Species distribution within improved pastures over central N.S.W. in relation to rainfall and altitude

1991 ◽  
Vol 42 (4) ◽  
pp. 647 ◽  
Author(s):  
DR Kemp ◽  
PM Dowling
Keyword(s):  
Linear Relationship ◽  
Subterranean Clover ◽  
Mean Annual Temperature ◽  
Botanical Composition ◽  
Perennial Species ◽  
Survey Area ◽  
Annual Species ◽  
Wide Range ◽  
Annual Grasses ◽  
Point Quadrat

Botanical composition has a large influence on pasture productivity, but little information is available about the botanical composition of pastures on farms, the interactions of species or reasons for their distribution. A survey was done, during two successive springs and using a point quadrat method, of the botanical composition of improved pastures in central New South Wales and maps prepared of the proportion of species or groups of species in pastures. The survey area covered a wide range in rainfall (600-1000 mm), altitude (300-1400 m) and the boundary where perennial and annual pasture species overlap. Subterranean clover was the most common legume and occurred in all parts of the region. Above 700 mm rainfall, white clover replaced subterranean clover in a linear relationship, though the proportion of the pasture occupied by both species never exceeded 30%. Annual grasses were found throughout the survey area, and they were also replaced by perennial species at higher rainfall, higher altitude sites, in a linear relationship. The total proportion of the pasture from both perennial and annual grasses did not exceed a mean of 55%. The high proportion of annual species was attributed in part to continuous grazing practices. Perennial species were found down to 600 mm rainfall but only exceeded the proportion of annual species when the rainfall exceeded 800 mm for legumes or 900 mm for grasses or where the altitude was above 900 m (<12�C mean annual temperature) for both groups. It was concluded that among perennial or annual groups, legumes and grasses occupied slightly different niches in the pasture, and they would not always replace one another exclusively. The legume content of pastures, especially in the higher rainfall areas, was considered to be less than satisfactory for animal production. Pasture recommendations need to consider the climatic limits where species are able to make a major contribution to production as well as the climatic limits for persistence.

Evaluation of some annual Trifolium spp. under irrigation

1986 ◽  
Vol 26 (1) ◽  
pp. 79 ◽  
Author(s):  
KB Kelly ◽  
WK Mason
Keyword(s):  
Dry Matter ◽  
Subterranean Clover ◽  
Early Summer ◽  
Annual Species ◽  
Dry Matter Digestibility ◽  
Wide Range ◽  
Plant Habit ◽  
Germinable Seed ◽  
Early Establishment

Eighteen annual species (38 lines) of the genus Trifolium were sown in 1982 as nursery plots to evaluate their potential under irrigation at Kyabram in northern Victoria. A wide range in plant habit, plant growth and flowering time was observed both within and between species. This experiment was used to select species for further agronomic evaluation; those selected were T. balansae CPI45856, T. purpureum cv. Paratta, T. resupinatum cv. Maral and the subterranean clover species T. brachycalycinum cv. Clare, T. subterraneum cv. Woogenellup and T. yanninicum cv. Trikkala. Pure swards of T. balansae, T. resupinatum and a mixture of subterranean clover cultivars were sown on five occasions in 1983. The first four sowings were established by irrigation on 7 February, 28 February, 21 March and 11 April; the fifth was sown on 20 June. T. purpureum was included only on 28 February and 20 June. Establishment was low (35% of germinable seed sown) at the first two times of establishment, when temperatures and evaporation rates were high. Early establishment increased the productivity of all species, by increasing autumn-winter production with only slight indications of a decline in spring growth. Spring productivity of T. resupinatum was superior to all other species. Irrigation into early summer maintained the growth of T. resupinatum but not of the other species. Data on growth rates, in vitro dry matter digestibility and nitrogen content are also presented.

A comparison of the effects of autumn deferment and continous grazing on the growth of an annual pasture

1973 ◽  
Vol 13 (65) ◽  
pp. 669 ◽  
Author(s):  
JG McIvor ◽  
DF Smith
Keyword(s):  
Shoot Apex ◽  
Plant Density ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Early Winter ◽  
Botanical Composition ◽  
Growing Seasons ◽  
Annual Grasses ◽  
One Year ◽  
Apex Height

The effects of deferred autumn grazing on a pasture comprising nearly equal proportions of subterranean clover (Trifolium subterraneum), capeweed (Arctotheca calendula) and annual grasses were measured over two growing seasons. Autumn deferment increased the survival of capeweed seedlings in both years and of clover in one year but had little effect on the annual grasses. Although there was more herbage present on the deferred plots in early winter, under later set stocking at normal levels by spring the amount of herbage present, plant density, botanical composition and seed numbers were similar on all plots. The accumulation of herbage under deferred grazing caused an elevation of shoot apex height in capeweed, but not in clover. When combined with subsequent intensive grazing, the number of capeweed plants surviving to flowering was sharply reduced. However, this management also resulted in a reduction in herbage production in spring.

Changes in the Quantitative Floristics in Some Astrebla Spp. (Mitchell Grass) Communities in South-Western Queensland in Relation to Trends in Seasonal Rainfall

1981 ◽  
Vol 29 (5) ◽  
pp. 533 ◽  
Author(s):  
DM Orr
Keyword(s):  
Relative Abundance ◽  
Perennial Grass ◽  
Grazing Pressure ◽  
Perennial Grasses ◽  
Seasonal Rainfall ◽  
Individual Species ◽  
Botanical Composition ◽  
Basal Cover ◽  
Wide Range ◽  
Annual Grasses

Seasonal changes in the quantitative floristics at a wide range of Astrebla grassland sites in south-western Queensland were monitored between 1972 and 1980 with a wheel point apparatus. Changes in the floristics were measured in terms of both relative abundance and basal cover. A large increase in the relative abundance of perennial grasses, particularly Aristida latifolia, Astrebla spp. and Dichanthium sericeum, occurred between 1972 and 1976. This increase was at the expense of annual grasses and forbs which declined in both relative abundance and number of genera present. The relative abundance of perennial grasses declined between 1978 and 1980 and this was associated with a large increase in the forbs such as Daucus glochidiatus and Plantago spp., particularly at southern sites. The contribution of annual grasses to botanical composition remained low throughout the period. Total basal cover differed between years although these differences were not significant. As perennial grass, particularly Astrebla spp., was the major vegetation component of total basal cover, changes in the latter were associated mainly with changes in the basal cover of Astrebla spp. Changes in the contribution of individual species to total basal cover were related to changes in the relative abundance of those species. Changes in botanical composition in Astrebla grassland may be influenced more by trends in seasonal rainfall than by grazing pressure.

Effects of management on soil fertility under pasture. 1. Influence of experimental grazing and fertilizer systems on growth, composition and nutrient status of the pasture

1974 ◽  
Vol 14 (69) ◽  
pp. 470 ◽  
Author(s):  
JR Simpson ◽  
SM Bromfield ◽  
GT McKinney
Keyword(s):  
Nitrogen Availability ◽  
Subterranean Clover ◽  
Nutrient Status ◽  
Grazing Pressure ◽  
Grass Species ◽  
Botanical Composition ◽  
Annual Grass ◽  
Growth And Nutrition ◽  
Animal Excreta ◽  
Annual Grasses

Pasture plots containing phalaris, subterranean clover and annual grass species were fertilized annually at suboptimal (P1), adequate (P2) or a 'luxury' rate (P3) of superphosphate. A fourth treatment combined rate P3 with fertilizer nitrogen (P3N). Each pasture was grazed during five years at a high (H) or a low (L) grazing pressure in such a way that there was little feed left on the H plots and a large amount on the L plots at the end of summer. In this way eight pasture situations were created which differed in botanical composition, nutrient availability, herbage production and the amount of nutrients returned as animal excreta. The plots were used to investigate the effects of fertilizer input and grazing pressure on the growth and nutrition of the different pasture components. Protected microplots during the fourth and fifth years showed that the P1 plots remained responsive to phosphate. The yields of annual grasses on the microplots were increased by H treatment but the proportion of phalaris to annual grasses was reduced, particularly at P1. Clover yields and total pasture yields were affected by previous grazing pressure only in the drier fourth year. At high levels of superphosphate and grazing (P3H), the greater grass-clover ratio and higher grass nitrogen uptake indicated greater nitrogen availability in this treatment.

Population dynamics and stability of Stylosanthes hamata cv. Verano in grazed pastures

1982 ◽  
Vol 33 (1) ◽  
pp. 63 ◽  
Author(s):  
CJ Gardener
Keyword(s):  
Perennial Grass ◽  
Perennial Grasses ◽  
Botanical Composition ◽  
Grazed Pastures ◽  
Stylosanthes Hamata ◽  
Wide Range ◽  
Annual Grasses ◽  
Seed Reserves ◽  
Stable Association

The longevity, regeneration and seed reserves of Stylosantes hamata cv. Verano were studied in grazed pastures at Lansdown, north Queensland, over a 9-year period. Stability was assessed in terms of frequency of appearance and fluctuations in botanical composition. Plants proved short-lived, with a half-life of only 3 months. The majority therefore died in their seedling year, and only 0.03 % survived to the end of the third year. In most years, S. hamata had to re-establish almost entirely from seed. Despite this, S. hamata was a highly persistent legume in the long term owing to its consistently high seed reserves and ready regeneration from seed. In one paddock, for example, it re-established in all quadrats after disappearing from 76% of them the previous year. This long-term persistence was not, however, reflected in yield stability; the content of S. hamata in one paddock changed from 6 to 68% in consecutive years. Low legume yields were recorded when seedlings of S, hamata competed poorly with the annual grasses. Higher yields occurred when more than 20 % of the population comprised perennial S. hamata plants. Retention of the perennial grasses reduced the amplitude of the fluctuations in yields of S. hamata. The perennial grass and S. hamata formed an intimate and stable association. There were only small effects of stocking rate and superphosphate on the persistence of S. hamata, which suggests that the legume is highly tolerant of a wide range of management levels, although more precise management is needed for high animal production.

The effects of grazing on the phosphorus requirement of an annual pasture

1971 ◽  
Vol 22 (1) ◽  
pp. 81 ◽  
Author(s):  
PG Ozanne ◽  
KMW Howes
Keyword(s):  
Subterranean Clover ◽  
Growing Season ◽  
Maximum Growth ◽  
Grazing Pressure ◽  
Light Interception ◽  
Botanical Composition ◽  
Stocking Rate ◽  
Phosphorus Requirement ◽  
Root Size

The applied phosphorus requirement of a pasture sown to subterranean clover was measured with and without grazing. Under moderate grazing pressure, in the year of establishment, the pasture required about 50 % more phosphorus than when ungrazed. In the following season, at a higher stocking rate, the grazed areas needed twice as much phosphorus as the ungrazed to make 90% of their maximum growth. In both years this difference in requirement between stocked and unstocked treatments was present throughout the growing season. Increased phosphorus requirement under grazing is associated with the need for greater uptake of phosphorus under conditions where redistribution of absorbed phosphorus within the plant is prevented by defoliation. It does not appear to be due to effects of defoliation on root size. Nor does it depend on differential light interception or on changes in botanical composition.

scholarly journals Effects of the MaxP (TM) endophyte in tall fescue on pasture production and composition, and the sheep grazing preference in a dryland environment

2007 ◽  
Vol 13 ◽  
pp. 259-262
Author(s):  
K.N. Tozer ◽  
S. Ates ◽  
N.R. Mapp ◽  
M.C. Smith ◽  
R.J. Lucas ◽  
...  
Keyword(s):  
New Zealand ◽  
Tall Fescue ◽  
Dry Matter ◽  
Early Spring ◽  
Botanical Composition ◽  
Sheep Grazing ◽  
Pasture Production ◽  
Basal Diameter ◽  
Matter Production ◽  
Annual Grasses

Pasture growth, botanical composition and sheep grazing preference were measured over 20 months in tall fescue (cultivar Advance), without endophyte (Nil) or infected with AR542 (MaxPTM) endophyte, and clover pastures sown into a dryland soil, Canterbury, New Zealand. Pastures were rotationally grazed with sheep, with grazing preference for the two endophyte treatments measured in late autumn and early spring. Annual dry matter production from April 2004 to April 2005 was not significantly different between AR542 (6293 kg DM/ha) and Nil (5864 kg DM/ha) tall fescue. The number of tall fescue plants/m2 and their basal diameter was greater for AR542 (35 plants/m2, 7.5 cm diameter) than Nil endophyte tall fescue (28 plants/m2, 6.8 cm diameter). AR542 endophyte tall fescue pastures had fewer weeds, mainly annual grasses, than Nil endophyte pastures throughout the trial. Grazing preference, measured by the number of sheep grazing each plot, and decline in pasture height did not differ between Nil and AR542 tall fescue. Keywords: tall fescue, novel endophyte, AR542, botanical composition, weed, grazing preference

The control of slender thistle, Carduus pycnocephalus L. and C. tenuiflorus Curt. (Compositae), in pasture by grazing management

1973 ◽  
Vol 24 (6) ◽  
pp. 831 ◽  
Author(s):  
GM Bendall
Keyword(s):  
Perennial Ryegrass ◽  
Subterranean Clover ◽  
Field Trials ◽  
Grazing Management ◽  
Botanical Composition ◽  
Economical Method ◽  
Farm Programme ◽  
Improved Pasture

The effect of grazing management on slender thistle populations and botanical composition of improved pasture was studied in two field trials in southern Tasmania. Deferring grazing until winter or spring reduced slender thistle populations in both trials. The reasons underlying these observations are discussed. Spring grazing favourably altered pasture botanical composition by increasing the frequency of perennial ryegrass and subterranean clover and reducing the frequency of weed grasses. These changes arc discussed in relation to thistle control. It is suggested that deferred autumn grazing may be incorporated into the farm programme as an economical method for the control of slender thistle in pasture.

Lucerne, phalaris, and wallaby grass in short-term pasture phases in two eastern Australian wheatbelt environments. 2. Effect of perennial density and species on subterranean clover populations and the relative success of 3 clover cultivars of different maturity

2007 ◽  
Vol 58 (2) ◽  
pp. 123 ◽  
Author(s):  
B. S. Dear ◽  
G. A. Sandral ◽  
J. M. Virgona ◽  
A. D. Swan ◽  
B. A. Orchard ◽  
...  
Keyword(s):  
Seed Yield ◽  
Seed Bank ◽  
Seedling Survival ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Climatic Conditions ◽  
Perennial Species ◽  
Growing Season Length ◽  
Herbage Yield ◽  
Clover Seed

The effect of the density of 3 perennial species, phalaris (Phalaris aquatica L.), wallaby grass (Austrodanthonia richardsonii Kunth), and lucerne (Medicago sativa L.), on seed set, regeneration, and the relative competitiveness of 3 cultivars of subterranean clover (Trifolium subterraneum L.) was examined in 2 environments in the south-eastern Australian wheatbelt. Seed yields of subterranean clover were inversely related to perennial density at both sites over the first 2 years, the relationship varying with perennial species. Phalaris depressed the seed yield of clover more than lucerne and wallaby grass in the second and third year at equivalent densities. Clover seed yield was positively related to clover herbage yield in late spring at both sites, and inversely related to perennial herbage yield. Clover seed yield displayed an increasing linear relationship with the proportion of light reaching the clover understorey in spring, which in turn was inversely related to perennial density and perennial herbage yield. Clover seedling regeneration in mixed swards in autumn was positively related to the size of the summer seed bank, but negatively related to perennial density. Clover seedling survival following a premature germination at Kamarah was inversely correlated to the density of phalaris and lucerne in the sward. The relative competitiveness of the 3 subterranean clover cultivars varied between sites, with climatic conditions (rainfall and growing-season length) having a greater effect on the relative cultivar performance than companion perennial species or density. The later maturing subterranean clover cv. Goulburn became the dominant cultivar at the wetter site, constituting 72% of the seed bank, but declined to only 3–8% of the seed bank at the drier site. The proportion of the early flowering cultivar Dalkeith in the seed bank increased over time at the drier site and was highest (53%) in plots with the highest perennial density. We concluded that although perennial pasture species will depress clover seed yield and subsequent regeneration, these effects could be minimised by reducing perennial densities and exploiting variations in competitiveness between perennial species as identified in this study. Sowing earlier maturing subterranean clover cultivars would only be an advantage in increasing clover content in low-rainfall environments. The findings suggest that clover seed reserves and regeneration could also be increased by using grazing management to reduce the level of shading of clover by perennials, a factor associated with reduced clover seed yield.

Seed yield and nutritive value of dry, mature subterranean clover (Trifolium subterraneum L.)

2001 ◽  
Vol 41 (2) ◽  
pp. 169 ◽  
Author(s):  
Y. J. Ru ◽  
J. A. Fortune
Keyword(s):  
Seed Yield ◽  
Dry Matter ◽  
Mineral Content ◽  
Nutritive Value ◽  
Subterranean Clover ◽  
Zinc Content ◽  
Trifolium Subterraneum ◽  
Crude Fibre ◽  
Dry Matter Digestibility ◽  
Wide Range

The nutritive value of 26 cultivars of dry, mature subterranean clover was evaluated at Shenton Park, Perth, Western Australia. The cultivars were divided into 3 maturity groups according to flowering time and each cultivar was sown in blocks comprising 4 replicates. The plots were grazed by sheep at 2-week intervals during the growing season. Dry mature plant material and soil were sampled in summer to examine the effect of grazing and cultivar on seed yield and nutritive value of feed residues. Cultivars heavily grazed in spring had a low herbage mass. There was no difference in seed yield and seed weight between heavily and lightly grazed cultivars. Dry matter digestibility and mineral content of dry residues was inconsistent for the 2 grazing treatments. The dry matter digestibility of dry, mature subterranean clover ranged from 40 to 56%, with a wide range of crude fibre, nitrogen and mineral content for the 26 cultivars. While most minerals in the dry residues were above the requirement for sheep, 7 cultivars had a zinc content less than the maintenance requirement for sheep. There was an imbalance for all cultivars in calcium: phosphorus with a range of 4–10: 1. Concurrent estimates on the yield and composition of seed indicated that seed can be resource of minerals for grazing animals in summer. Most cultivars had a seed yield over 100 g/m2 with that of 9 cultivars being over 130 g/m2. Seed was rich in nitrogen, sodium, phosphorus, potassium, magnesium, zinc and copper, and poor in sodium, calcium and manganese. However, there were no cultivars with an appropriate ratio of calcium and phosphorus. The imbalance in nitrogen and sulfur was a result of high nitrogen content with the ratio ranging from 19: 1 to 29: 1.

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