Effect of superphosphate, white clover and stocking rate on the productivity of natural pastures, Northern Tablelands, New South Wales

1976 ◽  
Vol 16 (79) ◽  
pp. 209 ◽  
Author(s):  
GG Robinson ◽  
A Lazenby

The species frequency, pasture availability and animal production on natural pastures oversown with white clover were examined over the five year period 1968-73. Superphosphate was applied annually at different levels (0, 250 and 500 kg ha-1) and the plots were grazed continuously at two stocking rates (7.8 and 15.6 wethers ha-1). An increase in the frequency of white clover (Trifolium repens) and a decrease in bare ground, Panicum spp-Eragrostis spp. and Sporobolus elongatus (in the case of the latter two the effect was particularly evident at the low stocking rate) followed the application of superphosphate. Increasing stocking rate resulted in a reduction in white clover and an increase in the frequency of Panicum spp.-Eragrostis spp. and bare ground. Pasture availability and animal production were increased by superphosphate. Apart from the first year, when the season was unusually dry, supplementary feeding was minimal on all topdressed treatments but was essential at the high stocking rate where no superphosphate was applied. Over the five year period animals on the pastures receiving superphosphate averaged 15 per cent heavier and gave 18 per cent more wool than those that were unfertilized. Wool production at the high stocking rate averaged 17.8 kg ha-1 (49 per cent) more than that from the low stocking rate.

1978 ◽  
Vol 18 (92) ◽  
pp. 370 ◽  
Author(s):  
JM George ◽  
RA Pearse

Merino ewes were grazed for 10 years at stocking rates of 8, 12 and 16 ha-1, lambing in winter, spring or summer on a phalaris/white clover pasture on the Northern Tablelands of New South Wales. Wool production, wool yield and count, and lambing and weaning rates were established for the wide range of climatic conditions experienced. A spring lambing is indicated under the within-year price relationships experienced. Under a wide range of wool and lamb prices the optimum stocking rate varied from 12 to 16 ewes ha-1 depending on labour costs.


1977 ◽  
Vol 17 (89) ◽  
pp. 899 ◽  
Author(s):  
Davies H Lloyd

The effect of stocking rate and sowing one-eighth of the area to lucerne on the liveweight change and carcase characteristics of Hereford steers grazing pastures dominated by Paspalum dilatatum was studied at the Wolverton Farm of the University of Sydney, Bringelly, New South Wales from 1971 to 1974. Stocking rate (1.5, 2.0, 2.5 and 3.0 steers ha-1) had an effect upon mean daily liveweight gain in some periods and this was reflected in the number of days taken to achieve 450 kg. (1.5 ha-1 took 509 days, 2.0 took 595, 2.5 took 802 and 3.0 took 842 days). There were significant differences in average daily gain between replicates in most periods. The lucerne did not persist after the first year. Having one-eighth of the area sown to lucerne did not significantly affect daily liveweight gain. There were highly significant period effects with the highest daily gain occurring in spring and summer, the lowest in winter and gain in autumn being dependent upon rainfall and stocking rate. In many periods increasing stocking rate above 2.0 steers ha-1 did not increase the per hectare liveweight gain.


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.


2005 ◽  
Vol 45 (12) ◽  
pp. 1603 ◽  
Author(s):  
G. M. Lodge ◽  
L. H. McCormick ◽  
S. Harden

Hyparrhenia hirta (L.) Stapf (Coolatai grass) has invaded large areas of grazed native grasslands on the North-West Slopes of New South Wales (NSW) and is widespread along roadsides and travelling stock routes. It is commonly regarded as an invasive, weedy species with low forage value when it is tall and rank, but may be more palatable when kept short, green and leafy. A study (1990–2001) of a naturalised stand of Coolatai grass in the Manilla district of northern NSW examined its herbage mass (kg DM/ha), persistence (basal cover %), and grazing value under 2 contrasting grazing treatments: pastures that had either large amounts of dry, unpalatable herbage [light grazing at 5 dry sheep equivalents (DSE)/ha] or were short, green and leafy (strategic heavy grazing at a stocking rate of 37 DSE/ha). Effects of pre-grazing treatments (slashing, burning, and no defoliation) were also examined and data (litter mass, plant basal area, ground cover, and soil and litter microbial carbon and nitrogen) collected to assess the long term sustainability of these grazing systems. Sheep grazed the light grazing treatment for about 34% of the experimental period, with the strategic heavy grazing treatment being grazed for about 7% of the time. Over the experimental period this equated to 6752 DSE grazing days/ha for the light grazing treatment compared with 10 120 DSE for the heavy grazing treatment. Herbage mass in the heavy grazing treatment declined to <1000 kg DM/ha within 6 months of the start of grazing and remained below this level until December 1998 when stocking rates were switched (i.e. plots previously grazed at low stocking rate were subjected to the heavier rate and vice versa). In contrast, mean herbage mass in the light grazing treatment was generally >3000 kg DM/ha from November 1990–98, but a high proportion of this was dead standing material that carried over from season to season. Mean Coolatai grass basal cover was 9.5% in November 1990, increasing over time to about 25% in both grazing treatments by December 2000. Coolatai grass herbage accumulation was highly seasonal, ranging from as high as 70 kg DM/ha.day in summer to 0 in winter. In both grazing treatments, forage quality was low for both green and dead material, with mean crude protein being 6.0 (green) and 3.4% (dead). Digestible dry matter values ranged from 41 to 62% (green) and 32 to 51% (dead) and mean metabolisable energy values were 7 (green) and 5.3 MJ/kg DM (dead). After 8 years, the heavy grazing treatment had lower (P<0.05) litter mass, ground cover, plant basal area and soil microbial C and N levels than the light grazing treatment, but switching of the stocking rates restored most indicators, except the soil microbial values.


1979 ◽  
Vol 19 (98) ◽  
pp. 297 ◽  
Author(s):  
JG Mulholland ◽  
JB Coombe

Two grazing experiments were conducted to evaluate buckwheat and sorghum stubbles as forage for sheep. The stubbles were stocked by young crossbred wethers at 10 and 20 ha-1 for 55 days on the buckwheat and 81 days on the sorghum. Measurements were made at regular intervals of the availability and composition of plant material, diet selection, the intake of digestible organic matter (DOM) and liveweight change, while wool production was measured over each experimental period. More than one-third of the sheep grazing buckwheat stubble were affected by fagopyrism (buckwheat poisoning) and this probably reduced both liveweight gain and wool production. Buckwheat residues had a similar nitrogen content to sorghum (1 .0% vs 0.87%), but a lower organic matter digestibility (43.7% vs 57.1%). Mature buckwheat plants were not eaten readily. Mean liveweights of sheep on buckwheat stubble declined throughout the experimental period and overall changes were -3.8 and -7.0 kg for the low and high stocking rates, respectively. Corresponding values for sheep on sorghum stubble were 0.3 and -4.6 kg, although weight losses at the higher stocking rate did not occur until after 40 days grazing. For the same length of grazing as the buckwheat (55 days) the liveweight changes for sorghum were 0.2 and -1.2 kg, respectively. Wool growth rate was low for both stubbles but was more than 60% higher for sheep on the sorghum. Values for each stocking rate were 3.86 and 2.67 (g clean dry wool day-1) for the buckwheat, and 5.39 and 4.33 for the sorghum. It was concluded that sorghum stubble is a useful source of grazing for sheep on the Southern Tablelands but buckwheat stubble, because of its low acceptability, poor nutritional value and the risk of fagopyrism, is of very limited value.


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.


Author(s):  
B.E. Allan

Continuous stocking was compared with intermittent (two paddock) and rotational (six paddock) grazing at low, medium and high stocking rates equivalent to 1.0x, 1.5x and 2.0x conventional rates for oversown tussock country (500 mm annual rainfall). 'By the sixth year liveweight gain/ha from Merino wether hoggets was improved 26% by intermittent and rotational grazing at medium stocking rates from that at conventional stocking rates. A strong interaction was demonstrated, with advantage in liveweight gain from intermittent and rotational grazing strengthening with increasing stocking rate. Total vegetative cover (75.8%) remained unchanged. Cocksfoot increased under low stocking while ryegrass increased under high stocking. A 60% overall loss in ryegrass during 1982 was attributed to unusually low winter soil temperatures. White clover cover was affected more b y climate than by grazing. A!!hough ?here *were interim differences, herbage production by the sixth year was similar for all treatments. Keywords: Tussock country, oversown, grazing, stocking rate, subdivision, pasture development, utilisation, Merino, liveweight.


1975 ◽  
Vol 15 (72) ◽  
pp. 102 ◽  
Author(s):  
GD Kohn ◽  
EG Cuthbertson

The influence of pasture topdressing with superphosphate and of stocking rate on the Chondrilla uncea population in a clover-ryegrass (Trifolium subterraneum-Lolium rigidum) pasture was measured in a grazing experiment at Wagga Wagga, New South Wales, over the period 1962 to 1966. Superphosphate application reduced final weed populations at all stocking rates. Continuous grazing maintained skeleton weed populations at a low level, but increasing the stocking rate from 5 to 15 sheep ha-1 had little influence on weed numbers. A management comparison at a high stocking rate-high fertilizer rate showed that rotational grazing increased the weed population compared with continuous grazing systems.


1970 ◽  
Vol 10 (44) ◽  
pp. 279 ◽  
Author(s):  
LF Myers ◽  
VR Squires

In two experiments at Deniliquin, New South Wales, the length of the prewinter growing season of an irrigated pasture was controlled by varying the date of the opening autumn irrigation : Irrigation began in February, March, or April for treatments T1, T2, and T3 respectively. In the first, winter yields of ungrazed pasture (July) fell by approximately 1500 lb DM/acre for each month that the first irrigation was delayed after February. Clover content of the pasture was progressively less as the opening irrigation was delayed. Seed yields were unchanged by length of growing season, but increased markedly with increased phosphate supply. In the second experiment, which was grazed at three stocking rates (5, 7, and 10 sheep/acre), the response to treatments was less than in the first (ungrazed) experiment. Pasture yield (available feed) and liveweight gain were similar on treatments T1 and T2. However, at the 10 sheep/acre rate, T1 plots survived for 14 months longer than T2plots. There was no evidence that a stocking rate of 7 sheep/ acre could not be maintained indefinitely on the treatment T1. Annual production exceeded 68 lb clean wool (90 lb greasy) an acre and the plots were supporting a total liveweight exceeding 1000 lb/acre. The influence of autumn rains on the response to early autumn irrigation and the practical implications of the results are discussed briefly.


1998 ◽  
Vol 38 (5) ◽  
pp. 433 ◽  
Author(s):  
H. Lloyd Davies ◽  
J. D. McFarlane ◽  
O. L. P. de Oliveira ◽  
G. W. King ◽  
J. W. James

Summary. The effect of 4 rates of superphosphate application (250 kg/ha. year, 125 kg/ha. year, 125 kg/ha every 2 years or 125 kg/ha every 4 years) and a low and high stocking rate (3.6 and 5.4 ewes/ha, 1980–86; and 4.0 and 7.0 ewes/ha, 1986–89) on sheep liveweight, fleece weight, lamb weaning weight, pasture production and botanical composition, soil pH, soil phosphorus, manganese and aluminium concentrations were measured on a Phalaris aquatica–subterranean clover pasture at Stuart Town, New South Wales. Only when 250 kg/ha of superphosphate had been applied annually was there a higher level of soil phosphorus than with the other 3 systems. None of the treatments affected soil pH, soil manganese or aluminium. There were large year effects and individual plot effects on pasture and sheep production but neither the superphosphate rates nor stocking rate significantly affected pasture or animal production. It was concluded that over a 9-year period the application of 125 kg/ha in alternate years can maintain adequate soil phosphorus levels, and satisfactory pasture and animal production on the central tablelands of New South Wales.


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