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.

Variation in seasonal stocking rate and the dynamics of Lotononis bainesii in Digitaria decumbens pastures

1992 ◽  
Vol 118 (1) ◽  
pp. 47-53
Author(s):  
H. Fujita ◽  
L. R. Humphreys
Keyword(s):  
Ecological Niche ◽  
Large Scale ◽  
Late Summer ◽  
Early Summer ◽  
Flowering Period ◽  
Stocking Rate ◽  
Seedling Density ◽  
Digitaria Decumbens ◽  
Cotton South ◽  
Seed Reserves

SUMMARYPastures of Digitaria decumbens (pangola grass) previously oversown with Lotononis bainesii at Mount Cotton, south-east Queensland, Australia, were grazed by sheep for 3 years (1985–87), using a factorial combination of seasonal variations in stocking rate.Lotononis behaved as a short-lived plant with a mean half-life of 4·2 months (range 1·6–10·3); rate of mortality was positively related to initial seedling density. The proportion of lotononis remained very low for the first 2 years of the experiment, when conditions were unsuitable for large-scale seedling regeneration, which was also limited by the hardness of the seed reserves. Subsequently, lotononis regenerated well in treatments which combined the following features: (i) light grazing (5 sheep/ha) during the main flowering period of spring-early summer, (ii) heavy short-duration grazing in mid-summer to create a ‘gap’ and (iii) medium or heavy (18 or 27 sheep/ha) grazing during late summer-autumn to reduce competition from pangola grass.The ecological niche of lotononis and the possible use of complementary pastures are discussed.

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.

Long-term grazing effects on grassland soil properties in southern British Columbia

2012 ◽  
Vol 92 (4) ◽  
pp. 685-693 ◽  
Author(s):  
C. R. W. Evans ◽  
M. Krzic ◽  
K. Broersma ◽  
D. J. Thompson
Keyword(s):  
British Columbia ◽  
Soil Properties ◽  
Bulk Density ◽  
Aggregate Stability ◽  
Soil Bulk Density ◽  
Mechanical Resistance ◽  
Stocking Rate ◽  
Grassland Soil ◽  
Grazing Effects

Evans, C. R. W., Krzic, M., Broersma, K. and Thompson, D. J. 2012. Long-term grazing effects on grassland soil properties in southern British Columbia. Can. J. Soil Sci. 92: 685–693. Although grazing effects on soil properties have been evaluated on various temperate grasslands, no study has dealt with these effects in the southern interior of British Columbia. The objective of this study was to determine the effects of spring versus fall season grazing as well as grazing [at a moderate rate of 0.6 animal unit months (AUM) ha−1] versus non-grazing by beef cattle on selected soil properties. Effects were determined 20 and 30 yr after the establishment of the field experiment. Soil properties were determined for the 0- to 7.5-cm, 7.5- to 15-cm, and 15- to 30-cm depths. In comparison with fall grazing, spring grazing had greater soil bulk density, greater mechanical resistance within the top 15 cm of the soil profile, higher pH, and lower polysaccharides. This was true for both 20 and 30 yr of treatment. Grazing effects on aggregate stability were observed only after 30 yr with spring grazing leading to a more stable structure with a mean weight diameter (MWD) of 1.5 mm and 32% and 10% of aggregates in the 2- to 6-mm and 1- to 2-mm size fractions, respectively, compared with a MWD of 1.0 mm and 20% and 6% under fall grazing. Greater soil bulk density, mechanical resistance, and pH were observed under the grazed treatment relative to the control without grazing, but as we used a moderate stocking rate the impacts were not as great as in previous studies, which used heavy stocking rates. Our findings show that long-term grazing at a moderate stocking rate of 0.6 AUM ha−1did not have critical detrimental effects on soil properties as some land managers and ranchers have suggested.

Soil hydrology and vegetation as impacted by goat grazing in Vertisols and Regosols in semi-arid shrublands of northern Mexico

2017 ◽  
Vol 39 (4) ◽  
pp. 363 ◽  
Author(s):  
Nallely A. Carbajal-Morón ◽  
Mario G. Manzano ◽  
Ricardo Mata-González
Keyword(s):  
Organic Matter ◽  
Bulk Density ◽  
Plant Cover ◽  
Grazing Intensity ◽  
Soil Bulk Density ◽  
Soil Hydrology ◽  
Goat Grazing ◽  
Heavy Grazing ◽  
The World ◽  
Tamaulipan Thornscrub

Shrubland ecosystems are less studied than grasslands regarding the role of domestic grazing on ecosystem degradation in the world, but particularly in Mexico. Of special concern is the paucity of research on soil hydrological responses to the impact of livestock. Here, we assessed the role that specific soil and surface characteristics play in soil hydrology as a response to goat grazing intensity in two different soil types, Regosol and Vertisol, in the Tamaulipan thornscrub of north-eastern Mexico. At each soil unit, a set of grazing regimes was identified, including heavy grazing (HG), moderate grazing (MG) and a no-grazing (NG) reference area, and selected soil properties and plant cover were evaluated. In Regosol sites, soil organic matter varied among all grazing regimes (4.6% higher on NG and 2.1% higher on MG with respect HG) and no dissimilarities on bulk density were recorded. For Vertisol sites, soil bulk density increased with grazing intensity (16% higher on MG and 37% higher on HG with respect to NG) whereas plant cover linearly decreased from 86% in NG to 29% in MG and 9% in HG sites. Soil organic matter content for Regosol, and plant cover and soil bulk density for Vertisol appeared as the best indicators of water infiltration and moisture retention for the grazing conditions assessed. Differences in those key driving variables may help explain surface hydrology responses to goat grazing in rangeland soils of Tamaulipan thornscrub ecosystems and possibly on similar rangelands around the world. Clear signs of vegetation degradation were also observed, manifested by a loss in species diversity and plant cover, especially under heavy grazing. This reflects unsustainable livestock management practices that should be avoided. This study contributes to improve our understanding of rangeland degradation processes and justifies devising more sustainable grazing management schemes.

Effects of soils, fertilizers and stocking rates on pastures and beef production on the Wallum of south-eastern Queensland. 1. Botanical composition and chemical effects on plants and soils

1973 ◽  
Vol 13 (64) ◽  
pp. 516 ◽  
Author(s):  
WW Bryan ◽  
TR Evans
Keyword(s):  
Botanical Composition ◽  
Stocking Rate ◽  
Total N ◽  
Organic C ◽  
Podzolic Soils ◽  
South Eastern ◽  
Digitaria Decumbens ◽  
Chloris Gayana ◽  
Species Frequencies ◽  
Stocking Rates

A complex pasture mixture was grazed by cattle at three stocking rates (1.23, 1.65 and 2.47 beasts a hectare) at Beerwah, south-eastern Queensland over six years. There were four fertilizer treatments involving two rates of superphosphate and three of KCl. On the basis of species frequencies, the seven major soil types on the area fell into two groups, the podzolic soils in one and the humic gleys in another. The podzolics were favoured by Chloris gayana, Desmodium intortum, D. uncinatum and Lotononis bainesii, whereas Paspalum dilatatum and Trifolium repens were more frequent on the humic gleys. The light stocking rate favoured Paspalum commersonii, Digitaria decumbens and both Desmodium species. At the high stocking rate P. dilatatum, T. repens and L. bainesii were more prominent, as were weeds in general. Application of KCl had no effect on botanical composition but the K content of soils and plants increased with increasing levels of application. As the superphosphate rate was increased, the proportion of all sown species except P. dilatatum and L. bainesii increased and the weed content decreased. Over time, the legume content in all plots decreased, weeds increased and the grass content remained about the same. The effects were more marked at low rates of superphosphate and high stocking rate. There was a lower legume content and a higher weed content in winter than in summer, but soils and treatments had similar effects in both seasons. Compared with virgin soils, those under fertilized pastures for eight years contained more organic C, available P, K and Ca, total N, and Zn and Fe.

Summer Grazing Management of a White Clover-Bahiagrass Pasture: Legume Survival

1986 ◽  
Vol 22 (4) ◽  
pp. 363-371 ◽  
Author(s):  
B. H. Dzowela ◽  
G. O. Mott ◽  
W. R. Ocumpaugh
Keyword(s):  
White Clover ◽  
Seedling Recruitment ◽  
Grazing Pressure ◽  
Grazing Management ◽  
Primary Mechanism ◽  
Heavy Grazing ◽  
Seed Reserves ◽  
Survival Potential ◽  
Summer Grazing ◽  
Pasture Legume

SUMMARYA grazing management study involving the new white clover cultivar Osceola grown in association with Bahiagrass cv. Pensacola was conducted on wet and dry sites with and without pesticide/herbicide treatment. A combination of heavy grazing pressure and a short deferment period before grazing during the summer and autumn resulted in the largest soil seed reserves and seedling recruitment by the white clover component. However, maximum survival of plants was recorded from a combination of a short deferment period and moderate grazing pressure.A slight increase in plant survival and seedling recruitment was shown on the wet site. Survival potential was least in pasture treated with pesticide and herbicide. Heavy grazing pressure and short deferment periods appear essential for the survival of the clover component. Annual seedling recruitment from soil seed reserves was the primary mechanism of white clover survival from spring to spring in pasture associations based on tropical bahiagrass.

Stocking intensity and pastoral production: I. Changes in the soil and vegetation of a sown pasture grazed by sheep at different stocking rates

1973 ◽  
Vol 81 (2) ◽  
pp. 193-204 ◽  
Author(s):  
J. P. Langlands ◽  
I. L. Bennett
Keyword(s):  
Soil Moisture ◽  
Bulk Density ◽  
Pore Space ◽  
Water Infiltration ◽  
Root Weight ◽  
Stocking Rate ◽  
Pasture Production ◽  
Basal Cover ◽  
Soil Pore Space ◽  
Stocking Rates

SummaryA Phalaris tuberosa and Trifolium repens pasture was grazed continuously at stocking rates varying from 2·5 to 37·1 sheep per ha between 1964 and 1969. During this period herbage availability and composition, basal cover, root weight, water infiltration, soil moisture content, bulk density and chemical composition of the soil were measured at intervals.As stocking rate was increased, herbage availability, root weight, basal cover, soil pore space and the rate of water infiltration declined, and bulk density and the nitrogen and calcium contents of the herbage on offer increased. In periods of below-average rainfall, soil moisture and nitrate levels were greater when herbage was of low availability.Herbage production was calculated from estimates of herbage consumption and of litter decomposition, and averaged 8·45 t dry matter/ha/year; it was insensitive to changes in stocking rate over the range from 2 to 22 sheep/ha. The ratio, herbage consumption/ pasture production increased by 0'045 per unit increase in 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.

Grazing trials on the Wallum of south-eastern Queensland. 3. A nursery grazed by sheep

1971 ◽  
Vol 11 (53) ◽  
pp. 633 ◽  
Author(s):  
WW Bryan ◽  
TR Evans
Keyword(s):  
Soil Fertility ◽  
White Clover ◽  
Trifolium Repens ◽  
Single Species ◽  
Grazing Pressure ◽  
Botanical Composition ◽  
Digitaria Decumbens ◽  
Heavy Grazing ◽  
Brachiaria Mutica ◽  
Coastal Lowlands

A nursery of single species and simple mixtures of 12 grasses and 9 legumes at Beerwah on the coastal lowlands of southern Queensland was grazed by sheep for over 16 years. For the last eight years 25.8 wethers a hectare (10.5/acre) were carried and thrived, heavy grazing pressure being maintained. Changes in botanical composition were recorded. The final mixture was dominated by Trifolium repens and Paspalm notatum. Other species to survive were Digitaria decumbens, Pennisetum clandestinum, Paspalum wettsteinii, and Brachiaria mutica. The majority of species failed to survive the close intense grazing by sheep. Annual replacements of phosphorus, sulphur, calcium, and potassium were made but nitrogen was never applied, and the highly productive pasture was maintained by legume nitrogen, mainly from white clover. Soil fertility improved under the pasture.

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.

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