Growth, Maintenance and Nitrogen Fixation of Nodulated Plants of Subterranean Clover (Trifolium subterraneum L.)

1979 ◽  
Vol 6 (2) ◽  
pp. 165 ◽  
Author(s):  
JH Silsbury
Keyword(s):  
Growth Rate ◽  
Nitrogen Fixation ◽  
Acetylene Reduction ◽  
Dry Matter ◽  
Accumulation Rate ◽  
Close Association ◽  
Co2 Exchange ◽  
Nitrogen Accumulation ◽  
Co2 Efflux ◽  
Fixation Rate

Plants were grown in a nitrogen-free medium in pots to form a closed canopy. Over a 50-day period, the net CO2 exchange of the pot was measured; nitrogen fixation was estimated by acetylene reduction assay; chemical analyses were performed; and dry matter was determined. Growth and maintenance requirements were estimated in terms of CO2. Dry matter growth rate was almost constant with time, the value half-way through the experiment agreeing with an estimate calculated from the daily CO2-exchange rate and 37.4% carbon in the biomass. Nitrogen accumulation rate was nearly constant. The total daytime CO2 influx for thirteen successive pots during the experiment was almost the same. By contrast, the total dark CO2 efflux increased with time. After partitioning into growth and maintenance components, the increase was due to increase in maintenance. The proportion of the dark efflux attributed to growth was constant with increase in biomass over the range 200-600 gm-2 but the maintenance coefficient may have decreased slightly over this range. Nitrogen fixation rate was constant during the growth period and reproducible between pots: 2.86 moles acetylene were concluded to be equivalent to each mole of nitrogen fixed. As CO2 efflux decreased to the maintenance level in a dark period longer than the usual 12 h, acetylene reduction decreased to near zero. This suggests a close association between growth rate and the rate of nitrogen fixation.

Effects of Irradiance and Solar Radiation on Dry Matter Growth and Net CO2 Exchange of Trifolium subterraneum L. Swards at a Constant Temperature

1977 ◽  
Vol 4 (4) ◽  
pp. 485 ◽  
Author(s):  
S Fukai ◽  
JH Silsbury
Keyword(s):  
Growth Rate ◽  
Solar Radiation ◽  
Exchange Rates ◽  
Dry Matter ◽  
Light Transmission ◽  
Dry Weight ◽  
Co2 Exchange ◽  
Crop Growth ◽  
Co2 Efflux ◽  
Crop Growth Rate

Small swards of subterranean clover were grown at 20°C at different times of the year and at the same time under shades of different light transmission. Dry matter production and net CO2 exchange rates at different levels of irradiance were measured during growth. Crop growth rates and net CO2 exchange rates are examined in relation to plant attributes and to the daily solar radiation. Dry matter growth curves varied according to the daily solar radiation. Increase in crop growth rate with increase in daily solar radiation was taken to be linear for swards with similar dry weight and was more rapid for closed canopies than for those not showing full light interception. Once a closed canopy was attained, further increase in total dry matter resulted in decreased crop growth rate due, apparently, to increased loss of dry weight through increased respiration rate. The shape of the CO2 exchange/irradiance curve was linear up to 100 W m-2 (PAR) and curvilinear above that value. The rate of net CO2 exchange at 50 W m-2 (PAR) decreased with increase in shoot dry matter above 100 g m-2 due, apparently, to an increased rate of dark CO2 efflux: the rate was not affected by daily solar radiation during growth. The net CO2 exchange rate at 250 W m-2 (PAR) increased with increase in LAI up to 3 after which it became almost constant, varying only with the variation in daily solar radiation during growth. The rate of dark CO2 efflux was strongly affected by the amount of dry matter present and to a smaller extent by the crop growth rate or the daily solar radiation.

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

1979 ◽  
Vol 25 (10) ◽  
pp. 1197-1200 ◽  
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.

scholarly journals BIOLOGICAL NITROGEN FIXATION STABILITY OF COWPEA CULTIVARS WITH TROPICAL SEMI-ARID RHIZOBIAL STRAINS

2021 ◽  
Vol 34 (2) ◽  
pp. 359-369
Author(s):  
AMANDA CORDEIRO DE MELO SOUZA ◽  
THIAGO PONTES LIRA ◽  
ANTONIO FÉLIX DA COSTA ◽  
FELIPE JOSÉ CURY FRACETTO ◽  
GISELLE GOMES MONTEIRO FRACETTO ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Biological Nitrogen Fixation ◽  
Dry Matter ◽  
Block Design ◽  
Nitrogen Accumulation ◽  
Arid Soils ◽  
Cowpea Cultivars ◽  
Nodule Number ◽  
Biological Nitrogen ◽  
Semi Arid

ABSTRACT Cowpeas (Vigna unguiculata L. Walp) are an economically and socially important legume in northern and north-eastern Brazil and can establish effective symbiosis with nitrogen-fixing bacteria. We evaluated the symbiotic compatibility and efficiency of rhizobial strains from Pernambuco semi-arid soils and determined their symbiotic stability on the IPA-206, BR 17-Gurguéia, and BRS Novaera cultivars, selected for different environments. The experiment was conducted in a greenhouse to evaluate a 3 × 28 factorial arrangement (cultivars selected for different environments × inoculation with the currently recommended strain, uninoculated plants with or without mineral nitrogen, and 25 rhizobial strains from semi-arid soils) in a randomized block design with four replicates. We determined nodule number, shoot and root dry matter, nodule dry matter by nodule number, nitrogen accumulated in the shoot by nodule dry matter, nitrogen content and accumulation in the shoot, relative efficiency of the recommended strain based on nitrogen accumulation, and shoot dry matter. Overall, the cultivars responded differently to different strains and cultivar biological nitrogen fixation potential. Strains G7.85 and BR 3262 showed potential for biological nitrogen fixation. BR 3262 was confirmed to be adequate for inoculation of different cowpea cultivars.

Effect of phosphate supply and competition from grasses on growth and nitrogen fixation of Medicago trunculata

1981 ◽  
Vol 32 (5) ◽  
pp. 761 ◽  
Author(s):  
ABK Dahmane ◽  
RD Graham
Keyword(s):  
Nitrogen Fixation ◽  
Nitrogen Content ◽  
Acetylene Reduction ◽  
Pure Culture ◽  
Dry Matter ◽  
Considerable Variability ◽  
Fixed Nitrogen ◽  
Intact Plants ◽  
Medicago Trunculata ◽  
Phosphate Supply

Medic plants and ryegrass were grown in small pots in a glasshouse in monoculture (six plants per pot) or in mixture (three plants of each species) at eight rates of phosphate application. After 10 weeks, the rate of nitrogen fixation was estimated by the acetylene reduction (AR) technique on the intact plants in soil, after which the plants were harvested, both shoots and roots. The yield of medic, in both monoculture and mixture, increased with increasing rate of phosphate application to an optimum at a level of 160 ppm phosphorus and then decreased again at higher phosphate levels. AR activity was similarly dependent on phosphate application and was optimal at the same phosphate level as was yield. AR activity was extremely low in the ryegrass monocultures, the yield of which was optimized at only 10 ppm phosphorus. The community x phosphate interaction on AR activity per plant of medic was not statistically significant, there being considerable variability in this measurement; the suppression of nitrogen fixation by competition from ryegrass near its own phosphate optimum was not therefore established in this study, but remains a possibility. Ryegrass plants benefited individually from growing in mixed culture with the legume, producing as much shoot dry matter from three plants in mixture as from six in monoculture. The advantage in mixture was due either to reduced competition offered by medic or to transfer of fixed nitrogen from legume to grass. Higher concentrations and contents of nitrogen per plant in mixture provided circumstantial evidence for the latter. However, on a pot basis, nitrogen content of ryegrass was similar in pure culture and in mixture. The relevance of the data to the results of a survey of farmers' fields is discussed.

Nodule biomass and acetylene reduction rates of red alder and Sitka alder on Vancouver Island, B.C.

1981 ◽  
Vol 11 (2) ◽  
pp. 282-287 ◽  
Author(s):  
Dan Binkley
Keyword(s):  
Nitrogen Fixation ◽  
Acetylene Reduction ◽  
Reduction Rate ◽  
Vancouver Island ◽  
Fixation Rate ◽  
Red Alder ◽  
Nodule Biomass ◽  
Closed Canopy ◽  
Management Alternative ◽  
Acetylene Reduction Rate

Three comparisons examined acetylene reduction rate and nodule biomass of red alder (Alnusrubra Bong.) and Sitka alder (Alnussinuata (Regel) Rydb.) on Vancouver Island, British Columbia. The first showed that the acetylene reduction rates of Sitka alder on four sites in early July 1979 varied from 8.8 to 22.0 μmol C2H2•g−1 dry nodule per hour; smaller nodules had the higher rates. In the second comparison, red alder and Sitka alder acetylene reduction rates for young plants were similar when assayed on the same day on the same site. Finally, acetylene reduction rates and nodule biomass were determined for both species growing in closed canopy stands on adjacent sites. In this pair of 20-year-old stands, red alder had double the acetylene reduction rate and three times the nodule biomass of the Sitka alder. Combining the nodule biomass estimates with the seasonal average reduction rates yielded current annual nitrogen fixation estimates (using C2H2) of 130 kg•ha−1•year−1 for the red alder plot and 20 kg•ha−1•year−1 for the Sitka alder plot. These estimates are within published ranges for the species. The lower fixation rate of Sitka alder is still substantial, relative to the nitrogen demands of conifers, and its shrub-like growth form makes it an attractive management alternative to red alder for biological nitrogen fixation in mixed conifer–alder plantations.

scholarly journals Nitrate levels and stages of growth in hypernodulating mutants of Lupinus albus. I. N2 fixation potential

1999 ◽  
Vol 30 (2) ◽  
pp. 91-97
Author(s):  
Hélio Almeida Burity ◽  
Manuel Chamber-Perez ◽  
Maria do Carmo Catanho Pereira de Lyra ◽  
Márcia do Vale Barreto Figueiredo
Keyword(s):  
Nitrogen Fixation ◽  
N2 Fixation ◽  
Dry Matter ◽  
Lupinus Albus ◽  
Growth Stages ◽  
Nitrate Level ◽  
Fixation Rate ◽  
Stages Of Growth ◽  
L 62 ◽  
Hypernodulating Mutants

This work aimed to evaluate physiological parameters, nodulation response and N2 fixation rate in mutants of Lupinus albus in comparison with the standard Multolupa cultivar. Two nitrate levels (0 and 5mM) and two evaluation periods (7 and 10 weeks) were used. Significant differences were observed among genotypes, in relation to fresh nodule weight, nitrate levels and growth stages. The overall average for nitrate level differed between them where 5mM severely inhibited the number of nodules, reaching a 49.5% reduction in relation to treatment without nitrate. There were no behaviour differences among genotypes, nor among evaluation periods. Although the level of nitrate did not influence the production of shoot dry matter in relation to the average among levels applied, the L-135 genotype, being an inefficient mutant, reached very low values. There were no significant differences in electron allocation coefficient (EAC) among nitrate levels, nor among genotypes studied. However, the evaluation periods revealed differences, where the EAC for the seventh week had a higher value than that for the tenth week, when a 5mM aplication was evaluated. The N2 fixation rate (N2 FIX) showed the existence of the nitrate interference in fixation, given that the application of 5mM severely reduced. However, there were no differences among the genotypes and it was noted that the fixation rate was much higher in those that received nitrate. The L-88 and L-62 genotypes were the ones that have shown best adaptability in this experiment, thus being able to be recommended for new studies with higher nitrate levels and different evaluation periods. The nitrate (5mM) interferes in the nitrogen fixation rate, given that all the genotypes were affected by the level applied.

The field pea crop in S.W. Australia. I. Patterns of growth, biomass production and photosynthetic performance in genotypes of contrasting morphology

1994 ◽  
Vol 45 (7) ◽  
pp. 1347 ◽  
Author(s):  
EL Armstrong ◽  
JS Pate
Keyword(s):  
Growth Rate ◽  
Dry Matter ◽  
Co2 Exchange ◽  
Photosynthetic Performance ◽  
Dry Matter Accumulation ◽  
Assimilation Rate ◽  
Area Index ◽  
Green Area ◽  
Co2 Exchange Rate ◽  
Net Assimilation

Biological yield and photosynthetic performance of six field pea genotypes of contrasting foliar morphology and growth habit were studied in a water-limited field environment at Wongan Hills, Western Australia. Dundale and Wirrega were tall, indeterminate, scrambling and conventionally leaved; Dinkum, L82 and L80 (semi-leafless) and Progreta (tare-leaved) were semi-dwarf and more erect. Green area index (green leaf area per unit of ground area), green area duration (time integral of green area), crop growth rate (rate of dry matter accumulation per unit ground area) during early spring, net photosynthetic rate (CO2 exchange rate per unit green area or unit green weight) and net assimilation rate (rate of dry matter accumulation per unit green area) all influenced crop productivity. Shoot and root biomass was highest in Wirrega, due mainly to superior green area index, extended green area duration and maintenance of high growth rate during pod fill. Inverse relationships amongst genotypes were evident between green area index and net assimilation rate, and between green area index and CO2 exchange rate of green area. Total net photosynthesis of the tendrils of semi-leafless types was similar to that of leaflets of conventional types, due mainly to larger biomass of tendrils compensating for poor photosynthetic rates. The poor growth of semi-leafless and tare-leaved types was attributed to lower vigour, green area, ground cover and photosynthate production. Future selection of such types for water-limited environments should concentrate on increasing shoot height, node number per plant, stipule and tendril size and photosynthetic efficiency of green area.

The effects of combined nitrogen on growth, nodulation, and nitrogen fixation of black locust seedlings

1983 ◽  
Vol 13 (6) ◽  
pp. 1251-1254 ◽  
Author(s):  
Dane R. Roberts ◽  
Richard W. Zimmerman ◽  
Jeff W. Stringer ◽  
Stanley B. Carpenter
Keyword(s):  
Growth Rate ◽  
Nitrogen Fixation ◽  
Black Locust ◽  
Nitrogen Deficiency ◽  
Biomass Accumulation ◽  
Leaf Nitrogen ◽  
Sand Culture ◽  
Leaf Nitrogen Content ◽  
Fixation Rate ◽  
Relative Growth

Black locust (Robiniapseudoacacia L.) seedlings grown for 50 days in sand culture with 5 mM NH4NO3-supplemented nutrient solution had 74% lower nitrogen-fixation rates (acetylene reduction) than seedlings grown without nitrogen. Nodule activity was not affected by treatment, and differences in nitrogen fixation between treatments reflected decreased nodulation in seedlings grown with NH4NO3. Relative growth rate was approximately 3 times greater in seedlings supplied with NH4NO3, indicating maximum biomass accumulation cannot be supported by nitrogen fixation alone. Growth was positively correlated with the nitrogen-fixation rate in seedlings grown without nitrogen, but this correlation was not found in NH4NO3-treated seedlings. Leaf nitrogen content was less for seedlings grown in the nitrogen-free sand culture and observations suggested that a nitrogen deficiency in these seedlings restricted their growth.

Grain yield, dry matter, and nitrogen accumulation in the grains of durum wheat and spring triticale cultivars grown in a Mediterranean environment

2005 ◽  
Vol 56 (1) ◽  
pp. 25 ◽  
Author(s):  
Francesco Giunta ◽  
Rosella Motzo
Keyword(s):  
Grain Yield ◽  
Durum Wheat ◽  
Dry Matter ◽  
Accumulation Rate ◽  
Grain Filling ◽  
Grain Weight ◽  
Nitrogen Accumulation ◽  
N Accumulation ◽  
Unit Surface ◽  
Lower Protein

Comparisons among species can be a valuable approach to identifying traits important for plant breeding. Differences between 2 durum wheat (Duilio and Creso) and 1 triticale (Antares) cultivar have been analysed in a 2-year field trial in Sardinia (Italy), in order to define a more productive durum wheat ideotype for Mediterranean-type environments. The greater grain yield (569 v. 447 g/m2) and the lower protein percentage (9.2 v. 10.6%) of triticale cv. Antares compared with the durum wheat cultivars, at a similar level of biomass produced at heading, were analysed in terms of number of grains per unit surface and rate and duration of dry matter (DM) and nitrogen (N) accumulation, calculated from a logistic curve. When the single grains were considered, Antares showed a lower rate but a longer duration of DM and N accumulation in the more favourable season, resulting in lower DM (40 v. 54 mg) and N (0.7 v. 1.0 mg) contents in the grain. On the other hand, when data were expressed on a per unit surface basis, the greater spike fertility of Antares (53 v. 39 grains per spike) and its longer duration of accumulation, were responsible for similar or even greater amounts of DM and N accumulated in the grains per m2. Growth rate of single grains, although able to explain differences in single grain weight, cannot explain differences in grain weight per m2 and hence in yield, which mainly result from variation in the number of grains per spike. Nitrogen percentage of the grains decreased from the maximum values observed at the beginning of grain filling, until a constant final value attained before the end of DM and N accumulation. Rate is more important than duration in determining the quality characteristics of grains, as higher grain weights and protein percentages correspond to higher rates of DM and N accumulation.

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