Persistence, productivity and seed yield of Medicago murex, M. truncatula, M. aculeata and Trifolium subterraneum on an acid red earth soil in the wheat belt of eastern Australia

1992 ◽  
Vol 32 (3) ◽  
pp. 319 ◽  
Author(s):  
BS Dear ◽  
L Jenkins

The persistence, productivity, and seed yield of 4 annual legume species, Trifolium subterraneum L. var. subterraneum, Medicago murex Willd, M. truncatula Gaertn var. truncatula, and M. aculeata, were compared on an acid red earth soil at Temora. New South Wales. All species persisted for 4 years but there were significant differences in herbage yields and seed reserves between species, and between cultivars and lines within species. The recently released T. subterraneum cultivar, Junee, produced superior seedling densities in 2 of the 3 regenerative years and maintained similar summer seed reserves, but carried over a higher proportion of seed (hard seed) through each winter and was as productive as the older cultivar, Woogenellup, except in late spring. The 6 M. murex lines persisted and remained well nodulated on the moderately acid [pH(CaCl2) 4.81 soil when grown with a new acid-tolerant Rhizobium strain, WSM 419. Medicago murex demonstrated potential as an alternative species to T. subterraneum for the eastern wheat belt; it maintained high seed reserves and was more hardseeded than T. subterraneum cultivars, but this did not reduce its ability to produce large populations of seedlings in autumn. While the M. aceuleata and M. truncatula lines demonstrated that they could persist and regenerate adequately over the 4-year period, neither proved to be superior to either the T. subterraneum or M. murex lines in any of the parameters.


1994 ◽  
Vol 34 (6) ◽  
pp. 745 ◽  
Author(s):  
RM Barclay ◽  
DM Hebb ◽  
J Brockwell

Two annual medics, Medicago murex and M. truncatula, were inoculated with specific strains of Rhizobium meliloti, WSM540 and CC169, respectively, and sown into a mildly acid red earth in a semi-arid environment at Cobar, New South Wales. A third medic, M. laciniata, volunteered abundantly at the experimental site and large populations of its specific strain(s) of R. meliloti were naturalised in the soil. Serial dilution, plant infection tests, using 3 test plants in parallel, were employed to count the populations of each of the 3 types of R. meliloti that colonised the roots (rhizospheres) of the 3 medics. The size of the rhizosphere populations was regarded as an index of nodulation potential. Large populations of the naturalised rhizobia (about 45000lplant) developed in the rhizospheres of M. laciniata; these rhizobia also colonised the root surfaces of the sown medics but in much lower numbers (< 80/plant). Strain WSM540 colonised the rhizospheres of M. murex in sufficient numbers (1121 rhizobia/plant) to indicate that an effective nitrogen-fixing symbiosis would have established had seasonal conditions permitted. By contrast, the colonisation of M. truncatula rhizospheres by CC169 was significantly lower (64 rhizobia/plant; P<0.05) and the likelihood of nodulation was uncertain. Both WSM540 and M. murex are known to be acid tolerant whereas both CC169 and M. truncatula are acid sensitive. There was very little colonisation of the rhizospheres of the sown medics by non-specific inoculant strains. Nor was there evidence that the large naturalised population of rhizobia for M. laciniata competed with the specific inoculant strains for colonisation of the roots of the sown medics or interfered with their potential nodulation.



1991 ◽  
Vol 42 (5) ◽  
pp. 735 ◽  
Author(s):  
JF Angus ◽  
RA Fischer

Dryland wheat was fertilized with ammonium nitrate or liquid urea-ammonium nitrate at the time of sowing or about 3 months later (generally at the terminal-spikelet stage) on a well-drained site near Harden on the south-west slopes of New South Wales. The experiments continued from the second to the fifth year (1981-1984) of the cropping phase of a crop-pasture rotation. The maximum agronomic efficiencies for yield in the four consecutive years were 19, 4, 23 and 25 kg grain per kg of applied nitrogen (N). The three large responses were obtained in wetter than average seasons and the small response was obtained during drought. In the last three years of the study the yield response to nitrogen at the terminal-spikelet stage was found to be close to but slightly less than that for N applied at sowing. In those years the agronomic efficiencies for the late-applied N were 0, 22 and 22. The apparent recovery of fertilizer N in the above-ground parts of the crop at maturity was up to 70% of the fertilizer applied in the year of sowing, and, after the drought during which there was little uptake of fertilizer N, up to 62% by the subsequent crop. The fertilizer efficiencies in the non-drought years were higher than generally reported in south-eastern Australia, and indicate potential for profitable delayed application of N fertilizer to wheat. Grain-protein responses were variable from year to year and are discussed against a simple theoretical background of the amount of N applied and grain-yield response.



1992 ◽  
Vol 14 (1) ◽  
pp. 26 ◽  
Author(s):  
DJ Eldridge ◽  
J Rothon

Some hydrological characteristics of a red earth soil were examined under two pasture types at Yathong in central-westem New South Wales using simulated rainfall. Runoff and rate of sediment loss from plots dominated by perennial grasses were lower than for plots dominated by ephemerals. Time-to-ponding was less on the plots dominated by ephemerals but time-to-runoff was similar for both pasture types. On both grass and ephemeral-dominant soils, measured soil and vegetation attributes explained very little of the variation in runoff and sediment yield. The results do not support the existence of a threshold level of vegetation cover below which runoff increases markedly.



2017 ◽  
Vol 68 (12) ◽  
pp. 1112 ◽  
Author(s):  
Richard C. Hayes ◽  
Guangdi D. Li ◽  
Graeme A. Sandral ◽  
Tony D. Swan ◽  
Andrew Price ◽  
...  

This study examined whether the productivity and persistence of mixed pastures that included subterranean clover (Trifolium subterraneum L.), lucerne (Medicago sativa L.), and/or phalaris (Phalaris aquatica L.) were improved if species were spatially separated rather than being sown together in each drill row. The study also compared the productivity and persistence of subterranean clover with alternative annual legume species biserrula (Biserrula pelecinus L.) and strand medic (Medicago littoralis Rhode ex Loisel). Twelve pasture treatments were sown in replicated field experiments at five locations across the medium-rainfall region of south-western New South Wales in 2012 and monitored for 3 years. Pastures that included lucerne, phalaris and subterranean clover were generally more productive than pastures with only one or two of those species, regardless of sowing configuration. Averaged across sites, subterranean clover regeneration in year 3 was 29% higher and total cumulative biomass 13% higher where subterranean clover was sown in a 1 : 1 configuration with lucerne than where the species were mixed together in every drill row. There were fewer consistent benefits of alternative spatial configurations on swards containing phalaris with subterranean clover or with lucerne. Results of the present study appeared to be highly site-specific, or season-dependent, and therefore alternative spatial configurations cannot be recommended as a universal strategy at this time. More research is required to understand the factors driving the responses to alternative spatial configurations observed in the present study. Neither biserrula nor strand medic was superior to subterranean clover in a 3-year pasture phase with lucerne, despite abundant rhizobia compatible with all species at all sites. The density of subterranean clover in year 3 was 29% and 41% higher than of biserrula and strand medic, respectively. A narrow choice of adapted cultivars as well as excessive levels of hard seed for the legumes used in phased pastures with lucerne are suggested as contributing to the inferior performance of the alternative legumes species tested in the study.



1959 ◽  
Vol 10 (6) ◽  
pp. 771 ◽  
Author(s):  
CM Donald

At an elevation of 2040 ft on the southern tablelands of Kew South Wales, seed production by swards of subterranean clover was apparently governed by mininnnn temperatures (frequency and intensity of frosts) during the flowering period. The aggregate deficit of the daily minimum temperature below 40°F in the 21 days from the commencement of flowering showed a high correlation with seed production per unit area in four successive seasons. Spring frosts account for the altitudinal limit of about 4000 ft to which subterranean clover grows in the alps of south-eastern Australia. Lateness of flowering has specific survival value at high altitudes in this region and in such areas as the high parts of the plateau of Spain. On the average 92 per cent. of the seed crop germinated in the year following its production, with 6.3 per cent. in the second year, and with falling values to 0.07 per cent. in the fifth year. Germination thereafter was nil or negligible. The early-flowering variety Dwalganup appeared to show a genetic difference in the persistence of more of its seed into the second and subsequent years. There was a regular seasonal pattern of seed germination, with the peak of germination occurring in the late summer and autumn. The "carry over" of seed into the second and subsequent years, and the germination peak in the autumn, have each considerable ecological significance.



1993 ◽  
Vol 33 (5) ◽  
pp. 581 ◽  
Author(s):  
BS Dear ◽  
PD Cregan ◽  
GM Murray

The density, productivity, flowering characteristics, and seed reserves of 14 lines (10 cultivars and 4 experimental lines) of subterranean clover were observed over 5 years (1983-87) on a red earth soil at Wagga Wagga, New South Wales. Plant density increased from 149-318 plants/m2 in 1983 to 1975-13925 plants/m'n 1987. Herbage yields of all cultivars during autumn-winter were similar in most years except in July 1985 when Seaton Park was superior. Cultivars in the midseason or later flowering groups were more productive in late spring and better able to utilise the extended growing seasons that occur periodically in this environment. The mean time from emergence to 5% flowering of all cultivars was 168 days with March germination in 1985 but decreased to 13.5 days with May germination in 1986. The number of days to flowering at Wagga Wagga was highly correlated with maturity ranking at Perth (r2 = 0.92 in 1985 and? = 0.93 in 1986). In the first year, average seed set was 295 kg seed/ha. but by summer of the fourth year the seed pool ranged from 124 kg/ha for Clare to 1190 kg/ha for Nungarin, the earliest flowering cultivar. The quantity of hard seed that carried over to the next year varied significantly between cultivars, with Enfield, Woogenellup, and Clare having the least, and Nungarin, Northam, Dalkeith, and Daliak the most. Seed set was related to maturity ranking only in 1984, although root disease probably affected seed yields in 1985-86. The proportion of hard seed that carried over was much higher than expected, particularly in soft-seeded cultivars. The newly released cultivar Junee was well adapted to the environment; it was later maturing than the recommended cultivar Seaton Park but was able to maintain high seed reserves. Karridale, another new cultivar, maintained higher seed reserves than the older Mount Barker.



1993 ◽  
Vol 15 (2) ◽  
pp. 234 ◽  
Author(s):  
DJ Eldridge ◽  
TB Koen

Three sites on red earth soils were examined at Yathong Nature Reserve and 'Coan Downs' in central- western New South Wales. The sites represented a gradient in soil surface condition from a stable, uneroded and productive site, supporting moderately dense perennial grasses (site 1) to a moderately unstable and degraded site with few perennials and evidence of erosion (site 3). The hydrological characteristics of the three sites were measured using a rainfall simulator on plots with varying vegetation cover. Water ponded earlier at the degraded site, and run-off and sediment removal increased as the soil surface became more degraded. Associated with this was an increase in the importance of vegetation cover, and a decrease in the importance of soil physico-chemical variables as descriptors of soil hydrological properties. The results are consistent with the notion that vegetation plays a more important role in maintaining soil hydrological processes as the soil surface becomes more degraded.



2007 ◽  
Vol 47 (5) ◽  
pp. 551 ◽  
Author(s):  
G. M. Lodge ◽  
S. Harden

Two subterranean clover (Trifolium subterraneum var. subterraneum and T. subterraneum var. brachycalycinum) evaluation studies were sown in replicated plots. The first study (experiment 1) comprised 30 entries sown in 1993 and 1994 and the second (experiment 2) had 85 entries sown in 1998. Green herbage mass (kg DM/ha) was assessed until spring 2000 (experiment 1) or 2001 (experiment 2). Limited data were also collected in experiment 1 to estimate hardseededness, seed yield and seedling regeneration. For each experiment, green herbage mass was examined using cubic smoothing splines. Plots of initial and final values assisted with data interpretation, and predicted values at the end of each experiment were used to assess significant (P = 0.05) cultivar/line differences. CPI 89846B (York), Junee and Clare performed better (P < 0.05) than Woogenellup, Seaton Park, Rosedale, Nuba and Goulburn (experiment 1, previously cultivated site). For the native pasture site, CPI 89846B, Junee, Clare and Woogenellup were better (P < 0.05) than Goulburn, Nuba and Rosedale. In experiment 2, the three cultivars, Clare, Antas and Rosedale, had similar predicted green herbage mass in spring 2001. In experiment 1, CPI 28012 had the lowest predicted green herbage mass in spring 2000. This line also had low seedling establishment and seed yield in 1993 and low seedling regeneration in 1994, 1995 and 1997. Early maturing cultivars/lines generally performed poorly in experiment 1 and, of the other lines, CPI 70100 performed best. However, in experiment 2, crosses with this line as a parent had variable green herbage mass in spring 2001.



1998 ◽  
Vol 38 (6) ◽  
pp. 583 ◽  
Author(s):  
A. Wallace ◽  
R. A. Lancaster ◽  
N. L. Hill

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.



2011 ◽  
Vol 62 (1) ◽  
pp. 1 ◽  
Author(s):  
R. J. Lawn ◽  
A. T. James

The purpose of this paper and its companion1 is to describe how, in eastern Australia, soybean improvement, in terms of both breeding and agronomy, has been informed and influenced over the past four decades by physiological understanding of the environmental control of phenology. This first paper describes how initial attempts to grow soybean in eastern Australia, using varieties and production practices from the southern USA, met with limited success due to large variety × environment interaction effects on seed yield. In particular, there were large variety × location, variety × sowing date, and variety × sowing date × density effects. These various interaction effects were ultimately explained in terms of the effects of photo-thermal environment on the phenology of different varieties, and the consequences for radiation interception, dry matter production, harvest index, and seed yield. This knowledge enabled the formulation of agronomic practices to optimise sowing date and planting arrangement to suit particular varieties, and underpinned the establishment of commercial production in south-eastern Queensland in the early 1970s. It also influenced the establishment and operation over the next three decades of several separate breeding programs, each targeting phenological adaptation to specific latitudinal regions of eastern Australia. This paper also describes how physiological developments internationally, particularly the discovery of the long juvenile trait and to a lesser extent the semi-dwarf ideotype, subsequently enabled an approach to be conceived for broadening the phenological adaptation of soybeans across latitudes and sowing dates. The application of this approach, and its outcomes in terms of varietal improvement, agronomic management, and the structure of the breeding program, are described in the companion paper.



Sign in / Sign up

Export Citation Format

Share Document