A survey of nitrogen fixation (acetylene reduction) associated with Typha in Minnesota

The acetylene-reduction technique was used on soil–root cores to examine the three species of Typha (Typhaceae) found in Minnesota for differences in rates of nitrogen fixation by associated rhizosphere diazotrophs. In 20 cattail stands sampled in 1985, Typha angustifolia showed a tendency for lower acetylene-reduction activity per ramet, with an average of 2.9 μmol∙ramer−1∙d−1, than T. latifolia and T. ×glauca, with averages of 6.5 and 7.1 μmol∙ramet−1∙d−', respectively. Regression analysis showed no significant differences in these values due to the variability within as well as between stands, and fixation rates were uncorrelated with the pH, soil percent carbon, and soil moisture of the study stands. In 1986, in situ assays of soil–root cores of ramets of T. angustifolia and T. latifolia from adjacent monospecific stands produced average acetylene-reduction rates of 1.4 for T. angustifolia and 1.8 μmol∙ramet−1∙d−1 for T. latifolia, with a substantial reduction in variability within stands over the 1985 data. It is estimated that, contrary to previously published reports, populations of Typha may receive as little as 1–2% of their annual nitrogen requirement from nitrogen fixation.

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A survey of angiosperms in Nova Scotia for rhizosphere nitrogenase (acetylene-reduction) activity

Canadian Journal of Botany ◽

10.1139/b78-266 ◽

1978 ◽

Vol 56 (18) ◽

pp. 2218-2223 ◽

Cited By ~ 9

Author(s):

D. Smith ◽

D. G. Patriquin

Keyword(s):

Nova Scotia ◽

Acetylene Reduction ◽

Nitrogenase Activity ◽

Reduction Technique ◽

Acetylene Reduction Activity ◽

Forage Grasses ◽

Reduction Activity ◽

Tropical Forage ◽

Poorly Drained Soils

Excised root samples from 901 plants, representing 130 species of nonnodulated angiosperms largely in upland, pioneering habitats, were assayed for nitrogenase activity by the acetylene-reduction technique after overnight preincubation of the samples under low pO2. Most samples and most species exhibited very low excised root acetylene-reducing activities, but for 19 species, maximum values were greater than 50 nmol C2H4∙g−1∙h−1. In situ C2H2 assays, conducted on 10 species which had exhibited maximum excised root activities greater than 10 nmol C2H4∙g−1∙h−1, indicated average belowground N2-fixation rates of 3 to 92 g N∙ha−1∙day−1 and maxima greater than 100 g N∙ha−1∙day−1 for 3 of the 10 species. The highest values were for grasses characteristic of poorly drained soils and for some dicotyledonous weeds. It is concluded that the potential of temperate-zone angiosperms for nitrogenase activity by 'associative symbioses' approaches that of tropical forage grasses.

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Nitrogen fixation associated with 'Park' Kentucky bluegrass (Poapratensis L.)

Canadian Journal of Microbiology ◽

10.1139/m79-186 ◽

1979 ◽

Vol 25 (10) ◽

pp. 1197-1200 ◽

Cited By ~ 8

Author(s):

R. C. Shearman ◽

W. L. Pedersen ◽

R. V. Klucas ◽

E. J. Kinbacher

Keyword(s):

Nitrogen Fixation ◽

Acetylene Reduction ◽

Poa Pratensis ◽

Kentucky Bluegrass ◽

Acetylene Reduction Activity ◽

Controlled Environment ◽

Nitrogen Accumulation ◽

Reduction Activity ◽

Significant Difference ◽

Reduction Assay

Associative nitrogen fixation in Kentucky bluegrass (Poa pratensis L.) turfs inoculated with five nitrogen-fixing bacterial isolates was evaluated using the acetylene reduction assay and nitrogen accumulation as indicators of fixation. 'Park' and 'Nugget' Kentucky bluegrass turfs were grown in controlled environment chambers and inoculated with Klebsiella pneumoniae (W-2, W-6, and W-14), Erwinia herbicola (W-8), and Enterobacter cloacae (W-11). 'Park' inoculated with K. pneumoniae (W-6) had significant acetylene reduction activity using undisturbed turfs. Other treatments including turfs treated with heat-killed cells had no significant difference in acetylene reduction. In a second study, 'Park' and 'South Dakota Certified' turfs were grown in a greenhouse and inoculated with K. pneumoniae (W-6) and E. herbicola (W-8). 'Park' inoculated with K. pneumoniae (W-6) had increased acetylene reduction activity rates and also a greater nitrogen accumulation in aerial tissues when compared to controls. Acetylene reduction activity was correlated (r = 0.92) to nitrogen accumulation. Other treatments did not effectively increase acetylene reduction activity or nitrogen accumulation.

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IN SITU NITROGEN FIXATION BY WHITE CLOVER IN MIXED SWARDS IN NOVA SCOTIA

Canadian Journal of Plant Science ◽

10.4141/cjps84-087 ◽

1984 ◽

Vol 64 (3) ◽

pp. 625-636 ◽

Cited By ~ 3

Author(s):

J. K. VESSEY ◽

D. G. PATRIQUIN

Keyword(s):

Nitrogen Fixation ◽

White Clover ◽

Management Strategy ◽

Acetylene Reduction Activity ◽

Total Rainfall ◽

Reduction Activity ◽

Main Factors ◽

Low Levels ◽

A Site

At three sites, clover cover increased from less than 10% in April to 50–70% during anthesis in July. It began to decline in September, reaching 20–30% in December. Acetylene-reduction activity (ARA), measured by an in situ technique, commenced in April when soil temperature was 5–7 °C. "Clover-specific ARA" (ARA measured in clover patches where cover of clover was 100%) was generally high through most of May, June and July, and then declined, reaching low levels by November. Clover-specific ARA was correlated with total rainfall during the period between 7 and 28 days before the assay (r = 0.720, P < 0.01). The amount of N2 fixed by white clover over a 1-yr period was estimated at 66 and 81 kg N/ha for two pasture sites and 100 kg N/ha at a lawn site. Clover cover and thermal regime appeared to be the two main factors influencing the amount of N2 fixed by white clover at a site. Eight sites of widely varying clover cover (2–53%) were compared in July with regard to cover, clover-specific ARA, edaphic characteristics and fertilizer and grazing management. Management strategy appeared to have the greatest influence on clover abundance in pasture.Key words: White clover, Trifolium repens, nitrogen fixation

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Nitrogen fixation activity by white clover pastures during flood irrigation cycles

Australian Journal of Agricultural Research ◽

10.1071/ar9880409 ◽

1988 ◽

Vol 39 (3) ◽

pp. 409 ◽

Cited By ~ 1

Author(s):

GN Mundy ◽

HR Jones ◽

WK Mason

Keyword(s):

Nitrogen Fixation ◽

Water Stress ◽

White Clover ◽

Nitrogen Fertilizer ◽

Ethylene Production ◽

Acetylene Reduction ◽

Acetylene Reduction Activity ◽

Flood Irrigation ◽

Reduction Activity ◽

Nitrogen Fixation Activity

The effect of flood irrigation on clover nitrogen fixation (acetylene reduction activity) was investigated in unfertilized pastures and pastures fertilized with 100 kg N/ha as NH4N03. During the experiment acetylene reduction activities were monitored between successive flood irrigations. The rate of ethylene production increased with decreasing soil water content, peaking 13 days after irrigation. Measured nodule activity then declined, possibly owing to water stress. Nitrogen fertilizer reduced acetylene reduction activities to about half that of the unfertilized pastures. For most of the irrigation cycle acetylene reduction by the pasture was below the measured maximum.

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Biological nitrogen fixation (acetylene reduction) associated with blue-green algal (cyanobacterial) communities in the Beachwood Mangrove Nature Reserve II. Seasonal variation in acetylene reduction activity

South African Journal of Botany ◽

10.1016/s0254-6299(16)30767-0 ◽

1993 ◽

Vol 59 (1) ◽

pp. 1-8 ◽

Cited By ~ 8

Author(s):

Fiona D. Mann ◽

T.D. Steinke

Keyword(s):

Nitrogen Fixation ◽

Seasonal Variation ◽

Acetylene Reduction ◽

Biological Nitrogen Fixation ◽

Nature Reserve ◽

Acetylene Reduction Activity ◽

Reduction Activity ◽

Green Algal ◽

Biological Nitrogen

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Nitrogen fixation by naturally occurring duckweed–cyanobacterial associations

Canadian Journal of Microbiology ◽

10.1139/m85-062 ◽

1985 ◽

Vol 31 (4) ◽

pp. 327-330 ◽

Cited By ~ 19

Author(s):

Tran Phuoc Duong ◽

James M. Tiedje

Keyword(s):

Nitrogen Fixation ◽

Annual Cycle ◽

Acetylene Reduction ◽

Acetylene Reduction Activity ◽

Lower Epidermis ◽

Reduction Activity ◽

Naturally Occurring ◽

Favorable Environment ◽

Nitrogen Inputs

Nitrogen fixation as measured by acetylene conversion to ethylene was found to be common for duckweed blooms on ponds, lakes, and streams in Michigan. Twenty-six of 29 sites with duckweed sampled over a 2-year period showed acetylene reduction activity (ARA). These activities corresponded to N inputs of 3.7–7.5 kg N∙ha−1 per annual cycle for typical blooms but dense Lemna trisulca blooms could be 10 times greater. The ARA was stimulated five- to six-fold by light, was not removed when plants were shaken in water, and was usually associated with the leaves and not the roots. Colonies of heterocyst-bearing cyanobacteria of the genera Nostoc, Gloeotrichia, Anabaena, Calothrix, and Cylindrospermum were observed attached to the lower epidermis or in the reproductive pockets of leaves of Spirodela and Lemna plants but not on Wolffia plants. The ARA correlated reasonably well with the density of cyanobacterial colonies observed. The duckweed appeared to provide a more favorable environment for the cyanobacteria which should result in enhanced nitrogen inputs to aquatic and sediment environments harboring duckweed. The N2 fixation was not sufficient, however, to meet all the nitrogen needs of the duckweed bloom.

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