scholarly journals Effect of wood ash and crushed rock soil amendments on red clover growth and dinitrogen fixation

2017 ◽  
Vol 26 (4) ◽  
Author(s):  
A Sigrun Dahlin ◽  
Maria Stenberg
Keyword(s):  
N2 Fixation ◽  
Soil Amendment ◽  
Red Clover ◽  
Wood Ash ◽  
Dinitrogen Fixation ◽  
15N Natural Abundance ◽  
Low Fertility ◽  
Crushed Rock ◽  
Chemical Analyses ◽  
Soil N Pools

The fertiliser effect of adding wood ash or crushed rock to a low-fertility soil, compared with an unamended control, was assessed in a pot experiment with a perennial ryegrass-red clover mixture. Dinitrogen (N2) fixation by the clover and translocation of fixed N to the grass were determined using 15N natural abundance. The wood ash produced the highest accumulated clover biomass over two cuts, followed by the crushed rock. Chemical analyses suggested that the increase was due to K supply by the amendments. The wood ash also led to larger amounts of fixed N compared with the control. However, N2 fixation was not increased as much as biomass amount, leading to dilution of plant N. There were minor or no treatment effects on mineralisation from soil N pools. This indicates that good-quality wood ash can be successfully used as a multi-element soil amendment to enhance clover growth on low-fertility soils.

scholarly journals Evidence for efficient regenerated production and dinitrogen fixation in nitrogen-deficient waters of the South Pacific Ocean: impact on new and export production estimates

2008 ◽  
Vol 5 (2) ◽  
pp. 323-338 ◽  
Author(s):  
P. Raimbault ◽  
N. Garcia
Keyword(s):  
Pacific Ocean ◽  
Nitrogen Uptake ◽  
N2 Fixation ◽  
Inorganic Nitrogen ◽  
South Pacific ◽  
Dinitrogen Fixation ◽  
The South ◽  
New Production ◽  
Marquesas Islands ◽  
South Pacific Ocean

Abstract. One of the major objectives of the BIOSOPE cruise, carried out on the R/V Atalante from October-November 2004 in the South Pacific Ocean, was to establish productivity rates along a zonal section traversing the oligotrophic South Pacific Gyre (SPG). These results were then compared to measurements obtained from the nutrient – replete waters in the Chilean upwelling and around the Marquesas Islands. A dual 13C/15N isotope technique was used to estimate the carbon fixation rates, inorganic nitrogen uptake (including dinitrogen fixation), ammonium (NH4) and nitrate (NO3) regeneration and release of dissolved organic nitrogen (DON). The SPG exhibited the lowest primary production rates (0.15 g C m−2 d−1), while rates were 7 to 20 times higher around the Marquesas Islands and in the Chilean upwelling, respectively. In the very low productive area of the SPG, most of the primary production was sustained by active regeneration processes that fuelled up to 95% of the biological nitrogen demand. Nitrification was active in the surface layer and often balanced the biological demand for nitrate, especially in the SPG. The percentage of nitrogen released as DON represented a large proportion of the inorganic nitrogen uptake (13–15% in average), reaching 26–41% in the SPG, where DON production played a major role in nitrogen cycling. Dinitrogen fixation was detectable over the whole study area; even in the Chilean upwelling, where rates as high as 3 nmoles l−1 d−1 were measured. In these nutrient-replete waters new production was very high (0.69±0.49 g C m−2 d−1) and essentially sustained by nitrate levels. In the SPG, dinitrogen fixation, although occurring at much lower daily rates (≈1–2 nmoles l−1 d−1), sustained up to 100% of the new production (0.008±0.007 g C m−2 d−1) which was two orders of magnitude lower than that measured in the upwelling. The annual N2-fixation of the South Pacific is estimated to 21×1012g, of which 1.34×1012g is for the SPG only. Even if our "snapshot" estimates of N2-fixation rates were lower than that expected from a recent ocean circulation model, these data confirm that the N-deficiency South Pacific Ocean would provide an ideal ecological niche for the proliferation of N2-fixers which are not yet identified.

scholarly journals The Comparative Effects of the Micro- and Macrosporogenesis of the Red Clover with Different Levels of Ploidy, in Relation with its Fertility

2011 ◽  
Vol 68 (1) ◽  
Author(s):  
Marioara GREBENISAN ◽  
Mircea SAVATTI
Keyword(s):  
Sexual Differentiation ◽  
Structural Modification ◽  
Red Clover ◽  
Bumble Bees ◽  
Low Fertility ◽  
Pollen Dispersion ◽  
Pollination Mechanisms ◽  
S Alleles ◽  
Clover Seed ◽  
Different Levels

. In this paper the di- and tetraploid red clover seedlings will be compared, under the aspects of micro and macrosporogenesys regarding his fertility. After a vast amount of research, the results obtained were that, often, the low seed yield in di- and tetraploid red clover is caused by fertility perturbance.One of the purpose of the experiments during the years 2004-2006, was to determine the low fertility effects and to offer important clues about di- and tetraploid red clover seed production. Red clover is a typical allogamous plant in which the autincompatibility system determined by the S alleles is very strong. The pollination is compulsorily done by honey and bumble bees, so the pollination mechanisms are being considerate as carrier of sexual differentiation, marked by microsporogenesys and macrosporogenesys, structural modification of flowers, pollen dispersion ecology and structural and physiological barriers as a reaction to fecundation process.

Nitrogen fixation by irrigated lucerne during the first three years after establishment

1995 ◽  
Vol 46 (7) ◽  
pp. 1401 ◽  
Author(s):  
RR Gault ◽  
MB Peoples ◽  
GL Turner ◽  
DM Lilley ◽  
J Brockwell ◽  
...  
Keyword(s):  
Soil Nitrogen ◽  
N2 Fixation ◽  
Dry Matter ◽  
Growing Season ◽  
15N Natural Abundance ◽  
Natural Abundance ◽  
Dry Matter Production ◽  
Available Phosphorus ◽  
The Third ◽  
Matter Production

Nodulation, N2 fixation (estimated by 15N natural abundance methods) and dry matter production were studied in a lucerne (Medicago sativa) crop managed for hay production at Ginninderra Experiment Station, A.C .T. Measurements were taken in the year of establishment and during two subsequent growing seasons. There were three treatments: (1) no inoculation and no annual fertilizer applied, (2) initial inoculation and superphosphate applied annually, (3) no inoculation, superphosphate applied annually and ammonium sulfate periodically. Before planting and after each growth season, soil was analysed for extractable mineral nitrogen, total nitrogen and the 15N natural abundance of this nitrogen, to the depth explored by lucerne roots. Before planting, no appropriate root-nodule bacteria (Rhizobium meliloti) were detected in the soil and initially plants were nodulated only in the inoculated treatment. Thereafter nodulation increased on the other treatments. Eight months after sowing there were no differences between treatments in numbers of R. meliloti g-l soil or in nodulation. In the third growing season, almost 30 kg ha-1 (dry wt) of nodules were recovered to a depth of 25 cm. These nodules were primarily located on fine, ephemeral roots and many appeared to be renewed after cutting of the lucerne. In the year of establishment, dry matter yields (0% moisture) totalled 3 to 4 t ha-1 in three hay cuts. In succeeding years, total yields were in the range 10 to 13 t ha-1 in four or five cuts per season. Nitrogen removed in the harvested lucerne reached 340 to 410 kg N ha-lyr-l in the second and third years and between 65 and 96% of this N arose from N2 fixation, depending on the method of calculation used. Poorer dry matter production and N2 fixation in treatment 1 in the third growing season was attributed to an insufficient supply of available phosphorus. Fixed N removed in Lucerne hay from treatment 2 totalled at least 640 kg N ha-1 in the three years of the experiment. Also, there were substantial increases in soil nitrogen due to lucerne growth. Although soil compaction made the quantification difficult, at the end of the experiment it was estimated that there was at least an extra 800 kg N ha-1 in the total soil nitrogen under lucerne compared to strips of Phalaris aquatica grown between the lucerne plots. It was concluded that lucerne contributed at least the same amount of fixed nitrogen to the soil as was being removed in the harvested hay.

Étude de l'influence des réserves azotées dans l'estimation par 15N de la fixation symbiotique d'une plante pérenne, Trifolium pratense

1985 ◽  
Vol 63 (6) ◽  
pp. 991-994
Author(s):  
Chantal Lescure ◽  
Alain Chalamet
Keyword(s):  
Trifolium Pratense ◽  
Control Plant ◽  
Red Clover ◽  
Good Control ◽  
Dinitrogen Fixation ◽  
Dilution Technique ◽  
Trifolium Pratense L ◽  
Perennial Legumes ◽  
Kinetics Of

A 15N dilution technique is proposed to determine the role of nitrogen reserves in the plant on the estimation of dinitrogen fixation, during regrowth of perennial legumes. It is based on labelling of nitrogen compartments of the plant. Since the kinetics of utilization of nitrogen reserves of ryegrass (Lolium italicum L.) and red clover (Trifolium pratense L.) appear similar, ryegrass would be a good control plant. Despite this observation, the comparison of two methods (based on two or three sources of nitrogen) to estimate dinitrogen fixation shows the difficulty in applying the technique using 15N-labelled substrate over earlier periods of regrowth. In this case, the 15N method described for determining symbiotic dinitrogen fixation could be applied in controlled conditions.

Nitrogen fixation in chickpea. II. Comparison of 15N enrichment and 15N natural abundance methods for estimating nitrogen fixation

1995 ◽  
Vol 46 (1) ◽  
pp. 225 ◽  
Author(s):  
JA Doughton ◽  
PG Saffigna ◽  
I Vallis ◽  
RJ Mayer
Keyword(s):  
Nitrogen Fixation ◽  
N2 Fixation ◽  
Full Range ◽  
15N Natural Abundance ◽  
Natural Abundance ◽  
Enrichment Method ◽  
Mineral N ◽  
Crop Establishment ◽  
15N Enrichment ◽  
15N Natural Abundance Method

The 15N enrichment and 15N natural abundance methods for estimating N2 fixation in chickpea were compared over a range of soil NO3-N levels at crop establishment varying from 10 to 326 kg N/ha (0-120 cm depth). Barley was used as a non-N2 fixing control crop. Both methods estimated reduced N2 fixation as soil NO3-N levels at crop establishment increased. Similar estimates of % N2 fixation were obtained at high values, but at low values the enrichment method gave lower estimates, some of which were negative. The 15N natural abundance method provided realistic estimates of % N2 fixation across all soil N03-N levels at crop establishment. An asymptotic curve described a close ( R2 = 0.95) relationship between these factors. Standard errors of estimates of means for the 15N natural abundance method remained acceptable and relatively stable over the full range of measurements; however, with the 15N enrichment method they became unacceptably large at low values of % N2 fixation. These large errors may have been partly due to legume and control plants assimilating mineral N of differing 15N enrichment. High mineral N levels associated with low values of % N2 fixation were also shown to reduce reliability of N2 fixation values estimated by the 15N enrichment method. These errors caused potentially greater inaccuracy at low values of % N2 fixation than at high values. To compare N2 fixation means statistically, transformations were necessary to stabilize variance and to impart lower weightings to plots with low values of % N2 fixation.

Soil microbial response to wood ash or lime applied to annual crops and perennial grass in an acid soil of northwestern Alberta

2009 ◽  
Vol 89 (2) ◽  
pp. 169-177 ◽  
Author(s):  
N Z Lupwayi ◽  
M A Arshad ◽  
R H Azooz ◽  
Y K Soon
Keyword(s):  
Microbial Biomass ◽  
Functional Diversity ◽  
Soil Amendment ◽  
Soil Acidity ◽  
Acid Soils ◽  
Wood Ash ◽  
Bulk Soil ◽  
C Mineralization ◽  
Soil Microbial ◽  
Annual Crops

More than 90% of acid soils in western Canada are in Alberta, yet the use of agricultural lime is limited because it is expensive. Wood ash, a by-product of pulp and lumber mills, can be used for liming acid soils. We investigated the effects of amending an acid Luvisol with wood ash or lime on soil microbiological properties at Beaverlodge, Alberta. Both soil amendments were applied at a calcium carbonate rate of 6.72 t ha-1, which was 8.40 t ha-1 for wood ash and 7.47 t ha-1 for lime, in 2002. Soil microbial biomass C (MBC) and the functional diversity and community structures of soil bacteria (indicated by substrate utilization patterns) were measured from 2002 to 2005 under barley (Hordeum vulgare L.), canola (Brassica napus L.), field pea (Pisum sativum L.), and timothy grass (Phleum pratense L.). In the rhizosphere, wood ash increased soil MBC between 2.4-fold in 2002 and 1.3-fold in 2005, and lime increased MBC from 3.2-fold in 2002 to 1.3-fold in 2005. In bulk soil, the increases in MBC ranged from 3.0-fold in 2003 to 1.8-fold in 2005 for wood ash, and from 4.9-fold in 2002 to 2.0-fold in 2005 for lime. Crop effects on MBC were not consistent. Because annual crops were grown in rotation, it is possible that the results obtained in one crop were confounded by effects of the preceding crop. In 2003 and 2004, both amendments increased Shannon index (H’) of bacterial functional diversity in the rhizosphere, and similar results were observed in 2005 in bulk soil. Shifts in the functional structure of bacterial communities due to soil amendment were observed in bulk soil, and shifts due to crop effects were observed in the rhizosphere. In 2003, the average soil pH(CaCl2) increased from 4.91 in control treatments of different crops to 6.60 in lime-amended plots and 6.70 in wood ash-amended plots. In 2004, both wood ash and lime significantly increased soil C mineralization (up to 10 d incubation), but basal respiration (11-24 d incubation) was not affected. The large effect (up to about fivefold) of soil amendments on MBC implies that soil acidity is a major limiting factor for biological processes and the productivity of some Luvisolic soils in Alberta. Wood ash could be used to alleviate these limitations. Key words: C mineralization, microbial diversity, microbial biomass, soil amendment, soil acidity

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