Quality and potential utility of ENSO-based forecasts of spring rainfall and wheat yield in south-eastern Australia

2008 ◽  
Vol 59 (2) ◽  
pp. 112 ◽  
Author(s):  
M. R. Anwar ◽  
D. Rodriguez ◽  
D. L. Liu ◽  
S. Power ◽  
G. J. O'Leary
Keyword(s):  
Grain Yield ◽  
Production Systems ◽  
Southern Oscillation ◽  
Wheat Yield ◽  
Good Reliability ◽  
South Eastern ◽  
South Wales ◽  
Eastern Australia ◽  
South Eastern Australia

Reliable seasonal climate forecasts are needed to aid tactical crop management decisions in south-eastern Australia (SEA). In this study we assessed the quality of two existing forecasting systems, i.e. the five phases of the Southern Oscillation Index (SOI) and a three phase Pacific Ocean sea-surface temperatures (SSTs), to predict spring rainfall (i.e. rainfall from 1 September to 31 November), and simulated wheat yield. The quality of the forecasts was evaluated by analysing four attributes of their performance: their reliability, the relative degree of shift and dispersion of the distributions, and measure of forecast consistency or skill. Available data included 117 years of spring rainfall and 104 years of grain yield simulated using the Agricultural Production Systems Simulator (APSIM) model, from four locations in SEA. Average values of spring rainfall were 102–174 mm with a coefficient of variation (CV) of 47%. Average simulated wheat yields were highest (5609 kg/ha) in Albury (New South Wales) and lowest (1668 kg/ha) in Birchip (Victoria). The average CV for simulated grain yields was 36%. Griffith (NSW) had the highest yield variability (CV = 50%). Some of this year-to-year variation was related to the El Niño Southern Oscillation (ENSO). Spring rainfall and simulated wheat yields showed a clear association with the SOI and SST phases at the end of July. Important variations in shift and dispersion in spring rainfall and simulated wheat yields were observed across the studied locations. The forecasts showed good reliability, indicating that both forecasting systems could be used with confidence to forecast spring rainfall or wheat yield as early as the end of July. The consistency of the forecast of spring rainfall and simulated wheat yield was 60–83%. We concluded that adequate forecasts of spring rainfall and grain yield could be produced at the end of July, using both the SOI and SST phase systems. These results are discussed in relation to the potential benefit of making tactical top-dress applications of nitrogen fertilisers during early August.

Opportunities and trade-offs in dual-purpose cereals across the southern Australian mixed-farming zone: a modelling study

2009 ◽  
Vol 49 (10) ◽  
pp. 759 ◽  
Author(s):  
Andrew D. Moore
Keyword(s):  
Western Australia ◽  
Production Systems ◽  
Wheat Yield ◽  
Livestock Production ◽  
Relative Reduction ◽  
Dual Purpose ◽  
South Eastern ◽  
Trade Offs ◽  
Eastern Australia ◽  
South Eastern Australia

Dual-purpose cereals are employed in the high-rainfall zone of southern Australia to provide additional winter forage. Recently there has been interest in applying this technology in the drier environments of South and Western Australia. It would therefore be useful to gain an understanding of the trade-offs and risks associated with grazing wheat crops in different locations. In this study the APSIM (Agricultural Production Systems Simulator) crop and soil simulation models were linked to the GRAZPLAN pasture and livestock models and used to examine the benefits and costs of grazing cereal crops at 21 locations spanning seven of the regions participating in the Grain & Graze research, development and extension program. A self-contained part of a mixed farm (an annual pasture–wheat rotation plus permanent pastures) supporting a breeding ewe enterprise was simulated. At each location the consequences were examined of: (i) replacing a spring wheat cultivar with a dual-purpose cultivar (cv. Wedgetail or Tennant) in 1 year of the rotation; and (ii) either grazing that crop in winter, or leaving it ungrazed. The frequency of early sowing opportunities enabling the use of a dual-purpose cultivar was high. When left ungrazed the dual-purpose cultivars yielded less grain on average (by 0.1–0.9 t/ha) than spring cultivars in Western Australia and the Eyre Peninsula but more (by 0.25–0.8 t/ha) in south-eastern Australia. Stocking rate and hence animal production per ha could be increased proportionately more when a dual-purpose cultivar was used for grazing; because of the adjustments to stocking rates, grazing of the wheat had little effect on lamb sale weights. Across locations, the relative reduction in wheat yield caused by grazing the wheats was proportional to the grazing pressure upon them. Any economic advantage of moving to a dual-purpose system is likely to arise mainly from the benefit to livestock production in Western Australia, but primarily from grain production in south-eastern Australia (including the Mallee region). Between years, the relationship between increased livestock production and decreased grain yield from grazing crops shifts widely; it may therefore be possible to identify flexible grazing rules that optimise this trade-off.

Longevity of wheat yield response to lime in south-eastern Australia

1997 ◽  
Vol 37 (5) ◽  
pp. 571 ◽  
Author(s):  
D. R. Coventry ◽  
W. J. Slattery ◽  
V. F. Burnett ◽  
G. W. Ganning
Keyword(s):  
Grain Yield ◽  
Soil Ph ◽  
Wheat Yield ◽  
Yield Response ◽  
South Eastern ◽  
Initial Application ◽  
Eastern Australia ◽  
Phosphorus Fertiliser ◽  
Lime Application ◽  
South Eastern Australia

Summary. A long-term experiment in north-eastern Victoria has been regularly monitored for wheat yield responses to a range of lime and fertiliser treatments, and the soil sampled for acidity attributes. Substantial grain yield increases have been consistently obtained over a period of 12 years with a single lime application. Lime applied at 2.5 t/ha in 1980 was still providing yield increases of 24% with an acid-tolerant wheat (Matong, 1992 season) and 79% with an acid-sensitive wheat (Oxley, 1993 season) relative to no lime treatment. The 2 wheat cultivars responded differently to phosphorus fertiliser, with the acid-sensitive wheat less responsive to phosphorus fertiliser in the absence of lime. The use of a regular lime application applied as a fertiliser (125 kg lime/ha) with the wheat seed gave only a small grain yield increase (8% Matong, 16% Oxley), despite 1 t/ha of lime applied over the 12-year period. Liming the soil at a rate of 2.5 t/ha (1980) initially raised the soil pH by about 1.0 unit and removed most soluble aluminium (0–10 cm). However, after 12 years of crop–pasture rotation after the initial 2.5 t lime/ha treatment the soil pH had declined by 0.7 of a pH unit and exchangeable aluminium was substantially increased, almost to levels prior to the initial application of lime. Given the continued yield responsiveness obtained following the initial application of lime, this practice, rather than regular applications of small amounts of lime, is recommended for wheat production on strongly acidic (pHw < 5.5) soils in south-eastern Australia.

Biology of angel sharks (Squatina sp.) and sawsharks (Pristiophorus sp.) caught in south-eastern Australian trawl fisheries and the New South Wales shark-meshing (bather-protection) program

2017 ◽  
Vol 68 (2) ◽  
pp. 207 ◽  
Author(s):  
V. Raoult ◽  
V. Peddemors ◽  
J. E. Williamson
Keyword(s):  
New South ◽  
Growth Curves ◽  
Commercial Fishing ◽  
South Eastern ◽  
Total Length ◽  
South Wales ◽  
Large Numbers ◽  
Eastern Australia ◽  
Trawl Fisheries ◽  
South Eastern Australia

Two species of angel shark (Squatina australis, S. albipunctata) and two species of sawshark (Pristiophorus nudipinnis, P. cirratus) are frequently caught in south-eastern Australia. Little is known of the biology of these elasmobranchs, despite being caught as secondary target species in large numbers. The present study collected morphometric and reproductive data from sharks caught in shark-control nets, commercial fishing trawlers and research trawlers in south-eastern Australia. All four species had female-biased sexual size dimorphism, but growth curves between sexes did not differ. Male S. australis individuals were fully mature at ~800-mm total length, male P. nudipinnis at ~900mm, and male P. cirratus at ~800mm. Anterior pectoral margins could be used to determine total length in all species. No morphometric measurement could reliably separate Squatina spp. or Pristiophorus spp., although S. albipunctata over 1000-mm total length had larger eyes than did S. australis.

Variation in Chondrilla juncea L. in south-eastern Australia

1973 ◽  
Vol 21 (1) ◽  
pp. 113 ◽  
Author(s):  
VJ Hill ◽  
RH Groves
Keyword(s):  
Stem Elongation ◽  
Leaf Shape ◽  
Weed Species ◽  
South Eastern ◽  
Leaf Emergence ◽  
South Wales ◽  
Eastern Australia ◽  
Wide Range ◽  
South Eastern Australia ◽  
Chondrilla Juncea

Three variants or forms of Chondrilla juncea L. (skeleton weed) are distinguished in south-eastern Australia. The forms (designated A, B, and C) differ in inflorescence morphology and fruit characters, but mainly in the shape of rosette leaves, for which quantitative expressions of the differences have been developed. There were no significant differences within each form in rosette leaf shape when grown in a wide range of environments. First and second progenies of the three forms, presumably apomictic, retained the identity of their parents, as did leaves of rosettes arising vegetatively from the root system after removal of the parental rosette. The geographical limits of distribution of the forms are given, based on results from field observations and from plants grown in a glasshouse either from seed or clonal material. Plants of form A are widespread and occur in south-eastern Australia over a wide range of latitude, climate, and soil type. With one exception, the distribution of plants of forms B and C in 1969 was restricted to central New South Wales, where the forms are distributed sympatrically with plants of form A. Form B plants are confined at present to an area bounded approximately by Young, Orange, Peak Hill, and Marsden, though these boundaries are extending. Leaf emergence rates, times to stem elongation, and times to flowering are presented for the three forms. Differences between forms in these characters under some conditions are shown to exist, as well as differences between forms in their ability to regenerate vegetatively. Form C plants, at present more restricted geographically, seem to have a greater potential for regeneration from rootstocks than form A plants, already widespread throughout south-eastern Australia. The variation described in this paper is discussed in relation to control of other weed species, especially apomicts.

Pastures in temperate rice rotations of south-eastern Australia

1994 ◽  
Vol 34 (7) ◽  
pp. 959 ◽  
Author(s):  
MAE Lattimore
Keyword(s):  
Soil Fertility ◽  
Weed Control ◽  
New South ◽  
New South Wales ◽  
Cropping System ◽  
Environmental Pressures ◽  
South Eastern ◽  
South Wales ◽  
Eastern Australia ◽  
South Eastern Australia

Legume-based pastures have long been an integral part of rice growing in the southern New South Wales irrigation areas and still offer potential to improve the productivity, profitability, and sustainability of the temperate rice-cropping system.This paper reviews both historical and current aspects of pastures in temperate rice rotations in southern New South Wales and highlights the importance of pastures in sustaining this cropping system as environmental pressures increase. Topics discussed include pasture species and rotations, their role in improving soil fertility and sustainability, the value of pastures in weed control, and their management for maximum profitability.

The El Nino-Southern Oscillation in south-eastern Australian waters

1991 ◽  
Vol 42 (3) ◽  
pp. 263 ◽  
Author(s):  
WW Hsieh ◽  
BV Hamon
Keyword(s):  
Sea Level ◽  
Coastal Upwelling ◽  
Southern Oscillation ◽  
Geostrophic Wind ◽  
Air Pressure ◽  
Ekman Transport ◽  
Hydrographic Data ◽  
South Eastern ◽  
Eastern Australia ◽  
South Eastern Australia

Using four decades of hydrographic data collected off the coast near Sydney, New South Wales, and sea-level data at Sydney, we studied the interannual variability in south-eastern Australian shelf waters. The first two empirical orthogonal function (EOF) modes of the band-pass-filtered 50-m-depth hydrographic data (temperature, T; salinity, S; nitrate, N; inorganic phosphate, P; and oxygen, O) and the sea level (SL) and adjusted sea level (ASL) data accounted respectively for 51 and 27% of the total variance. Both modes were significantly correlated with the Southern Oscillation Index (SOI). The first mode, with T, S, O and ASL varying in opposition to N and P, represented the internal or baroclinic response, associated with vertical displacements of the isopycnals. The second mode, with large in-phase fluctuations in SL and ASL but small changes in the hydrographic variables, represented mainly the external or barotropic response during the El Niiio-Southern Oscillation (ENSO). Three-year composites centred around seven ENSO warm episodes revealed that T, S, O and ASL were generally low and N, P, SL and SO1 were high in the year before each ENSO warm episode, but the former group rose while the latter group dropped in the year of the warm episode. The changes in the hydrographic variables at 50 m depth were consistent with relatively shallow isopycnals in the year before the ENSO warm episode, followed by a deepening of the isopycnals during the warm episode. Estimates of this downward displacement of isopycnals, as determined from T, N, P and O, were in the range 7-10 m. The geostrophic wind arising from the pressure fluctuations during ENSO is proposed as a probable cause for the vertical displacement of the isopycnals. In the year before the warm episode, the low air pressure over Australia would produce a clockwise geostrophic wind around south-eastern Australia, generating offshore Ekman transport and coastal upwelling. During the warm episode, air pressure over Australia rises, the geostrophic wind reverses, and downward movement of the isopycnals would occur off south-eastern Australia.

Population ranges of Miniopterus schreibersii (Chiroptera) in south-eastern Australia

1969 ◽  
Vol 17 (4) ◽  
pp. 665 ◽  
Author(s):  
PD Dwyer
Keyword(s):  
New South ◽  
New South Wales ◽  
South Australia ◽  
South Eastern ◽  
Navigational Cues ◽  
South Wales ◽  
Eastern Australia ◽  
North Eastern ◽  
Western Victoria ◽  
South Eastern Australia

In south-eastern Australia banding of M. schreibersii has been concentrated in four areas: north-eastern New South Wales, south-eastern New South Wales, south-eastern Victoria, and south-western Victoria and south-eastern South Australia. The present paper analyses 2083 reported movements. Only 17 of these are from one of the four areas to another with the longest movement being 810 miles. Biologically and geographically separate populations of M. schreibersii are recognized in both north-eastern and south-eastern New South Wales. Each population has its basis in dependence upon a specific nursery site which is used annually by nearly all adult females in that population. Boundaries of population ranges in New South Wales are considered to be prominent features of physiography (i.e. divides). Bats move between population ranges less often than they move within population ranges. This cannot be explained solely in terms of the distances separating roosts. Available movement records from Victoria and South Australia are consistent with the pattern described for New South Wales. Two biologically recognizable populations (i.e, different birth periods) occur in south-western Victoria and south-eastern South Australia but these may have overlapping ranges. Only one nursery colony of M. schreibersii is known from south-eastern Victoria. On present evidence it remains possible that the apparent integrity of the population associated with this nursery is merely a consequence of distance from other areas of banding activity. Detailed analyses of movements in bats may provide direct evidence as to the kinds of cues by which a given species navigates. Thus the physiographic basis described for population ranges in New South Wales is consistent with the view that M. schreibersii may orientate to waterways or divides or both. The probability that there are area differences in the subtlety or nature of navigational cues is implied by the different physiographic circumstances of south-western Victoria and south-eastern South Australia. It is suggested that knowledge of population range boundaries may aid planning of meaningful homing experiments.

A theory of prior streams as a casual factor of soil occurrence in the riverine plain of South-Eastern Australia

1950 ◽  
Vol 1 (3) ◽  
pp. 231 ◽  
Author(s):  
BW Butler
Keyword(s):  
Land Surface ◽  
Alluvial Fan ◽  
South Eastern ◽  
South Wales ◽  
Local Soil ◽  
Murray River ◽  
Eastern Australia ◽  
Soil Surveys ◽  
South Eastern Australia

A new theory is submitted on the origin of the soil formations in the alluvial plains region of southern New South Wales and Victoria embracing the Murray River and tributaries which has been given the name of the Riverine Plain of South-Eastern Australia. The Riverine Plain is delineated and the climate and physiography of the environment are briefly described. The theory postulates the occurrence of a system of prior streams independent of the present stream pattern; from the activity of this system the present soils and land surface were derived. The formations are discussed in terms of sedimentary array, salinity, and degree of leaching. Figures illustrate the ideal sediment pattern of a prior stream formation, a typical alluvial fan, and a simplified map of the region showing prior and present stream systems. A classification of the named soils from local soil surveys is given in the form of 15 sequences of general catenary relationship. The influence of halomorphism in soil development is discussed with the deduction that solonetzous and solodous soils occur generally throughout the region. The age of prior stream activity is set at late Pleistocene to early Recent.

Evaluating the accuracy of the Agricultural Production Systems Simulator (APSIM) simulating growth, development, and herbage nutritive characteristics of forage crops grown in the south-eastern dairy regions of Australia

2013 ◽  
Vol 64 (2) ◽  
pp. 147 ◽  
Author(s):  
K. G. Pembleton ◽  
R. P. Rawnsley ◽  
J. L. Jacobs ◽  
F. J. Mickan ◽  
G. N. O'Brien ◽  
...  
Keyword(s):  
Agricultural Production ◽  
Production Systems ◽  
Forage Crops ◽  
Crop Phenology ◽  
Forage Crop ◽  
South Eastern ◽  
Eastern Australia ◽  
Forage Rape ◽  
Agricultural Production Systems ◽  
South Eastern Australia

Pasture-based dairy farms are a complex system involving interactions between soils, pastures, forage crops, and livestock as well as the economic and social aspects of the business. Consequently, biophysical and farm systems models are becoming important tools to study pasture-based dairy systems. However, there is currently a paucity of modelling tools available for the simulation of one key component of the system—forage crops. This study evaluated the accuracy of the Agricultural Production Systems Simulator (APSIM) in simulating dry matter (DM) yield, phenology, and herbage nutritive characteristics of forage crops grown in the dairy regions of south-eastern Australia. Simulation results were compared with data for forage wheat (Triticum aestivum L.), oats (Avena sativa L.), forage rape (Brassica napus L.), forage sorghum (Sorghum bicolor (L.) Moench), and maize (Zea mays L.) collated from previous field research and demonstration activities undertaken across the dairy regions of south-eastern Australia. This study showed that APSIM adequately predicted the DM yield of forage crops, as evidenced by the range of values for the coefficient of determination (0.58–0.95), correlation coefficient (0.76–0.94), and bias correction factor (0.97–1.00). Crop phenology for maize, forage wheat, and oats was predicted with similar accuracy to forage crop DM yield, whereas the phenology of forage rape and forage sorghum was poorly predicted (R2 values 0.38 and 0.80, correlation coefficient 0.62 and –0.90, and bias correction factors 0.67 and 0.28, respectively). Herbage nutritive characteristics for all crop species were poorly predicted. While the selection of a model to explore an aspect of agricultural production will depend on the specific problem being addressed, the performance of APSIM in simulating forage crop DM yield and, in many cases, crop phenology, coupled with its ease of use, open access, and science-based mechanistic methods of simulating agricultural and crop processes, makes it an ideal model for exploring the influence of management and environment on forage crops grown on dairy farms in south-eastern Australia. Potential future model developments and improvements are discussed in the context of the results of this validation analysis.

Larval distribution and abundance of blue and spotted warehous (Seriolella brama and S. punctata: Centrolophidae) in south-eastern Australia

2001 ◽  
Vol 52 (4) ◽  
pp. 631 ◽  
Author(s):  
B. D. Bruce ◽  
F. J. Neira ◽  
R. W. Bradford
Keyword(s):  
Life Histories ◽  
New South ◽  
South Australia ◽  
South Eastern ◽  
Larval Distribution ◽  
South Wales ◽  
Spawning Areas ◽  
Eastern Australia ◽  
Commercially Important ◽  
South Eastern Australia

The early life histories of the commercially important blue and spotted warehous (Seriolella brama and S. punctata) were examined on the basis of archived ichthyoplankton samples collected over broad areas of southern Australia. Larvae of both species were widely distributed during winter and spring within shelf and slope waters. Larvae of S. brama were recorded from Kangaroo Island, South Australia (SA), to southern New South Wales (NSW). Seriolella punctata larvae were recorded from western Tasmania to southern NSW. Back-calculated spawning dates, based on otolith microstructure, indicated that spawning predominantly occurs during late July and August but that the timing of spawning varies between regions. The abundances of small larvae (<5. 0 mm body length) were highest for both species off western Tasmania and southern NSW. No small S. brama larvae were recorded between southern Tasmania and southern NSW, whereas low but consistent numbers of small S. punctata larvae were found between these regions. The data suggest that there are separate spawning areas for S. brama in western and eastern regions of Australia’s South East Fishery. The pattern for S. punctata is less clear, but suggests a more continuous link among populations in south-eastern Australia.

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