Levels of germinable seed in topsoil and cattle faeces in legume-grass and nitrogen-fertilized pastures in south-east Queensland

1991 ◽  
Vol 42 (6) ◽  
pp. 953 ◽  
Author(s):  
RM Jones ◽  
M Noguchi ◽  
GA Bunch
Keyword(s):  
Perennial Grasses ◽  
Stocking Rate ◽  
Heavy Grazing ◽  
Seed Content ◽  
Setaria Sphacelata ◽  
Seed Reserves ◽  
Cattle Faeces ◽  
Autumn And Winter ◽  
Stocking Rates ◽  
Germinable Seed

Measurements were made of germinable seed of all species in the top 5 cm of soil beneath 9 paddocks in an 11-year-old pasture experiment in south-east Queensland. The experiment comprised two pasture types grazed by cattle: legume-grass (Macroptilium atropurpureum- Setaria sphacelata) pastures grazed at four stocking rates and nitrogen fertilized S. sphacelata pastures grazed at five stocking rates. Levels of germinable seed in the soil varied with pasture type and stocking rate and ranged from 6760 to 45480 seeds/m2. Seed reserves increased on the legume-grass pastures as stocking rate increased. Fifty-seven different plant species were identified from the seedlings grown from the soil seed reserve. For 11 of these species, which contributed 70% of the seed reserves, there were significant trends in relation to pasture type and/or stocking rate. The only species where seed reserves significantly decreased with increasing stocking rate were the two sown species. Cattle faeces were also collected from lightly and heavily stocked legume-grass and nitrogen-fertilized pastures in spring, summer, autumn and winter. Germinable seed contents of all species were measured. Seed content of faeces was higher in the summer and autumn than in the winter and spring samplings, and in the heavily stocked than in the lightly stocked pastures. The highest content recorded was 20.5 germinable seeds g-1 faecal dry matter. The species with the highest germinable seed content in faeces were Digitaria didactyla, Axonopus affinis and Eleusine indica, the latter being restricted to nitrogen-fertilized pastures. Seed dissemination in faeces is a factor contributing to the invasiveness of prostrate perennial grasses such as D. didactyla and A. affinis under heavy grazing.

Persistence and growth of Lotononis bainesii–Digitaria decumbens pastures: 1. Sheep stocking rate

1983 ◽  
Vol 101 (1) ◽  
pp. 1-7 ◽  
Author(s):  
A. Pott ◽  
L. R. Humphreys
Keyword(s):  
Bulk Density ◽  
Soil Bulk Density ◽  
Grazing Pressure ◽  
Stocking Rate ◽  
Digitaria Decumbens ◽  
Heavy Grazing ◽  
Cotton South ◽  
Seed Reserves ◽  
Stocking Rates

SUMMARYSheep were grazed for 2 years at stocking rates of 7, 14, 21 and 28/ha on a pasture comprising Lotononis bainesii and Digitaria decumbens cv. Pangola at Mt Cotton, south–east Queensland. There were six replicates of each treatment grazed in rotation with 3 days' grazing followed by 15 days' rest.The initial dominance of lotononis was lost after 6 months of grazing and lotononis failed to persist satisfactorily at any stocking rate. Demographic studies showed that lotononis behaved as a short-lived plant, predominantly annual, with some vegetative perennation as stolon-rooted units under heavy grazing. Soil seed reserves varied from 5800 to 400 m2 at the lightest and heaviest stocking rates respectively. Lotononis failed to regenerate under Pangola shading or inopportune high grazing pressure. Soil bulk density (0–7 cm) increased from 1·2 to 1·4 g/cm3 according to stocking rate.

Renovation of Yarloop subterranean clover pastures with Trikkala

1988 ◽  
Vol 28 (6) ◽  
pp. 737 ◽  
Author(s):  
DL Little ◽  
PE Beale
Keyword(s):  
Dry Matter ◽  
Plant Density ◽  
Subterranean Clover ◽  
Stocking Rate ◽  
Seed Reserves ◽  
Minimal Damage ◽  
Stocking Rates ◽  
Germinable Seed ◽  
Clover Scorch

Pastures containing the oestrogenic subterranean clover, Yarloop, were renovated and sown to Trikkala subterranean clover at the rate of 9 kg ha-1 germinable seed. The resultant pastures were continually grazed at either 7, 9 or 12 ewes ha for 6 years. Control Yarloop pastures were grazed similarly. Trikkala established at approximately 50 plants m-2 and represented 80% of all clover present in the year of sowing. Six years later Trikkala was successfully persisting at all stocking rates in terms of clover dry matter in spring (Trikkala 77%, Yarloop 23%), soil seed reserves in spring (Trikkala 450-1000 kg ha-1, Yarloop 300-450 kg ha-1) and plant density in spring (Trikkala 600-1000 plants m-2, Yarloop 200 plants m-2). Over the 6 years of the trial the proportion of Trikkala and Yarloop approached an equilibrium of 75% Trikkala to 25% Yarloop in all agronomic data collected. Compared with the control Yarloop pastures, the renovated Trikkala pastures maintained a greater clover percentage at all stocking rates. Available dry matter at the high stocking rate was consistently greater in the Yarloop pastures during winter and spring. At the low and medium stocking rates available dry matter tended to be greater in the Yarloop treatments for the first 2 years but was similar for both treatments in the latter 3 years. Clover scorch disease in the Yarloop pasture was controlled by spraying with a fungicide. Trikkala pastures were not sprayed and suffered minimal damage from the disease. Trikkala should perform better relative to Yarloop where clover scorch is a problem. It is concluded that Trikkala subterranean clover can successfully replace Yarloop subterranean clover in pastures previously dominated by Yarloop.

The effect of stocking rate on the population dynamics of siratro in siratro (Macroptilium atropurpureum)-setaria (Setaria sphacelata) pastures in south-east Queensland. II. Seed set, soil seed reserves, seedling recruitment and seedling survival

1988 ◽  
Vol 39 (2) ◽  
pp. 221 ◽  
Author(s):  
RM Jones ◽  
GA Bunch
Keyword(s):  
Seed Set ◽  
Seedling Recruitment ◽  
Seedling Survival ◽  
Stocking Rate ◽  
Seedling Regeneration ◽  
Pasture Legumes ◽  
Setaria Sphacelata ◽  
Seed Reserves ◽  
Cattle Faeces

Measurements were made of the seed set, seed content in cattle faeces, soil seed reserves, seedling regeneration and seedling survival of Siratro (Macroptilurn atropurpureum) in south-east Queensland. Measurements were made from 1972 to 1985 in pastures of Siratro/setaria (Setaria sphacelata) sown in 1968 and stocked at 1.1, 1.7 and 2.3 and at 3.0 (1969-1973) reduced to 2.0 (1974-1985) heifers ha-1. Siratro seed set and seedling demography were markedly affected by stocking rate. At the highest stocking rate, Siratro yields were low and seed input ceased after 1972, yet appreciable seedling recruitment from the soil seed bank was maintained for a further 10 years. At the lightest stocking rate (1.1 heifers ha-1), seed set and soil seed reserves were highest, but seedling recruitment was of little importance as almost all seedlings died. Seedling recruitment and survival were best at an intermediate stocking rate (1.7 heifers ha-1), where they were the key to long-term persistence of Siratro. Soil seed reserves of Siratro ranged from 500 m-2 under light stocking to < 100 m-2 after several years of heavy stocking. Very little seed was recovered in cattle faeces. Likely factors responsible for seedling death (light, water, nutrients, grazing, frosting and insect damage) are discussed. The limitations of seed set and seedling regeneration in the persistence of Siratro are contrasted with some other perennial pasture legumes. Studies of this type can help in qualitatively predicting long-term persistence of pasture legumes under different conditions of management and climate.

Steer gains, pasture yield and pasture composition on native pasture and on native pasture oversown with Indian couch (Bothriochloa pertusa) at three stocking rates

1997 ◽  
Vol 37 (7) ◽  
pp. 755 ◽  
Author(s):  
R. J. Jones
Keyword(s):  
Perennial Grasses ◽  
Grass Species ◽  
Stocking Rate ◽  
Pasture Grass ◽  
Pasture Production ◽  
Heteropogon Contortus ◽  
Native Pasture ◽  
Unit Increase ◽  
Stocking Rates ◽  
Pasture Yield

Summary. Pasture production and steer liveweight gain were compared on native pasture (Bothriochloa decipiens, Heteropogon contortus, Themeda triandra and Chrysopogon fallax) and on native pasture oversown with Indian couch or Indian bluegrass (Bothriochloa pertusa). This grass was not a planned introduction to the area but is spreading in Central and North Queensland and its value as a pasture species is questioned by graziers. There were 3 nominal stocking rates of 0.3, 0.6 and 0.9 steers/ha. Each paddock was stocked with 3 steers of stratified ages. The experiment was sown in March 1988 and terminated in June 1993. The experiment, sited 50 km south of Townsville in eucalypt woodland on a solodic-solodised-solonetz soil, was sown in March 1988 and terminated in June 1993. Increases in stocking rate resulted in a linear decline in both pasture yield (by 3–5 t/unit increase in stocking rate) and steer gains (by more than 100 kg/unit increase in stocking rate). Differences between pastures were apparent only at the medium and high stocking rates where, over time, Indian couch gave higher pasture yields and steer gains. Younger steers gained far more weight than older steers. Mean gains over 3 years were weaners 125 kg/year, yearlings 93 kg/year and 2-year-old steers 46 kg/year. Native pasture remained fairly stable botanically at the low stocking rate, but the tufted perennial grass species declined at both the medium and high stocking rates. Sowing Indian couch hastened the botanical changes due to stocking rate, and it became the dominant species at these higher stocking rates. At the low stocking rate, the contribution of Indian couch declined from initial values indicating that this is not an invasive species in the area at a low stocking rate. Contribution of Indian couch to pasture yield was linearly related to stocking rate. Nutritional quality of the Indian couch was similar to the other native perennial grasses though calcium concentration was higher. Increased steer gains were related to higher yield on Indian couch pastures at the higher stocking rates rather than to improved quality. Maximum liveweight gain/ha was achieved at about 0.6 steers/ha. Stocking at 0.9 steers/ha was not sustainable. Even at the low stocking rate, steers would need to spend about 2.8 years on the pastures after weaning to reach 500 kg liveweight. It was concluded that B. pertusa is a useful pasture grass in this environment giving steer gains equal to, or higher than, the gains from the native pasture which it replaced.

Tactical versus continuous stocking in perennial ryegrass-subterranean clover pastures grazed by sheep in south-western Victoria. 1. Stocking rates and herbage production

2001 ◽  
Vol 41 (8) ◽  
pp. 1099 ◽  
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 ◽  
Stocking Rate ◽  
Soil Fertility Status ◽  
Western Victoria ◽  
Terminal Sire ◽  
Autumn And Winter ◽  
Stocking Rates

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 year-around 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 herbage production and stocking rate are presented in this paper. Herbage production was similar between the treatments, but tactical stocking significantly increased herbage mass during the growing season (P<0.05) compared with continuous stocking. In spring each year, the herbage mass generally exceeded 3000 kg dry matter/ha in tactically stocked paddocks and averaged 500–900 kg dry matter/ha higher than the mass on continuously stocked paddocks. This enabled the year-round stocking rate to be increased by an average of 9% over the 4 years of the experiment. We considered that the stocking rates could not be further increased, despite the higher herbage mass in spring, as stock reduced the dry herbage to a low residual mass by the opening rains in autumn. In contrast, stocking rates averaged 51% higher on the upgraded pasture compared with the typical pasture over the 4 years of the experiment. This indicates that pasture improvement and soil fertility status have a much greater impact on productivity than changes to grazing method. However, tactical stocking was able to increase the sustainability of prime lamb production on upgraded pastures in a dry summer climate, by maintaining herbage cover on the paddocks over the summer–autumn period.

Effect of stocking rate and grazing frequency on a Siratro (Macroptilium atropurpureum)/Setaria anceps cv. Nandi pasture

1979 ◽  
Vol 19 (98) ◽  
pp. 318 ◽  
Author(s):  
RM Jones
Keyword(s):  
Total Yield ◽  
Rest Period ◽  
Residual Effect ◽  
Stocking Rate ◽  
Animal Performance ◽  
Good Recovery ◽  
Seedling Regeneration ◽  
Seed Reserves ◽  
Macroptilium Atropurpureum ◽  
Stocking Rates

Five stocking rates, ranging from 0.8 to 2.8 beasts ha-1, and three frequencies of grazing were imposed on a five-year-old Siratro (Macroptilium atropurpureum)/Setaria anceps cv. Nandi pasture at Samford, south-east Queensland. The three grazing frequencies involved grazing for four days every three, six or nine weeks. Plots were individually grazed from 1972 to 1976 and the residual effect of treatments was measured over a grazing-free period in 1977. Within the three week grazing frequency both Siratro yield and total yield declined markedly with increased stocking rate, with an increased invasion of prostrate species such as blue couch (Digitaria didactyla). The decline in Siratro yield at higher stocking rates was less marked in the nine week system where there was much less invasion of prostrate species. However, it is suggested that the value of rotational grazing with a long rest period as a means of maintaining Siratro productivity could be largely at stocking rates where the pasture is overgrazed in terms of animal performance. Siratro density and seedling regeneration were largely unaffected by treatment and there was a good recovery of Siratro in the heavily grazed treatments during the grazing-free period at the end of the experiment. However, Siratro soil seed reserves declined with increased stocking rate and there was a much greater decline in flowering and seeding. On this basis it is predicted that if grazing treatments had been continued the heavily grazed pastures would eventually have reached the stage where Siratro would not recover with spelling.

Impact of phosphorus application and sheep grazing on the botanical composition of sown pasture and naturalised, native grass pasture

2004 ◽  
Vol 55 (12) ◽  
pp. 1213 ◽  
Author(s):  
J. O. Hill ◽  
R. J. Simpson ◽  
A. D. Moore ◽  
P. Graham ◽  
D. F. Chapman
Keyword(s):  
Trifolium Subterraneum ◽  
Perennial Grasses ◽  
Botanical Composition ◽  
Stocking Rate ◽  
Annual Species ◽  
Basal Cover ◽  
Grazing Systems ◽  
P Application ◽  
Phosphorus Application ◽  
Stocking Rates

Botanical composition (basal cover) was measured in 4 replicated pasture treatments based on Phalaris aquatica and Trifolium subterraneum at Hall, ACT (unfertilised with low and high stocking rate; fertilised with low and high stocking rate) and in 2 unreplicated pasture treatments based on native perennial grasses (Austrodanthonia spp. and Microlaena stipoides) and T. subterraneum at Bookham, NSW (unfertilised and low stocking rate; fertilised and high stocking rate). Current economic pressures are encouraging graziers to increase their use of phosphorus (P) fertiliser and to adopt higher stocking rates. The objective of the research was to determine the changes in botanical composition that may result from these changes in grazing systems management. At Hall, annual species differed in their responses to P fertility. Notably, basal cover of Bromus spp. increased significantly with P application, whereas Vulpia spp. decreased significantly. Basal cover of T. subterraneum also increased significantly with P application when stocking rate was high, but was reduced by P application if stocking rate was low. Basal cover of perennial grasses (P. aquatica and Holcus lanatus) was significantly higher at low stocking rate when P was applied. The botanical composition of high stocking rate treatments was relatively stable over time, which contrasted with less stable composition at low stocking rate. At Bookham, fertilised pasture in unreplicated paddocks appeared to have a higher basal cover of productive annual species (i.e. Bromus spp. and T. subterraneum), but native perennial grasses appeared to have lower basal cover in comparison with the unfertilised area. These results indicated that in some cases, the influence of P fertiliser and high stocking rates on botanical composition was favourable (i.e. increased basal cover of P. aquatica and T. subterraneum) and in others it could be detrimental (i.e. lower basal cover of native perennial grasses).

Grazing studies of a Hyparrhenia hirta (Coolatai grass) pasture in northern New South Wales

2005 ◽  
Vol 45 (12) ◽  
pp. 1603 ◽  
Author(s):  
G. M. Lodge ◽  
L. H. McCormick ◽  
S. Harden
Keyword(s):  
New South ◽  
Basal Area ◽  
Ground Cover ◽  
Experimental Period ◽  
Stocking Rate ◽  
Soil Microbial ◽  
Basal Cover ◽  
South Wales ◽  
Heavy Grazing ◽  
Stocking Rates

Hyparrhenia hirta (L.) Stapf (Coolatai grass) has invaded large areas of grazed native grasslands on the North-West Slopes of New South Wales (NSW) and is widespread along roadsides and travelling stock routes. It is commonly regarded as an invasive, weedy species with low forage value when it is tall and rank, but may be more palatable when kept short, green and leafy. A study (1990–2001) of a naturalised stand of Coolatai grass in the Manilla district of northern NSW examined its herbage mass (kg DM/ha), persistence (basal cover %), and grazing value under 2 contrasting grazing treatments: pastures that had either large amounts of dry, unpalatable herbage [light grazing at 5 dry sheep equivalents (DSE)/ha] or were short, green and leafy (strategic heavy grazing at a stocking rate of 37 DSE/ha). Effects of pre-grazing treatments (slashing, burning, and no defoliation) were also examined and data (litter mass, plant basal area, ground cover, and soil and litter microbial carbon and nitrogen) collected to assess the long term sustainability of these grazing systems. Sheep grazed the light grazing treatment for about 34% of the experimental period, with the strategic heavy grazing treatment being grazed for about 7% of the time. Over the experimental period this equated to 6752 DSE grazing days/ha for the light grazing treatment compared with 10 120 DSE for the heavy grazing treatment. Herbage mass in the heavy grazing treatment declined to <1000 kg DM/ha within 6 months of the start of grazing and remained below this level until December 1998 when stocking rates were switched (i.e. plots previously grazed at low stocking rate were subjected to the heavier rate and vice versa). In contrast, mean herbage mass in the light grazing treatment was generally >3000 kg DM/ha from November 1990–98, but a high proportion of this was dead standing material that carried over from season to season. Mean Coolatai grass basal cover was 9.5% in November 1990, increasing over time to about 25% in both grazing treatments by December 2000. Coolatai grass herbage accumulation was highly seasonal, ranging from as high as 70 kg DM/ha.day in summer to 0 in winter. In both grazing treatments, forage quality was low for both green and dead material, with mean crude protein being 6.0 (green) and 3.4% (dead). Digestible dry matter values ranged from 41 to 62% (green) and 32 to 51% (dead) and mean metabolisable energy values were 7 (green) and 5.3 MJ/kg DM (dead). After 8 years, the heavy grazing treatment had lower (P<0.05) litter mass, ground cover, plant basal area and soil microbial C and N levels than the light grazing treatment, but switching of the stocking rates restored most indicators, except the soil microbial values.

The colonization of a tropical grassland by Stylosanthes from seed transported in cattle faeces

1993 ◽  
Vol 44 (2) ◽  
pp. 299 ◽  
Author(s):  
CJ Gardener
Keyword(s):  
Seed Production ◽  
Wet Season ◽  
Dry Tropics ◽  
Grazing Cattle ◽  
Heavy Grazing ◽  
Seed Content ◽  
Native Grassland ◽  
Cattle Faeces ◽  
Highly Correlated ◽  
Grazing Pressures

The dynamics of the spread of four Stylosanthes species by grazing cattle from sown areas to nearby native grassland R& studied over ten years in the dry tropics of north Queensland. The first recruitment of Stylosanthes in the grassland occurred during the third growing season. Secondary colonization took place around the primary plants, and by the tenth year, 94% of the 0.25 m2 quadrats sampled in the grassland contained one or more species of Stylosanthes. Large seed numbers were produced by Stylosanthes on the sown areas during primary colonization. Mean yields of above-ground biomass were high (4000 kg ha-1year-1) despite heavy grazing pressures, and 6% of this biomass was channelled into seed production (25 000 seeds kg biomass-1). Seed content in the cattle faeces reached a peak at the end of the wet season and accounted for 8% of seed production. The numbers of seeds in the faeces were highly correlated with the numbers of seeds produced on the sown areas. Only 1.5% of the seed excreted in the grassland grew into established plants despite most seeds being viable. Varying the amount of grass had little effect on establishment. The two short-lived herbaceous species, S. guianensis and S. hamata, were more efficient colonizers (i.e. produced more seedlings per unit biomass) than the more perennial shrubby types, S. scabra and S. viscosa. The former two species produced more seeds per unit biomass and more plants per unit of seed in the faeces.

Evaluation of natural annual pasture at Trangie in central western New South Wales. 3. Effect of stocking rate on annual-dominated and perennial-dominated natural pastures

1978 ◽  
Vol 18 (92) ◽  
pp. 361 ◽  
Author(s):  
GE Robards ◽  
DL Michalk ◽  
RJ Pither
Keyword(s):  
New South ◽  
Perennial Grass ◽  
New South Wales ◽  
Perennial Grasses ◽  
Stocking Rate ◽  
Wool Production ◽  
South Wales ◽  
Natural Pasture ◽  
Ewe Lamb ◽  
Stocking Rates

A four year experiment is reported during which breeding Merino ewes grazed two natural pasture types at three stocking rates at Trangie in central-western New South Wales. Initially, the pasture on a red brown soil was dominated by cool season annual species, particularly Hordeum leporinum, Erodium species and Medicago species. The pasture on a heavier grey soil was dominated by the perennial grasses Chloris acicularis, C. truncata and Stipa variabilis. Clean wool production of ewes grazing the annual-dominated pasture was significantly (P< 0.05) higher than that of ewes grazing the perennial grass-dominated pasture even though the wool of the ewes grazing perennial pasture had a higher percentage clean yield (P < 0.05). The ewes on the annual-dominated pasture were significantly heavier in autumn and winter, and had a faster rate of wool growth in each season except spring, than ewes grazing perennial pasture. Number of lambs born per ewe, lamb birth weight and lamb growth rate were not affected by pasture type or stocking rate. Stocking rate had a small but statistically significant effect on clean wool production and only small effects on ewe liveweight, regardless of pasture type. When hand feeding of the pregnant ewes became necessary in the poor winters of 1971 and 1972 all stocking rates had to be commenced simultaneously. The significance of perennial grasses in these natural pastures is discussed in relationship to animal production, stocking rate, pasture and soil stability, and regeneration of grasses following favourable seasons.

Sign in / Sign up

Export Citation Format

Share Document