Biserrula and subterranean clover can co-exist during the vegetative phase but are out-competed by capeweed

2011 ◽  
Vol 62 (3) ◽  
pp. 236 ◽  
Author(s):  
S. A. Conning ◽  
M. Renton ◽  
M. H. Ryan ◽  
P. G. H. Nichols

Biserrula (Biserrula pelecinus L.) is a recently domesticated annual pasture legume developed for ley farming systems that have traditionally relied upon subterranean clover (Trifolium subterraneum L.). This study examined competitive interactions between biserrula and subterranean clover and the common broad-leaf weed capeweed (Arctotheca calendula L.) during seedling establishment and vegetative growth, in order to develop guidelines for successful legume pasture management. Two glasshouse experiments were conducted to investigate the allocation of biomass to roots and shoots in biserrula, capeweed, and subterranean clover and its relationship with competitive ability in the first 100 days after sowing. In Experiment 1, capeweed had a higher relative growth rate of shoots and roots than the two legumes and developed a more extensive root system. Experiment 2 consisted of growing binary mixtures of the three species at different densities. The effect of competition on the biomass of biserrula, capeweed, and subterranean clover was best modelled by a power–exponential model. Increasing capeweed densities suppressed the biomass production of both biserrula and subterranean clover, whereas capeweed biomass increased with increasing densities of subterranean clover. This study suggests that the competitive advantage of capeweed is mainly conferred during the seedling stage. It also suggests that biserrula and subterranean clover germinating at the same time can co-exist as a mixed sward, at least up until flowering, if biserrula density is high relative to subterranean clover.

1998 ◽  
Vol 49 (3) ◽  
pp. 459 ◽  
Author(s):  
M. B. Peoples ◽  
R. R. Gault ◽  
G. J. Scammell ◽  
B. S. Dear ◽  
J. Virgona ◽  
...  

The effects of different management regimes on N2 fixation by subterranean clover (Trifolium subterraneum) in annual pastures and lucerne (Medicago sativa) in perennial-based pastures were examined in 5 experiments and 55 commercial paddocks, in which the pastures were grown in phased rotation with crops. The objectives were to quantify the inputs of fixed N2 and to determine ways of increasing nitrogen (N) inputs into ley-farming systems of southern New South Wales and north-eastern Victoria. Estimates of annual amounts of N2 fixed, based on above-ground herbage production in grazed pastures, ranged from 5 to 238 kg N/ha for subterranean clover and from 47 to 167 kg N/ha for lucerne. Legume reliance upon N2 fixation for growth (Pfix) was high (>65%) in most annual and perennial pastures examined. The levels of Pfix were generally unaffected by management treatments. As a consequence the amounts of N2 fixed were predominantly regulated by the legume content and herbage yield of pastures rather than by any marked differences in the ability of the legume to fix N. When all experimental results were combined with on-farm measurements of N2 fixation, the data indicated that lucerne and subterranean clover fixed 22-25 kg N for every tonne of legume dry matter produced. Management inputs to annual pastures which improved the productivity of subterranean clover and the amounts of N2 fixed included applications of superphosphate and the removal of grass species with herbicide, although the response to these treatments was not consistent across all sites in all years. Potential inputs from N2 fixation were high in annual pastures, and improved management during a good clover season enhanced the levels of mineral N detected in the soil profile (0-200 cm) the following autumn by 100-200 kg N/ha. However, year-to-year variability in annual pasture productivity and clover content resulted in large fluctuations in amounts of N2 fixed. Perennial pastures containing lucerne provided consistently greater annual herbage production, had more stable legume contents, and fixed on average 90-150% more N2 than neighbouring subterranean clover-based pastures. Even during the 1994 drought when annual pastures failed, lucerne still managed to fix >70 kg N/ha. It is proposed that lucerne-based pastures could represent a more reliable means of improving soil fertility for subsequent crops than annual pastures.


1996 ◽  
Vol 36 (5) ◽  
pp. 533 ◽  
Author(s):  
MJ Blumenthal ◽  
RL Ison

Murex medic (Medicago murex Willd.) seedling recruitment is more sensitive to soil water at the time of emergence than subterranean clover (Trifolium subterraneum L.). Murex medic pods normally lay on the soil surface. Shallow burial of pods may be beneficial when soil moisture is marginal for germination and emergence. In addition, the tightly coiled structure of murex medic pods may also act as a barrier to water uptake by the seed. Two methods of burying murex medic pods were investigated in the field: (i) trampling by sheep hooves through summer grazing; and (ii) through light cultivation in autumn. A glasshouse experiment was also conducted to examine the interaction between the length of time that the soil stays moist and pod burial for CD26 and CD53 murex medic and Dalkeith, Junee, Seaton Park and Woogenellup subterranean clover. In the glasshouse, pod burial was important for the attainment of maximum emergence in all genotypes when soil water was limiting. However, pod structure did not appear to have a limiting role in germination and emergence in murex medic. When tested in the field, pod burial by sheep trampling through summer grazing improved emergence in CD26, possibly because the smaller more open pod was more easily trampled than that of CD53. Summer grazing in CD53 and Dalkeith and autumn cultivation in all genotypes did not improve emergence; possible reasons for this are discussed so to is the role of murex medic in ley farming systems in eastern Australia.


2021 ◽  
Vol 72 (3) ◽  
pp. 223
Author(s):  
Wesley M. Moss ◽  
Andrew L. Guzzomi ◽  
Kevin J. Foster ◽  
Megan H. Ryan ◽  
Phillip G. H. Nichols

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.


1998 ◽  
Vol 49 (1) ◽  
pp. 53 ◽  
Author(s):  
C. Tang ◽  
L. Barton ◽  
C. Raphael

The capacity of subterranean clover (Trifolium subterraneum L. cv. Clare), medic (Medicago murex Willd. cv. Zodiac), serradella (Ornithopus sativus Brot. line SP1/13), biserrula (Biserrula pelecinus L. line Mor99), and woolly clover (Trifolium tomentosum L.) to acidify soil under N2 fixation was compared in a pot experiment using a poorly buffered sandy soil. The amount of acid produced per kg shoot dry matter (specific acid production) varied betweefin species and with growth stages, ranging from 44 to 128 cmol/kg shoot. Subterranean clover and serradella acidied soil to a greater extent than woolly clover and medic, whereas biserrula acidified soil least. Irrespective of pasture species and growth stage, specific acid production correlated well with concentrations of excess cations and calcium in shoots. Furthermore, total excess cation, ash alkalinity, and calcium in shoots were all good indicators of total acid production across all of the species.


Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1630
Author(s):  
Ana Paço ◽  
José Rodrigo da-Silva ◽  
Denise Pereira Torres ◽  
Bernard R. Glick ◽  
Clarisse Brígido

Manganese (Mn) toxicity is a very common soil stress around the world, which is responsible for low soil fertility. This manuscript evaluates the effect of the endophytic bacterium Pseudomonas sp. Q1 on different rhizobial-legume symbioses in the absence and presence of Mn toxicity. Three legume species, Cicer arietinum (chickpea), Trifolium subterraneum (subterranean clover), and Medicago polymorpha (burr medic) were used. To evaluate the role of 1-aminocyclopropane-1-carboxylate (ACC) deaminase produced by strain Q1 in these interactions, an ACC deaminase knockout mutant of this strain was constructed and used in those trials. The Q1 strain only promoted the symbiotic performance of Rhizobium leguminosarum bv. trifolii ATCC 14480T and Ensifer meliloti ATCC 9930T, leading to an increase of the growth of their hosts in both conditions. Notably, the acdS gene disruption of strain Q1 abolished the beneficial effect of this bacterium as well as causing this mutant strain to act deleteriously in those specific symbioses. This study suggests that the addition of non-rhizobia with functional ACC deaminase may be a strategy to improve the pasture legume–rhizobial symbioses, particularly when the use of rhizobial strains alone does not yield the expected results due to their difficulty in competing with native strains or in adapting to inhibitory soil conditions.


2007 ◽  
Vol 47 (2) ◽  
pp. 226 ◽  
Author(s):  
P. G. H. Nichols ◽  
G. A. Sandral ◽  
B. S. Dear ◽  
C. T. de Koning ◽  
D. L. Lloyd ◽  
...  

Izmir is a hardseeded, early flowering, subterranean clover of var. subterraneum (Katz. et Morley) Zohary and Heller collected from Turkey and developed by the collaborating organisations of the National Annual Pasture Legume Improvement Program. It is a more hardseeded replacement for Nungarin and best suited to well-drained, moderately acidic soils in areas with a growing season of less than 4.5 months. Izmir seed production and regeneration densities in 3-year pasture phases were similar to Nungarin in 21 trials across southern Australia, but markedly greater in years following a crop or no seed set. Over all measurements, Izmir produced 10% more winter herbage and 7% more spring herbage than Nungarin. Its greater hardseededness and good seed production, makes it better suited to cropping rotations than Nungarin. Softening of Izmir hard seeds occurs later in the summer–autumn period than Nungarin, giving it slightly greater protection from seed losses following false breaks to the season. Izmir is recommended for sowing in Western Australia, New South Wales, Victoria, South Australia and Queensland. Izmir has been granted Plant Breeders Rights in Australia.


1969 ◽  
Vol 9 (40) ◽  
pp. 513
Author(s):  
JA Carpenter

The proportions of impermeable seeds, and the viability of permeable and impermeable seeds were measured in samples of Trifolium subterraneum seed that had been stored in a laboratory for up to 34 years. Viability of permeable seed decreased from 99 per cent after storage for 1 year to 8 per cent after 30 years. On the other hand, all impermeable seeds were viable for 1 to 5 years, and 83 per cent were viable after 30 years. The impermeable seed content of the older seed lots was generally higher than that of the younger ones. This difference was related to the high retention of impermeability of the seeds during storage, and to changes in the severity of threshing methods. The impermeable seed content was also correlated positively but poorly with the viability of both permeable and impermeable seeds, independent of the age of the seed. These associations are probably due to the common effect of the environment on all these variables during seed ripening. A small varietal component in each variable was detected. The implications of these data for the long-term storage of small samples of seed are discussed.


1986 ◽  
Vol 26 (1) ◽  
pp. 71 ◽  
Author(s):  
F Forcella ◽  
AM Gill

Environmental requirements for seed germination and seedling growth vary appreciably among pasture species. Therefore, it is possible that the botanical composition of pastures may be manipulated by timely seasonal exposure of the soil-seed reserve to conditions that promote germination differentially. This possibility was examined in two Mediterranean type pastures in which plots were tilled once per year, each in a different month, for 2 years. For several pasture species, effects were estimated with respect to numbers of soil seeds, numbers of emergent seedlings and canopy coverage. Individual species showed specific behaviour patterns. Seeds of sorrel (Rumex acetosella) and wireweed (Polygonum aviculare) maintained abundant seed in the soil, those of annual ryegrass (Lolium rigidum) and subterranean clover (Trifolium subterraneum) were less persistent, and seeds of red brome (Bromus rubens) and silvergrass ( Vulpia spp.) occurred only seasonally in the soil-seed pools. Mature plants of red brome, silvergrass and subterranean clover attained dominance only in summer and early autumn-tilled plots. Annual ryegrass was more abundant when soil was cultivated in late autumn and early winter, whereas sorrel and wireweed were significant only in plots ploughed in winter. Thus botanical composition may be altered radically by time of tillage, and this has several practical implications for pasture management and weed control.


1995 ◽  
Vol 35 (2) ◽  
pp. 189 ◽  
Author(s):  
JA Fortune ◽  
PS Cocks ◽  
CK Macfarlane ◽  
FP Smith

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.


1957 ◽  
Vol 8 (1) ◽  
pp. 1 ◽  
Author(s):  
JN Black

Three strains of subterranean clover (Bacchus Marsh, Clare, and Mount Barker) were grown in pot culture at the Waite Agricultural Research Institute; for each strain, seed of four widely separated sizes mere sown. Dry weight a t any one time in the early vegetative stage was linearly related to embryo weight, but was independent of strain. Hence differences in early growth noted under uniform environmental conditions between strains are the result not of differing relative growth rates, but of differences in the size distribution within the seed populations; evidence is presented suggesting that there may well be little difference in the size distribution of seed of Bacchus Marsh and Mt. Barker, but that Clare contains a higher proportion of large seed, and thus as a strain would be expected to give greater early production. Leaf area per plant was also linearly related to embryo weight but independent of strain; but for a common embryo weight, Clare was found to have fewer leaves than the other two strains. Examination of the areas of successive leaves showed that the maintenance of similar total leaf areas depended on a balance of rate of leaf production and size of individual leaves; in relation to Bacchus Marsh and Mt. Barker, Clare has fewer but large1 leaves.


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