought conditions experienced, which minimised differences between treatments. Some strategies to alter composition of natural pastures are suggested. In the Aristida–Bothriochloa pasture there was a general decrease in Aristida and an increase in Bothriochloa, which was largely unaffected by the type of grazing management applied. The combination of drought conditions and increasing grazing pressure was sufficient to alter composition without specific management strategies being necessary. In the Themeda–Austrodanthonia pasture, resting in spring, 12-month rests or cutting for hay (which involved a spring rest) allowed Themeda to increase in the pasture. The Microlaena–Austrodanthonia pastures were very stable, especially where annual grass content was low. However, certain treatments allowed Microlaena to increase, a result which is regarded as being favourable. The major effects in these latter pastures were on undesirable species. Vulpia spp. were reduced by resting in autumn and increased spring grazing pressure, while Holcus lanatus was increased dramatically by resting in spring and was also increased by resting in autumn or winter, but only when conditions were suitable for growth of this species. In many cases, treatment differences were only expressed following recovery from drought, showing that timing of grazing management to achieve change is critical.
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Rogers, M. E. "The response of four perennial grass species to sodium chloride salinity when irrigated with saline waters." Australian Journal of Agricultural Research 58, no. 3 (2007): 225. http://dx.doi.org/10.1071/ar06156.
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The response of 4 temperate grass species (Lolium perenne cv. Victorian, Thinopyrum ponticum cv. Tyrell, Austrodanthonia richardsonii cv. Taranna, A. bipartita cv. Bunderra) to saline irrigated conditions was evaluated over 4 seasons at Tatura in northern Victoria. This experiment followed earlier research where the salt tolerance of ~20 species of grasses was evaluated in the greenhouse. Field plots were established under non-saline conditions and were irrigated with saline water at 1.6, 2.5, and 4.5 dS/m. Measurements made on these plots included dry-matter production, tissue ion (Na+, Cl–, K+, Mg2+, Ca2+) concentrations, in vitro dry-matter digestibility, root distribution, and soil chemistry. Soil salinity (EC1 : 5) and sodicity (SAR1 : 5) levels peaked at 0.30–0.60 m depth and reached 1.3 dS/m and 9.8, respectively, for the highest saline irrigation treatment. Cumulative plant dry-matter production was lower in T. ponticum compared with the Austrodanthonia species and L. perenne at all salinity levels, but in relative terms there was no difference in the salt tolerance among any of the 4 species (the reduction in dry weight at 4.5 dS/m was 10–15% for all species). Leaf tissue concentrations of Na+ and Cl– were significantly lower in A. richardsonii and A. bipartita compared with T. ponticum and L. perenne, and in vitro dry-matter digestibility tended to be greater in L. perenne under saline conditions than in the other 3 species. This research suggests that the 2 native Austrodanthonia species can be grown under moderately saline conditions—either under saline irrigation or in a dryland discharge area—in environments where perennial ryegrass may also be grown.
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., M. A. Islam, P. M. Dowling ., P. J. Milham ., L. C. Campbell ., and B. C. Jacobs . "Evaluation of Austrodanthonia Accessions for Acid Tolerance and Growth Potential." International Journal of Agricultural Research 2, no. 10 (October 1, 2007): 849–61. http://dx.doi.org/10.3923/ijar.2007.849.861.
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Garden, D. L., P. M. Dowling, D. A. Eddy, and H. I. Nicol. "The influence of climate, soil, and management on the composition of native grass pastures on the central, southern, and Monaro tablelands of New South Wales." Australian Journal of Agricultural Research 52, no. 9 (2001): 925. http://dx.doi.org/10.1071/ar98184.
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Pastures on 126 properties on the central, southern, and Monaro tablelands were surveyed to determine their botanical composition. Data on climate, soils, pasture sowing, fertiliser history, and stock management were collected to relate current composition to environmental factors and previous management. Native grass-based pastures were found to be widespread, and in many cases, pastures were dominated by native grasses, despite many decades of pasture improvement. Seventeen genera of native perennial grasses comprising over 35 species were identified. The most common species on the central tablelands were Austrodanthonia spp., Bothriochloa macra, and Microlaena stipoides; on the southern tablelands, Austrodanthoniaspp. and M. stipoides; and on the Monaro, Poa spp., Austrodanthonia spp., Themeda australis, and Austrostipa spp. Soil type was the most important factor affecting species distribution, and other soil attributes such as texture, pH, P, and N were also important. Environmental (rainfall) and management (superphosphate application, stock type, stocking rate) factors also influenced distribution. The significant areas of native grass pastures that were found suggest a decline in sown species and a recolonisation of sown pastures with native grasses. The potential for manipulation of botanical composition of these grasslands is discussed, together with their value for production and sustainability.
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Waters, C., G. Melville, D. Coates, J. Virgona, A. Young, and R. Hacker. "Variation in morphological traits among and within populations of Austrodanthonia caespitosa (Gaudich.) H.P. Linder and four related species." Australian Journal of Botany 59, no. 4 (2011): 324. http://dx.doi.org/10.1071/bt10204.
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The native perennial grasses Austrodanthonia spp. are widespread and of great agricultural economic importance to large areas of southern Australia. However, little is known of the adaptive genetic variation that exists within wild populations. Intra-specific genetic variation has significant implications for the restoration and management of native plant communities because different seed sources may exhibit differences in adaptation. Using two common garden studies, we measured variation in morphological traits (flowering and growth) and water-use efficiency (carbon-isotope discrimination Δ) of Austrodanthonia caespitosa (Gaudich.) H.P. Linder and related species (A. bipartita, A. eriantha, A. fulva and A. setacea) and related this variation to environmental characteristics. Most variation for all species occurred among populations suggesting ecotypic variation. The significant relationship between flowering and growth characteristics of A. caespitosa and both large-scale climatic variables such as spring rainfall and sunshine hours and small-scale site characteristics such as shading provides evidence for trait-dependent adaptation at different scales. While components of fecundity such as flowering time and number of inflorescences represent important fitness traits, for other traits such as intrinsic water use there were no significant differences between populations. We discuss the implication of these results to both growth characteristics and sourcing seed.
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Thapa, R., D. R. Kemp, and M. L. Mitchell. "Climatic conditions for seedling recruitment within perennial grass swards in south-eastern Australia." Crop and Pasture Science 63, no. 4 (2012): 389. http://dx.doi.org/10.1071/cp12162.
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Recruitment of new perennial grass plants within existing grassland ecosystems is determined by seed availability, suitable microsites, nutrients and climatic conditions, water and temperatures. This paper reports on the development of criteria to predict recruitment events using modelled soil moisture conditions associated with recruitment of species in five field experiments at Orange (Phalaris aquatica), Trunkey Creek (Austrodanthonia spp.), and Wellington (Bothriochloa macra) in central New South Wales, Australia, and the frequency of those conditions during the past 30 years. Recruitment events were recorded when a rainfall event (median 68 mm across the three sites) kept the surface volumetric soil moisture (0–50 mm) above the permanent wilting point for at least 15 continuous days, allowing for, at most, two ‘dry days’ in between. A key finding from our study is that rainfall events creating favourable soil moisture conditions for seedling emergence typically occurred in the second half of February, sometimes extending to early March. Previously it was thought that recruitment would more likely occur through autumn, winter, and spring when rainfall in southern Australia is more reliable. The 30 years’ data (1975–2004) showed that the P. aquatica site had a median of 20 continuous moist days each year in February–March, whereas, there were 16 and 10 days for the Austrodanthonia and B. macra sites, respectively. The probabilities of exceeding seven or 15 continuous days of moist surface soil were 98% and 78% at the P. aquatica site, 91% and 49% at the Austrodanthonia site, and 73% and 30% at the B. macra site, and indicated that some recruitment is possible in most years. These analyses were extended to several sites across New South Wales, Victoria, and Tasmania to estimate the frequency with which recruitment could occur within natural swards. Across these sites, the probabilities of exceeding seven continuous days of soil moisture were >55% and of exceeding 15 continuous days were lower, which showed that suitable climatic conditions exist during late summer–early autumn across south-eastern Australia for a recruitment event to occur. Future research may show that the criteria developed in this paper could have wider regional application.
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Boschma, S. P., M. J. Hill, J. M. Scott, and G. G. Rapp. "The response to moisture and defoliation stresses, and traits for resilience of perennial grasses on the Northern Tablelands of New South Wales, Australia." Australian Journal of Agricultural Research 54, no. 9 (2003): 903. http://dx.doi.org/10.1071/ar02185.
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A field experiment was conducted to study the effects of defoliation and moisture stresses on perennial pasture grasses and to identify traits associated with their resilience. The experiment, conducted near Armidale on the Northern Tablelands of NSW, studied 4 introduced perennial grass species (Phalaris aquatica, Festuca arundinacea, Dactylis glomerata, and Lolium perenne) and 2 native grass species (Microlaena stipoides and Austrodanthonia richardsonii) subjected to 3 moisture regimes (non-stress moisture, moderate drought, and severe drought) and 2 defoliation intensities (severe and moderate). Basal area, herbage mass, phenological growth stage, nitrogen concentration, root mass, and rooting depth were compared over 2 independent 6-month periods: spring–summer (1 September 1994–28 February 1995) and summer–autumn (1 December 1994–31 May 1995). Multiple regression was used to determine which traits were important for determining plant resilience.The differences between species and their respective responses were evident in the traits measured. In general, basal area tended to increase over summer and show little change during autumn. Severe defoliation stimulated plant growth, resulting in higher harvested herbage mass than from those moderately defoliated. Reproductive development was suppressed by severe drought and reduced by moderate drought. Severe defoliation suppressed flowering of Dactylis and Lolium at both drought intensities, compared with moderate defoliation. Phalaris, Festuca, and Austrodanthonia were the deepest rooting species during spring–summer, and Dactylis the shallowest. All species had similar rooting depths during summer–autumn, with those under severe and moderate drought having the deepest and shallowest rooting, respectively.Carbohydrate reserves and basal area were important traits for determining plant resilience during spring–summer. During summer–autumn, maintaining basal area and plant biomass through moderate grazing was important for resilience.
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King, W. McG, P. M. Dowling, D. L. Michalk, D. R. Kemp, G. D. Millar, I. J. Packer, S. M. Priest, and J. A. Tarleton. "Sustainable grazing systems for the Central Tablelands of New South Wales. 1. Agronomic implications of vegetation - environment associations within a naturalised temperate perennial grassland." Australian Journal of Experimental Agriculture 46, no. 4 (2006): 439. http://dx.doi.org/10.1071/ea04039.
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Temperate perennial grass-based pastures dominate the high rainfall zone of south-eastern Australia and support a major livestock production industry. This area has experienced a recent change in overall pasture condition, however, typified by a reduction in the abundance of perennial grasses and an increasingly prominent winter-annual grass weed component. Improving the condition and productivity of these pastures can be achieved by improved management but this requires better knowledge of the interactions between management options and pasture species composition and of the interaction between pasture vegetation and the complex effects of a heterogeneous landscape. This paper reports the results of an intensive survey of a 60-ha paddock that was designed to identify the species present, determine their patterns of distribution and examine the relationships between pasture vegetation and the environment. The survey of species present in late summer was supplemented by the identification of seedlings that later emerged from extracted soil cores and by soil physical and chemical analyses. Data were analysed using ordination and interpreted with GIS software so that topographic features could be considered. The most frequently identified taxa were Hypochaeris radicata, Austrodanthonia spp. and Bothriochloa spp. (in late summer) and Vulpia spp., Bromus molliformis and Trifolium subterraneum (winter-annual species). Austrodanthonia spp. were commonly found on the drier ridges and more acid soils with lower phosphate levels. These were also the areas dominated in spring by Vulpia spp. and were generally lower in plant species richness overall. The most species-rich areas occurred downslope where soil fertility was higher and less moisture stress was presumably experienced. The measured environmental factors explained a substantial proportion of the variation in the vegetation dataset, which underlined the importance of considering landscape effects in the management of typical tablelands pastures.
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Lodge, G. M. "Effects of sowing method and competitor species and presence on Phalaris and Austrodanthonia establishment and persistence." Australian Journal of Experimental Agriculture 40, no. 6 (2000): 813. http://dx.doi.org/10.1071/ea99157.
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Two experiments were conducted on plots sown in autumn 1992, at Tamworth in northern New South Wales. The first compared the establishment of 3 perennial grasses when sown as monocultures or with competitors in either broadcast-sown swards or alternate row-sown plots. Sowing rate and species of competitor were also examined as factors affecting perennial grass establishment. Perennial grasses were Austrodanthonia richardsonii (synonym Danthonia richardsonii) cv. Taranna, A. bipartita (synonym D. linkii) cv. Bunderra, and Phalaris aquatica cv. Sirosa. Competitors were Trifolium subterraneum var. brachycalycinum cv. Clare, T. repens cv. Haifa, and Lolium rigidum cv. Wimmera. In spring 1992, competitors were removed from 144 of the 288 plots to prevent them from seeding. A second experiment compared the longer-term (1993–96) dry matter yield and persistence of these perennial grasses under continuous grazing in plots were the competitor was present in year 1 (1992) or in all years (1992–96). In spring 1992, mean dry matter yield of perennial grass was higher (P<0.001) in row-sown plots then those sown by broadcasting. Mean dry matter yield of perennial grass was lowest at low sowing rate, but not significantly different at medium and high sowing rates (about 350 kg DM/ha). Compared with the monocultures, the presence of a competitor reduced mean perennial grass dry matter yields by 48, 69 and 85%, respectively for white clover, subterranean clover and annual ryegrass. Perennial grass plant numbers were highest (P<0.001) in the medium and high sowing rates of the monocultures and in white clover competitor plots and lowest (P<0.001) in all broadcast-sown plots, where annual ryegrass was the competitor. By spring 1996, white clover and annual ryegrass had declined to a low level in the pasture in all plots and the only major competitor was subterranean clover (1200 kg DM/ha, 40% plant frequency). Mean dry matter yields were highest (P<0.001) for Sirosa in 1993, but with dry conditions in 1994 and continuous grazing they were highest for Bunderra in all other years. The implications of these data for devising sowing strategies to maximise the establishment of perennial grasses and their long-term persistence in this environment are discussed.
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Boschma, S. P., J. M. Scott, M. J. Hill, J. R. King, and J. J. Lutton. "Plant reserves of perennial grasses subjected to drought and defoliation stresses on the Northern Tablelands of New South Wales, Australia." Australian Journal of Agricultural Research 54, no. 8 (2003): 819. http://dx.doi.org/10.1071/ar02184.
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The effects of defoliation intensity and drought severity on levels of water-soluble carbohydrate (WSC), fructan, and etiolated regrowth of 6 important perennial grasses were investigated. The experiment was conducted under a rain-out shelter at Armidale, NSW, Australia, using 6 perennial grass species (Phalaris aquatica cv. Sirosa, Festuca arundinacea cv. Demeter, Dactylis glomerata cv. Porto, Lolium perenne cv. Victorian, Microlaena stipoides cv. Shannon, and Austrodanthonia richardsonii cv. Taranna) subjected to 3 moisture regimes (non-stress moisture, and moderate and severe drought) and 2 defoliation intensities (moderate and severe) over 2 seasonal sequences (spring–summer and summer–autumn).The range in WSC, fructan, and etiolated regrowth of the species varied, with Festuca and Lolium having the highest WSC and fructan concentrations. Austrodanthonia had the lowest WSC concentration of the species. Unlike the introduced species, the natives did not store fructans. The species varied in their response to the treatments imposed. Festuca and Phalaris had the highest etiolated regrowth and showed the greatest effect of defoliation intensity. Etiolated regrowth appeared to be a sensitive measure of plant status, showing the fragile nature of some of the species.The effect of defoliation intensity and drought varied with season. Defoliation intensity had little effect on carbohydrate reserves of all species, except Festuca, during summer of the spring–summer experimental season. During the summer–autumn experimental season, severe defoliation reduced the rate of accumulation during the period December–April. Drought affected carbohydrate accumulation and utilisation. Carbohydrates that had been accumulated at the end of spring of the spring–summer experimental season in plants affected by drought were utilised during summer. However, if drought commenced in summer, carbohydrate accumulation continued for 120 days in all species studied, and 180 days in Lolium and Phalaris.Autumn appeared to be a period when plant reserves were particularly susceptible to stress. The importance of WSC, fructans, and etiolated regrowth as measures of plant reserves, and their role in persistence were discussed.
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Cole, Ian, Jean Metcalfe, and Terry Koen. "The effect of removing seed from florets on germination and field establishment in a Wallaby Grass (Austrodanthonia fulva) accession." Ecological Management and Restoration 5, no. 2 (August 2004): 134–36. http://dx.doi.org/10.1111/j.1442-8903.2004.201-3.x.
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Hovenden, M. J., F. Miglietta, A. Zaldei, J. K. Vander Schoor, K. E. Wills, and P. C. D. Newton. "The TasFACE climate-change impacts experiment: design and performance of combined elevated CO2 and temperature enhancement in a native Tasmanian grassland." Australian Journal of Botany 54, no. 1 (2006): 1. http://dx.doi.org/10.1071/bt04194.
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The potential impacts of climate change on both natural and managed ecosystems are far-reaching and are only beginning to be understood. Here we describe a new experiment that aims to determine the impacts of elevated concentration of CO2 ([CO2]) and elevated temperature on a native Themeda–Austrodanthonia-dominated grassland ecosystem in south-eastern Tasmania. The experimental site contains 60 vascular plant species. The experiment combines the latest developments in free-air CO2 enrichment (FACE) technology with the use of infrared (IR) heaters to mimic environmental conditions expected to exist in the year 2050. The CO2 concentration in the FACE treatments is reliably maintained at 550 µmol mol–1 and leaf temperature is elevated by an average of 2.1°C by the IR treatment, with 1-cm soil temperature being elevated by 0.8°C. Measurements being made in the experiment cover plant ecophysiological responses, plant population dynamics and community interactions. Soil processes and ecosystem effects, including nutrient cycling and plant animal interactions, are also being investigated. Collaborations are invited from interested parties.
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Nie, Z. N., R. P. Zollinger, and J. L. Jacobs. "Performance of 7 Australian native grasses from the temperate zone under a range of cutting and fertiliser regimes." Crop and Pasture Science 60, no. 10 (2009): 943. http://dx.doi.org/10.1071/cp09067.
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This glasshouse study aimed to examine the performance of 7 Australian native grasses and their responses to different cutting and fertiliser regimes. The 7 native grasses comprised 2 wallaby grasses (Austrodanthonia bipartita cv. Bunderra and Austrodanthonia setacea, Woodhouse ecotype), 2 weeping grasses (Microlaena stipoides cv. Bremmer and ecotype Coleraine), 1 spear grass (Austrostipa mollis, ecotype Lexton), 1 red-leg grass (Bothriochlora macra, ecotype Hamilton), and 1 kangaroo grass (Themeda triandra, ecotype Yass). For each of the 7 grasses, 64 pots each containing 9 plants were arranged in a 4 cutting intensity × 4 fertiliser level factorial design with 4 replicates. The cutting intensity treatments involved (1) cutting to 2 cm at 3–5-week intervals; (2) cutting to 5 cm at 3–5-week intervals; (3) cutting to 10 cm at 3–5-week intervals; and (4) cutting to 2 cm based on leaf stage. The fertiliser regimes included low, medium, and high fertility treatments by applying various rates of phosphorus, and the treatment with addition of compost tea. Herbage accumulation, shoot and root growth, plant survival and tiller density, nutritive characteristics, and leaf stage were monitored. All grass lines produced the lowest herbage mass when cut to 2 cm above ground at 3–5-week intervals. Cutting to 5 cm or to 2 cm based on leaf stage favoured herbage accumulation of Lexton spear grass, Hamilton red grass, Yass kangaroo grass, and Coleraine weeping grass. Cutting to 10 cm favoured herbage accumulation of Bremmer weeping grass and wallaby grass. Cutting to 10 cm together with high fertiliser application considerably increased herbage accumulation in comparison with treatments with low fertiliser application or with compost tea. Shoot and root biomass were maximised when plants were cut to 10 cm above ground, except Lexton spear grass which had highest root biomass when plants were managed based on leaf stage. Plant survival was dramatically affected by defoliation intensity and varied among species. Plant survival declined when plants were cut to 2 cm above ground for most species. Overall, native grasses were considered to have good nutritive characteristics with crude protein ranging from 17 to 22% and neutral detergent fibre from 48 to 60%. Results from this study indicate that it may be possible to use leaf stage as a determinant for the commencement of grazing native species. Optimum leaf stages that could be used as a grazing management guide were on average 3.4 for wallaby grass, 4.2 for weeping grass, 3 for spear grass, 3.8 for red-leg grass, and 4.4 for kangaroo grass. However, further work is required to better define this for likely seasonal variation between C3 and C4 species.
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HOVENDEN, MARK J., KAREN E. WILLS, REBECCA E. CHAPLIN, JACQUELINE K. VANDER SCHOOR, AMITY L. WILLIAMS, YUI OSANAI, and PAUL C. D. NEWTON. "Warming and elevated CO2 affect the relationship between seed mass, germinability and seedling growth in Austrodanthonia caespitosa , a dominant Australian grass." Global Change Biology 14, no. 7 (March 26, 2008): 1633–41. http://dx.doi.org/10.1111/j.1365-2486.2008.01597.x.
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Hill, J. O., R. J. Simpson, J. T. Wood, A. D. Moore, and D. F. Chapman. "The phosphorus and nitrogen requirements of temperate pasture species and their influence on grassland botanical composition." Australian Journal of Agricultural Research 56, no. 10 (2005): 1027. http://dx.doi.org/10.1071/ar04279.
Full textAbstract:
Grassland production in southern Australia is generally based on phosphorus (P)- and nitrogen (N)-deficient soils. Use of P-fertiliser is necessary for high production in higher rainfall zones and economic pressures are increasing the need to apply fertiliser more widely and consistently. The P and N requirements of 10 temperate pasture species were examined to understand how increased fertiliser use will affect grassland botanical composition. The plant species fell into 2 main groups with respect to their critical external P requirements (P application rates required to achieve 90% of maximum yield) : those with a high requirement (Trifolium subterraneum, Hordeum leporinum, Bromus molliformis, Microlaena stipoides, and Phalaris aquatica), and those with a low requirement (Lolium rigidum, Vulpia spp., Austrodanthonia richardsonii, and Holcus lanatus). The critical external N requirements of H. leporinum, L. rigidum, and B. molliformis were significantly higher than those of A. richardsonii, Arctotheca calendula, and H. lanatus. Species that ‘tolerate’ nutrient stress were relatively abundant in unfertilised grazing systems and tall ‘competitor’ species were dominant in fertilised pasture under low grazing pressure. The abundance of the species present in fertilised pastures grazed for high utilisation was negatively correlated with their relative growth rates and it is hypothesised that this may indicate that abundance was determined by tolerance or avoidance of grazing.
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Waters, C., B. G. Murray, G. Melville, D. Coates, A. Young, and J. Virgona. "Polyploidy and possible implications for the evolutionary history of some Australian Danthonieae." Australian Journal of Botany 58, no. 1 (2010): 23. http://dx.doi.org/10.1071/bt09138.
Full textAbstract:
Polyploidy is a widespread feature of some plants that allows for rapid speciation and occurs widely in Poaceae. However, there have been few studies of Australian native grasses reporting the distribution patterns of cytotypes and examining the potential role of different cytotypes in adaptation. We determined chromosome number for 48, 113, 8, 43 and 33 plants of Austrodanthonia bipartita (Link) H.P.Linder, A. caespitosa (Gaudich.) H.P.Linder, A. eriantha (Lindl.) H.P.Linder, A. fulva (Vickery) H.P.Linder and A. setacea (R.Br.) H.P.Linder, respectively, representing 28 wild populations collected in central western New South Wales. A widespread distribution is reported for tetraploids (2n = 48), whereas diploids (2n = 24) and a limited number of hexaploids (2n = 72) appear to be associated with northern and western populations. In all populations, coexistent cytotypes were found, although tetraploids were the most widespread cytotype for the most commonly occurring species, A. caespitosa. The occurrence of low frequencies of putative intermediate cytotypes, particularly triploids, in all five species provides evidence for inter-specific hybridisation and/or intra-specific crossing between cytotypes. The lack of common ecological factors (climate, edaphic or micro-site) that clearly distinguish diploid from tetraploid A. caespitosa plants provides further evidence for hybridisation between cytological races of this species.
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Stevens, Toni A., Murray C. Evans, William S. Osborne, and Stephen D. Sarre. "Home ranges of, and habitat use by, the grassland earless dragon (Tympanocryptis pinguicolla) in remnant native grasslands near Canberra." Australian Journal of Zoology 58, no. 2 (2010): 76. http://dx.doi.org/10.1071/zo09076.
Full textAbstract:
The grassland earless dragon (Tympanocryptis pinguicolla) is a habitat specialist restricted to the highly fragmented native temperate grasslands of the Australian Capital Territory (ACT) and nearby New South Wales (NSW). These grasslands, which are listed as an endangered ecological community, continue to be affected by a range of processes including development and overgrazing. Although changes to its habitat present a significant threat to the grassland earless dragon, little is known about its spatial and habitat requirements. We used radio-tracking to study the home-range areas and habitat requirements of 10 adult lizards in native grassland adjacent to Canberra, ACT. We found that burrows excavated by arthropods are an important resource for grassland earless dragons, with individuals having one or two home burrows around which they maintained home ranges of between 925 m2 and 4768 m2. Fidelity to these burrows increased with the onset of winter, indicating their importance as over-winter refuge sites. Within the native grasslands, grassland earless dragons were found to use a broad range of grassland structure as habitat. This result contrasts with the prevailing view that these dragons are confined to well drained, minimally disturbed areas, which include large patches of short grass dominated by Austrodanthonia. We conclude that habitat management (i.e. grazing, mowing, burning) for this species should aim to retain structural heterogeneity of native grasslands rather than impose a uniform structure.
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Hovenden, Mark J., Karen E. Wills, Jacqueline K. Vander Schoor, Rebecca E. Chaplin, Amity L. Williams, Michaela J. Nolan, and Paul C. D. Newton. "Flowering, seed production and seed mass in a species-rich temperate grassland exposed to FACE and warming." Australian Journal of Botany 55, no. 8 (2007): 780. http://dx.doi.org/10.1071/bt07107.
Full textAbstract:
Long-term effects of climate change on plant communities must be mediated by reproductive and recruitment responses of component species. From spring 2003 until autumn 2006, we monitored flowering and seed-production responses to free air CO2 enrichment (FACE) and 2°C warming in a species-rich, nutrient-poor southern temperate grassland, by using the TasFACE experiment. There were no effects of either FACE or warming on the proportion of species flowering in any year. Flowering, seed production and seed mass were not significantly affected by FACE, warming or their interaction in most species. Some species, however, did respond significantly to simulated global changes. These responses generally were not governed by life history, but there were two distinct trends. First, warming increased the proportion of the population that flowered in perennial grasses but not in other species types. Second, flowering and seed production of both perennial woody dicots responded strongly to the interaction of FACE and warming, with Bossiaea prostrata producing most seeds in warmed FACE plots and Hibbertia hirsuta producing the most in unwarmed FACE plots. FACE increased seed mass 4-fold in the perennial C3 grass Elymus scaber (P < 0.01) but substantially reduced seed mass of the perennial C3 grass Austrodanthonia caespitosa (P < 0.02) and the perennial forb Hypochaeris radicata (P < 0.02), with the remainder of species unaffected. Our results indicate that warming and elevated CO2 had little effect on seed production in the temperate grassland ecosystem. The few significant affects there were, however, are likely to have substantial implications for community composition and structure.
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Nie, Z. N., S. Miller, G. A. Moore, B. F. Hackney, S. P. Boschma, K. F. M. Reed, M. Mitchell, et al. "Field evaluation of perennial grasses and herbs in southern Australia. 2. Persistence, root characteristics and summer activity." Australian Journal of Experimental Agriculture 48, no. 4 (2008): 424. http://dx.doi.org/10.1071/ea07136.
Full textAbstract:
Field experiments were carried out at seven sites in southern Australia from 2002 to 2006 to measure changes in plant frequency, root characteristics and summer activity for a range of grass and herb species or cultivars. Annual rainfall during the experimental period was on average 75 mm lower than the long-term average. Plant frequency differed significantly between species and between sites. Temperate grasses generally had higher frequencies than subtropical grasses, native grasses and herbs. Cocksfoot (Dactylis glomerata cvv. Currie, Porto), tall wheat grass (Thinopyrum ponticum cv. Dundas), winter-active tall fescue (Festuca arundinacea cvv. Fraydo, Resolute MaxP) and phalaris (Phalaris aquatica cvv. Atlas PG, Australian) were the most persistent of the temperate perennial species over the experimental period. The frequency of most cultivars declined from year 2 to year 4 after establishment, but the frequency of kikuyu (Pennisetum clandestinum cv.Whittet) and wallaby grass (Austrodanthonia richardsonii cv. Taranna) increased by over 5% from year 2 to year 3, and cocksfoot (cv. Currie) increased from year 3 to year 4. At two sites where measurements were made, there were significant differences in rooting depth between species. Whittet kikuyu was the deepest among all species with a rooting depth of up to 2 m, followed by phalaris, tall fescue, grazing brome (Bromus stamineus) and tall wheat grass. Root density was affected by plant genotype and soil structure. Root density of the species varied significantly in the subsoil (0.1–1.1 m) and deeper subsoil (1.1–2 m) but not in the topsoil (0–0.1 m). Green-leafiness over summer was generally higher for subtropical grasses, native grasses, herbs and some summer-active temperate grasses, than most temperate grasses with high summer dormancy.
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Boschma, S. P., G. M. Lodge, and S. Harden. "Seedling competition of lucerne in mixtures with temperate and tropical pasture species." Crop and Pasture Science 61, no. 5 (2010): 411. http://dx.doi.org/10.1071/cp09349.
Full textAbstract:
Two replacement series studies were conducted to quantify the competitive ability of seedlings of Medicago sativa (lucerne) sown in mixtures with temperate and tropical species. A temperate mixtures study (Expt 1) consisted of lucerne cv. Genesis sown with each of Phalaris aquatica (phalaris) cv. Atlas PG, Lolium arundinaceum (tall fescue) cv. Resolute MaxP, Cichorium intybus (chicory) cv. Puna, Trifolium subterraneum (subterranean clover) cv. Clare, Austrodanthonia richardsonii (wallaby grass) cv. Taranna and Avena sativa (forage oats) cv. Eurrabie. There was also an additional mixture of chicory and subterranean clover. A tropical grass mixtures study (Expt 2) included Genesis lucerne sown with each of Panicum coloratum var. makarikariense cv. Bambatsi, Dicanthium aristatum cv. Floren, Chloris gayana (Rhodes grass) cv. Katambora, Digitaria eriantha subsp. eriantha cv. Premier and Bothriochloa bladii subsp. glabra cv. Swann. In Expt 1, lucerne-phalaris mixtures were equally competitive, whereas lucerne-tall fescue mixtures over-yielded. Chicory was aggressive in mixtures with lucerne and subterranean clover; similarly forage oats was more competitive than lucerne. Subterranean clover was competitive against lucerne at harvest 1, but by harvest 2 the low cutting height had reduced its competitiveness. Lucerne was more aggressive than wallaby grass. In Expt 2, all tropical grass-lucerne mixtures over-yielded; however, lucerne was generally more competitive than the grasses, except for Rhodes grass at harvest 1. While our study indicated that mixtures of lucerne seedlings with phalaris or tall fescue may be compatible, mixtures with tropical grasses were more likely to result in lucerne seedling dominance. This competitiveness may be overcome by either spatial or temporal separation and we discuss the concept of using mixtures to exploit environmental niches.
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Hill, J. O., R. J. Simpson, A. D. Moore, P. Graham, and D. F. Chapman. "Impact of phosphorus application and sheep grazing on the botanical composition of sown pasture and naturalised, native grass pasture." Australian Journal of Agricultural Research 55, no. 12 (2004): 1213. http://dx.doi.org/10.1071/ar04090.
Full textAbstract:
Botanical composition (basal cover) was measured in 4 replicated pasture treatments based on Phalaris aquatica and Trifolium subterraneum at Hall, ACT (unfertilised with low and high stocking rate; fertilised with low and high stocking rate) and in 2 unreplicated pasture treatments based on native perennial grasses (Austrodanthonia spp. and Microlaena stipoides) and T. subterraneum at Bookham, NSW (unfertilised and low stocking rate; fertilised and high stocking rate). Current economic pressures are encouraging graziers to increase their use of phosphorus (P) fertiliser and to adopt higher stocking rates. The objective of the research was to determine the changes in botanical composition that may result from these changes in grazing systems management. At Hall, annual species differed in their responses to P fertility. Notably, basal cover of Bromus spp. increased significantly with P application, whereas Vulpia spp. decreased significantly. Basal cover of T. subterraneum also increased significantly with P application when stocking rate was high, but was reduced by P application if stocking rate was low. Basal cover of perennial grasses (P. aquatica and Holcus lanatus) was significantly higher at low stocking rate when P was applied. The botanical composition of high stocking rate treatments was relatively stable over time, which contrasted with less stable composition at low stocking rate. At Bookham, fertilised pasture in unreplicated paddocks appeared to have a higher basal cover of productive annual species (i.e. Bromus spp. and T. subterraneum), but native perennial grasses appeared to have lower basal cover in comparison with the unfertilised area. These results indicated that in some cases, the influence of P fertiliser and high stocking rates on botanical composition was favourable (i.e. increased basal cover of P. aquatica and T. subterraneum) and in others it could be detrimental (i.e. lower basal cover of native perennial grasses).
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Prober, Suzanne M., Kevin R. Thiele, and Ian D. Lunt. "Identifying ecological barriers to restoration in temperate grassy woodlands: soil changes associated with different degradation states." Australian Journal of Botany 50, no. 6 (2002): 699. http://dx.doi.org/10.1071/bt02052.
Full textAbstract:
Temperate grassy woodlands were once the dominant vegetation across many agricultural regions of south-eastern Australia, but most of these are now highly degraded and fragmented. Adequate conservation of these woodlands is dependent on successful ecological restoration; however, ecological barriers often limit ecosystem recovery once degrading processes are removed. To help identify these barriers, we used a state and transition framework to compare topsoils of little-disturbed (reference) and variously degraded remnants of grassy Eucalyptus albens Benth. and E. melliodora Cunn. ex Schauer woodlands. Topsoils of degraded remnants showed a repeated pattern, with the most compacted, most acidic and most depleted topsoils occurring in remnants dominated by Aristida ramosa R.Br. or Austrodanthonia H.P.Linder and Austrostipa scabra (Lindl.) S.W.L.Jacobs & J.Everett; the least compacted and most nutrient rich topsoils in remnants dominated by annual exotics; and generally intermediate topsoils in remnants dominated by Bothriochloa macra (Steud.) S.T.Blake or Austrostipa bigeniculata (Hughes) S.W.L.Jacobs & J.Everett. Surprisingly, topsoils beneath trees in reference sites (supporting Poa sieberiana Spreng.) were similar to topsoils supporting annual exotics for most soil properties. Chemical properties of topsoils from open areas of reference sites [supporting Themeda australis (R.Br.) Stapf] were usually intermediate and similar to Bothriochloa macra and Austrostipa bigeniculata topsoils. The most striking exception to these trends was for soil nitrate, which was extremely low in all reference topsoils and showed a high correlation with annual exotic abundance. We discuss the potential for positive feedbacks between soil nitrogen cycling and understorey composition and the need for intervention to assist possible nitrate-dependent transitions between annual and perennial understorey states. Dominant grasses, trees and annual weed abundance may be useful indicators of soil conditions and could inform selection of target sites, species and techniques for restoration projects.
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Lodge, G. M. "Effects of continuous grazing and seasonal closures on the performance and persistence of some sown temperate perennial grasses, North-West Slopes New South Wales." Australian Journal of Experimental Agriculture 42, no. 4 (2002): 431. http://dx.doi.org/10.1071/ea01114.
Full textAbstract:
A split-plot experiment was sown at Tamworth in 1992 to examine the effects of continuous sheep grazing and seasonal closures (autumn, spring, spring + autumn, and summer + winter) on the herbage mass, plant frequency and basal cover of 5 perennial grasses, when sown as monocultures or with a perennial (Trifolium repens cv. Haifa) or annual legume (Trifolium subterraneum var. subterraneum cv. Seaton Park). Plant basal area and crown density data were also collected. The perennial grasses were Phalaris aquatica cv. Sirosa, Festuca arundinacea, cv.� Demeter, Lolium perenne cv. Kangaroo Valley, Austrodanthonia richardsonii (syn. Danthonia richardsonii) cv.�Taranna, and A. bipartita (syn. D. linkii) cv. Bunderra. There was no significant effect of legume presence on the herbage mass or persistence of the perennial grasses. The only treatment that had a significant effect (P< 0.05) on either herbage mass, plant frequency or basal cover data was the grazing treatment × perennial grass interaction in each of the years 1993-98, except for herbage mass in December 1993 and basal cover in October 1998. In all of the grazing treatments examined, Kangaroo Valley ryegrass failed to persist after spring 1994; Demeter fescue had failed by spring 1997 and Sirosa phalaris by spring 1998. Six years after sowing the only temperate grass cultivars that were persisting in all grazing treatments were the native perennials, Taranna and Bunderra. Hence, the data represent the entire stand life from sowing to eventual failure for the 3 introduced cultivars. While grazing treatment effects within years for individual species were significant, overall grazing had little effect on the rate of decline in herbage mass and persistence of Kangaroo Valley, Demeter and Sirosa. By 1998, grazing treatment had no significant effect on the herbage mass and basal cover of Taranna and Bunderra, but their plant frequencies were lowest in the spring rest and summer + winter rest treatments.
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Huxtable, C. H. A., T. B. Koen, and D. Waterhouse. "Establishment of native and exotic grasses on mine overburden and topsoil in the Hunter Valley, New South Wales." Rangeland Journal 27, no. 2 (2005): 73. http://dx.doi.org/10.1071/rj05006.
Full textAbstract:
Native grasses have an important role to play in mine rehabilitation throughout Australia, but there have been few scientifically designed studies of field establishment of native grasses from sown seed in this country. Current recommendations for rehabilitation of open-cut coal mines in the Hunter Valley involve the sowing of exotic pasture species to reinstate mined land to Class IV and V under the Rural Land Capability System. Despite the importance of native grasses in the pre-mined landscape, they are currently not widely included in mine rehabilitation. To address this issue a project was conducted between 1994 and 2000 to research the use of native grasses for rehabilitation of open-cut coal mines in the Hunter Valley. This paper reports on 2 mine site experiments that aimed to assess establishment and persistence of a broad range of native and exotic grass species from an autumn sowing in both topsoil and raw spoil over a period of 61 months. The most promising natives in terms of early establishment, persistence and spread over time, included six C3 accessions (five Austrodanthonia spp. and Austrostipa bigeniculata) and one C4 accession (Cynodon dactylon). Persistence of these accessions was better in raw spoil than topsoil, despite initial low numbers, due to a lack of weed competition and their ability to spread by self-seeding. In topsoil, and in the absence of any biomass reduction, native species were mostly out-competed by vigorous exotic perennial grasses which were sown in these experiments and from seed influx from adjacent rehabilitation areas or from the soil seed bank. The effects of climatic conditions and differences in soil physical, chemical and seed bank characteristics at the 2 mine sites are also discussed.
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Dear, B. S., G. A. Sandral, and B. C. D. Wilson. "Tolerance of perennial pasture grass seedlings to pre- and post-emergent grass herbicides." Australian Journal of Experimental Agriculture 46, no. 5 (2006): 637. http://dx.doi.org/10.1071/ea04173.
Full textAbstract:
The tolerance of 5 perennial grasses during the seedling stage to pre- and post-emergent grass herbicides was examined in 3 glasshouse experiments. The perennial grass species screened were phalaris, (Phalaris aquatica L.), cocksfoot (Dactylis glomerata L.), wallaby grass [Austrodanthonia richardsonii (Cashm.) H.P. Linder], perennial ryegrass (Lolium perenne L.) and tall fescue (Festuca arundinacea Schreb.). Wheat (Triticum aestivum L.) and subterranean clover (Trifolium subterraneum L.) were included as non-target species and annual ryegrass (Lolium rigidum Gaudin) and oats (Avena spp.) as representatives of typical weed species. Herbicides evaluated were fluazifop-p, tralkoxydim, diclofop-methyl, fenoxaprop-p-ethyl, fenoxaprop-p-ethyl + pyrazoline, sethoxydim, flamprop-m-methyl, quizalofop-p-ethyl, clethodim, simazine, imazethapyr, propyzamide, carbetamide, clodinafop-propargyl + cloquintocet-mexyl, propaquizafop, atrazine, trifluralin, triallate, pendimethalin, metribuzin, trifluralin + oryzalin, cyanazine, chlorsulfuron and triasulfuron. Herbicide phytotoxicity was assessed 15 and 30 days after post-emergent herbicide application using the European Weed Research Committee (EWRC) visual score of leaf damage (1 indicating no effect, 9 indicating all plants dead) and plant herbage yield depression relative to the unsprayed control. Plant responses to pre-emergent herbicides were assessed 45 days after sowing. Most herbicides were highly phytotoxic (EWRC score 4–9) to the perennial grass seedlings. However, atrazine, flamprop-m-methyl, imazethapyr, fenoxaprop-ethyl, and triallate caused less severe phytotoxicity (EWRC score 1–4) in phalaris, fescue, cocksfoot and perennial ryegrass from which they could be expected to recover, with yield reductions of between 0 and 45%, 30 days after spraying. Simazine caused yield losses of 20–50% in fescue, phalaris and perennial ryegrass which may be acceptable in swards with high weed burdens. Wallaby grass showed tolerance to flamprop-m-methyl, carbetamide, propyzamide and imazethapyr. Subterranean clover was tolerant of most herbicides with yield losses less than 20% except for the post-emergent herbicides simazine and atrazine, and the pre-emergent herbicides triasulfuron, metribuzin, cyanazine and chlorsulfuron where yield suppression was between 50 and 99%.
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Boschma, S. P., G. M. Lodge, and S. Harden. "Establishment and persistence of perennial grass and herb cultivars and lines in a recharge area, North-West Slopes, New South Wales." Crop and Pasture Science 60, no. 8 (2009): 753. http://dx.doi.org/10.1071/cp08357.
Full textAbstract:
Two adjacent sites, one previously cropped and the other a native pasture, were sown with perennial temperate and tropical grasses and herbs (Expt 1), Phalaris aquatica (phalaris) and Festuca arundinacea (tall fescue) cultivars or lines (Expt 2), and perennial tropical grasses (Expt 3) near Manilla, NSW. Establishment, herbage mass and plant frequency were assessed in 2003–06 to (i) identify cultivars/lines with superior persistence, (ii) detect possible mechanisms required for successful production and persistence in a summer-dominant rainfall environment, and (iii) examine the comparative performance of the species groups when sown into previously cropped and native pasture areas. Plots were fertilised annually and grazed or mown at least seasonally. Most cultivars/lines persisted at the previously cropped site, while those on the native pasture site had to be resown and generally failed to persist beyond the first year. At the previously cropped site, summer-dormant tall fescue cv. Resolute MaxP® was the most persistent of the grasses evaluated in Expt 1. Grasses such as Lolium perenne cv. Avalon and Bromus stamineus cv. Gala did not perenneate, but regenerated annually from seed. Native grasses generally had poor establishment; however, Austrodanthonia richardsonii and A. fulva tended to increase in plant frequency over time. Chloris gayana (Rhodes grass) cv. Katambora and Panicum maximum (panic) cv. Gatton were the only tropical grasses that established in Expt 1, and both had plant frequencies similar (P > 0.05) to the temperate grasses at the final assessment. In Expt 2, Resolute MaxP again was the most persistent cultivar/line. Several experimental lines of phalaris (e.g. T39 and M225) had high herbage mass and good persistence compared with commercial cultivars. In Expt 3, Katambora Rhodes grass and Digitaria eriantha ssp. eriantha (digit grass) cv. Premier were the most persistent cultivars and had the highest herbage mass. These data highlighted summer dormancy in temperate grasses and frost tolerance in tropical grasses as two possible mechanisms important for persistence of grasses on the North-West Slopes of NSW and the risks associated with sowing perennial grasses into established native pastures.
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Garden, D. L., C. M. Waters, A. B. Smith, M. R. Norton, G. C. Auricht, and E. Kobelt. "Performance of native and introduced grasses for low-input pastures. 2. Herbage production." Rangeland Journal 27, no. 1 (2005): 41. http://dx.doi.org/10.1071/rj05003.
Full textAbstract:
A total of 62 perennial grasses were evaluated for herbage production under low-fertiliser conditions at eight sites in the temperate zone of southern Australia from 1999 to 2001. A brief assessment of relative preference ranking by sheep was also made at the end of the experimental period. Four sites were in the high rainfall areas of south-east Australia, two in the drier mixed farming areas of western NSW, and two sites in Mediterranean southern Australia. Seven standard cultivars were included in the comparisons. Plants were grown from seed in glasshouses and transplanted to the field as spaced plants at 6–8 weeks age. Plants were harvested at irregular intervals by clipping to determine herbage production. Relative preference was determined by enclosing sheep in the experimental area at high stocking rates and estimating the amount of herbage grazed after 1, 3 and 5 days. Herbage production data were analysed using a multi-environment trial approach in which the environments comprised all combinations of sites and sampling times over the 3-year period. Overall, 73.6% of the total genetic variation for herbage production was accounted for. Average seasonal comparisons revealed good herbage production from Eragrostis curvula cv. Consol in both winter and summer, but in spring, several Dactylis glomerata lines were the most productive. Consol was not generally preferred by sheep, while D. glomerata lines were. Apart from cv. Consol, C4 species, including Bothriochloa macra, Chloris truncata, Enteropogon acicularis and Dichanthium sericeum had low herbage production in winter and spring, and had low acceptability to grazing sheep. These particular grasses were also not highly ranked for production in summer, although other C4 lines, notably selections of Themeda australis, Paspalidium jubiflorum and P. constrictum were. Few native C3 grasses had superior herbage production, although selections of Elymus scaber, Austrodanthonia fulva and A. duttoniana showed good growth rates. When considering further evaluation, grasses with very high recruitment (e.g. A. caespitosa) may need to be included, and the acceptability of grasses to sheep should also be assessed.
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Waters, C. M., D. L. Garden, A. B. Smith, D. A. Friend, P. Sanford, and G. C. Auricht. "Performance of native and introduced grasses for low-input pastures. 1. Survival and recruitment." Rangeland Journal 27, no. 1 (2005): 23. http://dx.doi.org/10.1071/rj05001.
Full textAbstract:
Differential survival and recruitment patterns are commonly ignored within plant selection and breeding programs, where attention is focused largely on selection of cultivars with high biomass and seed yields. However, in low-input situations, where fertiliser application is limited, the use of pasture species with superior survival and recruitment characteristics can offer the potential of cost-effective pasture establishment. We investigated the comparative survival and seedling recruitment of 62 native and introduced perennial grasses under low-fertility conditions within three agro-ecological zones of temperate Australia: the temperate high-rainfall pasture zone; drier mixed-farming areas and Mediterranean southern Australia. Plants were grown from seed in glasshouses and transplanted to the field as spaced plants within 6–8 weeks. At regular intervals, survival of transplanted plants and recruitment of new plants were recorded. We found high mortality over a relatively short (24-month) period among both native and introduced grasses, despite good establishment. Frost damage at the cooler sites resulted in death of some C4 plants early in the experiment. Survival of some lines declined following the dry summer of 2000–01, and lines with best survival after this time were Eragrostis curvula cv. Consol, Austrodanthonia fulva (from Dalgety and Wagga, NSW) and Paspalidium jubiflorum (from Warren, NSW). C3 grasses, which generally had poor survival were a Microlaena stipoides selection from Nile, Tasmania, and two lines of Elymus scaber (Boorowa and Tumut, NSW). The C4 grasses Chloris truncata (Girilambone, NSW) and Dichanthium sericeum (Trangie, NSW) also exhibited poor survival, although there were exceptions at some sites. The native lines A. caespitosa Tas2407, M. stipoides cv. Shannon and A. racemosa were the most successful recruiters. Introduced lines generally had lower recruitment, although two lines of D. glomerata from Spain recruited well at some sites. C4 lines generally had poor recruitment, including E. curvula cv. Consol, Bothriochloa macra, Themeda australis, Enteropogon acicularis, D. sericeum, P. jubiflorum and P. constrictum. The role of plants adapted to low-input situations is discussed, as well as the implications of the attributes of survival and recruitment for selection of new cultivars for these situations.
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Dear, B. S., K. F. M. Reed, and A. D. Craig. "Outcomes of the search for new perennial and salt tolerant pasture plants for southern Australia." Australian Journal of Experimental Agriculture 48, no. 4 (2008): 578. http://dx.doi.org/10.1071/ea07118.
Full textAbstract:
The potential adaptation of a range of perennial pasture species to recharge environments in southern Australia is reviewed based on their performance in 20 field nurseries in a nationally coordinated project. Species were also evaluated for their suitability to discharge sites where salt and waterlogging are major restraints. Species are ranked according to their potential to be incorporated into farming systems and the scope for further breeding and selection. Medicago sativa L. (lucerne) was the most persistent of the perennial legumes across a diversity of recharge environments. Lotus corniculatus L. (birdsfoot trefoil) showed the most promise on soils prone to waterlogging. Other legumes that showed potential included Cullen australasicum (Schltdl.) J.W. Grimes (tall verbine) and Lotononis bainesii Baker (lotononis). The herb Chicoriyum intybus L. was superior to M. sativa on more acid soils. Phalaris aquatica L. (phalaris) and summer dormant cultivars of Dactylis glomerata L. (cocksfoot), Festuca arundinacea L. (tall fescue) and Lolium perenne L. (perennial ryegrass) were among the most persistent and productive of the perennial grasses. Further exploitation of temperate perennial grass germplasm with increased summer dormancy should be a priority to increase the role of these grass species in lower rainfall, summer-dry environments. Although difficult to establish, the indigenous grasses Austrodanthonia caespitosa (Gaudich.) H.P. Linder (wallaby grass) and A. richardsonii (Cashmore) H.P. Linder were persistent and showed good recruitment. They should be a priority for low rainfall, low input environments. Other grasses that showed promise were Chloris gayana Kunth (Rhodes grass), Secale montanum Guss. (mountain rye), Microlaena stipoides (Labill.) R. Br. (weeping grass), Ehrhata calcycina Sm. (veldt grass) and Bromus stamineus E. Desv. (grazing brome). For discharge environments, Melilotus siculus (Turra) Vitman ex B.D. Jacks. was one of the most salt tolerant legumes and should be a priority for further development. Medicago polymorpha L. (burr medic) appears underutilised in discharge environments. Increasing the waterlogging tolerance of this moderately salt tolerant species would further enhance its potential. Trifolium michelianum Savi. (balansa clover) owed its success in discharge areas more to ‘salt avoidance’ rather than salt tolerance per se. Melilotus sulcatus Desf., T. tomentosum L. and Lotus tenuis Waldst. & Kit. ex Willd. also had traits that may prove advantageous for discharge environments. Within the pasture grasses, Puccinellia ciliata Bor (pucinellia) was superior at sites prone to waterlogging whereas T. ponticum performed better in moderately drained saline sites.
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Lodge, G. M. "Seed dormancy, germination, seedling emergence, and survival of some temperate perennial pasture grasses in northern New South Wales." Australian Journal of Agricultural Research 55, no. 3 (2004): 345. http://dx.doi.org/10.1071/ar03147.
Full textAbstract:
A series of seed and seedling studies was undertaken in northern New South Wales for the temperate perennial grasses phalaris (Phalaris aquatica cv. Sirosa and Australian), tall fescue (Festuca arundinacea cv. Demeter), perennial ryegrass (Lolium perenne cv. Kangaroo Valley), and 2 wallaby grasses (Austrodanthonia bipartita syn. Danthonia linkii cv. Bunderra and A. richardsonii syn. D. richardsonii cv. Taranna). Studies were conducted to determine the level of dormancy in freshly harvested seed and the time required to overcome it, effects of alternating daily temperatures on the germination of non-dormant seed, effect of time-of-sowing on seedling emergence (2 studies) and survival, levels of seed production and soil seedbanks, and the effect of litter cover and soil type on the emergence of Sirosa phalaris seedlings.Grass species, time, and their interaction all had a significant effect (P < 0.05) on both dispersal unit and caryopses germination. One month after harvest, germination of caryopses was lower (P < 0.05, 2 and 1%, respectively) for Taranna and Bunderra than for Sirosa (79.5%). In March 1993, germination of the 2 wallaby grasses was also lower (P < 0.05) than that of Sirosa. Dormancy of freshly harvested seeds of Sirosa was mainly associated with the structures surrounding the caryopses (7.7 v. 79.5% mean germination), but for Taranna and Bunderra it was related to physiological dormancy of the caryopses.Germination levels that were not significantly different to the maximum occurred for temperature ranges of 35/30–15/10�C [Sirosa (commercial)], 35/25–15/10�C (Australian phalaris), and 35/30–15/05�C (Kangaroo Valley ryegrass). In contrast, maximum germination of wallaby grasses only occurred for Taranna in the temperature range 25/20–20/10�C, and for Bunderra at 25/15 and 20/15�C.Seedling emergence in the field was episodic, occurring on only 3 occasions from 1993 to 1996. No seedlings of Sirosa phalaris, Demeter tall fescue, or Kangaroo Valley ryegrass were successfully recruited, but Taranna and Bunderra successfully recruited new plants from natural seedfalls. Whereas seed production of the perennial grasses studied was relatively high (~10 000 seed/m2 in 1992), soil seedbank levels were much lower (generally <1000 seeds/m2). These data were used to indicate the likely successful establishment of sown perennial grasses or by regeneration from natural seedfall.
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Dear, B. S., G. A. Sandral, J. M. Virgona, A. D. Swan, B. A. Orchard, and P. S. Cocks. "Lucerne, phalaris, and wallaby grass in short-term pasture phases in two eastern Australian wheatbelt environments. 2. Effect of perennial density and species on subterranean clover populations and the relative success of 3 clover cultivars of different maturity." Australian Journal of Agricultural Research 58, no. 2 (2007): 123. http://dx.doi.org/10.1071/ar05324.
Full textAbstract:
The effect of the density of 3 perennial species, phalaris (Phalaris aquatica L.), wallaby grass (Austrodanthonia richardsonii Kunth), and lucerne (Medicago sativa L.), on seed set, regeneration, and the relative competitiveness of 3 cultivars of subterranean clover (Trifolium subterraneum L.) was examined in 2 environments in the south-eastern Australian wheatbelt. Seed yields of subterranean clover were inversely related to perennial density at both sites over the first 2 years, the relationship varying with perennial species. Phalaris depressed the seed yield of clover more than lucerne and wallaby grass in the second and third year at equivalent densities. Clover seed yield was positively related to clover herbage yield in late spring at both sites, and inversely related to perennial herbage yield. Clover seed yield displayed an increasing linear relationship with the proportion of light reaching the clover understorey in spring, which in turn was inversely related to perennial density and perennial herbage yield. Clover seedling regeneration in mixed swards in autumn was positively related to the size of the summer seed bank, but negatively related to perennial density. Clover seedling survival following a premature germination at Kamarah was inversely correlated to the density of phalaris and lucerne in the sward. The relative competitiveness of the 3 subterranean clover cultivars varied between sites, with climatic conditions (rainfall and growing-season length) having a greater effect on the relative cultivar performance than companion perennial species or density. The later maturing subterranean clover cv. Goulburn became the dominant cultivar at the wetter site, constituting 72% of the seed bank, but declined to only 3–8% of the seed bank at the drier site. The proportion of the early flowering cultivar Dalkeith in the seed bank increased over time at the drier site and was highest (53%) in plots with the highest perennial density. We concluded that although perennial pasture species will depress clover seed yield and subsequent regeneration, these effects could be minimised by reducing perennial densities and exploiting variations in competitiveness between perennial species as identified in this study. Sowing earlier maturing subterranean clover cultivars would only be an advantage in increasing clover content in low-rainfall environments. The findings suggest that clover seed reserves and regeneration could also be increased by using grazing management to reduce the level of shading of clover by perennials, a factor associated with reduced clover seed yield.
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Sandral, G. A., B. S. Dear, J. M. Virgona, A. D. Swan, and B. A. Orchard. "Changes in soil water content under annual- and perennial-based pasture systems in the wheatbelt of southern New South Wales." Australian Journal of Agricultural Research 57, no. 3 (2006): 321. http://dx.doi.org/10.1071/ar04017.
Full textAbstract:
Nine pasture treatments differing in species composition were monitored for changes in soil water content at a depth of 0.10–1.70 m, at 2 sites (Kamarah and Junee), in the wheatbelt of eastern Australia. Treatments containing perennial species, viz. lucerne (Medicago sativa L.), phalaris (Phalaris aquatica L.), cocksfoot (Dactylis glomerata L.), mixture (lucerne + phalaris + cocksfoot), wallaby grass (Austrodanthonia richardsonii Cashmore.), and lovegrass (Eragrostis curvula (Schrader) Nees.), were sown with subterranean clover (Trifolium subterraneum L.). In addition, 3 treatments based solely on annual species were examined: subterranean clover (sown by itself and kept weed-free with herbicides), annual (sown to subterranean clover but weed invasion not controlled), and serradella (Ornithopus compressus L.). The experiment was conducted from 1994–97 at the Junee site (annual average rainfall 550 mm/year) and from 1995–97 at the Kamarah site (annual average rainfall 450 mm per year). At the higher rainfall site (Junee), there were few differences among pasture types in soil water content to 0.70 m. Below 0.70 m the soil profile was drier under all the perennial swards than under the annual pasture treatments by the end of the 4-year pasture phase. At the drier Kamarah site, where the pasture phase was shorter due to an initial sowing failure, all the perennials, except cocksfoot, dried the profile below 1.05 m. At both sites, lucerne dried the 1.05–1.70 m section of the soil profile more rapidly than the other perennials, which apparently took longer to reach this depth. At the Junee site, the soil water deficit in May (SWD(MAY), defined as field capacity (mm) – stored soil water (mm) at the beginning of May) was largest in the phalaris, mixture, lucerne, and cocksfoot treatments (155–162 mm), whereas as under a pasture of subterranean clover alone, SWD(MAY) was only 89 mm. At the drier Kamarah site, the largest SWD(MAY) was created by the lovegrass (114 mm) and lucerne (107 mm) treatments. The cocksfoot and subterranean clover treatments created the smallest SWD(MAY) at this site, at 79 and 72 mm, respectively. The study showed that currently available C3 and C4 perennial grasses can be as effective as lucerne in drying the soil profile to 1.70 m in the 450–600 mm rainfall areas of the southern NSW wheatbelt, creating a dry soil buffer to reduce the risk of deep drainage during subsequent cropping phases. As the rate at which grasses dried the profile was slower than lucerne, pastures based on perennial grasses may have to be retained longer to achieve the same level of dewatering.
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Dear, B. S., J. M. Virgona, G. A. Sandral, A. D. Swan, and B. A. Orchard. "Lucerne, phalaris, and wallaby grass in short-term pasture phases in two eastern Australian wheatbelt environments. 1. Importance of initial perennial density on their persistence and recruitment, and on the presence of weeds." Australian Journal of Agricultural Research 58, no. 2 (2007): 113. http://dx.doi.org/10.1071/ar05323.
Full textAbstract:
The influence of initial plant density on the changes in the populations of 3 perennial pasture species, lucerne (Medicago sativa L.), wallaby grass (Austrodanthonia richardsonii (Cashm.) H.P. Linder), and phalaris (Phalaris aquatica L.), over a 3-year pasture phase was examined in the wheatbelt of southern New South Wales. The perennials were sown at 5 rates in combination with subterranean clover (Trifolium subterraneum L.) at 2 locations, Kamarah [430 mm average annual rainfall (a.a.r.)] and Junee (550 mm a.a.r). The range in initial plant populations for lucerne, phalaris, and wallaby grass was 4–74, 8–94, and 2–20 plants/m2, respectively, at Kamarah and 11–120, 9–149, and 6–48 plants/m2 at Junee. When sown at higher densities, the density of lucerne and phalaris declined curvilinearly over the 3 years at both sites. At the 3 lower densities, phalaris populations remained constant at both sites. Lucerne, in contrast, declined over all densities at both sites except at the lowest density at the wetter site (Junee). The rate of decline in lucerne was negatively related (R2 = 0.75) to initial density at Junee, but not at Kamarah. The density of the native grass, wallaby grass, increased with time at both sites through seedling recruitment. The invasion of experimental plots by the summer weed Eragrostis cilianensis (All.) Vign. ex Janchen (stinkgrass) was restricted by lucerne and phalaris, with a negative curvilinear relationship between perennial density and E. cilianensis seedlings in both environments (R2 = 0.65–0.70). In contrast, wallaby grass was ineffective at suppressing E. cilianensis. By the third year, phalaris had significantly higher herbage yields in spring than lucerne and wallaby grass at both sites and phalaris yield was independent of density. Lucerne yields at this time increased with density only at the wetter site (R2 = 0.64), but wallaby grass yields responded to increasing density at both sites (R2 = 0.27–0.59). The experiment demonstrated that establishing higher initial perennial populations of lucerne and phalaris, which did not recruit during the experiment, will result in the maintenance of higher populations over the life of a 3–4 year pasture phase despite proportionally higher rates of plant loss. The size of the initial population was less critical for wallaby grass, which was able to increase in density through recruitment. High initial populations are likely to be an advantage for suppressing weeds in swards of perennial species with limited ability to increase their basal area, such as lucerne and wallaby grass, but will be less beneficial for species such as phalaris, which can compensate by greatly increasing its basal area at lower densities.
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Dear, B. S., J. M. Virgona, G. A. Sandral, A. D. Swan, and S. Morris. "Changes in soil mineral nitrogen, nitrogen leached, and surface pH under annual and perennial pasture species." Crop and Pasture Science 60, no. 10 (2009): 975. http://dx.doi.org/10.1071/cp09026.
Full textAbstract:
Soil mineral nitrogen (N) profiles during the growing season and changes in total soil N and available N after 3–4 years were examined under 9 different pasture swards containing annual legumes, lucerne (Medicago sativa L.), or one of 4 perennial grasses at 2 sites representative of the low and medium rainfall belt of south-eastern Australia. The effect of the presence of phalaris (Phalaris aquatica L.) or lucerne on the spatial variation in surface pH was also measured. The 9 pastures were subterranean clover (Trifolium subterraneum L.), subterranean clover with annual weeds, yellow serradella (Ornithopus compressus L.), lucerne, phalaris, cocksfoot (Dactylis glomerata L.), lovegrass (Eragrostis curvula (Schrader) Nees), wallaby grass (Austrodanthonia richardsonii (Cashm.) H.P. Linder), and a mixture of lucerne, phalaris, and cocksfoot. All the perennial treatments were sown with subterranean clover. Available mineral N values in the surface 0.10 m of soil following summer rainfall were substantially higher in pure subterranean clover or serradella (Ornithopus compressus L.) swards (24–50 μg N/g) than those containing a mixture of subterranean clover and perennials (9–20 μg N/g). Apparent leaching of soil nitrate down the profile during winter was greatest in annual pasture treatments and least in swards containing perennials. Soil pH(CaCl2) at the 0–0.10 m depth varied with proximity to perennial plants and was significantly higher (+0.2–1.1 pH units) near the base of perennial plants than in gaps between the perennials or in annual-only swards. Available mineral N to 1.0 m before cropping at the end of the pasture phase was highest following subterranean clover (175–344 kg N/ha) and serradella (202–316 kg N/ha) at both sites. Available N was lowest (91–143 kg N/ha) following perennial grass–clover swards at the drier site where the annual legume content was lower, but perennial grass–clover swards produced larger soil N values (147–219 kg N/ha) at the higher rainfall site. Removal of the pasture in August–September compared with November in the year before cropping increased available N at the time of sowing by an average of 44% (51 kg N/ha) at the drier site and 43% (74 kg N/ha) at the wetter site. Incorporating perennial pasture species in swards was found to be advantageous in reducing nitrate leaching and preventing a decline in surface soil pH; however, available soil N to following crops could be lower if the annual legume content of perennial grass-based pastures declined due to competition from the perennial species.
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Ridley, A. M., B. P. Christy, R. E. White, T. McLean, and R. Green. "North-east Victoria SGS National Experiment site: water and nutrient losses from grazing systems on contrasting soil types and levels of inputs." Australian Journal of Experimental Agriculture 43, no. 8 (2003): 799. http://dx.doi.org/10.1071/ea02090.
Full textAbstract:
Water and nutrient losses, pasture and animal production were measured for a prime lamb enterprise at Maindample (rainfall 750 mm/year) and a wool enterprise at Ruffy (rainfall 671 mm/year) in north-east Victoria from 1998 to 2000. Each site comprised 3 paddock-scale treatments: control, unsown pasture receiving about 5�kg�phosphorus (P)/ha.year; medium input, sown pasture (about 10 kg P/ha.year); and high input, sown pasture (≥22 kg P/ha.year). Sown pastures were based on phalaris (Phalaris aquatica L.) at Maindample and cocksfoot (Dactylis glomerata L.) at Ruffy, and sheep were set stocked. Pastures at Maindample created a larger soil water deficit (commonly about 120 mm) compared with Ruffy (about 70 mm) in summer. Maximum soil water deficit at Maindample occurred under the high input pasture and was about 30 mm greater than the medium or control treatments. Phalaris content ranged between about 200 and 1300 kg DM/ha, between 10 and 70% of total composition (commonly about 20%). In contrast, at Ruffy the control, which had 20–40% native grasses (Austrodanthonia and Microlaena) achieved the greatest soil water deficit, about 25 mm greater than for sown pastures. Cocksfoot persisted poorly at the acid soil at Ruffy. Small differences in green leaf area over summer (about 200 kg DM/ha) between treatments could generate the soil water deficit differences over the summer.The most striking result was the markedly different pathways of water loss between surface losses and deep drainage at the 2 sites, which was of greater consequence than the effect of pasture type. At Maindample, on average, 166 mm of water was lost annually (22% of rainfall) with 110 mm of this as surface runoff. At Ruffy, annual water loss was 128 mm (19% of rainfall) with 110 mm of this total water loss estimated as loss through deep drainage.Phosphorus losses were low in all treatments (≤1 kg P/ha.year), and nitrate-N (NO3-N) losses (7–12 kg N/ha.year) were comparable with previous work. Concentrations of P in water were highest from the high treatments at both sites, averaging 0.91 and 0.83 mg P/L in surface runoff from Maindample high and Ruffy high treatments, respectively. Average soil water NO3-N concentrations ranged from 3 to 26 mg N/L. Both P and N concentrations were higher than acceptable for aquatic health.Environmental risks in terms of water and nutrient losses could be either higher or lower for sown than unsown pastures, depending upon soil type, botanical stability, persistence and the soil water extracting ability of the pasture. Results indicated that better environmental outcomes could be achieved if soil types were targeted for particular land uses. High management skills are needed if grazing enterprises are to be both profitable and have lower off-site impacts.
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Lodge, G. M., S. R. Murphy, and S. Harden. "Effects of grazing and management on herbage mass, persistence, animal production and soil water content of native pastures. 2. A mixed native pasture, Manilla, North West Slopes, New South Wales." Australian Journal of Experimental Agriculture 43, no. 8 (2003): 891. http://dx.doi.org/10.1071/ea02189.
Full textAbstract:
As part of the Sustainable Grazing Systems (SGS) National Experiment a study was conducted on a native pasture in the Manilla district of northern New South Wales to examine the effects of 5 grazing treatments on total herbage mass, litter mass, basal cover, ground cover, sheep liveweight, wool production and soil water content (SWC, mm) at different depths. The pasture was a mixture of native perennial grasses, with redgrass (Bothriochloa macra) and wiregrass (Aristida ramosa) dominant on a red Chromosol soil type and bluegrass (Dichanthium sericeum) on a brown Vertosol. Wallaby grasses (Austrodanthonia richardsonii and A. bipartita) were common on both soils. Plots were grazed with Merino wethers and data collected from spring 1997 to spring 2001 were analysed to determine the effect of treatments on both production and sustainability. Five grazing treatments were applied in a randomised 3 replicate design. Grazing treatments were: continuous grazing at 3.1 and 6.2�sheep/ha (C3 and C6), continuous grazing at 9.2 sheep/ha, with subterranean clover (Trifolium subterraneum) oversown and fertiliser applied (C9+sub) and rotational grazing at an annual stocking rate of 3.1 sheep/ha with pasture grazed for 4 weeks and rested for 4 weeks (R4/4), or rested for 12 weeks (R4/12). Over time, treatments had no significant effect on either total pasture herbage mass (compared with the C3�control) or the basal cover of the major perennial grasses. Treatments had inconsistent significant effects on ground cover, litter mass, sheep liveweight and wool production (kg/head) over time. Compared with all other treatments ground cover was less (P<0.05) in the C6 treatment in only May and September 2000 and litter mass less (P<0.05) in only December 1998 and March 1999. Treatment sheep liveweights were not significantly different from the C3 treatment from September 1997 to 1999. However, from October 1999 to October 2001 sheep liveweight in the C6 treatment was significantly less than in the C3 treatment, while in the C9+sub and R4/12 treatments it was significantly greater than the control. In 1999, wool production per head was higher (P<0.05) in the C9+sub and R4/12 treatments compared with all other treatments but treatment differences were not significant in all other years. Significant differences in SWC only occurred at the 0–30 cm depth between the C3 and the C6 and R4/12 treatments, but were predicted to be <1.5 mm/year. A sustainability index derived from economic [equivalent annual net return ($/ha) for a 10-year period], animal production, pasture, soil health and soil water data indicated that the overall indices were lowest for the C3, C6 and C9+sub treatments and highest for the R4/4 and R4/12 treatments.
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Dear, B. S., G. A. Sandral, J. M. Virgona, and A. D. Swan. "Yield and grain protein of wheat following phased perennial grass, lucerne, and annual pastures." Australian Journal of Agricultural Research 55, no. 7 (2004): 775. http://dx.doi.org/10.1071/ar04018.
Full textAbstract:
The effect of using 4 perennial grasses or lucerne (Medicago sativa L.) in the pasture phase on subsequent wheat grain yield, protein, and grain hardness was investigated at 2 sites (Kamarah and Junee) in the south-eastern Australian cereal belt. The 6 perennial treatments were 5 mixtures of subterranean clover (Trifolium subterraneum L.), with one of lucerne, phalaris (Phalaris aquatica L.), cocksfoot (Dactylis glomerata L), wallaby grass (Austrodanthonia richardsonii (Cashm.) H.P. Linder), or lovegrass (Eragrostis curvula (Schrader) Nees cv. Consol), or one mixture of cocksfoot, phalaris, and lucerne. The results were compared with wheat after one of 3 annual pastures consisting of either pure subterranean clover, subterranean clover with annual volunteer broadleaf and grass weeds, or yellow serradella (Ornithopus compressus L.). The duration of the pasture phase was 3 years at the drier Kamarah site (av. annual rainfall 430 mm) and 4 years at Junee (550 mm). The effect of time of removal of the pastures in the year prior to cropping (28 August–3 September or 6–7 November) and the effect of nitrogen (N) fertiliser application were also examined. In the absence of applied N, wheat grain yields at Kamarah were highest (4.7–4.9 t/ha) and grain protein lowest (10.3–11.1%) following phalaris, wallaby grass, and cocksfoot. Grain protein levels were highest (12.9–13.9%) in wheat following the 3 annual legume swards at both sites. Previous pasture type had no effect on wheat yields at the Junee site. Wheat grain protein and total N taken up by the crop were positively related to available soil N to 100 cm measured at sowing at both sites. Grain protein was inversely related to grain yield at both sites where additional N fertiliser was added, but not in the absence of fertiliser N. There was a positive response in grain protein to delayed time of pasture removal in second year wheat at Junee. The application of additional N fertiliser increased grain protein of wheat following all 9 pasture types at the drier Kamarah site, but at the Junee site there was only a positive grain protein response following phalaris, cocksfoot, and wallaby grass. Early removal of the pasture prior to cropping increased soil water (10–130 cm) at sowing by 18 mm, delayed wheat senescence, and increased crop yield by 11% (0.44 t/ha) at the drier Kamarah site. Early removal of the pasture at Junee increased soil water by 29 mm, crop yields by 2% (0.14 t/ha), and increased grain protein in wheat following cocksfoot, wallaby grass, and phalaris, but not following the 3 annual legume treatments. The study demonstrated that perennial grasses can be successfully incorporated into phased rotations with wheat without affecting grain yield, but protein levels may be lower and timing of pasture removal will be important to limit the effect of water deficits on grain yield.
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Dear, B. S., J. M. Virgona, G. A. Sandral, A. D. Swan, and B. A. Orchard. "Effect of companion perennial grasses and lucerne on seed yield and regeneration of subterranean clover in two wheatbelt environments." Australian Journal of Agricultural Research 52, no. 10 (2001): 973. http://dx.doi.org/10.1071/ar01059.
Full textAbstract:
Seed production of subterranean clover (Trifolium subterraneum L.) in mixtures with lovegrass (Eragrostis curvula (Schrader) Nees cv. Consol), cocksfoot (Dactylis glomerata L. cv. Currie), phalaris (Phalaris aquatica L. cv. Sirolan), danthonia (Austrodanthonia richardsonii (Cashm.) H.P. Linder, cv. Taranna), and lucerne (Medicago sativa L. cv. Aquarius) was compared with pure and degraded (invaded by annual volunteers) annual subterranean clover pasture at 2 sites (Junee and Kamarah) in the southern wheatbelt of New South Wales. Seed yields, clover seedlings in winter, and the change in the proportion of 3 subterranean clover cultivars (Dalkeith, Seaton Park, Goulburn) when grown with and without perennials were assessed. The effect of thinning the perennials to 10 plants/m2 on clover seed set was examined at the drier site. Seed production of subterranean clover in the mixtures was depressed by up to 50% compared with the pure and degraded annual swards. Initial clover seed poduction in the mixtures was at least 60 kg/ha even in the drought year at the wetter site (Junee), and >85 kg/ha at Kamarah, the drier site (seedling establishment at Kamarah failed in the drought year). Clover seed reserves in the following 2 years progressively increased to >300 kg/ha in the perennial swards at Junee but were <100 kg/ha by the end of the third year at Kamarah. In comparison, seed reserves in the pure clover and degraded annual swards were >650 kg/ha at Junee and >350 kg/ha at Kamarah. Reducing perennial density to 10 plants/m2 at the drier site increased clover seed yield about 3-fold in the first year compared with unthinned perennial swards. The increased seed yield was due to increased numbers of burrs set and increased seeds per burr and, in all perennial pasture treatments except lucerne, increased seed size. Clover seedling regeneration in 3rd and 4th year after sowing was substantially lower in the perennial-based mixtures than annual plots, with a significant (P < 0.05) positive correlation at both sites between clover seedling regeneration and seed bank size (1996, r2 = 0.46–0.64; 1997, r2 = 0.64–0.85). Following false breaks in early autumn, clover seedling populations were substantially higher in the pure and degraded clover treatments than in most perennial treatments. The proportion of the 3 cultivars present in the seed bank at the end of the pasture phase differed between sites but the sward type only influenced the proportion at the drier site. At the medium rainfall site, the later maturing cultivar Goulburn constituted 27–54% of the seed bank and the early flowering Dalkeith 25–46%, with unsown cultivars being insignificant ( <1%). At the low rainfall site, Dalkeith was the major component (33–52%) of the seed bank but the background population of unsown cultivars constituted 11–48%, the lowest proportion being in swards without a perennial component. The proportion of Goulburn was highest (23%) in the pure sward and lowest (10%) in lucerne and phalaris. It was concluded that subterranean clover could form relatively stable mixtures with perennials in medium rainfall environments, with clover populations increasing with time. In lower rainfall environments, clover seedling populations in perennial swards may be low due to reduced seed set and decreased seedling survival following early autumn rains. In these environments earlier maturing, hard-seeded cultivars are more likely to persist in mixtures and there is more potential for unsown cultivars to constitute a greater proportion of the sward. Decreasing perennial density offers scope for improving clover seed set and survival in these environments.
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Lodge, G. M., S. R. Murphy, and S. Harden. "Effects of grazing and management on herbage mass, persistence, animal production and soil water content of native pastures. 1. A redgrass - wallaby grass pasture, Barraba, North West Slopes, New South Wales." Australian Journal of Experimental Agriculture 43, no. 8 (2003): 875. http://dx.doi.org/10.1071/ea02188.
Full textAbstract:
A study was conducted on a native pasture (dominated by redgrass, Bothriochloa macra) in the Barraba district of northern New South Wales to examine the effects of 5 grazing treatments on total herbage mass, litter mass, basal cover, ground cover, sheep liveweight, wool production and soil water content (SWC, mm) at different depths. Plots were grazed with Merino wethers and data were collected from spring 1997 to spring 2001 and analysed to determine the effects of treatments on both production and sustainability. Five grazing treatments were applied in a randomised 3 replicate design. Grazing treatments were: continuous grazing at 4 and 6 sheep/ha (C4 and C6), continuous grazing at 8 sheep/ha, with subterranean clover (Trifolium subterraneum) oversown and fertiliser applied (C8+sub), and, rotational grazing at an annual stocking rate of 4 sheep/ha with pasture grazed for 4 weeks and rested for 4 weeks (R4/4), or rested for 12 weeks (R4/12).Total herbage mass declined in the C4 (control) treatment throughout the experiment and, compared with this treatment, the C6 treatment had less (P<0.007) linear trend over time, while the R4/12 treatment had a greater (P<0.001) linear trend. Stocking rates could not be maintained in the C4 and C6 treatments and sheep were supplementary fed or removed from these treatments for a total of 133 and 263 days, respectively. For ground cover, the linear trend was greater (P<0.05) in the C8+sub, R4/4, and R4/12 treatments compared with the continuously grazed C4 and C6 treatments and for litter mass this trend was also greater (P<0.05) for the R4/12 treatment than the C4 treatment. Basal cover of wiregrass (Aristida ramosa), wallaby grass (Austrodanthonia spp.) and windmill grass (Chloris truncata) was not affected by grazing treatment but for redgrass the linear trend was greater (P<0.05) in the C8+sub, R4/4, and R4/12 treatments compared with the C4 and C6 treatments. Sheep liveweight (kg/head) was greater (P<0.001) in the C8+sub treatment compared with the C4 treatment. Annual wool production (kg/head) was also higher (P<0.05) in the C8+sub treatment compared with all other treatments. Compared with the C4�treatment, significant differences in soil water content occurred in the R4/12 and C8+sub treatments, but these were predicted to be only 2.9 mm per year for the R4/12 treatment (0–30 cm depth) and 5.7 mm per year for the C8+sub treatment (30–170 cm). Use of a biophysical model indicated that evapotranspiration was the largest output term in the soil water balance and that both drainage and surface runoff of water were episodic events. A sustainability index derived from economic (equivalent annual net return ($/ha) for a 10-year period), animal production, pasture, soil health and soil water data indicated that the C4 and C6 treatments had the lowest scores for each of these parameters and the lowest overall indices. These scores were highly correlated with subjective assessments of the impact of the treatments (r�=�0.93). Overall, these data indicated substantial benefits of either rotationally grazing or the addition of fertiliser and subterranean clover to the production and sustainability of the native pasture studied.
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"Austrodanthonia racemosa." CABI Compendium CABI Compendium (January 7, 2022). http://dx.doi.org/10.1079/cabicompendium.112619.
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"Austrodanthonia setacea." CABI Compendium CABI Compendium (January 7, 2022). http://dx.doi.org/10.1079/cabicompendium.112620.
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"Austrodanthonia tenuior." CABI Compendium CABI Compendium (January 7, 2022). http://dx.doi.org/10.1079/cabicompendium.112621.
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