Distribution and abundance of annual legume seeds in the wheatbelt of Western Australia

1995 ◽  
Vol 35 (2) ◽  
pp. 189 ◽  
Author(s):  
JA Fortune ◽  
PS Cocks ◽  
CK Macfarlane ◽  
FP Smith
Keyword(s):  
Western Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Farming Systems ◽  
Annual Rainfall ◽  
Soil Parameters ◽  
Widespread Species ◽  
Legume Seeds ◽  
Clover Seed

The size and composition of pasture legume seedbanks were estimated from 2 surveys on a 460-km west-east transect of the wheatbelt of Western Australia. Survey 1 (in spring) sampled naturalised legumes, and survey 2 (in summer) measured the amount and botanical composition of legume seed from selected sites. Seedbanks were examined in greater detail on 2 farms in the higher rainfall part of the wheatbelt. Survey 2 revealed that mean seedbank size of the poorest 40% of sites (those with 5200 kg seed/ha) was 61 kg/ha, and that 72% of seeds were naturalised clovers. In contrast, the best 60% of sites (those with >200 kg seed/ha) averaged 533 kg seed/ha, of which only 35% was naturalised clover seed, the remainder in both surveys being mainly subterranean clover (Trifolium subterraneum). Mean seed bank size (kg/ha) varied from 359 (survey 2) to 587 (survey 1) and, in both surveys, was poorly correlated with long-term mean annual rainfall and a number of soil parameters. On the 2 farms, seedbank size ranged from 300 to 345 kg/ha (in spring) and from 650 to 740 kg/ha (in summer). Trifolium glomeratum (cluster clover) and subterranean clover were the most widespread species in both surveys. They were present at 35 and 30 of the 57 survey sites, respectively, and at both farms. Most of the subterranean clover collected was cv. Geraldton (22 of 30 sites), the next most frequent cultivar was Dwalganup (6 sites). The currently recommended cultivar, Dalkeith, was found at only 5 sites. Several other legumes including T. tomentosum (16 sites), T. suffocatum (8 sites), Medicago truncatula (7 sites), T. hirtum (4 sites), and M. minima (4 sites) were common, while M. littoralis, M. polymorpha, T. dubium, T. cernuum, T. cherleri, and T. carnpestre were found at single sites. With few exceptions, these are naturalised species and were characterised by flowering times about 20 days later than sown legume cultivars, and seed sizes < 1 mg. The value of these widespread annual legumes to agricultural productivity and sustainability needs to be quantified and their adaptation to wheatbelt farming systems assessed.

Factors affecting the productivity of irrigated annual pastures. 2. Defoliation by dairy cows

1986 ◽  
Vol 26 (3) ◽  
pp. 305 ◽  
Author(s):  
CR Stockdale
Keyword(s):  
Grazing Intensity ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Total Production ◽  
Pasture Production ◽  
Factors Affecting ◽  
Grazing Intensities ◽  
Seed Reserves ◽  
Clover Seed

The influence of grazing intensity on the productivity of an irrigated annual pasture was studied for 3 years in northern Victoria. Lax-, medium- and hard-grazing intensities were described by post-grazing pasture heights of 7.2, 5.2 and 3.0 cm, respectively. Also, one instance of variable grazing frequency occurred, in winter of year 1. Hard-grazed plots produced 1 3 and 17% less herbage in years 1 and 2, respectively, than did lax- and medium-grazed plots, which produced similar amounts of herbage. When the interval between grazings was extended, the variation in productivity was reversed; lax grazing resulted in 9% less total production than heavier grazing. In years 1 and 2, there was little effect of grazing treatment on botanical composition until spring, at which time there was a marked reduction in the amount of subterranean clover (Trifolium subterraneum) in the hard-grazed plots, with a concomitant increase in grass content. There were no significant effects of grazing intensity on the amounts of weeds in either year. However, in year 3, weeds were important contributors to pasture production early in the season. This, together with reduced clover seed reserves and increased incidence of disease in subterranean clover with hard grazing, suggests that the long-term regenerating ability of an annual pasture may be impaired if severely grazed at regular intervals.

Breeding and farming system opportunities for pasture legumes facing increasing climate variability in the south-west of Western Australia

2012 ◽  
Vol 63 (9) ◽  
pp. 840 ◽  
Author(s):  
C. K. Revell ◽  
M. A. Ewing ◽  
B. J. Nutt
Keyword(s):  
Western Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Farming System ◽  
Annual Rainfall ◽  
The South ◽  
Pasture Legumes ◽  
South West ◽  
Annual Medics ◽  
Phosphorus And Potassium

The south-west of Western Australia has experienced a declining trend in annual rainfall and gradual warming over the last 30 years. The distribution of rainfall has also changed, with lower autumn rainfall, patchy breaks to the season, and shorter springs. This has important implications for the productivity of legume pastures in the region, which is dominated by annual species, particularly subterranean clover (Trifolium subterraneum L.), annual medics (Medicago spp.), serradella (Ornithopus spp.), and biserrula (Biserrula pelecinus L.). For annual pasture legumes, appropriate patterns of seed softening and germination behaviour, efficiency of phosphorus and potassium uptake, responses to elevated levels of atmospheric CO2, and drought resistance of seedlings and mature plants will assume increasing importance. While these traits can be targeted in pasture breeding programs, it will also be important to exploit farming system opportunities to optimise the annual legume component of the feed base. These opportunities may take the form of incorporating strategic shrub reserves and grazing crops to allow for pasture deferment in autumn–winter. Perennial forages may become more important in this context, as discussed in terms of the development of the perennial legume tedera (Bituminaria bituminosa var. albomarginata C.H. Stirton).

Maximising the subterranean clover content on a summer-dry Wairarapa hill-country farm through grazing management

2019 ◽  
pp. 91-100 ◽  
Author(s):  
Sonya T. Olykan ◽  
Richard J. Lucas ◽  
Dan J. Nicholson ◽  
Crile Doscher ◽  
Derrick J. Moot
Keyword(s):  
Management Strategies ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Management Plan ◽  
Annual Rainfall ◽  
North West ◽  
Hill Country ◽  
Hill Slope ◽  
Clover Seed ◽  
Clover Content

Tokaroa Farm is a 608-ha sheep and beef farm, in the Wairarapa. Paddock slopes range from flat to steep (>25°) with a predominance of gentler north facing slopes and steeper south facing slopes. Annual rainfall is 810 mm and average summer dry is three months. Resident subterranean (sub) clover (Trifolium subterraneum L.) populations were identified on an uncultivatable north-west facing hill slope in 2015, and a management plan devised to increase its contribution to pastures. Exclosure plots showed that an eight-week spell in spring 2016 increased resident sub clover groundcover from 13 to 54%, while in the lightly grazed paddock control sub clover increased from 10 to 28%. There was a positive linear relationship (R2=0.51) between the total number of established sub clover seedlings on 30 March 2017 and the previous spring sub clover groundcover (%) on 25 November 2016. In October 2017, the effect of the spring 2016 exclosure treatments was still evident with 57% sub clover groundcover in the eight-week spelled areas compared with 37% in the control despite all the exclosures being grazed in 2017.Sub clover management strategies were developed, using slope and aspect, and applied to a GIS map of Tokaroa Farm. This suggested that 53% of the farm could have sub clover overdrilled into it and 29% could have the resident sub clover population actively managed and/or oversown with sub clover seed.

Application of non-selective herbicides during flowering of pasture legumes can reduce seed yield and alter seed characteristics

1998 ◽  
Vol 38 (6) ◽  
pp. 583 ◽  
Author(s):  
A. Wallace ◽  
R. A. Lancaster ◽  
N. L. Hill
Keyword(s):  
Seed Yield ◽  
Seed Set ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Farming Systems ◽  
Early Summer ◽  
Hard Seed ◽  
Time Of Application ◽  
Pasture Legumes ◽  
Clover Seed

Summary. Spraytopping, the application of a low rate of non-selective herbicide (usually glyphosate or paraquat) to annual grass seed heads in the spring or early summer for seed set control is widely practised throughout Australia. While grasses are the targets of the spray treatment, annual pasture legumes may also be damaged by spraytopping, particularly if the legumes are flowering at the time of application. The effect of applying glyphosate (90, 112 or 162 g a.i./ha), paraquat (100 g a.i./ha) and glyphosate plus MCPA (90 + 150 g a.i./ha) to subterranean clover (Trifolium subterraneum L. cv. Dalkeith) and annual medic (Medicago polymorpha L. cvv. Serena, Santiago and Circle Valley) pastures at various times during flowering was investigated during the spring of 1993 and 1994. Experiments were located at Tincurrin and Tenindewa, Western Australia. Subterranean clover seed yield was most affected by applications of glyphosate (90 and 162 g a.i./ha) and glyphosate plus MCPA (90 + 150 g a.i./ha) during early–mid flowering. Seed yield was reduced by as much as 88% following application of glyphosate plus MCPA when 20% of the subterranean clover plants were flowering. Treatment with paraquat (100 g a.i./ha) during mid–late flowering reduced seed yield of subterranean clover by 25–50% in experiment 1 only. Medic seed yield was reduced up to 90% depending on cultivar when glyphosate (112 g a.i./ha) was applied during early–mid flowering. In addition to seed yield, the level of hard seed was assessed. Treatment of subterranean clover during early–mid flowering with glyphosate (90 and 162 g a.i./ha) significantly reduced the quantity of hard seed produced. Thirty–forty percent of subterranean clover seed was germinable soon after seed set, compared with 7–17% germinable for the seed from untreated plants. Treatment with glyphosate (112 g a.i./ha) reduced the proportion of hard seed in the medics when applied during mid flowering. Treatment with paraquat had little effect on the proportion of hard seed formed. This work demonstrates that using a spraytopping technique for control of seed set in annual grasses may dramatically reduce seed yield in pasture legumes. Spraytopping can further reduce the ability of legumes to persist in cropping rotations by reducing the amount of hard seed formed. Implications for practical farming systems are outlined.

scholarly journals Harvesting subterranean clover seed – current practices, technology and issues

2021 ◽  
Vol 72 (3) ◽  
pp. 223
Author(s):  
Wesley M. Moss ◽  
Andrew L. Guzzomi ◽  
Kevin J. Foster ◽  
Megan H. Ryan ◽  
Phillip G. H. Nichols
Keyword(s):  
Soil Erosion ◽  
Case Studies ◽  
Seed Production ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Root Cause ◽  
Pasture Plant ◽  
Clover Seed ◽  
Production Industry ◽  
Pasture Legume

Subterranean clover (Trifolium subterraneum L.) is Australia’s most widely sown annual pasture legume. Its widespread use as a pasture plant requires a well-functioning seed production industry, and Australia is the only significant producer of subterranean clover seed globally. However, the sustainability of this industry is under threat due to its reliance on ageing harvest equipment and the resultant environmental impacts. In order to evaluate seed harvesting practices, technology, and issues, we report on case studies, workshops, and a survey of seed producers across southern Australia. The Horwood Bagshaw Clover Harvester, designed in the 1950s, remains the most popular subterranean clover seed harvester. We discuss its use and modifications, and document several contemporary issues facing the seed production industry. Issues are primarily soil erosion and degradation; the expensive, slow and labour-intensive harvest process; and poor reliability and maintainability of harvesters that are now at least 30 years old. We conclude the root cause of these issues is the suction harvest technology utilised by the Horwood Bagshaw Clover Harvester. Analysis of the current harvest system is provided to support the development of new approaches to harvest subterranean clover seeds.

Effect of perennial pasture species on surface soil moisture and early growth and survival of subterranean clover (Trifolium subterraneum L.) seedlings

1997 ◽  
Vol 48 (5) ◽  
pp. 683 ◽  
Author(s):  
B. S. Dear ◽  
P. S. Cocks
Keyword(s):  
Mineral Soil ◽  
Subterranean Clover ◽  
Late Summer ◽  
Soil Surface ◽  
Trifolium Subterraneum ◽  
Annual Grass ◽  
Growth And Survival ◽  
Eastern Australia ◽  
Standing Dead ◽  
Clover Seed

Subterranean clover seedling numbers and growth in swards containing 1 of 5 perennial pasture species [phalaris (Phalaris aquatica) cv. Sirolan, cocksfoot (Dactylis glomerata) cv. Currie, lucerne (Medicago sativa) cv. Aquarius, wallaby grass (Danthonia richardsonii) cv. Taranna, and lovegrass (Eragrostis curvula) cv. Consol] were compared with those in typical annual pastures and pure clover swards in the wheatbelt of eastern Australia. Presence of a perennial species or the volunteer annual grass (Eragrostis cilianensis) increased the rate of drying of the soil surface (0–5 cm) after late February and May rain, compared with subterranean clover swards. Perennials differed in the rate they dried the soil surface, with the more summer-active lucerne and consul lovegrass drying the profile more rapidly than phalaris. The amount of water in the surface 5 cm, 6 days after the rainfall event on 27–28 February, was strongly negatively correlated (r = –0·75, P < 0·01) with the amount of green perennial biomass, but not related to standing dead material or surface residues. Where perennials were present, a smaller proportion (2–4%) of the clover seed pool produced seedlings in response to late summer rain, compared with pure clover swards (18%). A higher proportion of the seed pool produced seedlings (19–36%) following rain in late autumn but there was no difference between species. The more summer-active perennials (cocksfoot, danthonia, and lucerne) markedly depressed the survival of emerged clover seedlings following both germinations. Of the seedlings that emerged in early March, the proportion remaining by 29 March was 57% in phalaris, 21% in lucerne, 13% in danthonia, and 1% in cocksfoot, compared with a 78% increase in seedlings in pure subterranean clover swards. By 15 May, all perennials had <2 clover seedlings/m2 surviving, compared with 37 in the annual pasture and 964 plants/m2 in pure subterranean clover. Following the May germination, the highest proportion of emerged seedlings surviving until 29 May was in the phalaris swards (40%) and least in the cocksfoot and danthonia swards (2–4%). Presence of a perennial or annual grass decreased (P < 0·05) relative water content of clover seedlings on 15 March from 74% in pure clover swards, to 48% in annual pasture, 34% in phalaris, and 29% in lucerne swards. Clover seedlings growing in pure subterranean swards on 15 March (17 days after germinating rain) were 4 times larger than those in lucerne and twice as large as those in either phalaris or annual pasture. Seed size did not differ between treatments, but available mineral soil nitrogen was significantly higher (P < 0·001) in pure subterranean clover swards (32 mg N/g) compared with perennials (3–13 mg N/g). Strategies such as heavy grazing in late summer to reduce green biomass of the perennials or sowing the perennials at lower densities may reduce the adverse effects that perennials have on subterranean clover seedlings in these drier environments.

Lucerne, phalaris, and wallaby grass in short-term pasture phases in two eastern Australian wheatbelt environments. 2. Effect of perennial density and species on subterranean clover populations and the relative success of 3 clover cultivars of different maturity

2007 ◽  
Vol 58 (2) ◽  
pp. 123 ◽  
Author(s):  
B. S. Dear ◽  
G. A. Sandral ◽  
J. M. Virgona ◽  
A. D. Swan ◽  
B. A. Orchard ◽  
...  
Keyword(s):  
Seed Yield ◽  
Seed Bank ◽  
Seedling Survival ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Climatic Conditions ◽  
Perennial Species ◽  
Growing Season Length ◽  
Herbage Yield ◽  
Clover Seed

The effect of the density of 3 perennial species, phalaris (Phalaris aquatica L.), wallaby grass (Austrodanthonia richardsonii Kunth), and lucerne (Medicago sativa L.), on seed set, regeneration, and the relative competitiveness of 3 cultivars of subterranean clover (Trifolium subterraneum L.) was examined in 2 environments in the south-eastern Australian wheatbelt. Seed yields of subterranean clover were inversely related to perennial density at both sites over the first 2 years, the relationship varying with perennial species. Phalaris depressed the seed yield of clover more than lucerne and wallaby grass in the second and third year at equivalent densities. Clover seed yield was positively related to clover herbage yield in late spring at both sites, and inversely related to perennial herbage yield. Clover seed yield displayed an increasing linear relationship with the proportion of light reaching the clover understorey in spring, which in turn was inversely related to perennial density and perennial herbage yield. Clover seedling regeneration in mixed swards in autumn was positively related to the size of the summer seed bank, but negatively related to perennial density. Clover seedling survival following a premature germination at Kamarah was inversely correlated to the density of phalaris and lucerne in the sward. The relative competitiveness of the 3 subterranean clover cultivars varied between sites, with climatic conditions (rainfall and growing-season length) having a greater effect on the relative cultivar performance than companion perennial species or density. The later maturing subterranean clover cv. Goulburn became the dominant cultivar at the wetter site, constituting 72% of the seed bank, but declined to only 3–8% of the seed bank at the drier site. The proportion of the early flowering cultivar Dalkeith in the seed bank increased over time at the drier site and was highest (53%) in plots with the highest perennial density. We concluded that although perennial pasture species will depress clover seed yield and subsequent regeneration, these effects could be minimised by reducing perennial densities and exploiting variations in competitiveness between perennial species as identified in this study. Sowing earlier maturing subterranean clover cultivars would only be an advantage in increasing clover content in low-rainfall environments. The findings suggest that clover seed reserves and regeneration could also be increased by using grazing management to reduce the level of shading of clover by perennials, a factor associated with reduced clover seed yield.

An analysis of the frequency and timing of false break events in the Mediterranean region of Western Australia

2001 ◽  
Vol 52 (3) ◽  
pp. 367 ◽  
Author(s):  
R. Chapman ◽  
S. Asseng
Keyword(s):  
Western Australia ◽  
Mediterranean Region ◽  
Meteorological Data ◽  
Seasonal Pattern ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dormancy Release ◽  
The Poor ◽  
Time Periods ◽  
The Mediterranean

Historical meteorological data were used to estimate the frequency and timing of false break events at 10 locations in the annual pasture and wheat producing area in the Mediterranean climatic region of Western Australia. The seasonal pattern of false breaks identified by this analysis was compared with the dynamics of dormancy release in a field population of subterranean clover (Trifolium subterraneum L.) to determine the influence that these events may have on the legume content of annual pasture communities in this region. False break events were estimated to occur on approximately 2 of every 3 years (611–72% of years) with no significant differences across the area investigated. Changes in the risk of false break events were examined over discrete time periods. The period of greatest risk was predicted to occur during early autumn (early March to mid April). Seed softening is virtually complete in subterranean clover at this point. The seed bank strategy of this species is, therefore, not well adapted to withstand the effects of false breaks. This might largely explain the poor persistence of subterranean clover in the annual pasture communities in the Mediterranean region of Western Australia. The legume content of these pastures might be improved by selecting species with late dormancy release strategies that will give better protection from false breaks.

Comparing different sources of sulfur for high-rainfall pastures insouth-western Australia

2003 ◽  
Vol 43 (10) ◽  
pp. 1221 ◽  
Author(s):  
M. D. A. Bolland ◽  
J. S. Yeates ◽  
M. F. Clarke
Keyword(s):  
Western Australia ◽  
Field Experiments ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Residual Value ◽  
Single Superphosphate ◽  
Pasture Production ◽  
Leaching Losses ◽  
S Deficiency ◽  
Different Sources

The dry herbage yield increase (response) of subterranean clover (Trifolium subterraneum L.)-based pasture (>85% clover) to applications of different sources of sulfur (S) was compared in 7 field experiments on very sandy soils in the > 650 mm annual average rainfall areas of south-western Australia where S deficiency of clover is common when pastures grow rapidly during spring (August–November). The sources compared were single superphosphate, finely grained and coarsely grained gypsum from deposits in south-western Australia, and elemental S. All sources were broadcast (topdressed) once only onto each plot, 3 weeks after pasture emerged at the start of the first growing season. In each subsequent year, fresh fertiliser-S as single superphosphate was applied 3 weeks after pasture emerged to nil-S plots previously not treated with S since the start of the experiment. This was to determine the residual value of sources applied at the start of the experiment in each subsequent year relative to superphosphate freshly-applied in each subsequent year. In addition, superphosphate was also applied 6, 12 and 16 weeks after emergence of pasture in each year, using nil-S plots not previously treated with S since the start of the experiment. Pasture responses to applied S are usually larger after mid-August, so applying S later may match plant demand increasing the effectiveness of S for pasture production and may also reduce leaching losses of the applied S.At the same site, yield increases to applied S varied greatly, from 0 to 300%, at different harvests in the same or different years. These variations in yield responses to applied S are attributed to the net effect of mineralisation of different amounts of S from soil organic matter, dissolution of S from fertilisers, and different amounts of leaching losses of S from soil by rainfall. Within each year at each site, yield increases were mostly larger in spring (September–November) than in autumn (June–August). In the year of application, single superphosphate was equally or more effective than the other sources. In years when large responses to S occurred, applying single superphosphate later in the year was more effective than applying single superphosphate 3 weeks after pasture emerged (standard practice), so within each year the most recently applied single superphosphate treatment was the most effective S source. All sources generally had negligible residual value, so S needed to be applied each year to ensure S deficiency did not reduce pasture production.

Occurrence of Phytophthora clandestina in Trifolium subterraneum paddocks in Australia

2001 ◽  
Vol 41 (2) ◽  
pp. 187 ◽  
Author(s):  
R. Aldaoud ◽  
W. Guppy ◽  
L. Callinan ◽  
S. F. Flett ◽  
K. A. Wratten ◽  
...  
Keyword(s):  
Western Australia ◽  
Root Rot ◽  
New South ◽  
New South Wales ◽  
South Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Soil Samples ◽  
South Wales ◽  
Differential Cultivars

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.

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