The impact of pasture development and grazing on water-yielding catchments in the Murray - Darling Basin in south-eastern Australia

2003 ◽  
Vol 43 (8) ◽  
pp. 817 ◽  
Author(s):  
W. H. Johnston ◽  
D. L. Garden ◽  
A. Rančić ◽  
T. B. Koen ◽  
K. B. Dassanayake ◽  
...  
Keyword(s):  
Perennial Grasses ◽  
Wagga Wagga ◽  
Deep Drainage ◽  
Nitrogen And Phosphorus ◽  
South Wales ◽  
Murray Darling Basin ◽  
Productivity Gain ◽  
Eastern Australia ◽  
Annual Grasses ◽  
The Impact

Experiments conducted from November 1996 to June 2002 in adjacent small catchments near Wagga Wagga, New South Wales, compared the productivity and hydrology of a heavily fertilised (about 30 kg phosphorus/ha.year) Phalaris aquatica (phalaris) pasture with that of a lightly fertilised (about 14 kg phosphorus/ha every second year) native grassland that contained a mixture of C3 and C4 perennial grasses, dominantly C4 Bothriochloa macra (redgrass).In summer, the native catchment was dominated by C4 perennial grasses while the phalaris catchment was dominated by annual C4 weedy species. During the cooler months, the phalaris pasture contained higher proportions of Vulpia spp., and other less-desirable annual grasses. Throughout the experiment, the native catchment was dominated by redgrass, whereas in the phalaris catchment the persistence of phalaris declined. Redgrass became prominent on the more arid aspects of the phalaris catchment as the experiment progressed.Pasture production in the phalaris catchment was higher in most seasons than the native catchment, which resulted in an overall stocking rate advantage of about 80%. The productivity gain per unit of P input was 0.4 for the phalaris catchment compared with 1 for the native catchment, implying that phosphorus was applied to the phalaris catchment at an excessive rate.During wet periods the native catchment produced substantially more runoff than the phalaris catchment, while in dry times it developed substantially larger soil water deficits. Runoff from the phalaris catchment was higher in suspended and dissolved nitrogen and phosphorus than for the native catchment. Higher runoff from the native catchment combined with its drier soil profile in summer indicated that its deep drainage potential was less than in the phalaris catchment.

LIGULE: An evaluation of indigenous perennial grasses for dryland salinity management in south-eastern Australia. 2. Field performance and the selection of promising ecotypes

2001 ◽  
Vol 52 (3) ◽  
pp. 351 ◽  
Author(s):  
Meredith L. Mitchell ◽  
T. B. Koen ◽  
W. H. Johnston ◽  
D. B. Waterhouse
Keyword(s):  
Field Performance ◽  
Perennial Grasses ◽  
Wagga Wagga ◽  
South Eastern ◽  
Eastern Australia ◽  
Dactylis Glomerata L ◽  
Salinity Management ◽  
Selection Of ◽  
Broad Overview ◽  
South Eastern Australia

This paper reports the results of an initial evaluation of a large collection of Australian perennial native grasses. The overall aim of the research was to identify accessions that may be useful for pastoral purposes and for controlling land degradation on hill-lands in the high (>500 mm) rainfall zone of south-eastern Australia. Accessions (807) representing 37 target species were established in spaced plant nurseries at Rutherglen and Wagga Wagga. Dactylis glomerata L. cv. Porto and Eragrostis curvula (Schrad) Nees. Complex cv. Consol were established as comparator (control) species. A range of attributes was observed over a 2-year period (19900—1992), including persistence, vigour, productivity, palatability, morphology, and characteristics related to seed production. Accessions were initially culled on the basis of their persistence. Data for a range of attributes were separately analysed using pattern analysis to provide a broad overview of the performance and characteristics of the remaining accessions. A number of selection criteria were applied which resulted in selection of a promising group of 20 accessions (12 species from 8 genera). The promising group of accessions will be evaluated further at field sites typical of hilly landscapes in the 500mp;mdash;600 mm rainfall zone of south-eastern Australia.

Fingerprinting windblown dust in south-eastern Australian soils by uranium-lead dating of detrital zircon

Soil Research ◽  
2001 ◽  
Vol 39 (1) ◽  
pp. 7 ◽  
Author(s):  
Robyn D. Gatehouse ◽  
I. S. Williams ◽  
B. J. Pillans
Keyword(s):  
New England ◽  
New South ◽  
Fold Belt ◽  
Fine Grained ◽  
South Eastern ◽  
South Wales ◽  
Murray Darling Basin ◽  
Eastern Australia ◽  
Uranium Lead Dating ◽  
Eastern Highlands

The U-Pb ages of fine-grained zircon separated from 2 dust-dominated soils in the eastern highlands of south-eastern Australia and measured by ion microprobe (SHRIMP) revealed a characteristic age ‘fingerprint’ from which the source of the dust has been determined and by which it will be possible to assess the contribution of dust to other soil profiles. The 2 soils are dominated by zircon 400–600 and 1000–1200 Ma old, derived from Palaeozoic granites and sediments of the Lachlan Fold Belt, but also contain significant components 100–300 Ma old, characteristic of igneous rocks in the New England Fold Belt in northern New South Wales and Queensland. This pattern closely matches that of sediments of the Murray-Darling Basin, especially the Mallee dunefield, suggesting that weathering of rocks in the eastern highlands has contributed large quantities of sediment to the arid and semi-arid inland basins via internally draining rivers of the present and past Murray–Darling River systems, where it has formed a major source of dust subsequently blown eastwards and deposited in the highland soils of eastern Australia.

Scattered native trees and soil patterns in grazing land on the Northern Tablelands of New South Wales, Australia

Soil Research ◽  
2007 ◽  
Vol 45 (3) ◽  
pp. 199 ◽  
Author(s):  
Brian R. Wilson ◽  
Ivor Growns ◽  
John Lemon
Keyword(s):  
New South ◽  
New South Wales ◽  
Tree Canopy ◽  
Deep Drainage ◽  
Grazing Land ◽  
Near Surface ◽  
Soil Layers ◽  
South Wales ◽  
Eastern Australia ◽  
Canopy Effect

Over large areas of south-eastern Australia, the original cover of native woodland has been extensively cleared or modified, and what remains is often characterised by scattered trees beneath which the ground-storey vegetation is largely grazed or otherwise managed. This study investigated the influence of scattered Blakely’s red gum (Eucalyptus blakelyi) trees on both near-surface and deeper soil layers in temperate grazed pastures on the Northern Tablelands of New South Wales, Australia. A significant canopy effect was observed with elevated soil pH, carbon, and nutrient status inside the tree canopy indicating soil enrichment in a zone around the tree. This effect, however, was largely restricted to the surface (0–0.20 m) soil layers. Chloride concentrations were elevated near to trees but only in the deeper soil layers, suggesting that a modified water use and deep drainage mechanism occurred near the trees. Close to the tree, however, a significant acidification was observed between 0.40–0.60 m depth in the soil, without any obvious depletion in other soil element concentrations. It is concluded that this acidification provides strong evidence in support of a ‘biological pumping’ mechanism that has been proposed elsewhere. Key questions remain as to the management implications of these results, whether the subsurface acidification that was observed is common among native Australian trees, if it might be persistent through time, and if this might be a soil issue that requires management.

scholarly journals Catchment modelling of sediment, nitrogen and phosphorus nutrient loads with SedNet/ANNEX in the Tully - Murray basin

2009 ◽  
Vol 60 (11) ◽  
pp. 1091 ◽  
Author(s):  
J. D. Armour ◽  
L. R. Hateley ◽  
G. L. Pitt
Keyword(s):  
Biophysical Model ◽  
Nutrient Loads ◽  
Inorganic N ◽  
Nitrogen And Phosphorus ◽  
Total N ◽  
Hill Slope ◽  
Eastern Australia ◽  
North Eastern ◽  
Wet Tropics ◽  
The Impact

A long-term, annual-average catchment biophysical model (SedNet/ANNEX) was used to calculate sediment, nitrogen (N) and phosphorus (P) loads in the Tully–Murray catchment of north-eastern Australia. A total of 119 000 t year–1 of suspended sediment, equivalent to 430 kg ha–1 year–1, was calculated to be exported to the Great Barrier Reef (GBR). Most of the sediment (64%) was generated from hill-slope erosion. The modelled load of dissolved inorganic N (1159 t year–1 or 4.2 kg N ha–1 year–1) was similar to that from other wet tropics catchments in Queensland with similar areas of sugarcane. Sugarcane produced 77% of this load. The annual loads of total N and total P were 2319 t and 244 t, respectively. Simulations (scenarios) were run to evaluate the impact of improved land management on pollutant loads to the GBR. A combination of improved cultivation and fertiliser management of sugarcane and bananas (99% of cropping land) and restoration of the most degraded riparian areas reduced sediment by 23 000 t year–1 (18%) and dissolved inorganic N by 286 t year–1 (25%). However, this reduction is much less than the reduction of 80% that may be needed in the catchment to meet target chlorophyll loads in the marine environment.

Changes in spider assemblages along grassland and savanna grazing gradients in northern Australia

2004 ◽  
Vol 26 (1) ◽  
pp. 3 ◽  
Author(s):  
T. B. Churchill ◽  
J. A. Ludwig
Keyword(s):  
Grazing Intensity ◽  
Perennial Grasses ◽  
Patch Type ◽  
Habitat Changes ◽  
The Family ◽  
Shrub Canopy ◽  
Annual Grasses ◽  
Dry Seasons ◽  
The Impact ◽  
Local Habitat

Spiders are beneficial predators that respond to those land uses that modify their habitat. Cattle grazing is an extensive land use across northern Australian rangelands, yet the impact of grazing on spider habitat is poorly understood. In this study, we evaluated the way in which spider assemblages varied between grassland and savanna habitats in the Victoria River District of the Northern Territory, and also between dry and wet seasons in the savanna habitat. We also investigated changes in spider assemblages, and some common taxa, with distance from cattle watering points, which was used as a surrogate for a gradient in grazing intensity. Spiders were sampled using pitfall traps and sweep nets along two distance from water-grazing gradients. The first gradient was in savanna on calcareous red loam soils at Kidman Springs, and the second was in grassland on cracking black clays at Mount Sanford. Ordinations revealed that spider assemblages differed between grassland and savanna, and between the late-wet and late-dry seasons in savanna. Spider assemblages also markedly changed along the two distance-grazing gradients in response to habitat changes. For example, orb weavers in the family Araneidae increased in abundance as the cover of perennial grasses and litter increased with distance from water; this response was consistent for both grassland and savanna gradients. Patch type was also important to the distribution of spiders. For example, more individuals of Habronestes sp. were caught when the local habitat was patches of perennial grasses rather than patches of annual grasses and litter, bare ground, or tree-shrub canopy. These results suggest that spiders are good indicators of the habitat changes that may occur with grazing in the rangelands of Australia.

Low rainfall rarely limits wheat yields in southern New South Wales

1989 ◽  
Vol 29 (1) ◽  
pp. 77 ◽  
Author(s):  
PS Cornish ◽  
GM Murray
Keyword(s):  
Triticum Aestivum ◽  
Water Use ◽  
Empirical Model ◽  
New South ◽  
South Australia ◽  
Wagga Wagga ◽  
Potential Yield ◽  
South Wales ◽  
Eastern Australia ◽  
Use Efficiency

Alternative models were compared for predicting the yield of wheat (Triticum aestivum) from water-use and water-use efficiency. A locally derived empirical model most closely predicted experimental yields at Wagga Wagga and was used to compute water-limited potential yields for the district surrounding Wagga Wagga for the period 1960-84. District yields were close to the predicted potential in dry years, but reached a plateau of about 2.0 t/ha regardless of rainfall and the water-limited potential yield. The yields were less than 50% of potential when water-use exceeded 300 mm, which occurred in 19 years between 1960 and 1984. Some individual farmer-yields approached the potential. These results are similar to others from South Australia. Together, they suggest that low rainfall does not directly limit yield in many years over much of the wheat belt of southern and south-eastern Australia. We suggest therefore that an analysis of the reasons for low yield on farms could lead to substantial increases in yield for many farmers.

The Influence of Recent Grazing Pressure and Landscape Position on Grass Recruitment in a Semi-Arid Woodland of Eastern Australia.

1996 ◽  
Vol 18 (1) ◽  
pp. 3 ◽  
Author(s):  
VJ Anderson ◽  
KC Hodgkinson ◽  
AC Grice
Keyword(s):  
Seedling Emergence ◽  
Perennial Grass ◽  
Soil Surface ◽  
Grazing Pressure ◽  
Perennial Grasses ◽  
Run Off ◽  
Eastern Australia ◽  
Annual Grasses ◽  
History Of ◽  
Semi Arid

This study examined the effects of previous grazing pressure, position in the landscape and apparent seed trapping capability of soil surface micro-sites on recruitment of the perennial grass Monachather paradoxa (mulga oats) in a semi-arid woodland. Seedling emergence was counted on small plots which had been kept moist for one month. The plots were on bare ground, or at grass tussocks, or at log mounds, sited in the run-off, interception and run-on zones of paddocks that had been grazed for six years at 0.3 and 0.8 sheep equivalent/ha. Few naturally occurring perennial grass seedlings emerged on any of the sites. The level of previous grazing pressure influenced the recruitment of grasses from natural sources as well as from seed of M. paradoxa broadcast on the soil surface; significantly more grass seedlings recruited in paddocks stocked at 0.3 than at 0.8 sheep/ha. Emergence of the sown grass did not differ significantly between the three zones in the landscape, but trends in the data suggest the interception zone may have been the most favourable. Recruitment from in situ grass seed was highest in the mulga grove (run-on) zone. Most seedlings of the sown grass emerged around the bases of existing perennial grass tussocks, but recruitment of volunteer perennial and annual grasses was more evenly distributed between the mulga log-mounds and perennial grass tussocks. It is concluded that very low levels of readily germinable seed of perennial grasses remained in the soil at the end of the drought and that areas with a history of high grazing pressure have less probability of grass recruitment when suitable rain occurs.

Runoff and Sediment Yield From a Semi-Arid Woodland in Eastern Australia. 1. The Effect of Pasture Type.

1992 ◽  
Vol 14 (1) ◽  
pp. 26 ◽  
Author(s):  
DJ Eldridge ◽  
J Rothon
Keyword(s):  
Sediment Yield ◽  
New South ◽  
Threshold Level ◽  
Perennial Grasses ◽  
Rainfall Runoff ◽  
South Wales ◽  
Eastern Australia ◽  
Sediment Loss ◽  
Red Earth ◽  
Runoff And Sediment Yield

Some hydrological characteristics of a red earth soil were examined under two pasture types at Yathong in central-westem New South Wales using simulated rainfall. Runoff and rate of sediment loss from plots dominated by perennial grasses were lower than for plots dominated by ephemerals. Time-to-ponding was less on the plots dominated by ephemerals but time-to-runoff was similar for both pasture types. On both grass and ephemeral-dominant soils, measured soil and vegetation attributes explained very little of the variation in runoff and sediment yield. The results do not support the existence of a threshold level of vegetation cover below which runoff increases markedly.

Evaluation of chicory cultivars and accessions for forage in south-eastern Australia

2010 ◽  
Vol 61 (7) ◽  
pp. 554 ◽  
Author(s):  
Guangdi D. Li ◽  
Zhongnan Nie ◽  
Amanda Bonython ◽  
Suzanne P. Boschma ◽  
Richard C. Hayes ◽  
...  
Keyword(s):  
South Australia ◽  
Farming Systems ◽  
Wagga Wagga ◽  
Severe Drought ◽  
Climate Conditions ◽  
South Eastern ◽  
Mixed Farming ◽  
South Wales ◽  
Eastern Australia ◽  
South Eastern Australia

The comparative herbage production and persistence of 7 chicory cultivars and 14 accessions collected from diverse regions of the world were evaluated over 3 years in 5 agro-ecological environments across New South Wales (NSW), Victoria (Vic.) and South Australia (SA). Results showed that all cultivars had higher herbage yields than the accessions, but varied greatly among sites. Averaged across all cultivars, total herbage yields were up to 24.6 t DM/ha over 3 years at the Hamilton, Vic. site, but as low as 6.9 and 5.7 t DM/ha at the Wagga Wagga and Bookham, NSW sites, respectively, where chicory only persisted for 2 years. In contrast, the average herbage yield of all accessions was only one-half of that produced by the cultivars at the Hamilton site and about one-third of that at the other 4 sites. All cultivars and accessions persisted well under the favourable climate conditions experienced at the Hamilton site. In contrast, severe drought in 2006 resulted in the death of chicory swards at the Wagga Wagga and Bookham sites, and substantial declines in persistence at the Manilla, NSW and Willalooka, SA sites. Nevertheless, accessions collected from Australia and Asia were more persistent than some of the cultivars and may provide opportunities to select genotypes better adapted to intermittently dry mixed farming systems in south-eastern Australia. Our findings indicated that the current cultivars were best suited to sites similar to the Hamilton site in the winter-dominant, higher rainfall zone of south-eastern Australia. Under these conditions chicory was likely to be productive and persistent for 4 years or longer. In the drier mixed farming zone, chicory may be more suitable in shorter (2–3-year) pasture phases. Further research is required to identify those factors contributing to poor persistence.

Natural revegetation of hydrocarbon-contaminated soil in semi-arid grasslands

2004 ◽  
Vol 82 (1) ◽  
pp. 22-30 ◽  
Author(s):  
Diana Bizecki Robson ◽  
J Diane Knight ◽  
Richard E Farrell ◽  
James J Germida
Keyword(s):  
Functional Groups ◽  
Plant Species ◽  
Contaminated Soils ◽  
Oil Spills ◽  
Abundant Species ◽  
Perennial Grasses ◽  
Soil Conditions ◽  
Nitrogen And Phosphorus ◽  
Litter Cover ◽  
The Impact

One way to identify hydrocarbon-tolerant plant species for reclamation is to sample vegetation at contaminated sites allowed to recover naturally. We compared vegetation and soils of 14 hydrocarbon-contaminated plots in southern Saskatchewan to those of nearby uncontaminated plots to determine the impact on plant communities and soil properties. Contaminated plots had less vegetation and litter cover than uncontaminated plots, and significantly higher soil carbon to nitrogen ratios, pH, and hydrocarbon concentration, and lower nitrogen and phosphorus. Although species richness was not significantly different, Shannon's diversity was lower on contaminated plots. Mean compositional similarity of the plots, measured using Jaccard's index, was only 31%, and cover similarity, measured using Spatz's index, was only 22%. Vegetation composition differences occurred because mycorrhizal, woody and vegetatively reproducing species, and species using birds or unassisted means for seed dispersal were significantly less common on contaminated than uncontaminated plots. Self-pollinated species were significantly more common on contaminated plots. The most abundant species on contaminated soils were the annual forb Kochia scoparia and the native perennial grasses Hordeum jubatum, Distichlis stricta, Agropyron smithii, Agropyron trachycaulum, and Poa canbyi. This research shows that some plant species and functional groups are tolerant of the altered soil conditions at hydrocarbon-contaminated sites.Key words: functional groups, oil spills, phytoremediation, reclamation, succession, vegetation recovery.

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