The effects of grazing and season on the stability of Chloris Spp. (Windmill grasses) in natural pasture at Trangie, New South Wales.

1978 ◽  
Vol 1 (2) ◽  
pp. 106 ◽  
Author(s):  
DL Michalk ◽  
PK Herbert

A study of the density and basal diameter of Chloris acicularis Lindl. (syn. Enteropogon acicularis (LindlJLazar. - curly windmill grass) and C. truncata R. Br. (windmill grass) was made at two stocking rates over a period of eight years. The propor- tion of ground covered by these Chloris species varied widely with season, and to a lesser extent with grazing pressure. The density of both species increased in good seasons, while the mean diameter decreased because of the number of new seedlings. Although C. truncata seedlings were more numerous in good seasons, they did not survive as well as did C. acicularis seedlings during prolonged dry periods.

1973 ◽  
Vol 13 (62) ◽  
pp. 238
Author(s):  
RJ Campbell ◽  
DG Saville ◽  
GE Robards

Natural annual pasture at Trangie, New South Wales, was set stocked from August, 1967 to December 1970 at rates of 2.5, 3.7, and 4.9 merino wethers per ha to determine an optimum stocking rate for the pasture type. All stocking rates were supported without the necessity to hand feed any sheep. Wool production per head was reduced significantly by increased stocking rate in 1968, but not in 1969 and 1970. The suppression of barley grass at the higher stocking rates appeared to benefit animal production in 1969. Substitution of portion of the natural annual pasture with areas of lucerne or natural perennial pasture was also investigated and found to be ineffective in increasing wool production per head above that of wethers at similar rates of stocking on natural annual pasture alone. Possible reasons for the apparent failure of the grazing supplements, particularly lucerne, are discussed in terms of grazing pressure and management strategies.


1978 ◽  
Vol 18 (92) ◽  
pp. 361 ◽  
Author(s):  
GE Robards ◽  
DL Michalk ◽  
RJ Pither

A four year experiment is reported during which breeding Merino ewes grazed two natural pasture types at three stocking rates at Trangie in central-western New South Wales. Initially, the pasture on a red brown soil was dominated by cool season annual species, particularly Hordeum leporinum, Erodium species and Medicago species. The pasture on a heavier grey soil was dominated by the perennial grasses Chloris acicularis, C. truncata and Stipa variabilis. Clean wool production of ewes grazing the annual-dominated pasture was significantly (P< 0.05) higher than that of ewes grazing the perennial grass-dominated pasture even though the wool of the ewes grazing perennial pasture had a higher percentage clean yield (P < 0.05). The ewes on the annual-dominated pasture were significantly heavier in autumn and winter, and had a faster rate of wool growth in each season except spring, than ewes grazing perennial pasture. Number of lambs born per ewe, lamb birth weight and lamb growth rate were not affected by pasture type or stocking rate. Stocking rate had a small but statistically significant effect on clean wool production and only small effects on ewe liveweight, regardless of pasture type. When hand feeding of the pregnant ewes became necessary in the poor winters of 1971 and 1972 all stocking rates had to be commenced simultaneously. The significance of perennial grasses in these natural pastures is discussed in relationship to animal production, stocking rate, pasture and soil stability, and regeneration of grasses following favourable seasons.


1977 ◽  
Vol 17 (89) ◽  
pp. 905 ◽  
Author(s):  
Davies H Lloyd

Hereford-type steers were grazed at 1.5, 2.0, 2.5 and 3.0 ha-1 on a Paspalum dilatatum dominant pasture for three years at Bringelly, New South Wales. There were large differences in mean daily liveweight gain between replicates; sometimes steers at the lowest stocking rate had a lower mean daily liveweight gain than those run at higher stocking rates. The mean plasma copper concentration varied from 0.28 to 0.41 �g ml-1 for the steers on the plots having a low liveweight gain and 0.50 to 0.87 for steers a with higher daily gain. The mean liver copper content varied from 11 to 46 mg kg-1. The copper concentration in the pasture ranged from 7 to 16 mg kg-1. The range in molybdenum concentration was from 0.08 to 0.38 mg kg-1. The plasma and liver copper data suggest that some of the poorer performance may have been due to copper deficiency in the animals but this was not caused by the low levels of copper in the pasture nor induced by high levels of molybdenum.


1997 ◽  
Vol 19 (1) ◽  
pp. 40 ◽  
Author(s):  
AM Bowman ◽  
DJ Munnich ◽  
KY Chan ◽  
J Brockwell

Thirty-eight paddocks on 23 properties in the Walgett Shire of north-westem New South Wales were surveyed in April and May 1993 to identify factors that affected Mitchell grass (Astrebla lappacea) plant density. Low densities of Mitchell grass were associated with the occurrence of at least one flood in the last 20 years. Soils from paddocks described by landholders as in poor condition, and where Mitchell grass density was low, were more alkaline and had significantly higher electrical conductivity than soils from paddocks described as in good condition, and where Mitchell grass density was high. Paddocks in poor condition had higher organic carbon and mineralisable nitrogen levels and higher soil populations of Rhizobium meliloti. These latter characteristics were attributed to these pastures having a high component of annual species, including Medicago species, which returned substantial amounts of carbon and nitrogen to the soil. Where Mitchell grass density was moderate, other palatable species were common and biodiversity was high. However, in paddocks with the lowest densities of Mitchell grass, both annual species and unpalatable perennials were common. Low basal diameter of Mitchell grass plants and low Mitchell grass density, were associated with higher grazing pressure. The data suggested that the Mitchell grass ecosystem in north-westem New South Wales is prone to deterioration on the more alkaline and saline soils and where inundation by flooding or waterlogging is common.


1998 ◽  
Vol 46 (2) ◽  
pp. 153 ◽  
Author(s):  
Damon L. Oliver

The regent honeyea ter, Xanthomyza phrygia, is an endangered woodland bird whose range and population size have decreased in the last thirty years. Suggested reasons for this decline include abnormal breeding behaviour, poor reproductive output, and excessive inter- and intra-specific aggression. This study investigated the breeding behaviour and aggressive interactions of regent honeyeaters during the nest construction, incubation, nestling, and fledgling stages in two consecutive breeding seasons in the Bundarra–Barraba region near Armidale, New South Wales. The female was entirely responsible for nest construction and incubation, which is typical of many honeyeaters. Both parents fed the nestlings, and at a similar rate, although only the female brooded chicks on the nest. Both parents fed the fledglings. The mean frequency at which nestlings (23 times per hour) and fledglings (29 times per hour) were fed is the highest published rate of any non-cooperative honeyeater. Breeding males were involved in significantly more aggressive interactions with conspecifics and other nectarivores than were females, although the overall percentage of day-time spent in aggression for both sexes was low (2.5%). It appears that abnormal breeding behaviour, poor reproductive effort, or excessive aggression are not experienced by this species in northern New South Wales, and that other factors are likely to be responsible for its current low population level.


1994 ◽  
Vol 34 (1) ◽  
pp. 33 ◽  
Author(s):  
GM Lodge

Burrs were collected from paddocks on 3 properties in northern New South Wales where the age of the Trifolium subterraneum var. brachycalycinum cv. Clare swards varied from 19 to 28 years. At 1 site burrs were also sampled from swards sown 2 and 10 years previously. Twenty seedlings from these burrs and 20 plants of certified cv. Clare were grown as spaced plants in a nursery. These were assessed for vegetative and floral characters, flowering time, number of seeds per burr, seed weight, and percentage hardseed after storage at 25/25�C for 6 months and 25/45�C for a further 6 months. For most plants the mean number of days from sowing to first flower was similar to that of Clare. Compared with the naturalised strains, Clare had the lowest (P<0.05) mean number of seeds per burr: about 25% below the mean of the strains (2.7 seeds per burr). While the lowest mean seed weights of the strains were not significantly different from those of Clare, the seed weights of plants from 3 sites were higher (P<0.05) than those of Clare. After storage for either 6 or 12 months, hardseed levels were also lowest (P<0.05) for Clare. Plants from the 2-year-old sward had the same median number of seeds per burr (2.0) as Clare. As sward age increased, the median number of seeds per burr increased to 2.8. Hardseed percentages were lowest for plants of Clare and for those from the 2-year-old sward after 6 months, and for Clare after 12 months. These studies indicated the presence of divergent strains in old swards of Clare in a summer rainfall environment. Natural selection among variability within Clare is the most likely reason for the development of these strains in an environment marginal for the long-term persistence of this softseeded cultivar. Although strains had the same vegetative and floral markings as Clare, differences in ecologically important characters such as number of seeds per burr, seed weight, and hardseededness may result in plants that are better adapted to the environment in which they evolved. From these studies 23 plants of T. subterraneum var. brachycalycinum were selected for further evaluation.


1999 ◽  
Vol 21 (2) ◽  
pp. 177
Author(s):  
T.R. Grant ◽  
P.C. Gehrke ◽  
J.H. Harris ◽  
S. Hartley

Data from the New South Wales Rivers Survey on the occurrence of platypuses have provided the most recent and comprehensive record of platypus distribution in the State. The species was most commonly reported from the montane and coastal regions, being less common on the western slopes and uncommon in the rivers of the western lowlands. The observations confirmed those from earlier community-based surveys. In contrast to the distribution of native fish species, there appears to have been little change in the overall state-wide distribution of the platypus in response to degrading processes in the rivers of New South Wales, although nothing is known of the stability of their population numbers.


1967 ◽  
Vol 7 (24) ◽  
pp. 7 ◽  
Author(s):  
P McInnes ◽  
TJ Grainger ◽  
MD Smith

Data are presented on the recovery and reproductive performance of 2 1/2-year-old maiden Merino ewes after a prolonged period of undernutrition. The 217 sheep had been hand-fed on a submaintenance ration in pen feeding trials at Glenfield, New South Wales. During the seven months of the trials they had lost 6 kg (28 to 22 kg) body weight. They were transported to Condobolin in south-western New South Wales, divided into two treatment groups and run on good quality pastures. One group was joined immediately (May 1959) and again ten months later, and the other group was mated after six months at Condobolin (in October 1959) and again 12 months later. The ewes recovered rapidly. The mean weight of both groups had reached 30 kg within six weeks and 40 kg within six months. In the first year 73 of the 100 May-mated ewes bore lambs, but only 38 of these lambs were weaned. Ewes bearing lambs had a higher body weight at the start of joining and gained more during joining than the barren ewes. At the other three joinings (October 1959, May 1960, October 1960) lambing percentage was from 86-89 and weaning percentage from 62-69-both normal for the district. The proportion of twin lambs (3-6 per cent) was low. Wool weight in 1959 was not affected by time of mating or by pregnancy.


1972 ◽  
Vol 12 (58) ◽  
pp. 455 ◽  
Author(s):  
RDH Cohen

The effect of phosphorus supplementation on liveweight and digestibility of dietary components was studied in two experiments with beef steers at Grafton, New South Wales. In one experiment, three groups of 15 steers grazed a pasture that was deficient in phosphorus and nitrogen throughout the year and received a supplement of 0, 35, or 70 g phosphorus each week for twelve months. The phosphorus supplements had no effect on liveweight. In a second experiment, five pairs of steers were individually fed a phosphorus deficient diet to which urea, molasses, and minerals were added. The steers received a daily supplement of either 0, 2, 4, G, or 8 g phosphorus. The supplements had no effect on liveweight or apparent digestibility of dry matter, energy, or nitrogen. The apparent digestibility of phosphorus increased with supplementation up to 4 g a day (P<0.001) but there was no further increase at the higher rates. The apparent retention of phosphorus increased with each increment of phosphorus (P<0.01). It is concluded that supplements of phosphorus will not improve liveweight performance when beef cattle graze natural pasture of such low quality as that frequently found in north-eastern New South Wales.


1978 ◽  
Vol 1 (2) ◽  
pp. 167
Author(s):  
VR Squires

In order to assess the current level of stock watering facilities on pastoral properties within the western Riverina district of New South Wales and to relate this information to paddock size and vegetation type, large of areas of land (785,000 ha) within the region were surveyed. Paddock boundaries and the location of watering points were plotted. Watering points were classified as to type. Three broad vegetation types were represented: chenopod shrublands (Atriplex and Maireana spp.) degraded grasslands (Stipal Danthonia spp.), and mallee woodlands (Eucalyptus socinlis F. Meull., E, oleosa, F. Meull.) Size of paddocks was related to the dominant vegetation type. On the degraded grasslands in the eastern part of the study area the mean paddock size was 746 ha; on the chenopod shrublands it was 780 ha, and in the Malleedominated areas it was 1,553 ha. The number of permanent watering points per paddock varied from one to four. Less than half the paddocks (43%) had fresh water available as well as saline waters from sub-artesian bores. Almost half the paddocks (47%) were so large, or the watering points so positioned, that the sheep would need to walk more than 3 km to reach the most remote parts of the paddock when temporary waters had dried up. Overall 18% of the land in the non- mallee areas was more than 3 km from permanent water. Therefore the majority of the land could be used in all seasons. Generally the central and northern Riverina district is adequately watered. It would be uneconomic to supply permanent water in the mallee woodlands. In some paddocks in the chenopod dominated area extra watering points may be justified.


Sign in / Sign up

Export Citation Format

Share Document