Effect of grazing strategy, ryegrass overdrilling and herbicide application on vulpia content, tiller density and seed production in perennial pastures

2008 ◽  
Vol 48 (5) ◽  
pp. 632 ◽  
Author(s):  
K. N. Tozer ◽  
D. F. Chapman ◽  
P. E. Quigley ◽  
P. M. Dowling ◽  
R. D. Cousens ◽  
...  
Keyword(s):  
Soil Seed Bank ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Integrated Approach ◽  
Annual Rainfall ◽  
Herbicide Application ◽  
Effective Strategies ◽  
Annual Grasses ◽  
Western Victoria ◽  
Tiller Density

Vulpia species C.C. Gmel. are annual grass weeds that can reduce the productivity of perennial pastures throughout southern Australia. To develop more effective strategies to manage vulpia, a 3-year experiment was established in western Victoria (average annual rainfall: 625 mm) comparing different methods currently used to control this weed. Overdrilling perennial ryegrass (Lolium perenne L.) seed and simazine application treatments were applied to phalaris (Phalaris aquatica L.) pastures that were set-stocked or rotationally grazed (either as a four-paddock or strategic rotation) with Merino ewes. The content of vulpia, subterranean clover (Trifolium subterraneum L.) and other annual grasses as a proportion of total dry matter increased, and the proportion of phalaris decreased in most grazing treatments throughout the experiment. The mean vulpia content was lowest and the phalaris content was highest in the four-paddock rotation, whereas vulpia content was greatest and phalaris content was lowest under set-stocking. Simazine application in June with or without ryegrass overdrilling reduced the number of vulpia tillers/m2 in 2000 and 2001 and vulpia panicle production in 2000, although vulpia populations increased to pretreatment levels in herbicide-treated swards by 2002. The number of vulpia seeds in the soil seed bank was not affected by any of the treatments. The most effective treatment was a combination of ryegrass overdrilling and herbicide application in the four-paddock, rotationally grazed pastures. This experiment highlights the need for an integrated approach to manage vulpia since relying on herbicide application alone is ineffective. This is particularly the case when competitive pasture species are unable to adequately utilise available resources and prevent a recovery in vulpia populations.

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.

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.

scholarly journals Comparative effects of grazing, herbicide or forage conservation on barley grass content in Trifolium subterraneum L. clover-based pasture

2019 ◽  
Vol 70 (9) ◽  
pp. 800
Author(s):  
John W. Piltz ◽  
Simon J. Flinn ◽  
Leslie A. Weston
Keyword(s):  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Annual Ryegrass ◽  
Lolium Rigidum ◽  
Herbicide Application ◽  
High Quality ◽  
Harvest Timing

Barley grass (Hordeum spp.) is a relatively short lived annual that provides high quality grazing early in the season, but its seed heads cause contamination of wool and carcasses, and may irritate the mouth, eyes and nose of sheep. Treatments were imposed on established subterranean clover (Trifolium subterraneum L.) annual pasture in the same plots for three consecutive years (2015 to 2017) to evaluate changes in barley grass content. Treatments included: grazing alone (G), herbicide followed by grazing (HG), or a forage conservation harvest in early October, late October or early November consistent with an early silage harvest (ES), late silage harvest (LS) or hay cut (H). Grazing plus herbicide markedly reduced (P &lt; 0.05) barley grass numbers compared with all other treatments, but increased (P &lt; 0.05) the growth of annual ryegrass (Lolium rigidum L.). ES reduced (P &lt; 0.05) barley grass and increased (P &lt; 0.05) subterranean clover compared with H, but broadleaf weed content benefitted by LS in contrast to either ES or H. Although herbicide application was the most effective method for barley grass control, forage harvest timing could be used to beneficially manipulate pasture composition.

Long-term persistence of subterranean clover Trifolium subterraneum L.) cultivars at three sites in south-western Victoria

1997 ◽  
Vol 37 (5) ◽  
pp. 531
Author(s):  
S. G. Clark ◽  
J. Li ◽  
A. M. Johnson ◽  
G. N. Ward ◽  
J. F. Chin
Keyword(s):  
Perennial Grass ◽  
Subterranean Clover ◽  
Late Summer ◽  
Trifolium Subterraneum ◽  
Contamination Level ◽  
Black And White ◽  
Small Plot ◽  
Black Seeds ◽  
Western Victoria ◽  
Annual Weeds

Summary. The seed banks of 6 subterranean clover (Trifolium subterraneum L.) cultivars were sampled at 3 abandoned cultivar evaluation experiments in south-western Victoria (Hamilton, Macarthur and Timboon). Two were var. yanninicum (Trikkala and Larisa) and 4 were var. subterraneum (Denmark, Goulburn, Karridale and Leura). Seed was sampled in late summer–early autumn 1993, between 6 and 10 years after the sites were established and between 3 and 7 years after the sites were abandoned. The collected seed was separated into black and white seed, and a sample of the black seed was grown in a glasshouse and identified as either belonging to the sown cultivar or belonging to another cultivar/genotype. All white seed was assumed to belong to the sown cultivar. The aim was to determine if these widely used cultivars were persisting under farm management conditions and competition from perennial grass, other subterranean clover and annual weeds. With some variation between sites all cultivars were found to be persisting satisfactorily. Over the 3 sites, white-seeded cultivars averaged 460 kg/ha and 6640 seeds/m2; black-seeded cultivars averaged 260 kg/ha and 5590 seeds/m2. Contamination with other subterranean clover cultivars/ecotypes was generally low, except at Macarthur where the white-seeded cultivars were heavily contaminated (Trikkala 39% pure; Larisa 57% pure) with black seeds highlighting the poor adaptation of var. yanninicum to light soil types. Of the black seeds, over the 3 sites, average contamination level was 13% and ranged from 41% (Goulburn at Macarthur) to 1% (Leura at Timboon). The study indicates that in south-western Victoria, all the recently released cultivars are likely to persist and be productive, and that the small-plot evaluation techniques used to identify potential new cultivars are likely to be adequate if replicated in space and if the clovers are sown in mixed swards with perennial grass.

Phosphorus, sulphur, and molybdenum deficiencies in soils from eastern Australia in relation to nutrient supply and some characteristics of soil and climate.

1955 ◽  
Vol 6 (5) ◽  
pp. 673 ◽  
Author(s):  
KD McLachlan
Keyword(s):  
Phosphorus Deficiency ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Parent Material ◽  
The Other ◽  
Podzolic Soils ◽  
Sulphur Deficiency ◽  
Eastern Australia ◽  
Yield Responses ◽  
Western Victoria

Subterranean clover (Trifolium subterraneum L.) was grown on 32 virgin soils in pot cultures, and the yield responses to phosphorus, sulphur, and molybdenum were determined for each soil. The soils were collected from a wide area in eastern Australia, extending from south-western Victoria to southern Queensland. Sulphur deficiency occurred almost as frequently as phosphorus deficiency. In fact, 75 per cent. of the soils were deficient in both phosphorus and sulphur. Thirty-one per cent. were deficient in all three elements. The effect of the interaction between the elements on the occurrence and intensity of the deficiencies is shown. Molybdenum responses were obtained only after the other deficiencies had been corrected. A deficiency in one of the elements is no indication of deficiency or sufficiency of either of the other two. There was no correlation between the occurrence or intensity of the deficiencies and the geological origin of the soil parent material, the climate of the regions from which the soils were collected, or such soil characters as colour, organic matter, and texture. Responses to phosphorus were less on the black earths than on the red or yellow podzolic soils; those on the red earths were intermediate. The intensity of sulphur deficiency increased, and the intensity of molybdenum deficiency decreased, with increasing soil pH.

Symbiotic effectiveness of Rhizobium leguminosarum bv. trifolii collected from pastures in south-western Victoria

1997 ◽  
Vol 37 (6) ◽  
pp. 623 ◽  
Author(s):  
P. E. Quigley ◽  
P. J. Cunningham ◽  
M. Hannah ◽  
G. N. Ward ◽  
T. Morgan
Keyword(s):  
Rhizobium Leguminosarum ◽  
Subterranean Clover ◽  
Annual Rainfall ◽  
Test Plant ◽  
Available Phosphorus ◽  
Symbiotic Effectiveness ◽  
Plant Weight ◽  
Commercial Inoculant ◽  
Shoot Weight ◽  
Western Victoria

Summary. The whole-soil inoculation method was used to assess the symbiotic effectiveness of rhizobia populations in soils collected from 18 randomly-selected pastures in south-western Victoria. This was part of a larger study which described the condition of pasture within this region. Based on the shoot weights of test subterranean clover plants, cv. Mount Barker, effectiveness varied from 36 to 94% depending on the site of rhizobia collection. This range was wider than that found in an earlier survey of rhizobia effectiveness conducted nearby. WU95, the commercial inoculant for subterranean clover, was significantly more effective than 9 of the rhizobia samples. Rhizobia from 2 sites were especially poor and their effectiveness (37%) was not significantly different from the nil inoculum control (28%). Symbiotic effectiveness was not related to soil pH, available sulfur, available phosphorus, total nitrogen or mean annual rainfall for each site where rhizobia were collected. After pooling data for all sites, the shoot weights were significantly related to the proportions of plants with nodules assigned high nodulation scores. In contrast, low scores, within 1 of 6 categories, did not significantly affect shoot weight. The technique of using mean nodulation score was less capable of discriminating differences in symbiotic effectiveness, compared with assessment based on test plant weight.

Monitoring ley pastures and their response to winter cleaning

2006 ◽  
Vol 46 (8) ◽  
pp. 1023 ◽  
Author(s):  
E. C. Wolfe ◽  
J. A. Paul ◽  
P. D. Cregan
Keyword(s):  
Rapid Development ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Total Biomass ◽  
Seedling Density ◽  
Bare Ground ◽  
Herbicide Application ◽  
Seeding Rate ◽  
The Impact ◽  
Legume Growth

The purposes of this study were to evaluate subterranean clover-based leys on farms and in experiments using several pasture parameters, and to assess the impact of winter cleaning on the productivity and botanical composition of clover swards. Annual pastures were monitored on a group of 5 farms in the Wagga district and compared with an experimental subterranean clover (Trifolium subterraneum L.) pasture. The major problem in the farm paddocks was a lack of legume biomass due to poor legume densities, a consequence of the use of the soft-seeded cultivar Woogenellup and a high content of grassy weeds. The farmers in the group were unaware of the tools, parameters and benchmarks for making quantitative pasture comparisons. In 2 experiments, a range of subterranean clover swards were generated through the use of cultivars, seeding rate and winter cleaning treatments, grazed at 15 sheep/ha and monitored for 3 years. Appropriate benchmark values for the seed pool of subterranean clover were 300–350 kg/ha in winter and 600–700 kg/ha in summer. On the basis of both winter production, a function of May seedling density (target >1000 seedlings/m2) and spring production, which depended on the cultivar maturity, Junee was superior at Wagga to either Dalkeith (earlier maturing) or Woogenellup (softer seeded). Winter cleaning, using selective herbicides (fluazifop, simazine) to remove grasses and weeds, was advantageous in achieving a high content (>90%) and productivity of subterranean clover, provided that the legume content of the pasture was at least 28%, or >20% of total ground area before herbicide application in winter. In winter-cleaned swards, legume growth increased by up to 80%, legume biomass was improved by up to 46% and legume content increased from <50 to >95%. The main disadvantages of winter cleaning were increased areas of bare ground and reduced total biomass for several weeks after herbicide application, and the rapid development of ryegrass that was resistant to at least 1 of the herbicides used. The strategic use of observations to monitor the performance of pastures and their response to management is discussed.

Lucerne, phalaris, and wallaby grass in short-term pasture phases in two eastern Australian wheatbelt environments. 1. Importance of initial perennial density on their persistence and recruitment, and on the presence of weeds

2007 ◽  
Vol 58 (2) ◽  
pp. 113 ◽  
Author(s):  
B. S. Dear ◽  
J. M. Virgona ◽  
G. A. Sandral ◽  
A. D. Swan ◽  
B. A. Orchard
Keyword(s):  
Plant Density ◽  
Seedling Recruitment ◽  
Initial Density ◽  
Basal Area ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Annual Rainfall ◽  
Curvilinear Relationship ◽  
Initial Population ◽  
South Wales

The influence of initial plant density on the changes in the populations of 3 perennial pasture species, lucerne (Medicago sativa L.), wallaby grass (Austrodanthonia richardsonii (Cashm.) H.P. Linder), and phalaris (Phalaris aquatica L.), over a 3-year pasture phase was examined in the wheatbelt of southern New South Wales. The perennials were sown at 5 rates in combination with subterranean clover (Trifolium subterraneum L.) at 2 locations, Kamarah [430 mm average annual rainfall (a.a.r.)] and Junee (550 mm a.a.r). The range in initial plant populations for lucerne, phalaris, and wallaby grass was 4–74, 8–94, and 2–20 plants/m2, respectively, at Kamarah and 11–120, 9–149, and 6–48 plants/m2 at Junee. When sown at higher densities, the density of lucerne and phalaris declined curvilinearly over the 3 years at both sites. At the 3 lower densities, phalaris populations remained constant at both sites. Lucerne, in contrast, declined over all densities at both sites except at the lowest density at the wetter site (Junee). The rate of decline in lucerne was negatively related (R2 = 0.75) to initial density at Junee, but not at Kamarah. The density of the native grass, wallaby grass, increased with time at both sites through seedling recruitment. The invasion of experimental plots by the summer weed Eragrostis cilianensis (All.) Vign. ex Janchen (stinkgrass) was restricted by lucerne and phalaris, with a negative curvilinear relationship between perennial density and E. cilianensis seedlings in both environments (R2 = 0.65–0.70). In contrast, wallaby grass was ineffective at suppressing E. cilianensis. By the third year, phalaris had significantly higher herbage yields in spring than lucerne and wallaby grass at both sites and phalaris yield was independent of density. Lucerne yields at this time increased with density only at the wetter site (R2 = 0.64), but wallaby grass yields responded to increasing density at both sites (R2 = 0.27–0.59). The experiment demonstrated that establishing higher initial perennial populations of lucerne and phalaris, which did not recruit during the experiment, will result in the maintenance of higher populations over the life of a 3–4 year pasture phase despite proportionally higher rates of plant loss. The size of the initial population was less critical for wallaby grass, which was able to increase in density through recruitment. High initial populations are likely to be an advantage for suppressing weeds in swards of perennial species with limited ability to increase their basal area, such as lucerne and wallaby grass, but will be less beneficial for species such as phalaris, which can compensate by greatly increasing its basal area at lower densities.

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.

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.

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