Ecological studies of root-nodule bacteria introduced into field environments. 3. Persistence of Rhizobium trifolii in association with white cover at high elevations

1972 ◽  
Vol 12 (57) ◽  
pp. 407 ◽  
Author(s):  
J Brockwell ◽  
WG Bryant ◽  
RR Gault
Keyword(s):  
White Clover ◽  
Root Nodule ◽  
New South ◽  
Single Step ◽  
Rhizobium Trifolii ◽  
Nodule Bacteria ◽  
Legume Seed ◽  
South Wales ◽  
Inoculant Strain ◽  
High Elevations

Eight strains of Rhizobium trifolii were tested for ability to persist in association with white clover (Trifolium repens) sown at three sites at different elevations in the Snowy Mountains region of New South Wales. The standard clover inoculant strain, TA1, persisted poorly. Five strains of Tasmanian origin (representing two distinct serotypes), all highly effective in nitrogen fixation in combination with white clover, were recovered from the soils at high frequency over a period of three years. A single-step technique of pelleting and seed inoculation was slightly but consistently superior to the more complicated method that has been employed routinely for inoculation of legume seed used in revegetation undertakings in the Snowy Mountains.

The root-nodule bacteria as factors in clover establishment in the red basaltic soils of the Lismore district, NSW. I. A survey of "Native" strains.

1954 ◽  
Vol 5 (1) ◽  
pp. 55 ◽  
Author(s):  
JM Vincent
Keyword(s):  
Root Nodule ◽  
New South ◽  
Field Observations ◽  
Nodule Bacteria ◽  
Root Nodule Bacteria ◽  
Seed Inoculation ◽  
South Wales ◽  
Basaltic Soils ◽  
Native Strains ◽  
Medicago Species

Tests of 84 cultures of root-nodule bacteria isolated from four species of clover growing in the Lismore district of New South Wales (three soil types, 18 localities) showed them to be generally effective in association with white and red clovers, but almost always parasitic on subterranean and crimson clovers. Successful seed inoculation with beneficial strains of rhizobia is, therefore, essential to the introduction of subterranean and crimson clovers in these soils. Field observations have also demonstrated the need to inoculate seed of Medicago species, cowpea, and vetch.

The effects of high temperatures on certain root-nodule bacteria

1967 ◽  
Vol 18 (2) ◽  
pp. 299 ◽  
Author(s):  
J Wilkins
Keyword(s):  
New England ◽  
High Temperatures ◽  
Root Nodule ◽  
New South ◽  
New South Wales ◽  
Nodule Bacteria ◽  
Natural Conditions ◽  
Root Nodule Bacteria ◽  
South Wales ◽  
Native Strains

Rhizobia present in soils from western New South Wales and from the New England Tableland were subjected to a series of high temperature survival tests. Rhizobia present in air-dry soils survived temperatures higher than would be experienced under natural conditions. In moist soils the tolerance of medic rhizobia to high temperatures was much lower. Strains of Acacia, Lotus and Psoralea rhizobia from western New South Wales survived higher temperatures than strains from the New England Tableland, but the tolerance to high temperatures of medic rhizobia did not vary with source. This suggests an ecological adaptation of the three native strains not found in the introduced Medicago rhizobium.

Survey of the productivity, composition and estimated inputs of fixed nitrogen by pastures in central-western New South Wales

2004 ◽  
Vol 44 (12) ◽  
pp. 1165 ◽  
Author(s):  
A. M. Bowman ◽  
W. Smith ◽  
M. B. Peoples ◽  
J. Brockwell
Keyword(s):  
White Clover ◽  
N2 Fixation ◽  
Dry Matter ◽  
New South ◽  
Perennial Grass ◽  
New South Wales ◽  
Subterranean Clover ◽  
Legume Species ◽  
Forage Production ◽  
South Wales

Total productivity and legume nitrogen fixation (N2 fixation) in dryland pastures were examined in a 2 year study (1999–2001) on 118 farms in central-western New South Wales. Pasture exclosure cages, placed at 217 on-farm sites, were harvested on 7 occasions and the foliage hand-sorted according to species in order to measure shoot dry matter (DM). The separated legume shoot material collected in spring 1999 (52 different legume samples) and 2000 (76 different legume samples) from a subset of representative pastures (41 cages on 28 different farms in 1999, 32 cages on 25 different farms in 2000) was also analysed for concentration of nitrogen (%N) and 15N natural abundance. These data were subsequently used to calculate the proportion of the legume shoot N derived from atmospheric N (%Ndfa), comparative measures of the relative efficiency of N2 fixation (kg N fixed/t DM accumulated) and the amounts of shoot N fixed (kg N/ha). The survey encompassed 8 common pasture types, and 5 others that were less common, ranging from native perennial grass pastures with little legume content to lucerne (Medicago sativa L.) pastures with and without companion clovers. Fifteen legume species were found in the pastures, some only occasionally. Lucerne and white clover (Trifolium repens L.) were the only perennials. Mean spring estimates of %Ndfa were similar in 1999 and 2000 for lucerne (72 and 81%, respectively), rose clover (T. hirtum All., 82 and 77%) and annual medics (Medicago spp., 89 and 86%). For the remaining 12 legume species, measures of %Ndfa ranged from 64 to 95% and averaged 83%. Shoot %N contents were greater for lucerne than for the other 14 legumes and this was reflected in the comparative measures of N2 fixation which ranged from 14.5 kg N/t DM for rose clover to 25.7 kg N/t DM for lucerne in 2000. The most productive pasture type comprised lucerne plus balansa clover [T. michelianum Savi var. balansae (Boiss.) Azn.], white clover or arrowleaf clover (T. vesiculosum Savi), but all pasture types that contained lucerne were highly productive. Spring was the most productive season and summer the least. Lucerne was overwhelmingly the most productive legume and was responsible for >83% of the fixed N in those pastures that contained both lucerne and other legumes. Lucerne productivity was approximately uniform throughout the year whereas, for other pastures, especially those based on rose clover or subterranean clover (T. subterraneum L.), there were sharp peaks in spring and little or no dry matter production over summer. The presence of lucerne in pastures significantly (P<0.05) reduced broadleaf weeds. It was concluded that, where there are requirements in central-western New South Wales agriculture for uniform forage production throughout the year and a high input of fixed N, lucerne is substantially superior to other species.

The role of stolons and seedlings in the persistence and production of white clover (Trifolium repens L. cv. Huia) in temperate pastures on the Northern Tablelands, New South Wales

1989 ◽  
Vol 40 (3) ◽  
pp. 605 ◽  
Author(s):  
KA Archer ◽  
GG Robinson
Keyword(s):  
Soil Moisture ◽  
White Clover ◽  
Seedling Establishment ◽  
New South ◽  
New South Wales ◽  
Late Summer ◽  
South Wales ◽  
Cool Temperate ◽  
Plant Frequency ◽  
Temperate Pastures

This paper reports the findings of a five-year study on the growth patterns, production and means of persistence of white clover in a cool temperate environment with summer dominant rainfall, on the Northern Tablelands of New South Wales. White clover essentially persisted as a perennial, but large and rapid declines in plant frequency occurred during late summer if soil moisture levels became depleted. The critical combination of conditions at which plant frequency was adversely affected occurred when available soil moisture levels declined below 35 mm and mean weekly maximum temperatures exceeded 20�C; conditions which often occur in late summer in this environment. During one prolonged period of moisture stress in the second spring and summer period of the study, all plants died. Regeneration was due to germination of seeds and seedling establishment, but plants subsequently persisted as perennials. Relationships were developed to predict the probability of survival of white clover over the range of temperatures and soil moistures recorded in these experiments. Germination occurred to a variable extent each year, but was observed only during winter and spring. Seedling establishment was effective in only one year, which followed the death of white clover in summer, 1980-81. The sward was slow to recover after seedling regeneration owing to low winter temperatures and competition from established temperate perennial grasses in spring. Seedlings contributed little to dry matter production in spring. These results indicate that white clover is unlikely to be of value as an annual in temperate pastures. Strategies aimed at improving white clover in cool temperate environments, either by management or selection/breeding programs, should therefore focus upon improving the ability of white clover to persist as a perennial.

Competition between effective and ineffective strains of Rhizobium trifolii in the nodulation of Trifolium subterraneum

1969 ◽  
Vol 20 (5) ◽  
pp. 827 ◽  
Author(s):  
AC Robinson
Keyword(s):  
Competitive Ability ◽  
Root Nodule ◽  
Effective Strain ◽  
Substantial Reduction ◽  
Trifolium Subterraneum ◽  
Bacterial Cells ◽  
Rhizobium Trifolii ◽  
Parallel Study ◽  
Nodule Bacteria ◽  
Tube Culture

The competitive ability of effective and ineffective strains of Rhizobium trifolii to form nodules on two cultivars of Trifolium subterraneum was examined under bacteriologically controlled conditions in tube culture. Seedlings were inoculated with mixtures of known numbers each of effective and of ineffective strains and the strains forming the nodules subsequently determined. In all instances, the effective strains formed a much greater proportion of nodules than would be expected from the relative numbers of each strain in the inoculum. Moreover, a reduction in the numbers of an effective strain relative to the numbers of an ineffective strain failed to result in a corresponding increase in the proportion of nodules formed by an ineffective strain. Instead, the ratio of ineffective to effective strains had to be of the order of 108/104 or wider (c. 10,000/1) before there was a substantial reduction in the number of nodules formed by the effective strains. Even when this ratio was of the order of 108/102, the effective strains still produced some of the nodules. A parallel study of the rates of nodulation of seedlings inoculated with mixtures of strains showed that these rates were characteristic of the proportions of nodules being formed by each strain. Subsequently seedlings were inoculated with mixtures of effective and ineffective strains, and after 66, 90, and 114 hr the roots were surface-sterilized and their contents isolated and identified. Independently of the mixture of strains used, most of the bacterial cells were identified as the effective strains. Because the strains of effective and ineffective bacteria used produce nodules freely when inoculated separately onto these hosts, it is postulated that the hosts distinguished between effective and ineffective strains, and that this recognition is related to compatibility in association with the host. The significance of the results in relation to studies of the root-nodule bacteria is discussed.

Production of two species and two interspecific hybrids of phalaris under irrigation in south-west New South Wales

1980 ◽  
Vol 20 (103) ◽  
pp. 181 ◽  
Author(s):  
JW Read ◽  
JV Lovett
Keyword(s):  
White Clover ◽  
Nitrogen Fertilizer ◽  
Interspecific Hybrids ◽  
New South ◽  
New South Wales ◽  
Paspalum Dilatatum ◽  
Suitable Alternative ◽  
South West ◽  
South Wales ◽  
High Production

Two phalaris hybrids (Siro 11 46 and allopolyploid) and the parent lines (Phalaris aquatica and P. arundinacea) were compared in monoculture with nitrogen fertilizer and in a mixed sward with white clover and lucerne. The experiment was flood irrigated and the effects of defoliating the swards at intervals of 21, 42 and 84 days were measured. The hybrid (Siro 11 46) was the most productive genotype at all defoliation intervals. Eighty one % of its annual yield occurred in spring and summer. This production imbalance renders Siro 11 46 unsuitable as the foundation of a pasture for high production throughout the year. The mixed sward produced more than the monoculture sward when defoliated every 21 or 42 days and there was increased production associated with increased defoliation interval. The monoculture sward was more productive than the mixed sward at an 84 day defoliation interval. The yield of Siro 1146 + white clover was 2.25 t ha-1 per 84 days, compared with a mean yield of phalaris + white clover of 1.78 t ha-1 per 84 days for the three other genotypes. The results indicate that Siro 11 46 grown with white clover and defoliated approximately every 42 days would be a suitable alternative pasture to Paspalum dilatatum and white clover in the two-pasture system used in irrigation areas of southern New South Wales. The problems of low acceptability and suspected toxicity of Siro 1146 are discussed.

scholarly journals Overwintering of Clover Nodules in Alpine Conditions

1963 ◽  
Vol 16 (4) ◽  
pp. 920 ◽  
Author(s):  
FJ Bergersen ◽  
FW Hely ◽  
AB Costin
Keyword(s):  
Soil Conservation ◽  
New South ◽  
New South Wales ◽  
Nodule Formation ◽  
Nodule Bacteria ◽  
Trifolium Ambiguum ◽  
South Wales ◽  
Large Numbers ◽  
Complete Fertilizer

As part of a programme investigating soil conservation in the Snowy Mountains area of New South Wales, trials were conducted in which seedlings of Trifolium ambiguum M. Bieb. and T. repens L. (Ladino clover) were planted in the spring of 1960 in eroded areas on Carruthers Peak adjacent to Mt. Kosciusko (lat. 36� 24'S., long. 14So IS'E.) at an elevation of about 7000 ft. Seedlings were raised in seed boxes of soil which had been massively inoculated with appropriate strains of nodule bacteria. Effectively nodulated seedlings were transplanted into peat cups filled with soil. This step was necessary because of the extreme host variation with respect to nodule formation and effectiveness in T. ambiguum (Hely 1957, 1963). The cups were planted intact together with a complete fertilizer mixture; at that stage all plants were well nodulated and the soil in the cups contained large numbers of nodule bacteria.

Growth of pasture species on the Northern Tablelands of New South Wales

1975 ◽  
Vol 26 (2) ◽  
pp. 269 ◽  
Author(s):  
A Lazenby ◽  
JV Lovett
Keyword(s):  
White Clover ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
New South ◽  
New South Wales ◽  
Botanical Composition ◽  
South Wales ◽  
Available Soil Moisture ◽  
Capacitance Probe

The production of herbage by five pasture species—Phalaris tuberosa (phalaris), Festuca arundinacea (tall fescue), Lolium perenne (perennial ryegrass), Trifolium repens (white clover) and Medicago sativa (lucerne)—was measured when they were grown in the field in monoculture, and by phalaris and white clover when grown in mixture. The plots were irrigated to prevent water deficits, and five levels of nitrogen were included; the mixture was also grown under dryland conditions. All plots were defoliated at intervals during a period of 3 years. A capacitance probe was used in an attempt to determine harvest times more objectively, and to establish long-term relationships between meter readings and components of plant yield. Major differences in production were detected between the species, lucerne producing most in the first 2 years of the experiment. Nitrogen and available soil moisture affected both production and botanical composition, and significant differences were detected in species' responses to applied nitrogen and in nitrogen recovery. The performance of lucerne and tall fescue suggests that both species deserve to be more widely grown on the Northern Tablelands of New South Wales.

Survival of Rhizobium trifolii strains on inoculated seed held at 35°C

1977 ◽  
Vol 17 (89) ◽  
pp. 995 ◽  
Author(s):  
H Philpotts
Keyword(s):  
High Temperature ◽  
Death Rate ◽  
New South ◽  
North Coast ◽  
Good Survival ◽  
Rapid Decline ◽  
Rhizobium Trifolii ◽  
Far North ◽  
Commercial Strain ◽  
South Wales

Fifteen Rhizobium trifolii strains, selected from 62 isolations from naturalized white clover (Trifolium repens) plants on the far north coast of New South Wales, were tested for their tolerance to high temperature. They were compared with TAI (the current commercial strain) and CC275e, when used as peat cultures to inoculate seed held at 35�C. TAI showed the most rapid decline and its death rate was significantly higher than that of all except one of the isolates. CC275e showed good survival, and its death rate was similar to the lowest in two out of the three groups in which it was included. Differences between local isolates were small except for two which showed poorer survival.

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