Soil pH is a major determinant of the numbers of naturally occurring Rhizobium meliloti in non-cultivated soils in central New South Wales

1991 ◽  
Vol 31 (2) ◽  
pp. 211 ◽  
Author(s):  
J Brockwell ◽  
A Pilka ◽  
RA Holliday
Keyword(s):  
Soil Ph ◽  
Rhizobium Meliloti ◽  
New South ◽  
New South Wales ◽  
Acid Soils ◽  
Alkaline Soils ◽  
Naturally Occurring ◽  
South Wales ◽  
Dominant Soil ◽  
The Relationship

Measurements were made of soil pH, frequency of occurrence of annual species of Medicago (medics) and populations of Rhizobium meliloti at 84 sites on 7 dominant soil groups of the Macquarie region of central-western New South Wales. Over all sites, soil pH (0-10 cm; 1:5 soil: water) ranged from 5.26 to 8.07, medic frequency from 0 to 100% and most probable numbers of R. meliloti from undetectable to 675 000/g soil. There was a highly significant (P<0.001) relationship between soil pH and number of R. meliloti. Above pH 7.0, the mean soil population of R. meliloti was 89000/g; below pH 6.0, it was 37/g. Medics occurred most frequently on the more alkaline soils and with least frequency on the more acid soils, but the relationship between soil pH and medic frequency was weaker than between pH and R. meliloti number. Medics were more tolerant of low soil pH than their rhizobia were; at 2 sites, of pH 5.49 and 5.35, medics occurred at 100% frequency but R. meliloti was undetected. There was an indication of some acidification in these soils over a period of 35 years but this remains to be confirmed.

The effect of biosolids on cereals in central New South Wales, Australia. 1. Crop growth and yield

2005 ◽  
Vol 45 (4) ◽  
pp. 435 ◽  
Author(s):  
J. L. Cooper
Keyword(s):  
Sewage Sludge ◽  
Soil Ph ◽  
New South ◽  
New South Wales ◽  
Acid Soils ◽  
Crop Growth ◽  
Growth And Yield ◽  
South Wales ◽  
Sludge Cake ◽  
Dewatered Sewage Sludge

Two forms of biosolids, with and without lime, were applied to acid soils at 2 sites in central New South Wales. Wheat and triticale were then grown on these sites to determine the effect of biosolids on crop growth and yield. The forms of biosolids used were dewatered sewage sludge cake, and N-Viro Soil which is a lime amended sewage sludge. Dewatered sewage sludge cake was applied at rates of 0, 6, 12 and 24 dry Mg/ha, and N-Viro soil at 0, 1.5, 3.0 and 4.5 dry Mg/ha. Biosolids produced grain yield increases of over 50% at both sites, with the largest yield increases at the highest rate of dewatered sewage sludge. Continued cropping at 1 of the sites showed that significant yield increases were still obtained 3 years after the initial application. The addition of lime and N-Viro Soil raised soil pH, and produced small but long lasting yield increases. However, the main benefit of biosolids seems to have come from the nutrients they supplied rather than changes in soil pH.

Erratic nodulation and nitrogen fixation in field-grown pigeonpea [Cajanus cajan (L.) Millsp.]

1991 ◽  
Vol 31 (5) ◽  
pp. 653 ◽  
Author(s):  
J Brockwell ◽  
JA Andrews ◽  
RR Gault ◽  
LG Gemell ◽  
GW Griffith ◽  
...  
Keyword(s):  
N2 Fixation ◽  
Cajanus Cajan ◽  
New South ◽  
Acid Soils ◽  
Grain Legume ◽  
Alkaline Soils ◽  
Naturally Occurring ◽  
South Wales ◽  
Series Of Experiments ◽  
Experimental Findings

Following numerous reports of nodulation failures in pigeonpea [Cajanus cajan (L.) Millsp.] crops in New South Wales, a series of experiments was conducted in glasshouses and at 6 locations in the field. When inoculated seed was grown in moist vermiculite or in sand beds in the glasshouse, pigeonpea nodulated, and fixed N2, normally; but at 3 sites in the field, we could detect neither nodulation nor N2 fixation, despite adequate inoculation or a population of suitable rhizobia in the soil. At another site there was only sporadic occurrence of effective nodules. Nitrogen was fixed at 2 of the 3 field sites on acid soils, but at 1 site it appeared that nodulation was due to a naturally occurring population of soil rhizobia and not to the inoculant. When comparisons were made, pigeonpea was invariably inferior to symbiotically related legumes, cowpea and adzuki bean, in nodulation and N2 fixation. This inferiority was associated with substantially poorer rhizobial colonisation of pigeonpea rhizospheres. The experimental findings confirmed the anecdotal evidence that pigeonpea is an erratically nodulating grain legume on neutral and alkaline soils.

An evaluation of eight soil phosphate extractants on acidic wheat growing soils

Soil Research ◽  
1985 ◽  
Vol 23 (4) ◽  
pp. 647 ◽  
Author(s):  
ICR Holford ◽  
BR Cullis
Keyword(s):  
Field Experiments ◽  
New South ◽  
New South Wales ◽  
Acid Soils ◽  
Critical Values ◽  
Alkaline Soils ◽  
Wheat Field ◽  
Extraction Procedures ◽  
Soil Phosphate ◽  
South Wales

In a study using earlier data from 44 wheat field experiments on acidic (pH < 5.6) soils in southern New South Wales, eight soil phosphate extractants (Bray,, Bray,, neutral fluoride, Mehlich, Truog, lactate, Olsen and Colwell) were evaluated and calibrated in terms of responsiveness (�) and response curvature (C) parameters derived from the Mitscherlich equation. All extraction procedures, except Colwell, had a standard shaking time of 30 min and so1ution:soil ratio of 50. The order of efficacy of the tests was different from that obtained on moderately acid to alkaline soils of central and northern New South Wales. Neutral fluoride and acidic sulfate (Truog) replaced lactate as the best extractant, followed by the double acid Mehlich extractant. The Colwell test was more effective on these very acid soils than on the more alkaline soils, being equal to Bray1 and greatly superior to Bray2 and Olsen. The critical values of the fluoride, Mehlich, Truog, lactate and Colwell tests were significantly lower than they were for more alkaline soils in central New South Wales. The changes in extraction procedures could explain the lower critical values of the lactate and Truog tests, but differences in the critical values of the other three tests were inconsistent with changes in extraction procedures. The results support the hypothesis that a different phosphate extractant is required on very acid soils from that required on moderately acid to alkaline soils.

Symbiotic characteristics of Rhizobium meliloti from the brown acid soils of the Macquarie region of New South Wales.

1961 ◽  
Vol 12 (4) ◽  
pp. 630 ◽  
Author(s):  
J Brockwell ◽  
FW Hely
Keyword(s):  
Rhizobium Meliloti ◽  
New South ◽  
New South Wales ◽  
Acid Soils ◽  
Nodule Formation ◽  
Seed Inoculation ◽  
South Wales ◽  
High Level ◽  
Bacterial Groups ◽  
Selection Of

Thirty-three isolates of Rhizobim meliloti were obtained from the brown acid soils of the Macquarie region of New South Wales and their symbiotic behaviour in association with 11 species of Merlicago and three species of Melilotus was investigated in the laboratory. In respect of nodule formation, there were two distinct types of Rhizobiurn and the hosts formed three groups. In respect of nitrogen fixation there were six strain types and seven host, groupings. These host and bacterial groups could be arranged in a series. Several of the strains of rhizobia, and one in particular, were found to fix a high level of nitrogen with a number of hosts, but, except for ;Medicago denticulata Willd. and Melilotus indica (L.) All. which behaved identically in all features of the symbiosis studied, no definit'e groupings on this criterion were apparent in either hosts or bacteria. The possible application of the results to the selection of strains of' Rhizobium meliloti suitable for seed inoculation is discussed.

Effect of soil pH on the distribution ofDanthoniaspecies on the tablelands of central and southern New South Wales

1996 ◽  
Vol 39 (4) ◽  
pp. 619-621 ◽  
Author(s):  
P. M. Dowling ◽  
D. L. Garden ◽  
D. A. Eddy ◽  
D. I. Pickering
Keyword(s):  
Soil Ph ◽  
New South ◽  
New South Wales ◽  
South Wales

The growth of improved pastures on acid soils. 1. The effect of superphosphate and lime on soil pH and on the establishment and growth of phalaris and lucerne

1985 ◽  
Vol 25 (1) ◽  
pp. 149 ◽  
Author(s):  
LJ Horsnell
Keyword(s):  
Soil Ph ◽  
New South ◽  
Acid Soils ◽  
Potassium Sulfate ◽  
First Year ◽  
Growth Responses ◽  
South Wales ◽  
Large Growth ◽  
Lime Application ◽  
Effect Of Surface

The response of improved pastures to the application of superphosphate is low on the acid sedimentary soils, of the Southern Tablelands of New South Wales, which contain high levels of exchangeable aluminium. An investigation was made into the effect of surface-applied fertilizers on soil pH and on the establishment and growth of lucerne and phalaris on these soils. At 6 weeks after the application of gypsum, superphosphate, or superphosphate plus potassium sulfate, soil pH (H2O) had decreased markedly. This effect extended to a depth of 20 cm, but decreased with time. Initially, lime application increased the pH of the surface soil only. When superphosphate was applied with lime the pH of the soil under the lime layer decreased to the same level as that found in the soil treated with superphosphate alone. Lime, however, had penetrated into the subsoil 102 weeks after application and substantially more so after 13 years. Soil pH (0.01 M CaCl2) was not depressed by the application of fertilizers. Growth and persistence of both species in the first summer were poor, but growth responses to phosphorus, lime and nitrogen increased after the first year. Lucerne showed large growth responses to lime, greater than those found on plots receiving nitrogen fertilizer. Lime reduced aluminium levels both in lucerne plants and in soil. It is suggested that the slow penetration of lime into the soil, the relatively quick effect of superphosphate in increasing subsoil acidity, and high soil aluminium levels are together responsible for the poor persistence and slow growth of both lucerne and phalaris in the early stages. The subsequent large dry matter responses of lucerne to lime are possibly related to increased nitrogen fixation and a lowering of plant and soil aluminium levels. It is suggested that the lime responses of phalaris are also related to lower aluminium levels.

Rhizobium as a factor in the re-establishment of legume-based pastures on clay soils of the wheat belt of north-western New South Wales

1998 ◽  
Vol 38 (6) ◽  
pp. 555 ◽  
Author(s):  
A. M. Bowman ◽  
D. M. Hebb ◽  
D. J. Munnich ◽  
J. Brockwell
Keyword(s):  
Nitrogen Fixation ◽  
Rhizobium Meliloti ◽  
New South ◽  
New South Wales ◽  
Clay Soils ◽  
Natural Fertility ◽  
Fixed Nitrogen ◽  
South Wales ◽  
Annual Medics ◽  
North Western

Summary. Populations of Rhizobium meliloti in self-mulching clay soils (Vertisols) at 48 sites on 27 properties in north-western New South Wales were classified according to number and ability to fix nitrogen with several species of Medicago. Rhizobia were counted using serial dilution, nodulation frequency, plant infection tests. Abilities of the soil populations to fix nitrogen were determined in the laboratory with whole-soil inoculation of Medicago seedlings in test tubes with shoots exposed to the atmosphere and roots within the tubes under bacteriological control, and in the field using a technique based on the natural abundance of 15N in the soil. The majority of soils contained >1000 cells of R. meliloti per gram. The major component of those populations fixed nitrogen with lucerne (Medicago sativa) and some components of some soils also fixed nitrogen with M. polymorpha, M. scutellata, M. littoralis, M. tornata, M. laciniata and Trigonella suavissima. However, a number of soils were located which contained few if any rhizobia effective in nitrogen fixation with M. polymorpha. Overall, the effectiveness of nitrogen fixation of the naturally occurring populations of R. meliloti in association with M. polymorpha, M. scutellata, M. littoralis and M. tornata was only 46% of the effectiveness of standard strains. At one particular site, where 10 lines of annual Medicago spp. were growing experimentally, fixed nitrogen as a proportion of shoot nitrogen averaged only 28%. At that site, there were no effective rhizobia for M. scutellata and it was wholly dependent on the soil as the source of its nitrogen. The results are discussed in relation to the need for a substantial input of legume nitrogen for restoring the natural fertility of self-mulching clay soils in degraded wheat lands of north-western New South Wales. It is suggested that lucerne, or perhaps other perennial Medicago spp., might fill this role better than annual medics such as M. polymorpha and M. scutellata that are more dependent than lucerne on specific strains of R. meliloti to meet their requirements for symbiotic nitrogen fixation.

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