Nitrogen fixation characteristics of Rhizobium surviving in soils 'equilibrated' with sewage biosolids

2001 ◽  
Vol 52 (10) ◽  
pp. 963 ◽  
Author(s):  
Kellie J. Munn ◽  
Jeffrey Evans ◽  
Phillip M. Chalk
Keyword(s):  
N2 Fixation ◽  
Soil Type ◽  
Rhizobium Leguminosarum ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Subterranean Clover ◽  
Isotope Dilution Method ◽  
Dilution Method ◽  
Symbiotic Effectiveness ◽  
Amended Soils

To determine the effects of urban sewage biosolids on the symbiotic effectiveness of Rhizobium leguminosarum bv. trifolii and N2 fixation, glasshouse and laboratory studies were carried out with several soils, biosolids, and biosolid application levels. Symbiotic effectiveness of R. l. trifolii was estimated as the dry weight or N content of seedlings of subterranean clover grown with only N2 fixation and seed N as the available nitrogen sources. The N fixed by legumes in unamended and biosolid-amended soils was determined using the 15N isotope dilution method. Six soils were represented in the experiments. Each of these was equilibrated over a period of 12 months with dried, finely ground biosolids (DWS) from the Malabar sewage treatment plant, at biosolids levels ranging from the equivalent of 60 to 240 t DWS/ha. One of the soils was also equilibrated with each of 4 other biosolids. The maximal concentration of heavy metals in soil amended with biosolids was 1026 mg/kg. The effect of biosolids on symbiotic effectiveness depended on the soil type and biosolid applications level. Thus, biosolids reduced the symbiotic effectiveness of R. l. trifolii in 2 of the 6 soils, although at different levels of biosolid. In most soil treatments N2 fixation was detected in subterranean clover, confirming the persistence of symbiotically effective rhizobia in most biosolids-amended soils. In addition, in strongly acidic soils plant N and N2 fixation increased significantly with biosolids addition, probably in response to higher soil pH, exchangeable Ca, and available P. In the treatments in which the symbiotic effectiveness of R. l. trifolii was reduced by biosolids, this was reflected in poor N2 fixation. However, symbiotic effectiveness did not correlate well with N2 fixation, probably because increases in soil nitrate at higher biosolids levels inhibited N2 fixation. Nevertheless, there were instances at 240 t DWS/ha where this was unlikely to explain the decrease in N2 fixation. It was concluded that adverse effects of biosolids on symbiotic effectiveness depend first on soil type, and then on biosolid type and application level; and the response in symbiotic effectiveness to adding biosolids to soil needs to be determined for each distinctively different site of biosolids reuse.

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.

Diversity and symbiotic effectiveness of Rhizobium leguminosarum bv. trifolii isolates from pasture soils in south-western Australia

Soil Research ◽  
2002 ◽  
Vol 40 (8) ◽  
pp. 1319 ◽  
Author(s):  
M. T. Collins ◽  
J. E. Thies ◽  
L. K. Abbott
Keyword(s):  
Western Australia ◽  
Rhizobium Leguminosarum ◽  
Subterranean Clover ◽  
Most Probable Number ◽  
Enzyme Linked Immunosorbent Assay ◽  
Symbiotic Effectiveness ◽  
Probable Number ◽  
Pcr Fingerprinting ◽  
Rapd Pcr ◽  
Inoculant Strain

The abundance of the Australian inoculant strain of Rhizobium leguminosarum bv. trifolii for subterraneum clover (WU95) and the diversity of naturalised rhizobia were assessed in 3 subterranean clover pastures in the Albany region of south-western Western Australia. Most probable number, enzyme linked immunosorbent assay (ELISA), and polymerase chain reaction (PCR) techniques were used. A putative strain similar to inoculant strain WU96 was uncommon at one site (South Stirling) and not isolated at 2 other sites. Randomly amplified polymorphic DNA (RAPD) PCR fingerprinting using the RPO1 primer identified 45 different profiles amongst the 208 isolates examined. RAPD-PCR fingerprinting using the primers RPO4 and RPO5 confirmed most groupings based on RPO1 fingerprint patterns and revealed further genetic diversity within some groups. Overall, 54 putative strains were defined by RAPD-PCR fingerprint profiles across the 3 sites. Subterranean clover rhizobia at the Manypeaks and Mount Shadforth sites were dominated by isolates with 1 or 2 RPO1 RAPD profiles at 2 sampling times, while the population at South Stirling was much more diverse. The symbiotic effectiveness of 11 rhizobial isolates, representing the major RPO1 RAPD profile groups within naturalised rhizobial populations, were compared in pot culture with those of the 2 commercial inoculant strains for subterranean clover, WU95 and TA1, on 3 cultivars. Differences in effectiveness among 3 of the 11 isolates were observed in comparison to both the commercial strains and other naturalised isolates. The nitrogen fixing effectiveness of 8 isolates representing different subgroups from one RP01 group was not the same. The use of all 3 primers increased the precision in defining putative strains of Rhizobium leguminosarum bv. trifolii, and although naturalised rhizobia from these pastures are saprophytically competent, their dominance in nodules does not appear to be linked to symbiotic effectiveness.

Boron deficiency in pasture based on subterranean clover (Trifolium subterraneum L.) is linked to symbiotic malfunction

2015 ◽  
Vol 66 (11) ◽  
pp. 1197 ◽  
Author(s):  
Leo J. Hamilton ◽  
Kevin F. M. Reed ◽  
Elainne M. A. Leach ◽  
John Brockwell
Keyword(s):  
N2 Fixation ◽  
Rhizobium Leguminosarum ◽  
Root Nodule ◽  
Effective Strain ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Boron Deficiency ◽  
Initial Application ◽  
Clover Root ◽  
Clover Seed

Field and glasshouse experiments confirmed the occurrence of boron (B) deficiency in subterranean clover (Trifolium subterraneum L.) pasture in eastern Victoria. Diminished productivity was linked to the small-seededness of clover and the poor effectiveness of clover root-nodule bacteria (rhizobia, Rhizobium leguminosarum bv. trifolii). Productivity, especially of clover and clover seed, increased following applications of up to 6 kg B ha–1 (P < 0.001). The response was delayed, occurring several years after the initial application of B, unless the land was resown with fresh clover seed inoculated with an effective strain of rhizobia. B deficiency in the nodulated legume induced conditions within the plant and or its rhizobia that led to impaired nitrogen (N2) fixation. Glasshouse research indicated that populations of soil-borne rhizobia taken from B-deficient soils were poorly effective in N2 fixation and that rhizobia from soils growing subterranean clover cv. Leura were significantly less effective (P < 0.05) than rhizobia from a soil growing cv. Mt Barker. Additionally, subterranean clover seed generated in B-deficient soils was at least one-third smaller than the seed of commercial seed but responded to inoculation with effective rhizobia. This indicated that any symbiotic malfunction of clover from B-deficient soils was not due to an inability to respond to nitrogen per se. On the other hand, cv. Leura from B-deficient soils fixed significantly less N2 than commercial cv. Leura when each was inoculated with rhizobia from B-deficient soils.

The interactions of Rhizobium leguminosarum biovar trifolii in nodulation of annual and perennial Trifolium spp. from diverse centres of origin

2005 ◽  
Vol 45 (3) ◽  
pp. 199 ◽  
Author(s):  
J. G. Howieson ◽  
R. J. Yates ◽  
G. W. O'Hara ◽  
M. Ryder ◽  
D. Real
Keyword(s):  
N2 Fixation ◽  
Rhizobium Leguminosarum ◽  
Subterranean Clover ◽  
South American ◽  
Equatorial Africa ◽  
Centres Of Diversity ◽  
Mediterranean Regions ◽  
North And South America ◽  
North And South ◽  
Rhizobium Leguminosarum Biovar Trifolii

The release of effective inocula for new perennial clovers into cropping zones where subterranean clover is important might compromise N2 fixation by this valuable annual clover if symbiosis between the new inoculants and subterranean clover is not optimal. To assist our understanding of the interactions between clovers and their microsymbionts, rhizobial strains and clovers from South and equatorial Africa, North and South America, and the Euro–Mediterranean regions were tested. Glasshouse-based studies of the cross-inoculation characteristics of 38 strains of Rhizobium leguminosarum bv. trifolii associated with 38 genotypes of annual and perennial Trifolium spp. from these world centres of diversity were undertaken. Less than 7.5% of the perennial clover symbioses were effective whereas 40% of associations were effective for many of the annual clover species of Euro–Mediterranean origin. There was substantial specificity within the African clovers for effective nodulation. Rhizobial strains from the South American perennial T. polymorphum or from the African clovers were unable to nodulate subterranean clover effectively. Also, 7 of the 17 strains from these regions were unable to form nodules with the less promiscuous Mediterranean annual clovers, T. glanduliferum and T. isthmocarpum. Fifty-three of about 400 cross-inoculation treatments examined, which included annual and perennial clovers, were incapable of forming nodules, while only 65 formed effective nodules. There are 2 barriers to effective nodulation: a ‘geographic’ barrier representing the broad centres of clover diversity, across which few host-strain combinations were effective; and, within each region, a significant ‘phenological’ barrier between annual and perennial species. Clovers and their rhizobia from within the Euro–Mediterranean region of diversity were more able to cross the phenological barrier than genotypes from the other regions. It appears that only the relatively promiscuous clovers, whether annual or perennial, have been commercialised to date. The data indicate that, for perennial clovers, it will be a substantial challenge to develop inocula that do not adversely affect N2 fixation by subterranean clover and other annual clovers available commercially, especially if the perennial clovers were originally from Africa or America. Some future strategies for development of inoculants for clovers are proposed.

Distribution, abundance and symbiotic effectiveness of Rhizobium leguminosarum bv. trifolii from alkaline pasture soils in South Australia

2000 ◽  
Vol 40 (1) ◽  
pp. 25 ◽  
Author(s):  
M. D. Denton ◽  
D. R. Coventry ◽  
W. D. Bellotti ◽  
J. G. Howieson
Keyword(s):  
N2 Fixation ◽  
Rhizobium Leguminosarum ◽  
South Australia ◽  
Shoot Biomass ◽  
Alkaline Soil ◽  
Symbiotic Effectiveness ◽  
Management Options ◽  
Soil Constraints ◽  
Reference Strains ◽  
Rhizobial Population

The current dissatisfaction with low productivity of annual medic (Medicago spp.) pastures has highlighted the need to seek alternative legumes to provide efficient N2 fixation in low rainfall, alkaline soil environments of southern Australia. Clover species adapted to these environments will have limited N2 fixation if effective rhizobia are not present in sufficient quantities. A survey of 61 sites was conducted across South Australia to determine the size, distribution and effectiveness of Rhizobium leguminosarum bv. trifolii (clover rhizobia) populations resident in these low rainfall, alkaline soil environments. Clover rhizobia were detected at 56 of the sites, with a median density of 230–920 rhizobia/g soil. Most rhizobial populations were poor in their capacity to fix nitrogen. Rhizobial populations from fields provided 11–89% and 10–85% of the shoot biomass of commercial reference strains when inoculated onto host legumes T. purpureum (purple clover) and T. resupinatum (persian clover), respectively. Rhizobial population size was correlated negatively to pH and the percentage of CaCO3 in the soil, and was significantly increased in the rhizospheres of naturalised clover, found at 17 sites. Management options for rhizobial populations to improve legume diversity and productivity are discussed in terms of rhizobial population dynamics and likely soil constraints to successful rhizobial colonisation.

Sowing date and varietal effects on the N2 fixation of field pea and implications for improvement of soil nitrogen

1993 ◽  
Vol 44 (1) ◽  
pp. 151 ◽  
Author(s):  
GE O'Connor ◽  
J Evans ◽  
NA Fettell ◽  
I Bamforth ◽  
J Stuchberry ◽  
...  
Keyword(s):  
N2 Fixation ◽  
Dry Matter ◽  
Sowing Date ◽  
Isotope Dilution Method ◽  
Dilution Method ◽  
Total N ◽  
Sowing Dates ◽  
Eastern Australia ◽  
Biomass N ◽  
Varietal Variation

Dry matter, biomass N, N2 fixation (determined by the 15N isotope dilution method), grain yield and grain N, were determined for five pea cultivars grown with three sowing times at six sites in south-eastern Australia. Earlier sowing (late April to early May) increased N2 fixation (by as much as 96 kg N/ha compared to sowing in late June to early July). Early sowing improved the probability of peas contributing to soil total N. The potential increment in soil N from the pea stubbles left after harvesting grain, averaged over the varieties, was as high as 98 kg N/ha with early sowing, and as low as -38 kg N/ha with late sowing. The benefits from earlier sowing were due to larger dry matter production with a higher N concentration and a greater proportion of plant N from N2 fixation. Varietal variation in fixed N and potential for augmenting soil total N, was generally smaller than the variation in these parameters due to different sowing dates.

Corrigendum to: Boron deficiency in pasture based on subterranean clover (Trifolium subterraneum L.) is linked to symbiotic malfunction

2017 ◽  
Vol 68 (8) ◽  
pp. 805
Author(s):  
Leo J. Hamilton ◽  
Kevin F. M. Reed ◽  
Elainne M. A. Leach ◽  
John Brockwell
Keyword(s):  
N2 Fixation ◽  
Rhizobium Leguminosarum ◽  
Root Nodule ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Boron Deficiency ◽  
Nodule Bacteria ◽  
Clover Root ◽  
Per Se ◽  
Clover Seed

Field and glasshouse experiments confirmed the occurrence of boron (B) deficiency in subterranean clover (Trifolium subterraneum L.) pasture in eastern Victoria. Diminished productivity was linked to the small-seededness of clover and the poor effectiveness of clover root-nodule bacteria (rhizobia, Rhizobium leguminosarum bv. trifolii). Productivity, especially of clover and clover seed, increased following applications of up to 6 kg B ha–1 (P B deficiency in the nodulated legume induced conditions within the plant and or its rhizobia that led to impaired nitrogen (N2) fixation. Glasshouse research indicated that populations of soil-borne rhizobia taken from B-deficient soils were poorly effective in N2 fixation and that rhizobia from soils growing subterranean clover cv. Leura were significantly less effective (P Additionally, subterranean clover seed generated in B-deficient soils was at least one-third smaller than the seed of commercial seed but responded to inoculation with effective rhizobia. This indicated that any symbiotic malfunction of clover from B-deficient soils was not due to an inability to respond to nitrogen per se. On the other hand, cv. Leura from B-deficient soils fixed significantly less N2 than commercial cv. Leura when each was inoculated with rhizobia from B-deficient soils.

ON THE VALUE OF SOME PARAMETERS OF ADRENOCORTICAL GLUCOCORTICOID FUNCTION

1963 ◽  
Vol 44 (4) ◽  
pp. 499-504 ◽  
Author(s):  
M. Van Der Straeten ◽  
A. Vermeulen ◽  
N. Orie ◽  
P. Regniers
Keyword(s):  
Urinary Excretion ◽  
Adrenal Cortex ◽  
Isotope Dilution ◽  
Isotope Dilution Method ◽  
Dilution Method ◽  
Steroid Excretion ◽  
Colorimetric Methods

ABSTRACT The authors studied the correlation between cortisol production, as measured by an isotope dilution method, and the urinary excretion of total and free Porter-Silber chromogens, as well as of 17-ketogenic steroids. Although a significant correlation exists between total Porter-Silber chromogens, 17-ketogenic steroid excretion and cortisol production, discrepancies are occasionally observed. Hence, different colorimetric methods should be used to assess the glucocorticoid activity of the adrenal cortex.

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