Tactical versus continuous stocking in perennial ryegrass-subterranean clover pastures grazed by sheep in south-western Victoria. 2. Ryegrass persistence and botanical composition

2001 ◽  
Vol 41 (8) ◽  
pp. 1109 ◽  
Author(s):  
R. A. Waller ◽  
P. W. G. Sale ◽  
G. R. Saul ◽  
G. A. Kearney
Keyword(s):  
Perennial Ryegrass ◽  
Dry Matter ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Summer Rainfall ◽  
Grazing Pressure ◽  
Botanical Composition ◽  
Average Mass ◽  
Gravelly Soil ◽  
Western Victoria

A 4-year field experiment was carried out in south-western Victoria to determine whether tactical stocking might improve perennial ryegrass (Lolium perenne L.) persistence and prime lamb production, compared with the more common practice of continuous stocking. Tactical stocking consisted of variable-length summer, autumn and winter rotations and continuous stocking in spring. The 2 grazing strategies were compared on 2 contrasting pastures: an upgraded pasture, sown with newer cultivars of perennial ryegrass and subterranean clover (Trifolium subterraneum L.) with 26 kg phosphorus/ha.year, and a more typical naturalised perennial ryegrass pasture receiving 6 kg phosphorus/ha.year. Paddocks were grazed by Border Leicester x Merino ewes, which were mated to a terminal sire to lamb in September. The effects of the grazing systems and pasture treatments on ryegrass persistence and pasture botanical composition are presented in this paper. The perennial ryegrass component of the sward decreased from an average mass of 1000 kg dry matter/ha on the upgraded pasture and 400 kg dry matter/ha on the typical pasture in spring 1996 to 100 kg dry matter/ha and <50 kg/ha for the 2 pasture types, respectively, in spring 1998. This occurred irrespective of the grazing system imposed. The decline of ryegrass was attributed to several factors including the very dry 3-year period, summer rainfall events that caused ryegrass buds to break dormancy then die when dry conditions resumed, the gravelly soil type where the experiment was located, and the high grazing pressure used. A number of species became more prevalent in the pastures as the ryegrass disappeared. Silver grass (Vulpia spp.) increased 4–5-fold on all treatments. By the fourth year, barley grass (Hordeum leporinum) and Bromus spp. had increased significantly with tactical stocking compared with continuous stocking. Capeweed (Arctotheca calendula L.) and Erodium spp. increased on both the continuously stocked and upgraded pastures. The subterranean clover component was maintained across all treatments over the 4 years, indicating that tactical stocking did not adversely affect clover persistence. Since ryegrass declined irrespective of treatment, the tactical stocking system used in this study cannot be recommended for improving ryegrass persistence.

The performance of subterranean, rose, and cupped clovers under set-stocking

1972 ◽  
Vol 12 (59) ◽  
pp. 608 ◽  
Author(s):  
RC Rossiter ◽  
GB Taylor ◽  
GW Anderson
Keyword(s):  
Dry Matter ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Grazing Pressure ◽  
Wool Production ◽  
Four Seasons ◽  
Gravelly Soil ◽  
Digestible Organic Matter ◽  
The Rose ◽  
Clover Pasture

Pasture swards of the annual clovers Trifolium subterraneum (CV. Geraldton), T. hirtum (CV. Kondinin), and T. cherleri (CV. Yamina), and a mixture of all three were sown on a gravelly soil at Bakers Hill, Western Australia, in 1964. All pastures were set-stocked at 5 sheep ha-l from April 1965-April 1968, and at 8 sheep ha-1 from April 1968-March 1970. From 1966 onwards the amount of pasture dry matter on offer in July and September was two to four times as great on the subterranean clover pasture as on rose or cupped clover pastures. Moreover, the subterranean clover pasture resisted invasion by volunteer annuals more strongly. The mixed clover pasture was dominated by subterranean clover by 1966, and remained so thereafter. For the first four seasons of grazing, wool production was consistently higher (on average, 14 per cent higher) on rose clover than on subterranean clover pasture, and slightly lower still on cupped clover. In the fifth season, when grazing pressure was higher than previously, the rose and cupped clovers 'crashed', and subterranean clover produced most wool. We argue that the higher wool production on rose clover during 1965-1969 was due to some factor additional to digestible organic matter intake.

Tactical versus continuous stocking in perennial ryegrass-subterranean clover pastures grazed by sheep in south-western Victoria. 1. Stocking rates and herbage production

2001 ◽  
Vol 41 (8) ◽  
pp. 1099 ◽  
Author(s):  
R. A. Waller ◽  
P. W. G. Sale ◽  
G. R. Saul ◽  
G. A. Kearney
Keyword(s):  
Perennial Ryegrass ◽  
Dry Matter ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Stocking Rate ◽  
Soil Fertility Status ◽  
Western Victoria ◽  
Terminal Sire ◽  
Autumn And Winter ◽  
Stocking Rates

A 4-year field experiment was carried out in south-western Victoria to determine whether tactical stocking might improve perennial ryegrass (Lolium perenne L.) persistence and prime lamb production, compared with the more common practice of year-around continuous stocking. Tactical stocking consisted of variable length summer, autumn and winter rotations and continuous stocking in spring. The 2 grazing strategies were compared on 2 contrasting pastures: an upgraded pasture, sown with newer cultivars of perennial ryegrass and subterranean clover (Trifolium subterraneum L.) with 26 kg phosphorus/ha.year, and a more typical naturalised perennial ryegrass pasture receiving 6 kg phosphorus/ha.year. Paddocks were grazed by Border Leicester x Merino ewes, which were mated to a terminal sire to lamb in September. The effects of the grazing systems and pasture treatments on herbage production and stocking rate are presented in this paper. Herbage production was similar between the treatments, but tactical stocking significantly increased herbage mass during the growing season (P<0.05) compared with continuous stocking. In spring each year, the herbage mass generally exceeded 3000 kg dry matter/ha in tactically stocked paddocks and averaged 500–900 kg dry matter/ha higher than the mass on continuously stocked paddocks. This enabled the year-round stocking rate to be increased by an average of 9% over the 4 years of the experiment. We considered that the stocking rates could not be further increased, despite the higher herbage mass in spring, as stock reduced the dry herbage to a low residual mass by the opening rains in autumn. In contrast, stocking rates averaged 51% higher on the upgraded pasture compared with the typical pasture over the 4 years of the experiment. This indicates that pasture improvement and soil fertility status have a much greater impact on productivity than changes to grazing method. However, tactical stocking was able to increase the sustainability of prime lamb production on upgraded pastures in a dry summer climate, by maintaining herbage cover on the paddocks over the summer–autumn period.

Effects of time and rate of paraquat application on yield and botanical composition of annual pastures containing subterranean clover in a Mediterranean climate

1973 ◽  
Vol 13 (64) ◽  
pp. 556
Author(s):  
DW Barrett ◽  
GW Arnold ◽  
NA Campbell
Keyword(s):  
Dry Matter ◽  
Mediterranean Climate ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Botanical Composition ◽  
Minimum Loss ◽  
Major Species ◽  
Nitrogen Phosphorus ◽  
Clover Content ◽  
Made In

Pastures containing subterranean clover (Trifolium subterraneum) and either Vulpia spp. or Bromus rigidus as the other major species were sprayed at 0, 0.07, 0.14 and 0.21 kg a.i. ha-1 of paraquat ion between June and early October in Western Australia. Spraying removed the grasses and produced pastures containing up to 95 per cent clover. Mid-winter applications were more effective in increasing clover content than those made in spring. These changes in botanical composition were evident in the year following spraying, but were less marked. Yields of dry matter were reduced by paraquat, especially 'in the period immediately following spraying. These losses tended to decline as the growing season progressed, but at the close they were still evident on the Bromus rigidus pasture sprayed in July. Yields at the end of the subsequent season were similar on all treatments. Paraquat applied in mid-August at 0.14 kg a.i. ha-1 to both pastures produced the greatest change in botanical composition with the minimum loss of yield. The concentrations of nitrogen, phosphorus, calcium and magnesium were higher in mature herbage on paraquat treatments. Total yields of nutrients were similar between treatments because of reduced dry matter yield.

Tactical versus continuous stocking for persistence of perennial ryegrass (Lolium perenne L.) in pastures grazed by sheep in south-western Victoria

1999 ◽  
Vol 39 (3) ◽  
pp. 265 ◽  
Author(s):  
R. A. Waller ◽  
P. E. Quigley ◽  
G. R. Saul ◽  
G. A. Kearney ◽  
P. W. G. Sale
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Seedling Recruitment ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Fold Increase ◽  
Early Summer ◽  
Lolium Perenne L ◽  
Western Victoria ◽  
Tiller Density

The survival of perennial ryegrass (Lolium perenne L.) plants was studied in sheep pastures in south-western Victoria during the dry summer of 1996–97. Recruitment of perennial ryegrass seedlings into the pasture sward was also monitored in the autumn–winter periods in 1997 and 1998. The objective was to investigate whether a tactical stocking strategy, consisting of variable length summer, autumn and winter rotations and continuous stocking in spring, might increase perennial ryegrass tiller survival and seedling recruitment in the autumn, compared with continuous stocking all year. The grazing strategies were compared on 2 contrasting pastures: an upgraded pasture [sown with newer cultivars of perennial ryegrass and subterranean clover (Trifolium subterraneum L.) with 26 kg phosphorus/ha.year as applied fertiliser] and a naturalised perennial ryegrass pasture receiving 6 kg P/ha.year. Paddocks were grazed by Border Leicester × Merino ewes, mated to a terminal sire so as to lamb in September. Perennial ryegrass tiller density was higher on the upgraded pasture with a mean density of 7750 tillers/m2 in early summer which declined to zero live tillers by mid summer. Live tillers began to reappear before the opening rains and then increased after the rain. Mean tiller density in the upgraded pasture declined over the 2 summers, with only 2050 tillers/m2 being present 2 months after the opening rains in 1998. There were no effects (P>0.05) of pasture type or grazing strategy on the number of tagged tillers that survived the summer period. Only 12% of the vegetative tillers, randomly tagged in December 1996, survived to May 1997. More than half of the tillers (56%) that produced a seedhead produced daughter tillers which survived the dry summer–autumn period. A significant (P<0.05) interaction between grazing strategy and pasture type occurred with the number of perennial ryegrass seedlings that had established 4 weeks after the opening rains in 1997. There was a 5–11-fold increase in seedling numbers which regenerated in the tactically stocked, upgraded pasture compared with the other treatments. Seedling recruitment was considerably lower in the autumn of 1998, due presumably to an overall decline in perennial ryegrass density relative to annual grasses in 1997. A second experiment investigated the effect of excluding sheep from grazing at anthesis until seedhead maturation or until the opening rains, together with a mechanical seed dislodgment treatment at seed maturity. All exclusion treatments increased seedling recruitment 4–7-fold, compared with continuous stocking. The results suggest a possible mechanism by which perennial ryegrass density can be increased without expensive reseeding.

Long-term persistence of subterranean clover (Trifolium subterraneum) cultivars in south-western Victoria

1991 ◽  
Vol 31 (5) ◽  
pp. 625 ◽  
Author(s):  
SG Clark ◽  
RM McDonald ◽  
HC Street
Keyword(s):  
Dry Matter ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Seed Banks ◽  
Sheep Grazing ◽  
Level Of Invasion ◽  
Small Seed ◽  
Low Levels ◽  
Western Victoria

The long-term persistence of 6 subterranean clover (Trifolium subterraneum) cultivars was determined by sampling seed from 2 experiments at Hamilton and Beeac in south-western Victoria, 8 or 12 years after sowing. For most of this period the plots were managed as part of the surrounding pasture and were closely grazed by sheep. Herbage yield measurements were made and seed was collected from each plot and grown in a glasshouse, in order to identify the cultivar(s) present. Cultivars used were Yarloop, Trikkala, Larisa and Meteora (spp. yanninicum), and Mount Barker and Woogenellup (spp. subterranean). At both sites, plots sown to Trikkala and Larisa had the greatest seed banks and experienced the lowest level of invasion by other cultivars or ecotypes. Mount Barker and Yarloop appeared to have persisted at low levels; their plots were moderately invaded. Plots sown to the unsuccessful Woogenellup were heavily invaded and contained only a small seed bank of Woogenellup seed. Eight to 12 years after sowing, plots at Hamilton and Beeac that were sown to Larisa produced 3-15 times as much clover dry matter in spring as plots sown to Mount Barker. At Hamilton, the plots sown to Trikkala produced 3 times as much clover in winter as those sown to Mount Barker. This study indicates that Trikkala and Larisa offer clear advantages over the older cultivars, Mount Barker and Woogenellup, for the high rainfall areas of western Victoria, by demonstrating their persistence and long-term productivity when subjected to normal sheep-grazing practice.

Effects of superphosphate fertiliser and stocking rate on the nutritive value of perennial ryegrass and subterranean clover herbage

1999 ◽  
Vol 50 (4) ◽  
pp. 537 ◽  
Author(s):  
G. R. Saul ◽  
G. A. Kearney ◽  
P. C. Flinn ◽  
C. L. Lescun
Keyword(s):  
Perennial Ryegrass ◽  
Crude Protein ◽  
Dry Matter ◽  
Nutritive Value ◽  
Subterranean Clover ◽  
Stocking Rate ◽  
Western Victoria ◽  
Stocking Rates ◽  
Infertile Soils

The effect of superphosphate fertiliser on digestible dry matter (DDM) and crude protein (CP) percentages of perennial ryegrass and subterranean clover was assessed on a long-term, grazed experiment in western Victoria. CP of both species increased significantly (3–6 units) where long-term average phosphorus (P) applications were 33 kg/ha.year compared with 1 kg/ha.year. CP of herbage was also greater on paddocks grazed at higher (9–23 ewes/ha) than lower (5–13 ewes/ha) stocking rates (1–3 units). DDM of subterranean clover significantly increased (8–10 units) with higher superphosphate applications but there was little effect on the DDM of perennial ryegrass. Long-term applications of superphosphate were associated with larger increases in both DDM and CP than if the same rate was applied in autumn of the year of measurement. For subterranean clover, 30 kg/ha of P applied to infertile soils (Olsen P 5 mg/kg) in autumn increased the DDM of herbage collected in September by only 4–6 units. The nutritive value of most volunteer pasture species also increased with higher superphosphate applications but the DDM of these species was usually inferior to perennial ryegrass. The results highlight the importance of monitoring nutritive value, pasture composition, and herbage production to quantify fully the likely effect of fertiliser applications on animal production.

scholarly journals Integrated management of vulpia in dryland perennial pastures of southern Australia

2009 ◽  
Vol 60 (1) ◽  
pp. 32 ◽  
Author(s):  
K. N. Tozer ◽  
D. F. Chapman ◽  
P. E. Quigley ◽  
P. M. Dowling ◽  
R. D. Cousens ◽  
...  
Keyword(s):  
Seed Production ◽  
Integrated Management ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Summer Rainfall ◽  
Annual Rainfall ◽  
Herbicide Application ◽  
South Wales ◽  
Fertiliser Application ◽  
Western Victoria

Vulpia (Vulpia species C.C. Gmel.) are annual grass weeds that can reduce pasture quality and stock-carrying capacity of perennial pastures throughout southern Australia. To develop more effective strategies to control vulpia, an experiment was established in western Victoria (average annual rainfall 565 mm) in phalaris (Phalaris aquatica L.) pastures comparing the effects of control methods [comprising combinations of fertiliser addition (Fert), a single herbicide (simazine) application (Sim), and pasture rest from grazing (Rest)] on vulpia populations. A further herbicide treatment [paraquat-diquat (SpraySeed®)] was imposed on some of these treatments. Measurements included botanical composition, phalaris and vulpia tiller density, seed production, and number of residual seeds in the soil. Vulpia content remained unchanged in the Sim-Rest treatment but increased in all other management treatments over the duration of the 3 year study and especially where paraquat-diquat was applied, despite paraquat-diquat causing an initial reduction in vulpia content. Vulpia content was lowest in the Fert-Sim-Rest treatment. The Fert-Sim treatment and in some cases paraquat-diquat application reduced vulpia tiller production. Vulpia seed production and the residual seed population were not influenced by any of the management treatments, while the single paraquat-diquat application increased vulpia seed production 18 months after application. Phalaris content was enhanced by the Sim-Rest and Fert-Sim-Rest treatments and initially by paraquat-diquat. No treatment affected phalaris tiller production and basal cover. The subterranean clover (Trifolium subterraneum L.) content declined during the experiment, but to a lesser extent where paraquat-diquat was applied. Volunteer species content was initially suppressed in the year following paraquat-application, although populations recovered after this time. Of the two Vulpia spp. present (V. bromoides (L.) S.F. Gray and V. myuros (L.) C.C. Gmelin), V. bromoides was the most prevalent. Results show how a double herbicide application can increase vulpia fecundity and rate of re-infestation of herbicide-treated sites. Pasture rest shows some promise, but to a lesser extent than in the New South Wales tablelands, where summer rainfall may increase the growth of perennial species. In lower rainfall, summer dry areas, responses to pasture rest may be slower. Despite this, integrated management (which combines strategies such as pasture rest, herbicide application, and fertiliser application) increases the perennial content and reduces vulpia seed production, thus improving vulpia control.

Effect of rate and time of nitrogen application from autumn to midwinter on perennial ryegrass - white clover dairy pastures in western Victoria. 1. Growth and composition

1999 ◽  
Vol 50 (6) ◽  
pp. 1059 ◽  
Author(s):  
J. L. Jacobs ◽  
F. R. McKenzie ◽  
M. J. Ryan ◽  
G. Kearney
Keyword(s):  
Species Composition ◽  
Perennial Ryegrass ◽  
Dry Matter ◽  
Yield Response ◽  
Botanical Composition ◽  
N Application ◽  
Leaf Stage ◽  
Stage Of Development ◽  
Residual N ◽  
Western Victoria

Field experiments were carried out at 2 sites to study the effects of time and rate of nitrogen (N) application from autumn to midwinter on perennial ryegrass–white clover pasture dry matter (DM) yield and species composition. Nitrogen (0, 15, 25, 30, 45, and 60 kg/ha) was applied in mid-April, early May, mid-May, early June, and mid-June 1996 onto a grazed pasture. Dry matter yield was estimated when perennial ryegrass in the 45 kg N/ha treatment reached the 3-leaf stage of development. Species composition estimates were made on all plots in autumn, late winter, and late spring (November). Asecond DM yield estimate was taken one regrowth cycle after the primary DM yield estimate to determine residual N impact on pasture growth, and then the pastures were returned to the grazing routine of the farm. Increasing levels of N fertiliser resulted in a linear (Site 1) and curvilinear (Site 2) primary DM yield response. Residual DM yield responses were linear at both sites. The highest primary DM yield response at Site 1 was 9.1 kg DM/kg N (mid-April application), whereas the highest residual N response was 9.4 kg DM/kg N (mid-May application). The time taken for the 45 kg N/ha treatment to reach the 3-leaf stage of development ranged from 38 (early June application) to 47 (mid-April application) days for the primary harvest, and from 46 (early May application) to 72 (early June application) days for the residual harvest. At Site 2, the highest primary DM yield response to N was 15.8 kg DM/kg N at 45 kg N/ha (mid-April application), whereas the highest residual N response was 8.3 kg DM/kg N (mid-June application). The time taken for the 45 kg N/ha treatment to reach the 3-leaf stage of development ranged from 24 (early June application) to 36 (mid-April and early May applications) days for the primary harvest, and from 30 (mid-April) to 57 (early June application) days for the residual harvest. Based on the current cost of urea, the study concluded that N fertiliser use during autumn to midwinter is economically viable for dairy farmers. Botanical composition was unaffected by N application. There were no treatment effects on botanical composition of the sward at either site the following spring (November). It is concluded that a ‘once-off’ strategic N application up to 60 kg N/ha during autumn to midwinter is not likely to influence dairy pasture composition in western Victoria.

Tactical versus continuous stocking in perennial ryegrass-subterranean clover pastures grazed by sheep in south-western Victoria. 3. Herbage nutritive characteristics and animal production

2001 ◽  
Vol 41 (8) ◽  
pp. 1121 ◽  
Author(s):  
R. A. Waller ◽  
P. W. G. Sale ◽  
G. R. Saul ◽  
G. A. Kearney
Keyword(s):  
Perennial Ryegrass ◽  
Negative Impact ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Animal Production ◽  
Herbage Quality ◽  
Fleece Weight ◽  
Western Victoria ◽  
Terminal Sire ◽  
Autumn And Winter

A 4-year grazing experiment was carried out in south-western Victoria to compare the effect of tactical stocking with continuous stocking on the persistence of perennial ryegrass (Lolium perenne L.) and the productivity of sheep used for prime lamb production. Tactical stocking consisted of variable length summer, autumn and winter rotations and continuous stocking in spring. The 2 grazing strategies were compared on 2 contrasting pastures: an upgraded pasture, sown with newer cultivars of perennial ryegrass and subterranean clover (Trifolium subterraneum L.) with 26 kg phosphorus/ha.year, and a naturalised perennial ryegrass pasture receiving 6 kg phosphorus/ha.year. Paddocks were grazed by Border Leicester x Merino ewes, which were mated to a terminal sire to lamb in September. In this final paper of the series, the effects of the grazing systems and pasture treatments on animal production and herbage quality are presented. The liveweights of the ewes were similar across all treatments during autumn and winter, but the tactically stocked ewes were 3–6 kg lighter than continuously stocked ewes during spring and summer. The lower liveweight was attributed to the lower (P<0.001) herbage quality on the tactically stocked pastures in spring (P<0.001). Both digestibility and crude protein concentration were about 4 percentage units lower with tactical stocking in spring. This lower quality was associated with the higher herbage mass (by 500–900 kg dry matter/ha) on the tactically stocked pastures, which presumably had a higher stem:leaf ratio and showed reproductive growth earlier than the continuously stocked pastures. Although there were differences in ewe liveweight, this did not affect individual lamb weaning weight or ewe fleece weight. There were significant increases in production per hectare from tactically stocked or upgraded pasture treatments due to the higher stocking rates that could be carried, 9 and 51%, respectively. In 1998, 544 kilograms of lamb per hectare was weaned from continuously stocked paddocks and 607 kg/ha from tactically stocked paddocks (P<0.05), and 449 and 702 kg/ha from the typical and upgraded pastures, respectively. This study reinforces the view that soil fertility and pasture improvement have a much greater impact on animal productivity than changes to grazing method with little effect on per head productivity. The negative impact of rotational stocking on herbage quality reinforces the need to use these systems strategically when benefits from increased herbage mass are expected to increase animal production or overcome sustainability or pasture persistence problems.

The productivity of pastures sown with Phalaris tuberosa or Lolium perenne. 1. Pasture growth and composition

1974 ◽  
Vol 14 (70) ◽  
pp. 640 ◽  
Author(s):  
KFM Reed
Keyword(s):  
Lolium Perenne ◽  
Dry Matter ◽  
Protein Concentration ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Stocking Rate ◽  
Basal Cover ◽  
Western Victoria ◽  
Cutting Height ◽  
Stocking Rates

Pastures at Glenormiston in western Victoria, sown with Phalaris tuberosa cv. Australian (phalaris) or Lolium perenne cv. Victorian (ryegrass) each with Trifolium subterraneum (subterranean clover), were grazed continuously by wethers at six rates of stocking over the range 19.8 to 32.1 sheep ha-1 from October 1966 to March 1971. Pasture growth was measured at three rates of stocking. During a four-year period, the phalaris and ryegrass pastures produced average annual yields of 10.4 and 8.0 t dry matter ha-1 respectively. The growth of phalaris pasture was usually greater in winter when it produced approximately 30 per cent more dry matter than ryegrass pasture. The effect of rate of stocking on pasture growth was rarely significant except in the final six months of the experiment when there was a reduction in growth rate as stocking rate increased. The basal cover of phalaris declined in the two years after a drought in 1967-68 to about 20 per cent irrespective of stocking rate. The basal cover of ryegrass also declined during this period, to a greater extent than phalaris, but in 1969 and 1970 there was some recovery at the lower stocking rates when the ryegrass was able to set seed. The basal cover of subterranean clover was about 20 per cent at 19.8 sheep ha-1 in most years and usually less at the higher stocking rates. The main species that replaced the sown species were Poa annua, Trifolium cernuum, Trifolium glomerata, Arctotheca calendula and Holcus lanatus. The amount of pasture present above a cutting height of 1.5 cm was less than 2 t ha-1 during most of the experiment and decreased as rate of stocking increased. The crude protein concentration of pasture present was always greater than 11 per cent except during the drought in 1967-68, when it fell as low as 5.2 per cent on the ryegrass pastures and to half this level on the phalaris pastures.

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