Effectiveness of single and annual applications of potassium fertilizer on mown pasture in southeastern South Australia

1979 ◽  
Vol 19 (100) ◽  
pp. 599 ◽  
Author(s):  
AP Meissner ◽  
AL Clarke

In south-eastern South Australia, experiments lasting three years were conducted at 22 sites to compare the effects of single and annual applications of KCl on mown subterranean clover-rye grass pastures. Data from the sites were analyzed using the model

1977 ◽  
Vol 17 (88) ◽  
pp. 765 ◽  
Author(s):  
AP Meissner ◽  
AL Clarke

Trials lasting three years were conducted at 27 sites in the south-east of South Australia to examine the responses of mown subterranean clover-ryegrass pastures to repeated annual applications of potassium chloride. At 20 sites, yield of dry matter (DM) was increased by potassium in one or more harvests. Responses were measured in 9 out of 55 winter harvests and 42 out of 86 spring harvests; mean responses to 100 kg ha-1 KCl (-Y100) at responsive sites were 380 and 560 kg DM ha-1 in winter and spring respectively. When potassium dressing increased yield, the proportion of clover in the sward was either maintained or increased. The herbage concentration of potassium was usually increased, and its magnesium concentration sometimes depressed, by potassium application. Although the K:Mg ratio was thereby increased, especially during winter, it rarely reached 15, the value considered necessary to induce grass tetany in cattle. Multivariate regression analysis showed that the exchangeable potassium concentration (Kex) of the top 10 cm of soil, the depth of soil overlying clay or limestone, and the sand content of the topsoil were factors affecting yield response. The best regression equations, however, explained less than half of the response variations. In practice, Kex alone would have usefully diagnosed potassium responsive sites. Responses occurred often when Kexwas less than 0.2 me 100 g-1 and rarely when it was greater. The use of potassium fertilizer is likely to be worthwhile to establish new pasture, to maintain the clover content of old pasture, and to increase the yield and quality of hay, where soils have less than 0.20 me 100 g-1 Kex. Such soils are most commonly sands more than 30 cm deep.


1985 ◽  
Vol 25 (2) ◽  
pp. 455 ◽  
Author(s):  
GR Stirling ◽  
MF Wachtel

In south-eastern South Australia root-knot nematode (Meloidogyne hapla) caused losses to potato crops in fields that were sown once every 5- 15 years and were used for grazing in the intervening years. Although seed used by some growers was infested with M. hapla, the nematode also survived between potato crops on subterranean clover (Trifolium subterraneum), the dominant pasture species, and capeweed (Cryptostemma calendula). Subterranean clover was the most abundant alternate host. Nematodes invaded clover seedlings that established following rain in April and produced eggs about 12 weeks later. A second generation was produced in late winter and spring, so that a relatively high root-knot nematode population was present when potatoes were planted. The population increased rapidly on potatoes and numbers capable of causing severe root damage were observed 10- 15 weeks after planting. The growing of non-host crops, or the use of herbicides or cultivation to eliminate subterranean clover in the winter prior to the potato crop, should be investigated. In a nematicide trial, ethylene dibromide at 70 and 110 kg/ha increased yields of potato cv. Pontiac by about 90%.


1959 ◽  
Vol 10 (2) ◽  
pp. 150 ◽  
Author(s):  
AM Olsen

The maximum yield of the school shark fishery in south-eastern Australian waters was 4.09 million lb in 1949. The catch has fluctuated since then about a declining trend to 3.18 million lb in 1956. In 1944, 7.3 hooks were required to catch a shark of mean weight 14.7 lb. In 1956 the number of hooks required was almost doubled: 13.6 hooks were needed to catch sharks of mean weight 13.7 lb; the catch per hook dropped from 2.01 to 0.99 lb. Whereas the catch per boat-month remained relatively stable at 4765 lb for 1944 and 4643 for 1956, the number of hooks used per boat-month increased from 2366 to 4668 hooks in 12 years. Throughout this period the mean weight of sharks in eastern Bass Strait remained fairly steady (11-13 lb) whereas there was a drop of 3 lb from a mean weight of 17-20 lb in the predominantly mature portion of the stock in western Bass Strait. Fishermen in South Australia have reported a comparable drop in the mean weight of sharks in their catches. During the period 1941-46 there was unrestricted inshore fishing of juveniles and pregnant females with a consequent severe drop in the inshore population. The subsequent decline in the annual total catch is believed to be due not only to a too intensive offshore fishery but also to the resultant reduced recruitment and depressed reproductive potential caused by the earlier destruction of juveniles and pregnant females. In the data presented in this paper there is evidence that the school shark fishery, which is operating on a single stock of sharks with a slow growth rate, a late sexual maturity, and a low fecundity, shows trends which are suggestive of depletion. Because similar trends in the soupfin shark fishery of California and in the dogfish fishery of British Columbia were followed by depletion, it has been inferred that regulations to protect the vulnerable phases of the life history of the school shark of Australia may be required. Measures for conservation are discussed.


2019 ◽  
Vol 70 (2) ◽  
pp. 147 ◽  
Author(s):  
Sajid Latif ◽  
Saliya Gurusinghe ◽  
Paul A. Weston ◽  
William B. Brown ◽  
Jane C. Quinn ◽  
...  

Mixed farming systems have traditionally incorporated subterranean clover (Trifolium subterraneum L.) and lucerne (Medicago sativa L.) as key components of the pasture phase across south-eastern Australia. However, poor adaptation of subterranean clover to acidic soils, insufficient and inconsistent rainfall, high input costs, soil acidification and the emergence of herbicide-resistant weeds have reduced efficacy of some traditional clover species in recent years. To overcome these challenges, numerous novel pasture species have been selectively improved and released for establishment in Australia. Despite their suitability to Australian climate and soils, limited knowledge exists regarding their weed-suppressive ability in relation to establishment and regeneration. Field trials were therefore conducted over 3 years in New South Wales to evaluate the suppressive potential of selected pasture legume species and cultivars as monocultures and in mixed stands against dominant annual pasture weeds. Pasture and weed biomass varied significantly between pasture species when sown as monocultures, but mixtures of several species did not differ with regard to establishment and subsequent weed infestation. Arrowleaf clover (T. vesiculosum Savi.) and biserrula (Biserrula pelecinus L.) cv. Casbah showed improved stand establishment, with higher biomass and reduced weed infestation compared with other pasture species. Generally, weed suppression was positively correlated with pasture biomass; however, yellow serradella (Ornithopus compressus L.) cv. Santorini exhibited greater weed suppression than other pasture legumes while producing lower biomass, thereby suggesting a mechanism other than competition for resources affecting weed-suppressive ability. Over the period 2015–17, arrowleaf clover and biserrula cv. Casbah were generally the most consistent annual pasture legumes with respect to yearly regeneration and suppression of annual pasture weed species.


2020 ◽  
Vol 42 (3) ◽  
pp. 321
Author(s):  
B. D. Cooke

Swamp wallabies have dramatically extended their distribution through western Victoria and south-eastern South Australia over the last 40 years. Newspaper reports from 1875 onwards show that on European settlement, wallaby populations were confined to eastern Victoria, including the ranges around Melbourne, the Otway Ranges and Portland District of south-western Victoria, and a tiny part of south-eastern South Australia. Populations contracted further with intense hunting for the fur trade until the 1930s. In the late 1970s, however, wallabies began spreading into drier habitats than those initially recorded. Possible causes underlying this change in distribution are discussed; some seem unlikely but, because wallabies began spreading soon after the introduction of European rabbit fleas as vectors of myxomatosis, the cumulative effects of releases of biological agents to control rabbits appear important. A caution is given on assuming that thick vegetation in high-rainfall areas provides the only habitat suitable for swamp wallabies, but, most importantly, the study shows how native mammals may benefit if rabbit abundance is reduced.


1999 ◽  
Vol 50 (7) ◽  
pp. 1233 ◽  
Author(s):  
G. H. Baker ◽  
P. J. Carter ◽  
V. J. Barrett

The earthworm fauna of pastures in south-eastern Australia is dominated by exotic lumbricid earthworms, in particular the endogeic species, Aporrectodea caliginosa and A. trapezoides. Anecic species such as A. longa are very rare. All 3 species were introduced within cages in 10 pastures on a range of soil types within the region. Five months later, A. longa had generally survived the best and A. trapezoides the worst. The survivals and weights of individual worms varied between sites for all 3 species. The survivals of A. caliginosa and A. longa, and to a lesser extent A. trapezoides, were positively correlated with soil clay content. The weights of A. caliginosa and A. longa, but not A. trapezoides, were positively correlated with soil P content. The survivals and weights of A. longa and A. trapezoides and the weights only of A. caliginosa decreased with increasing inoculation density, suggesting increased intraspecific competition for resources, particularly in the first two species. A. longa reduced the abundance and biomass of the exotic acanthodrilid earthworm, Microscolex dubius, at one site, and the total biomass of 3 native megascolecid species at another, when these latter species occurred as contaminants in A. longa cages. The addition of lime had no effect on the survivals and weights of A. caliginosa, A. longa, and A. trapezoides, although the soils were acid at the sites tested. The addition of sheep dung increased the survival and weights of some species at some sites. Mechanical disturbance of the soil within cages reduced the survivals of A. longa and A. trapezoides. A. longa was released without being caged at 25 sites within one pasture in South Australia. Four years later, it was recovered at all release points. A. longa has the potential to colonise pastures widely throughout the higher rainfall regions of south-eastern Australia.


1996 ◽  
Vol 47 (7) ◽  
pp. 1095 ◽  
Author(s):  
MJ Hill

Potential adaptation zones were modelled for major temperate pasture species using climate data and knowledge-based logical rules. A GIs database was constructed using a 0.025 degree digital elevation model and the Australian Climate Surfaces to create layers of monthly mean climate data for Australia. Soil pH maps for New South Wales, Victoria, and south-eastern South Australia were digitised and added to the database. Simple models using logical operators were constructed using estimates of temperature and aridity thresholds for the main temperate pasture species. The logical models were executed using primary and derived climate layers to create raster maps of potential adaptation zones for pasture species in eastern and south-western Australia. Areas of adaptation on freehold/leasehold land were expressed relative to a potential temperate pasture adaptation zone described by the lower (arid) limit of annual legume adaptation in temperate Australia and the northern limit of lucerne adaptation. Potential adaptation within this area ranged from 66% for lucerne down to <20% for perennial ryegrass in eastern Australia, and 93% for subterranean clover down to zero for perennial ryegrass in south-western Australia. Utility of the species adaptation zones could be enhanced using soil pH maps: a zone for serradella in NSW was refined by restricting adaptation to areas of climatic suitability with low soil pH. Maps for lucerne and Mount Barker subterranean clover showed good agreement with validation data for NSW. The zones may be readily adjusted by simple changes to parameter values in the algorithms. This knowledge-based approach has potential as an aid to targeting resources for plant improvement or to provide advice for more efficient utilisation of existing commercial pasture plants.


2001 ◽  
Vol 41 (2) ◽  
pp. 187 ◽  
Author(s):  
R. Aldaoud ◽  
W. Guppy ◽  
L. Callinan ◽  
S. F. Flett ◽  
K. A. Wratten ◽  
...  

In 1995–96, a survey of soil samples from subterranean clover (Trifolium subterraneum L.) paddocks was conducted across Victoria, South Australia, New South Wales and Western Australia, to determine the distribution and the prevalence of races of Phytophthora clandestina (as determined by the development of root rot on differential cultivars), and the association of its occurrence with paddock variables. In all states, there was a weak but significant association between P. clandestina detected in soil samples and subsequent root rot susceptibility of differential cultivars grown in these soil samples. Phytophthora clandestina was found in 38% of the sampled sites, with a significantly lower prevalence in South Australia (27%). There were significant positive associations between P. clandestina detection and increased soil salinity (Western Australia), early growth stages of subterranean clover (Victoria), mature subterranean clover (South Australia), recently sown subterranean clover (South Australia), paddocks with higher subterranean clover content (Victoria), where herbicides were not applied (South Australia), irrigation (New South Wales and Victoria), cattle grazing (South Australia and Victoria), early sampling dates (Victoria and New South Wales), sampling shortly after the autumn break or first irrigation (Victoria), shorter soil storage time (Victoria) and farmer’s perception of root rot being present (Victoria and New South Wales). Only 29% of P. clandestina isolates could be classified under the 5 known races. Some of the unknown races were virulent on cv. Seaton Park LF (most resistant) and others were avirulent on cv. Woogenellup (most susceptible). Race 1 was significantly less prevalent in South Australia than Victoria and race 0 was significantly less prevalent in New South Wales than in South Australia and Western Australia. This study revealed extremely wide variation in the virulence of P. clandestina. The potential importance of the results on programs to breed for resistance to root rot are discussed. in South Australia.


1985 ◽  
Vol 25 (2) ◽  
pp. 347 ◽  
Author(s):  
WM Blowes ◽  
KJ Schmalzl ◽  
SM Jones

In field trials carried our in 1983 at Gama and Horsham (Victoria), Hart (South Australia) and York (Western Australia), the effect of two rates of glyphosate (0.54 and 1.08 kg/ha active ingredient), applied 1-8 days before sowing, on the establishment, growth and nodulation of four cultivars of subterranean clover and 10 medic cultivars was investigated. No significant adverse effects were observed on establishment, growth or nodulation even at the high rate (2x field rate) of glyphosate. The absence of any adverse effect was attributed to rapid absorption and inactivation of glyphosate in soil and possibly also the manner of seed placement below the glyphosate-treated topsoil layer.


2015 ◽  
Vol 21 (4) ◽  
pp. 271 ◽  
Author(s):  
Gregory R. Johnston ◽  
Maxwell H. Waterman ◽  
Clare E. Manning

Globally, pelican populations have decreased, with three species being of conservation concern. Australian pelicans (Pelecanus conspicillatus) are not regarded as endangered, but have declined across south-eastern Australia. Information on their movements and causes of mortality are required to interpret the importance of these regional declines to the species’ global population. We explored patterns of movement and causes of mortality by analysing recoveries from 14 615 Australian pelicans banded over 37 years between 1969 and 2006. Data from 243 leg band recoveries showed that Australian pelicans move distances of up to 3206 km, and travel across the species’ entire geographic range, within a year of fledging. We found little evidence for the popular notion that these birds move en masse from the coast to inland areas in response to flooding rains. Maximum recorded age of a banded Australian pelican was 15 years. The banding data suggest that the regional pelican declines could reflect long-distance movements rather than an overall population response. However, a concentration of band returns from south-eastern Australia where the declines have been recorded, and the high incidence of human-induced deaths (16.4%) suggest otherwise. Accurate assessment of population trends in long-lived, long-distance nomads such as Australian pelicans requires assessment at a continental scale. Our results emphasise the importance of knowledge about fundamental aspects of a species’ biology for accurate interpretation of regional population declines.


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