Superphosphate and stocking rate effects on a native pasture oversown with Stylosanthes humilis in central coastal Queensland. 1. Pasture production

1978 ◽  
Vol 18 (95) ◽  
pp. 788 ◽  
Author(s):  
NH Shaw
Keyword(s):  
Soil Phosphorus ◽  
Total Yield ◽  
Botanical Composition ◽  
Stocking Rate ◽  
Pasture Production ◽  
Average Percentage ◽  
Heteropogon Contortus ◽  
Native Pasture ◽  
Nitrogen Concentrations ◽  
Stocking Rates

Changes in the yield, botanical composition and chemical composition of a native pasture (Heteropogon contortus dominant) oversown with S. humilis (T.S.) were measured in a grazing experiment from 1966 to 1973. The 24 treatments were factorial combinations of two sowing methods for T.S. (ground sowing into spaced cultivated strips, or aerial sowing), three levels of molybdenized superphosphate (F0 = nil ; F1 = 125 kg ha-1 annually; F2 = 250 kg ha-1 annually plus an extra 250 kg ha-1 initially) and four stocking rates. Stocking rates were gradually increased during the experiment and for the last three years overlapping ranges were used for the three fertilizer levels; the overall range was then from 0.55 to 1.65 beasts ha 1 T.S. establishment by ground sowing was much more reliable than from aerial sowing, giving twice the average percentage frequency, and this proportion was maintained over years. High fertilizer improved establishment and the best legume stands were in the high fertilizer high stocking rate treatments. Total presentation yield of pasture was increased by fertilizer and reduced by high stocking rates. Over the last two years the means for March, adjusted by regression to the overall average stocking rate of 0.98 beasts ha-1, were 31 20,4020 and 5370 kg ha-1 for F0, F1 and F2 respectively, but these yields were reduced by ca 25 per cent for an increase of 0.5 beasts ha-1. H. contortus remained dominant and its mean contribution to total yield increased from 48 per cent in 1969 to 67 per cent in 1973. This proportion was reduced by 12.8 per cent over the range from 0.55 to 1.65 beasts ha-1, but high fertilizer had the opposite effect so that differences between the extremes low stocked F0 and high stocked F2 were small. The DM percentage yield of T.S. was strongly increased by fertilizer, and, most importantly, also by high stocking rates in the presence of fertilizer. Values for F0 treatments remained below 10 per cent, but in the final year values for F1 and F2 at the highest stocking rates were 36 and 27 per cent, respectively. Despite these large changes in T.S., there was overall stability of botanical composition. Phosphorus and nitrogen concentrations in T.S. and H. contortus were increased by superphosphate but there was an overall decline in potassium concentration. Soil phosphorus levels were greatly increased

Impacts of grazing management options on pasture and animal productivity in a Heteropogon contortus (black speargrass) pasture in central Queensland. 1. Pasture yield and composition

2010 ◽  
Vol 61 (2) ◽  
pp. 170 ◽  
Author(s):  
D. M. Orr ◽  
W. H. Burrows ◽  
R. E. Hendricksen ◽  
R. L. Clem ◽  
P. V. Back ◽  
...  
Keyword(s):  
Total Yield ◽  
Summer Rainfall ◽  
Stocking Rate ◽  
Management Options ◽  
Pasture Production ◽  
Heteropogon Contortus ◽  
Native Pasture ◽  
Stylosanthes Scabra ◽  
Animal Diet ◽  
Stocking Rates

An extensive grazing study was conducted between 1988 and 2001 in a Heteropogon contortus (black speargrass) pasture in central Queensland. The study was designed to measure the effects of stocking rate on native pasture, native pasture with legume oversown, and native pasture with animal diet supplement/spring burning on pasture and animal production. Summer rainfall throughout the study was below the long-term mean. Mean annual pasture utilisation ranged from 13% at 8 ha/steer up to 61% at 2 ha/steer. Increasing stocking rate treatments reduced total pasture yields while total yields in legume oversown treatments were similar to those in native pasture at the same stocking rate. When spring burning was possible, total yields were reduced in the subsequent autumn. Increasing stocking rate in native pasture tended to reduce H. contortus and Bothriochloa bladhii, increased the composition of intermediate species, such as B. decipiens and Chloris divaricata, and also changed the frequencies of a range of minor species. Oversowing legumes resulted in Stylosanthes scabra cv. Seca increasing from <1% of pasture composition in 1988 to 50% in 2000 and was associated with a reduction in H. contortus and changes in the frequencies of some minor species. Stocking rates heavier than 4 ha/steer resulted in annual pasture utilisation greater than 30% and were unsustainable because they reduced total yield and resulted in undesirable changes in species composition. It was concluded that pasture production was sustainable when stocking rates were maintained at 4 ha/steer, which equates to 30% annual pasture utilisation, and through the judicious use of spring burning.

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.

Herbage and animal production from native pastures and pastures oversown with Stylosanthes hamata. 1. Fertiliser and stocking rate effects

1993 ◽  
Vol 33 (5) ◽  
pp. 561 ◽  
Author(s):  
CJ Gardener ◽  
MR McCaskill ◽  
JG McIvor
Keyword(s):  
Animal Production ◽  
Stocking Rate ◽  
Heteropogon Contortus ◽  
Stylosanthes Hamata ◽  
Stylosanthes Humilis ◽  
Native Pasture ◽  
Utilisation Rate ◽  
Native Pastures ◽  
Fertiliser Application ◽  
Stocking Rates

Native pastures dominated by Heteropogon contortus (speargrass) were sown to Stylosanthes hanzata cv. Verano in 1972, and herbage production and steer growth rates were compared with those of native pastures from 1973 to 1985. The native pastures also contained naturalised Stylosanthes humilis, but its contribution to pasture yield diminished rapidly, after infection by Colletotrichum gloeospoirioides (anthracnose) in 1973. The experiment was a factorial design of 2 pasture types (native, native plus Verano) x 2 stocking rates (0.6, 1.2 steers/ha) x 2 superphosphate treatments (nil, 300 kg/ha.year) x 2 replicates. Fertiliser application decreased the proportion of legume but had no significant effect on herbage or animal production on this comparatively fertile site (extractable P, 18 mg/kg). Annual liveweight gains at the high and low stocking rates, respectively, on the native pasture averaged 100 and 120 kg/steer. Sowing to Verano did not affect herbage yields but increased annual liveweight gains by 28 and 36 kg/steer at low and high stocking rates. The high stocking rate of 1.2 steers/ha was sustainable for the first 9 years of the experiment, when above-average rainfall was received. However, in the following 3 below-average years, there was a shift to less-desirable species, and a decline in pasture productivity. Relative to the low stocking rate, herbage production on the native pasture in the final season was reduced by 60% and on the Verano pasture by 26%. The highest annual herbage utilisation rate that appeared sustainable in the long term was about 45%, which corresponded to a utilisation rate of 30% during the growing season (about November-May). When oversown with Verano, speargrass tended to decline in favour of annual grasses, weeds, and the introduced grass Urochloa mosanzhicensis, which had been sown on an adjacent experiment. Urochloa appeared to be a more suitable companion species than speargrass for Verano.

Pasture yield and composition changes in a Central Queensland black speargrass (Heteropogon contortus) pasture in relation to grazing management options

2001 ◽  
Vol 41 (4) ◽  
pp. 477 ◽  
Author(s):  
D. M. Orr ◽  
W. H. Burrows ◽  
R. E. Hendricksen ◽  
R. L. Clem ◽  
M. T. Rutherford ◽  
...  
Keyword(s):  
Total Yield ◽  
Individual Plant ◽  
Stocking Rate ◽  
Management Options ◽  
Heteropogon Contortus ◽  
Diet Supplements ◽  
The Stability ◽  
The Individual ◽  
Stocking Rates ◽  
Pasture Yield

A grazing study commenced in 1988 at Calliope, Central Queensland, measured the effects of stocking rate, legume over-sowing and animal diet supplements/burning on pasture and animal production in a native black speargrass (Heteropogon contortus) pasture. This paper reflects on changes in yield and pasture composition between 1988 and 1996, during which time the seasonal rainfall was below average. At the pasture community scale, the highest stocking rate of 1 steer/2 ha reduced pasture yield but had little impact on pasture composition. The frequency of H. contortus showed no clear differences due to stocking rate although there was a slight overall trend for it to decline with time. The frequency of increaser species such asChloris divaricata was highest at the highest stocking rate. At the individual plant scale, the density of H. contortus plants declined at high stocking rate. The proportion of the sown legume Stylosanthes scabra cv. Seca increased with time reaching a density of 15 plants/m 2 and contributing 33% to the total yield in the legume treatments. Burning has reduced the occurrence of H. contortus compared with that in unburnt native pasture and this may be due to the stocking rates being too high following the fire. These results indicate the stability of pasture composition across a 4-fold range of stocking rates from 1988 to 1996. This study needs to continue, at least through a period of above average rainfall, to determine further effects of stocking rate and pasture type on pasture composition.

Impacts of grazing management options on pasture and animal productivity in a Heteropogon contortus (black speargrass) pasture in central Queensland. 3. Diet composition in autumn

2010 ◽  
Vol 50 (4) ◽  
pp. 276 ◽  
Author(s):  
R. E. Hendricksen ◽  
D. J. Myles ◽  
D. J. Reid ◽  
D. M. Orr
Keyword(s):  
Diet Composition ◽  
Plant Density ◽  
Stocking Rate ◽  
Management Options ◽  
Heteropogon Contortus ◽  
Native Pasture ◽  
Stylosanthes Scabra ◽  
Animal Diet ◽  
Palatable Species ◽  
Stocking Rates

The diet selected in autumn by steers fistulated at the oesophageous was studied in a subset of treatments in an extensive grazing study conducted in a Heteropogon contortus pasture in central Queensland between 1988 and 2001. These treatments were a factorial array of three stocking rates (4, 3 and 2 ha/steer) and three pasture types (native pasture, legume-oversown native pasture and animal diet supplement/spring-burning native pasture). Seasonal rainfall throughout this study was below the long-term mean and mean annual pasture utilisation ranged from 30 to 61%. Steers consistently selected H. contortus with levels decreasing from 47 to 18% of the diet as stocking rate increased from 4 ha/steer to 2 ha/steer. Stylosanthes scabra cv. Seca was always selected in legume-oversown pastures with diet composition varying from 35 to 66% despite its plant density increasing from 7 to 65 plants/m2 and pasture composition from 20 to 50%. Steers also selected a diet containing Chrysopogon fallax, forbs and sedges in higher proportions than they were present in the pasture. Greater availability of the intermediate grasses Chloris divaricata and Eragrostis spp. was associated with increased stocking rates. Bothriochloa bladhii was seldom selected in the diet, especially when other palatable species were present in the pasture, despite B. bladhii often being the major contributor to total pasture yield. It was concluded that a stocking rate of 4 ha/steer will maintain the availability of H. contortus in the pasture.

Effect of deferred autumn grazing and stocking rate of sheep on pasture production in a Mediterranean-type climate

1976 ◽  
Vol 16 (79) ◽  
pp. 181 ◽  
Author(s):  
TH Brown
Keyword(s):  
South Australia ◽  
Grazing Management ◽  
Research Centre ◽  
Botanical Composition ◽  
Stocking Rate ◽  
Pasture Production ◽  
Continuous Grazing ◽  
Wimmera Ryegrass ◽  
June July ◽  
Stocking Rates

The effect of deferred autumn grazing and stocking rate on an annual pasture was monitored for five years at Kybybolite Research Centre in the south-east of South Australia. Pasture availability, yearly production and botanical composition were measured under a series of eight stocking rates from 12.4 to 29.7 Merino wethers per hectare. Autumn deferment resulted in extra available pasture during the winter months of June, July and August. However, the continously grazed pastures reached the same level of availability as the deferred pastures in spring. By the third year of the experiment yearly pasture production irrespective of grazing management was greatly reduced at the higher stocking rates. This reduction was associated with an invasion of Poa annua and Juncus bufonius. Autumn deferment tended to favour the growth of Wimmera ryegrass at the lower stocking rates whereas continuous grazing tended to favour clover growth at these stocking rates.

Impacts of grazing management options on pasture and animal productivity in a Heteropogon contortus (black speargrass) pasture in central Queensland. 2. Population dynamics of Heteropogon contortus and Stylosanthes scabra cv. Seca

2010 ◽  
Vol 61 (3) ◽  
pp. 255 ◽  
Author(s):  
D. M. Orr ◽  
M. C. Yee ◽  
M. T. Rutherford ◽  
C. J. Paton
Keyword(s):  
Plant Density ◽  
Seedling Recruitment ◽  
Population Data ◽  
Lag Phase ◽  
Stocking Rate ◽  
Management Options ◽  
Heteropogon Contortus ◽  
Native Pasture ◽  
Stylosanthes Scabra ◽  
Stocking Rates

The dynamics of Heteropogon contortus and Stylosanthes scabra cv. Seca populations were studied in a subset of treatments in an extensive grazing study conducted in central Queensland between 1988 and 2001. These treatments were 4 stocking rates in native pasture and 2 of these stocking rates in legume oversown and supplement/spring burning treatments. For the 1999–2000 summer, population data for H. contortus in 5 of these native pasture and supplement/burning treatments were compared with those for an additional burnt treatment. Seasonal rainfall throughout this study was below the long-term mean and mean annual pasture utilisation ranged from 24 to 61%. Increasing stocking rate from 5 to 2 ha/steer in native pasture reduced H. contortus plant density. Increasing stocking rate reduced seedling recruitment as a result of its effect on soil seedbanks. Seedling recruitment was the major determinant of change in plant density, although some individual H. contortus plants did survive throughout the study. Burning in spring 1999, particularly at light stocking rate, promoted seedling recruitment above that in both unburnt native and legume oversown pasture and resulted in increased H. contortus plant density. In the legume oversown treatments, S. scabra cv. Seca density increased rapidly from 15 plants/m2 in 1988 to 140 plants/m2 in 2001 following a lag phase between 1988 and 1993. This increased S. scabra density was associated with an eventual decline in H. contortus plant density through reduced seedling recruitment. It was concluded that H. contortus population density is sustainable at stocking rates of 4 and 5 ha/steer (30% pasture utilisation) and that spring burning at light stocking rate can promote H. contortus populations. Increasing densities of S. scabra need to be managed to prevent its dominance.

OBSERVATIONS ON THE RELATIONSHIP BETWEEN SOIL FERTILITY, PASTURE BOTANICAL COMPOSITION, AND PASTURE GROWTH RATE; FOR A NORTH ISLAND LOWLAND PASTURE

1988 ◽  
pp. 141-144
Author(s):  
C. Matthew ◽  
R.W. Tillman ◽  
M.J. Hedley ◽  
M.C. Thompson
Keyword(s):  
Soil Fertility ◽  
Botanical Composition ◽  
Stocking Rate ◽  
Pasture Production ◽  
Mean Values ◽  
Olsen P ◽  
Sheep Farm ◽  
Tiller Density ◽  
Stocking Rates ◽  
The Relationship

Soil chemical fertility, pasture composition and pasture production data were collected for seven 'microsites' within two farmlets at Massey University's No. 1 sheep farm. Palmerston North. The two farmlets had been maintained for twenty years at stocking rates of 26 and 16 su/ha, and were found to have gradients (presumed to result from sheep grazing and camping behaviour) of increasing soil fertility away from a road and towards a shelterbelt. Microsites were placed along these gradients to include contrasting fertility levels for the two stocking rates. Mean values for soil pH, Olsen P and 'quicktest' K tiller density for the various pasture species and pasture production at each of the seven microsites are presented. A microsite where Olsen P = 109 was barley grass dominant and produced 10.5 t DM/ha/year. For other microsites ryegrass tillers per m2 increased with P and stocking rate; and white clover and sweet vernal growing points/tillers per m2 decreased with increasing P. Production ranged from 9.9 t DM/ha/year where Olsen P = 14 to 19.1 t DM/ha/year with different seasonal timing where Olsen P = 66.

Superphosphate and stocking rate effects on a native pasture oversown with Stylosanthes humilis in central coastal Queensland. 2. Animal production

1978 ◽  
Vol 18 (95) ◽  
pp. 800 ◽  
Author(s):  
NH Shaw
Keyword(s):  
Animal Production ◽  
Early Years ◽  
Stocking Rate ◽  
Heteropogon Contortus ◽  
Stylosanthes Humilis ◽  
Rate Effects ◽  
Native Pasture ◽  
The Difference ◽  
Stocking Rates ◽  
Main Factor

Liveweight changes of beef cattle were measured over eight years in a grazing experiment on a native pasture (Heteropogon contortus dominant) oversown with S. humilis (T.S.). The pastures were subjected to three levels of molybdenized superphosphate (F0 = nil; F1 = 125 kg ha-2 annually; F2 = 250 kg ha-1 annually plus an extra 250 kg ha-1 initially) in factorial combination with four stocking rates and two sowing methods for T.S. (ground sowing into spaced cultivated strips, or aerial sowing). Stocking rates were gradually increased during the experiment and for the last three years overlapping ranges were used for the three fertilizer levels; the overall range was then from 0.55 to 1.65 beasts ha-1. Superphosphate increased liveweight gain per head in all years. The main effect was in the period of weight gain and the difference between rates of gain on fertilized and unfertilized pastures increased over years. The mean for F, and F, ranged from 370 to 71 0 g head-1 day-1 compared with 270 to 470 g head-1 day-1 for F0. Except for the last year, there were liveweight losses in all three fertilizer treatments in winter; treatment differences then were mostly small, with significant effects in only three of the eight years. F, gave higher annual liveweight gains than F1 in three of the first six years, but by years seven and eight these two treatments were equal. Comparisons with pasture data described in a previous paper showed highly significant linear relations between annual gains per head and T.S. yield (log10 kg ha-1), and it is concluded that this is the main factor in the liveweight response to fertilizer. Increasing stocking rate depressed gain per head in F, in all years (mean of 35 kg head-1 for an increase of 0.5 beasts ha-1). A similar effect occurred in F1 and F2 in early years, but there was virtually no stocking rate depression in F2 in the last two years, and a significant increase for F1 in the final year. This effect is ascribed to the increase in T.S. yield in fertilized pastures at high stocking rates. Sowing method had no effect on animal production.

A comparison of levels of production and profit from grazing Merino ewes and wethers at various stocking rates in northern Victoria

1980 ◽  
Vol 20 (104) ◽  
pp. 296 ◽  
Author(s):  
DH White ◽  
BJ McConchie ◽  
BC Curnow ◽  
AH Ternouth
Keyword(s):  
Subterranean Clover ◽  
Early Spring ◽  
Botanical Composition ◽  
Stocking Rate ◽  
Pasture Production ◽  
Fleece Weight ◽  
Sheep Production ◽  
Rate Of Decline ◽  
One Year ◽  
Stocking Rates

Merino wethers and breeding ewes were grazed at various stocking rates on an annual pasture in the sheep-wheat zone of Northern Victoria from 1966 to 1973. There was considerable variation between years in botanical composition, the incidence of subterranean clover in the pasture plots varying by up to 80 percentage units between years. Total pasture production was measured in one plot during the last 4 years of the experiment, varying from 2.1 t ha-1 in the drought year (325 mm rain) of 1972, to 8.8 t ha-1 in the higher rainfall (883 mm) year of 1973. The large year-to-year variations in pasture production and botanical composition were reflected in differences between years in sheep production at various stocking rates. Wethers produced about 20% more wool than breeding ewes grazing at the same stocking rate, providing no supplements were fed. August-lambing ewes either lost weight in early spring or gained weight more slowly than wethers of the same age and flock background. The consequence of this was that maximum weights of ewes were consistently about 10 kg less than wethers at the same stocking rate. Both ewes and wethers had similar rates of weight loss from November to March. In one year ewes at 3.7 ha-1 were fed supplements in autumn, since they were lighter than the feeding weight of 41 kg, whereas wethers stocked at 11.1 ha-1, were not. An economic analysis of the experimental data indicated that the most profitable stocking rates of Merino wethers were up to 1.7 times that of August-lambing ewes. This ratio varies with season, and is also likely to vary with changes in lambing date or environment. The most sensitive determinants of optimal stocking rate were the rate of decline of fleece weight, and lambs born relative to ewes joined, with increasing stocking rate. Sheep liveweight at time of sale could also be important.

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