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.

Low rates of phosphorus fertiliser applied strategically throughout the growing season under rain-fed conditions did not affect dry matter production of perennial ryegrass (Lolium perenne L.)

2010 ◽  
Vol 61 (5) ◽  
pp. 353 ◽  
Author(s):  
L. L. Burkitt ◽  
D. J. Donaghy ◽  
P. J. Smethurst
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Dry Matter ◽  
Growing Season ◽  
Dry Matter Production ◽  
Pasture Production ◽  
Lolium Perenne L ◽  
Matter Production ◽  
Extractable P ◽  
Intensively Managed

Pasture is the cheapest source of feed for dairy cows, therefore, dairy pastures in Australia are intensively managed to maximise milk production and profits. Although soil testing commonly suggests that soils used for dairy pasture production have adequate supplies of phosphorus (P), many Australian dairy farmers still apply fertiliser P, often by applying smaller rates more frequently throughout the year. This study was designed to test the hypotheses that more frequent, but lower rates of P fertiliser applied strategically throughout the growing season have no effect on dry matter production and P concentration in perennial ryegrass (Lolium perenne L.), when soil extractable P concentrations are above the critical value reported in the literature. Three field sites were established on rain-fed dairy pasture soils ranging in P sorption capacity and with adequate soil P concentrations for maximising pasture production. Results showed that applied P fertiliser had no effect on pasture production across the 3 sites (P > 0.05), regardless of rate or the season in which the P was applied, confirming that no P fertiliser is required when soil extractable P concentrations are adequate. This finding challenges the viability of the current industry practice. In addition, applying P fertiliser as a single annual application in summer did not compromise pasture production at any of the 3 sites (P > 0.05), which supports the current environmental recommendations of applying P during drier conditions, when the risk of surface P runoff is generally lower. The current results also demonstrate that the short-term cessation of P fertiliser application may be a viable management option, as a minimal reduction in pasture production was measured over the experimental period.

A relation between wool production per animal and annual pasture dry matter production per animal

1982 ◽  
Vol 33 (4) ◽  
pp. 705 ◽  
Author(s):  
BA Rowe
Keyword(s):  
Dry Matter ◽  
Simple Relation ◽  
Dry Matter Production ◽  
First Year ◽  
Stocking Rate ◽  
Pasture Production ◽  
Wool Production ◽  
The Third ◽  
Matter Production ◽  
Curvilinear Relation

A simple relation between the annual wool production per animal (y) and the amount of pasture dry matter produced per animal (x) was derived and tested using the results from a grazing experiment in which the effects of superphosphate and stocking rate on wool and pasture dry matter production were measured from pastures which were continuously grazed by Merino wethers for 3 years. The linear relation, y = a + b/x, accounted for 63% of the variance in wool production per animal in the first year, 82 % in the second and 97 % in the third. Exclusion of an outlier from the first year results increased the variance accounted for to 85 %. This model is simpler and more precise than some others that have been published. It is also consistent with the curvilinear relation between production per animal (y) and pasture production per animal (x).

SEASONAL PATTERNS OF NITROGEN FIXATION AND DRY MATTER PRODUCTION BY CLOVERS GROWN IN THE PEACE RIVER REGION

1980 ◽  
Vol 60 (3) ◽  
pp. 847-858 ◽  
Author(s):  
W. A. RICE
Keyword(s):  
Dry Matter ◽  
Nitrogenase Activity ◽  
Red Clover ◽  
Growing Season ◽  
Forage Yield ◽  
Dry Matter Production ◽  
Flower Initiation ◽  
Matter Production ◽  
River Region ◽  
Gray Luvisol

Alsike clover (Trifolium hybridum L.) and red clover (T. pratense L.) were established in field plots on an Orthic Gray Luvisol (Hazelmere CL) and a Black Solod (Landry CL) in 3 consecutive yr, 1972, 1973 and 1974. Data were collected in the 2 yr following the year of establishment. The factors measured included seed and forage yield, dry matter production rate, potential nitrogenase activity (acetylene reduction), soil temperature, air temperature, soil moisture and NH+4-N and NO−3-N content of the soil. Based on calculations using the theoretical C2H2:N2 ratio of 3:1, alsike clover annually fixed 20.8–143.0 kg N/ha, and red clover fixed 15.3–77.3 kg N/ha on the Orthic Gray Luvisol. Also, alsike clover fixed more N2 earlier in the growing season than red clover. The estimate of annual N2(C2H2) fixation by both clovers on the Black Solod was less than one half that on the Orthic Gray Luvisol. There was little difference between the N2(C2H2) fixation by clover crops harvested for forage and those used for seed production. However, the amount of N2(C2H2) fixed always equalled or exceeded the amount of nitrogen removed in the seed, but only occasionally exceeded the amount removed in the forage. Yield and N2(C2H2) fixation varied widely among years, suggesting considerable climatic influence. However, the measured climatic and soil factors were not consistently correlated with potential nitrogenase activity. The seasonal pattern of potential nitrogenase activity appeared to be influenced by the phenological development of the plant. Activity commenced early in May, increased to a maximum about mid-June (flower initiation), and then decreased and generally remained low for the remainder of the growing season. Significant deviations from the usual seasonal profile of potential nitrogenase activity occurred in years with periods of moisture stress or with above average precipitation and soil heat units.

scholarly journals HERBAGE PRODUCTION OF PASTURE LEGUMES AT THREE SITES IN OTAGO

1975 ◽  
pp. 182-195
Author(s):  
R.B. Allen ◽  
I.R. Mcdonald ◽  
N.A. Cullen
Keyword(s):  
Lolium Perenne ◽  
White Clover ◽  
Dry Matter ◽  
Red Clover ◽  
Low Fertility ◽  
Dry Matter Production ◽  
High Fertility ◽  
The Third ◽  
Pasture Legumes ◽  
Matter Production

White clover (Trifolium repens), red clover (T. pratense), subtcrrnnean clover (T. subterraneum) and alsike clover (T. hybridum) were sown singly or in combinations at three sites in Otago. Ryegrass (Lolium perenne) was included in all clover treatments and was also sown alone. Lucerne (Medicago sativa) was sown alone at two sites. Herbage dry matter production was measured over a three-year period. At the high fertility lnvermay site, white and red clovers gave similar total and legume dry matter production and were markedly superior to alsike and subterranean clovers. White and nlsike clovers were most productive at the higher altitude, low fertility Berwick site, and at the dry, medium fertility Dunback site red clover produced the highest yields. Lucerne greatly outyielded all other species in the second and third years at Invermay and in the third year at Dunback.

A comparative analysis of the growth of sweet and forage sorghum crops. I. Dry matter production, phenology and morphology

1986 ◽  
Vol 37 (5) ◽  
pp. 495 ◽  
Author(s):  
R Ferraris ◽  
DA Charles-Edwards
Keyword(s):  
Dry Matter ◽  
Leaf Tissue ◽  
Sowing Date ◽  
High Density ◽  
Dry Matter Production ◽  
Morphological Development ◽  
Forage Sorghum ◽  
The Third ◽  
Matter Production ◽  
Use Efficiency

A sweet sorghum (cv. Wray) and a forage sorghum (cv. Silk) were grown in south-east Queensland without water deficit at two densities in 0.75 m rows on four occasions between late September and mid January. Tiller and branch numbers, and dry matter production, were recorded at appearance of the third leaf ligule, panicle initiation, anthesis, soft-dough stage, maturity and 3 weeks after maturity. Light interception was measured every 2 weeks. The time between all the studied phenological events up to anthesis was shortened with delay in sowing date except for that between appearance of the third ligule and initiation in cv. Silk. The time between anthesis and maturity lengthened with the delay in sowing date of both cultivars. Rate of development was a function of ambient temperature to the third ligule stage and again during maturation. Tiller and branch production were greatest in cv. Silk, decreased with delay in sowing date for both sorghums and was increased by the high density. The estimated assimilate flux required to sustain basal tillers was substantially lower in cv. Silk than in cv. Wray. This flux increased with temperature. In early sown crops, dry matter yields of cv. Wray were greater than those of cv. Silk. Close spacing increased dry matter yields up to anthesis, but by maturity the effect of spacing had been reduced. Cv. Wray produced a larger leaf canopy more rapidly than cv. Silk, although the partitioning of dry matter to leaf tissue only differed between cultivars after canopy closure. The efficiency with which crops used intercepted light energy to produce new above-ground dry matter changed during their ontogeny. It is suggested that early changes in efficiency were a consequence of altered partitioning to roots. The effect of sowing date and spacing on efficiency of light use was slight until the maturation phase, when efficiency decreased with delay in sowing date and at high density. Water use efficiency differed in a similar way to light use efficiency. The relationships found in this study indicate that sorghum growth models need to recognise differences in the morphological development of sorghum types.

scholarly journals EFFECT OF VARIOUS PELLETING MATERIALS ON ESTABLISHMENT AND GROWTH OF LOTUS PEDUNCULATUS

1975 ◽  
pp. 221-227
Author(s):  
W.L. Lowther
Keyword(s):  
Dry Matter ◽  
Treatment Effects ◽  
Rock Phosphate ◽  
Gum Arabic ◽  
Growing Season ◽  
Lower Degree ◽  
Dry Matter Production ◽  
Consistent Trend ◽  
Matter Production ◽  
Lotus Pedunculatus

The effects of inoculation and pelleting, with two storage periods, were investigated on the establishment of 'Grasslands Maku' Lotus pedunculatus at three sites. When seeds were sown one day after treatment, none of the treatments gave consistently better establishment than inoculationonly, although the addition of gum arabic adhesive alone significantiy increased establishment on one site. However, after 15-day storage of the seed, establishment was higher from gum arabic adhesive alone than from inoculated-only seed although the effect attained significance on only two sites. In contrast, establishment of pelleted seed, apart from rock-phosphate/dolomite on one site, was similar to or less than that from inoculated-only seed. There was a consistent trend for all pelleting treatments to give a lower degree of establishment than did gum arabic adhesive alone. Lotus dry matter production in the second growing season was measured on one site and the importance of maximizing establishment was demonstrated by the marked treatment effects on lotus yield.

scholarly journals EFFECT OF SHEEP GRAZING REGIME ON PERFORMANCE OF MATUA PRAIRIE GRASS

1985 ◽  
pp. 151-156
Author(s):  
R.T. Alexander
Keyword(s):  
Dry Matter ◽  
Grazing Management ◽  
Annual Production ◽  
Dry Matter Production ◽  
First Year ◽  
Sheep Grazing ◽  
The Third ◽  
Matter Production ◽  
Prairie Grass

Persistency and productivity of irrigated 'Grasslands Matua' prairie grass pastures were measured under four sheep grazing regimes, frequent or infrequent (grazed 3 weekly or 6 weekly) coupled with lax or severe defoliation (grazed to 7.5 cm or 2.5 cm). Matua was also compared with 'Grasslands Nui' and Yates 'Ellett' perennial ryegrasses under frequent severe grazing. These are interim results from two experiments sown in successive years. There were few consistent differences among grazing treatments of Matua pastures. However, the Matua content of pastures tended to be less under frequent grazing. In the third year of Experiment 1, infrequent grazing to 2.5 cm resulted in significantly hlgher annual production than other Matua treatments. 'Eiiett' ryegrass tended to outyield 'Grasslands Nui' in the first year but subsequently there was little difference in yields. The dry matter production of 'Ellett ryegrass was not significantly different from the best Matua treatment in any year. More herbage was lost through trampling and decay in the infrequently grazed Matua pastures than in the frequently grazed Matua or ryegrass pastures. After three years, all Matua pastures contained more weeds and more volunteer grasses than did ryegrass pastures. Keywords: prairie grass, Matua, ryegrass, Nul, Ellett, grazing management, lax grazing, severe grazing, irrigation.

scholarly journals EVALUATION OF DRY MATTER PRODUCTION OF MISCANTHUS SINENSIS (TATAI) IN THE CONDITIONS OF SOUTH-WESTERN SLOVAKIA

2013 ◽  
Vol 10 (2) ◽  
pp. 55-58
Author(s):  
Martin Prčík ◽  
Marián Kotrla
Keyword(s):  
Dry Matter ◽  
Dry Weight ◽  
Dry Matter Production ◽  
Miscanthus Sinensis ◽  
Aboveground Phytomass ◽  
Growing Period ◽  
The Third ◽  
Matter Production ◽  
Number Of Stems ◽  
Total Dry Weight

Abstract In this paper, we present the results of research of phytomass production allocated to aboveground organs, leaves and stalks, after the third growing year. The research was conducted in the field experiment conditions of Farm holding in Kolíňany. The results of the aboveground dry matter production are expressed in tonnes of dry weight produced on the area of one hectare (t.ha-1). The total dry weight of the aboveground biomass was 6.89 t.ha-1 at the end of the first growing year 2010. In the growing year 2011, it reached 15.21 t.ha-1 (an increase by 121 %.) The total dry weight of the aboveground phytomass increased by 37% compared to 2011, and it reached 20.82 t.ha-1 in the third growing year (2012). The increase of phytomass is directly proportional to off shoot circle. Average off shoot circle of individuals in the first growing year was 300 mm and the average number of stems produced in a clump was 37.60. In 2011, the average off shoot circle of individuals was 502 mm and there were 43.73 stems created in a clump. In the third growing period of 2013, the extension of the off shoot circle by 113.7% (641 mm) was registered in comparison with 2010 and the amount of 80.19 stems per clump was recorded.

Sign in / Sign up

Export Citation Format

Share Document