Annual nitrogen fixation in grazed dairy pastures in south-western Victoria

1999 ◽  
Vol 50 (2) ◽  
pp. 273 ◽  
Author(s):  
Penny A. Riffkin ◽  
Paul E. Quigley ◽  
Fiona J. Cameron ◽  
Mark B. Peoples ◽  
Janice E. Thies
Keyword(s):  
Nitrogen Fixation ◽  
White Clover ◽  
Dry Matter ◽  
Experimental Studies ◽  
15N Natural Abundance ◽  
N Fixation ◽  
Botanical Composition ◽  
Fixed Nitrogen ◽  
Western Victoria ◽  
On Farm

Amounts of biologically fixed nitrogen (kg N/ha) were determined in grazed dairy pastures in 3 different areas of south-western Victoria over 12 months between October 1995 and 1996 using measurements of pasture growth, botanical composition, and the 15N natural abundance of white clover (Trifolium repens) and non-legume components. Estimates of the amounts of N fixed, based on N in clover shoots, were similar in each pasture (11, 16, and 18 kg N/ha.year), despite different environmental and management conditions. These on-farm determinations were low compared with experimental studies on N fixation by white clover undertaken in New Zealand (224–291 kg N/ha.year) and elsewhere in Australia (44–135 kg N/ha). Low fixation levels were attributed to low pasture yields (average 8.2 t dry matter (DM)/ha.year) and poor legume content in the swards (average 8%). Despite this, most of the white clover N was derived from atmospheric N2 (65%), and therefore, N fixation could potentially be playing an important role in the N economy of milk production on these farms.

Factors associated with biological nitrogen fixation in dairy pastures in south-western Victoria

1999 ◽  
Vol 50 (2) ◽  
pp. 261 ◽  
Author(s):  
Penny A. Riffkin ◽  
Paul E. Quigley ◽  
Gavin A. Kearney ◽  
Fiona J. Cameron ◽  
Robert R. Gault ◽  
...  
Keyword(s):  
White Clover ◽  
Soil Texture ◽  
Dry Matter ◽  
Chemical Properties ◽  
Soil Chemical Properties ◽  
Available Phosphorus ◽  
N Fixation ◽  
Nematode Density ◽  
Factors Associated ◽  
Western Victoria

A survey of 71 sites was conducted in the dairying districts of south-western Victoria in October 1994 to determine factors associated with nitrogen (N) fixation in white clover based pastures. Twenty-eight factors (environmental, microbiological, management, soil, and pasture) were considered in relation to 2 indicators of N fixation by white clover, %Ndfa (percentage of total plant N derived from the atmosphere, as determined by the 15N natural abundance method) and kg of N fixed per tonne herbage dry matter (legume and non-legume). On light-textured soils (sandy loams), soil potassium, rhizobia numbers, total soil N, and density of the nematode Pratylenchus sp. accounted for 72% of variation in %Ndfa. On medium-textured soils (clay loams), crude protein of perennial ryegrass and plant-available phosphorus in the soil accounted for 30% of variation in %Ndfa. The amount of N fixed was influenced by different factors, again depending on soil texture. Soil chemical properties accounted for 31% variation on the medium-textured soils with nematode density, pasture quality, and soil chemical properties accounting for 77% of variation on light-textured soils. Amounts of N fixed per tonne herbage dry matter produced averaged 8.2 kg on the light-textured soils and 7.3 kg on the medium-textured soils. Average %Ndfa values were 67% and 60% on light- and medium-textured soils, respectively. Effects of soil texture on N fixation were attributed to the different cation exchange and water-holding capacities of the soils and highlight the importance of considering soil type in N fixation studies.

scholarly journals Nitrogen fixation by subterranean and white clovers in dryland cocksfoot pastures

2010 ◽  
pp. 141-146 ◽  
Author(s):  
R.J. Lucas ◽  
M.C. Smith ◽  
P. Jarvis ◽  
A. Mills ◽  
D.J. Moot
Keyword(s):  
Nitrogen Fixation ◽  
White Clover ◽  
Dry Matter ◽  
N Fixation ◽  
Grazing Experiment ◽  
Enrichment Technique ◽  
15N Enrichment ◽  
Lincoln University

The amount of nitrogen (N) in clover dry matter (DM) herbage derived from N fixation in subterranean or white clover was estimated using the 15N enrichment technique in a dryland grazing experiment at Lincoln University.

The quality of pork when included in the diet of the drug Permaite

2021 ◽  
pp. 3-11
Author(s):  
N. I. Kulmakova ◽  
L. B. Leontiev
Keyword(s):  
Dry Matter ◽  
Silicon Oxide ◽  
Experimental Studies ◽  
Live Weight ◽  
Biologically Active ◽  
Potassium Oxide ◽  
Control Group ◽  
Chuvash Republic ◽  
On Farm

It is well known that the growth rate of an animal depends on the level of feeding. However, the diets used in farms do not always meet the body’s needs for biologically active substances. In recent years numerous studies have been conducted to study the eff ect of natural and synthetic complex biologically active drugs on the productivity, metabolism of pigs and the quality of the products obtained. The imbalance or lack of certain nutrients in the diet reduces the productivity of animals, reduces the conversion of feed. The purpose of our research was to study the effect of the drug Permaite included in the diet of pigs on some indicators of the quality and safety of pork. Permaite is a standardized zeolite-containing trepel of the Chuvash Republic. Its chemical composition is (%): silicon oxide – 64,39, iron oxide – 3,25. aluminum oxide – 8,42, titanium oxide – 0,45, calcium oxide – 7,74, calcium carbonate – 14,7, magnesium oxide – 1,71, potassium oxide – 1,81, sodium oxide – 0,03, phosphorus pentoxide – 0,20 and other impurities – 11,9. Experimental studies have been conducted on 2 groups of pigs on rearing and subsequent fattening. Pigs of the experimental group have been received the main diet with the inclusion of the drug Permaite at a dose of 3 % to the dry matter of the main diet in the form of a fraction of 0,1–0,3 mm. The drug has been prescribed once a day in a mixture with compound feed for 60 days. The control group of pigs during this period was on farm diet without the inclusion of the drug. Upon reaching the live weight of 100–110 kg the pigs have been sent for slaughter. The results of the research allow us to conclude that the inclusion of the drug Permaite in the dose of 3 % to the dry matter of the main diet provides the increase in the nutritional, biological, energy value, technological properties and safety of pork.

scholarly journals Liveweight changes in lambs grazing six perennial ryegrass cultivars

1999 ◽  
pp. 31-35
Author(s):  
C.T. Westwood ◽  
M.G. Norriss
Keyword(s):  
New Zealand ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Dry Matter ◽  
Moisture Stress ◽  
Botanical Composition ◽  
Independent Research ◽  
Ewe Lambs ◽  
Research Organisation ◽  
Clover Content

Liveweight changes were measured for lambs grazing six high endophyte perennial ryegrasses, in a grazing experiment run by an independent research organisation in Canterbury, New Zealand. Ryegrass cultivars were sown under code in a binary mix with white clover in February 1997. Plots were strategically irrigated to avoid moisture stress, and stocked at approximately 27 Coopworth ewe lambs per ha in May 1997. Common pasture residual mass was maintained across cultivars by strategic addition of extra lambs, with extra grazing days recorded for each replicate. Lamb liveweight gains and botanical composition of replicates were assessed quarterly. Lamb liveweight gains differed significantly between treatments in Years 1 and 2 of this ongoing 3 year study. Lambs grazing 'Quartet' tetraploid perennial ryegrass gained, on average, 37.4 kg and 36.1 kg liveweight during Years 1 and 2 respectively, and together with 'Aries HD' (35.0 and 35.9 kg) produced significantly greater liveweight gain compared with 'Grasslands Nui' (22.0 and 23.7 kg) and 'Bronsyn' (22.5 and 24.1 kg), LSD0.05 = 6.0 and 7.4. Lambs grazing 'Embassy' gained 31.6 kg and 28.7 kg, and 'Vedette' 29.8 kg and 28.0 kg. Extra grazing days expressed as a percentage of base grazing days were between 3.8 and 6.7% across cultivars for Year 1 and between 2.0 and 6.5% across cultivars for Year 2. This study demonstrated significant differences in animal productivity between perennial ryegrass cultivars that produce comparable yields of dry matter. Differences may reflect variation in forage quality, endophyte toxins, clover content in the sward or other unidentified cultivar characteristics. Keywords: digestibility, endophyte, lamb, liveweight, perennial ryegrass, tetraploid

Tactical versus continuous stocking in perennial ryegrass-subterranean clover pastures grazed by sheep in south-western Victoria. 2. Ryegrass persistence and botanical composition

2001 ◽  
Vol 41 (8) ◽  
pp. 1109 ◽  
Author(s):  
R. A. Waller ◽  
P. W. G. Sale ◽  
G. R. Saul ◽  
G. A. Kearney
Keyword(s):  
Perennial Ryegrass ◽  
Dry Matter ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Summer Rainfall ◽  
Grazing Pressure ◽  
Botanical Composition ◽  
Average Mass ◽  
Gravelly Soil ◽  
Western Victoria

A 4-year field experiment was carried out in south-western Victoria to determine whether tactical stocking might improve perennial ryegrass (Lolium perenne L.) persistence and prime lamb production, compared with the more common practice of continuous stocking. Tactical stocking consisted of variable-length summer, autumn and winter rotations and continuous stocking in spring. The 2 grazing strategies were compared on 2 contrasting pastures: an upgraded pasture, sown with newer cultivars of perennial ryegrass and subterranean clover (Trifolium subterraneum L.) with 26 kg phosphorus/ha.year, and a more typical naturalised perennial ryegrass pasture receiving 6 kg phosphorus/ha.year. Paddocks were grazed by Border Leicester x Merino ewes, which were mated to a terminal sire to lamb in September. The effects of the grazing systems and pasture treatments on ryegrass persistence and pasture botanical composition are presented in this paper. The perennial ryegrass component of the sward decreased from an average mass of 1000 kg dry matter/ha on the upgraded pasture and 400 kg dry matter/ha on the typical pasture in spring 1996 to 100 kg dry matter/ha and <50 kg/ha for the 2 pasture types, respectively, in spring 1998. This occurred irrespective of the grazing system imposed. The decline of ryegrass was attributed to several factors including the very dry 3-year period, summer rainfall events that caused ryegrass buds to break dormancy then die when dry conditions resumed, the gravelly soil type where the experiment was located, and the high grazing pressure used. A number of species became more prevalent in the pastures as the ryegrass disappeared. Silver grass (Vulpia spp.) increased 4–5-fold on all treatments. By the fourth year, barley grass (Hordeum leporinum) and Bromus spp. had increased significantly with tactical stocking compared with continuous stocking. Capeweed (Arctotheca calendula L.) and Erodium spp. increased on both the continuously stocked and upgraded pastures. The subterranean clover component was maintained across all treatments over the 4 years, indicating that tactical stocking did not adversely affect clover persistence. Since ryegrass declined irrespective of treatment, the tactical stocking system used in this study cannot be recommended for improving ryegrass persistence.

Grass-white clover relationships during pasture development. 1. Effect of superphosphate

1973 ◽  
Vol 13 (64) ◽  
pp. 567 ◽  
Author(s):  
EC Wolfe ◽  
A Lazenby
Keyword(s):  
White Clover ◽  
Tall Fescue ◽  
Dry Matter ◽  
New South ◽  
Major Effect ◽  
Grass Species ◽  
Botanical Composition ◽  
Seeding Rate ◽  
South Wales ◽  
Clover Content

The effects of superphosphate (0, 42, 125, and 375 kg ha-1 year-1), grass species (tall fescue, perennial ryegrass, and phalaris) and grass seeding rate (0, 1.1, 4.5, and 17.9 kg ha-1) on the productivity and botanical composition of grass-white clover pastures were investigated from 1967 to 1970 on a previously unfertilized site at Armidale, New South Wales. In all years, total pasture yields were increased by each additional increment of superphosphate applied. During the establishment year, the addition of 375 kg ha-1 superphosphate increased clover dry matter yield by more than 3500 kg ha-1, whereas grass production was low (< 1500 kg ha-1) on all treatments. Thereafter, the increases in grass yields at each level of superphosphate were the equal of, or exceeded, the clover responses, which were mainly linear throughout the experiment. Neither grass seeding rate nor grass species had a major effect on total pasture productivity. Their effects on the relative yields of the grass and clover components were most evident at the highest rate of superphosphate. At SP0, grass and clover percentages declined from 1967 to 1970 and at SP125 the proportions of grass, clover and weeds were about equal in all years. At SP375, the strong overall trend from clover-dominance in 1967 to grass-dominance in 1970 was most rapid in treatments sown with 4.5 or 17.9 kg ha-1 grass and least rapid in phalaris-white clover pastures. In 1969 and 1970, when most pastures at SP375, had reached the grass-dominant stage of their development, within-year fluctuations in grass and clover content were least in the fescue-white clover pastures.

Dry Matter Yield and Botanical Composition of an Orchardgrass‐Ladino White Clover Mixture Under Clipping and Grazing Conditions 1

1960 ◽  
Vol 52 (4) ◽  
pp. 217-220 ◽  
Author(s):  
T. H. Taylor ◽  
J. B. Washko ◽  
R. E. Blaser
Keyword(s):  
White Clover ◽  
Dry Matter ◽  
Dry Matter Yield ◽  
Botanical Composition

Comparison of a herbal ley with a ryegrass-white clover pasture and pure ryegrass sward receiving fertiliser nitrogen

1991 ◽  
pp. 225-230 ◽  
Author(s):  
B.E. Ruz-Jerez ◽  
P.Roger Ball ◽  
R.E. White ◽  
P.E.H. Gregg
Keyword(s):  
White Clover ◽  
Symbiotic Nitrogen Fixation ◽  
Total Yield ◽  
Red Clover ◽  
N Fixation ◽  
Botanical Composition ◽  
Forage Legumes ◽  
Pasture Production ◽  
Intensively Managed ◽  
Intensive System

This paper compares a herbal ley (of particular interest to farmers involved in the 'organic' branch of agriculture) with a conventional pasture (ryegrass-white clover) and a more intensive system (pure ryegrass receiving 400 kg fertiliser N/ha/yr) in a study lasting 2 years. The herbal ley seeds mixture was prepared following the pioneering ideas of Robert Elliot in his "Clifton ~~ ~~~~~Park"mixture,-whichbasically-included~a-group of 'non-aggressive' grasses, forage legumes and herbs. Pasture production (average of 2 years) from Herbal ley was 15 t DM/ha/yr, representing approximately 90% of the yield from the intensively managed pure ryegrass pasture receiving 400 kg N/ ha&r and some 2530% more than from ryegrassclover. A major feature of the herbal ley was substantialproductionduringlate.springandsummer, when chicory (the most dominant herb), and red clover and white clover made a major contribution to herbage yield. In winter the total yield was similar tothatI?omthegrass-cloverpasture.L.egumecontent was 23 and 3 1% (averaged over the year) for Grassclover and Herbal ley pastures respectively. In spite of this difference, symbiotic N fixation was similar. So fixation efficiency on a legume yield basis was 50.3 and 3 1.6 kg N fixed/t legume DM harvested, respectively. These results could reflect a different pattern of utilisation of soil N, as a consequence of the different botanical composition of the swards. In summary, the performance of the herbal ley offers the promise of an alternative, 'specialist' pasture and would be highly beneficial if quality feed is required in summer. Keywords herbal ley, biological fertility, nitrogen, symbiotic nitrogen fixation, pasture mixtures

scholarly journals A reduced fraction of plant N derived from atmospheric N (%Ndfa) and reduced rhizobial nifH gene numbers indicate a lower capacity for nitrogen fixation in nodules of white clover exposed to long-term CO<sub>2</sub> enrichment

2013 ◽  
Vol 10 (12) ◽  
pp. 8269-8281 ◽  
Author(s):  
T. Watanabe ◽  
S. Bowatte ◽  
P. C. D. Newton
Keyword(s):  
Nitrogen Fixation ◽  
Elevated Co2 ◽  
White Clover ◽  
Trifolium Repens ◽  
Nifh Gene ◽  
Shoot Biomass ◽  
N Fixation ◽  
Dna Amount ◽  
Trifolium Repens L ◽  
Nifh Genes

Abstract. Using the δ15N natural abundance method, we found that the fraction of nitrogen derived from atmospheric N (%Ndfa) in field-grown white clover (Trifolium repens L.) plants was significantly lower (72.0% vs. 89.8%, p = 0.047 in a grassland exposed to elevated CO2 for 13 yr using free air carbon dioxide enrichment (FACE). Twelve months later we conducted an experiment to investigate the reasons behind the reduced N fixation. We took cuttings from white clover plants growing in the FACE and established individual plants in a glasshouse using soil from the appropriate ambient or elevated CO2 treatments. The established plants were then transplanted back into their "rings of origin" and sampled over a 6-week period. We used molecular ecological analyses targeting nifH genes and transcripts of rhizobia in symbiosis with white clover (Trifolium repens L.) to understand the potential mechanisms. Shoot biomass was significantly lower in eCO2, but there was no difference in nodule number or mass per plant. The numbers of nifH genes and gene transcripts per nodule were significantly reduced under eCO2, but the ratio of gene to transcript number and the strains of rhizobia present were the same in both treatments. We conclude that the capacity for biological nitrogen fixation was reduced by eCO2 in white clover and was related to the reduced rhizobia numbers in nodules. We discuss the finding of reduced gene number in relation to factors controlling bacteroid DNA amount, which may imply an influence of nitrogen as well as phosphorus.

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