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).

Productivity and intensive sheep stocking over a five-year period

1967 ◽  
Vol 69 (1) ◽  
pp. 47-69 ◽  
Author(s):  
C. R. W. Spedding ◽  
J. E. Betts ◽  
R. V. Large ◽  
I. A. N. Wilson ◽  
P. D. Penning
Keyword(s):  
Milk Yield ◽  
Botanical Composition ◽  
Stocking Rate ◽  
Economic Implications ◽  
Production Processes ◽  
Percentage Weight ◽  
Grazing Systems ◽  
Sheep Production ◽  
Stocking Rates

During the last ten years or so, the management of sheep for intensive lamb production has been studied on a considerable scale, and a variety of grazing systems have been investigated (Dickson, 1959; Cooper, 1959; Spedding & Large, 1959; Boaz, 1959). It is still too soon to specify precisely the place that any of these systems should occupy in sheep-production processes, in relation to breed, lambing percentage, weight of lamb at slaughter, stocking rate, botanical composition of the pasture, size of ewe and level of her milk yield. Quite apart from these biological considerations, the full economic implications are by no means clear. What has emerged most clearly, however, is that much higher stocking rates can be tolerated than had generally been regarded as safe and that, at these stocking rates, productivity can be extremely high.

Grazing system and stocking rate effects on the productivity, botanical composition and soil surface characteristics of alfalfa-grass pastures

1997 ◽  
Vol 77 (4) ◽  
pp. 669-676 ◽  
Author(s):  
J. D. Popp ◽  
W. P. McCaughey ◽  
R. D. H. Cohen
Keyword(s):  
Soil Surface ◽  
Surface Characteristics ◽  
Botanical Composition ◽  
Stocking Rate ◽  
Forage Production ◽  
Basal Cover ◽  
Grazed Pastures ◽  
Litter Cover ◽  
Grazing System ◽  
Stocking Rates

A 4-yr experiment was conducted (1991 to 1994) near Brandon, MB, to determine the effects of grazing system (continuous and rotational) and stocking rate [light (1.1 steers ha−1); heavy (2.2 steers ha−1)] on the productivity, botanical composition and soil surface characteristics of an alfalfa (Medicago sativa L.; approximately 70%), meadow bromegrass (Bromus biebersteinii Roem & Schult.; 25%) and Russian wild ryegrass [Psathyrostachys juncea (Fisch.) Nevski; 5%] pasture. Grazing season length was shorter (P < 0.05) for cattle in continuously compared with rotationally stocked pastures in 1991, while in 1993 and 1994 it was shortest (P < 0.05) in heavily stocked continuously grazed pastures. Carrying capacity (steer days ha–1) was greater (P < 0.05) in heavily stocked rotationally grazed pastures compared with other treatments in 1991, 1993 and 1994. In 1992, it was greater (P < 0.05) in heavy than light stocking rate treatments for both rotationally and continuously grazed pastures. Cattle usually gained more (P < 0.05) per day (kg d−1) and during the season (kg hd−1) at light than at heavy stocking rates, while total liveweight production (kg ha−1) was greater (P < 0.05) at heavy than at light stocking rates. Forage production and disappearance did not differ (P > 0.05) within grazing systems and stocking rates from 1991 to 1993, but in 1994, production and disappearance were greater (P < 0.05) at heavy than at light stocking rates. Mean seasonal herbage mass available and carry-over were greater (P < 0.05) in lightly stocked pastures than heavily stocked pastures from 1991 to 1994. After the first year of grazing, the proportion of alfalfa increased (P < 0.05), while grasses declined (P < 0.05) within all grazing treatments. In subsequent years, a trend was observed, where alfalfa declined and grasses increased in all pastures, except those stocked heavily and grazed continuously, which by 1994 had the greatest (P < 0.05) percentage of alfalfa. As years progressed, increases (P < 0.05) in basal cover concurrent with declines in bare ground were recorded on all grazing treatments, while litter cover often did not differ (P > 0.05) within either grazing system or stocking rate, except in 1992, when basal cover was lowest (P < 0.05), while litter cover was greatest (P < 0.05) on lightly stocked continuously grazed pastures compared with other treatments. Stocking rates were a key factor to optimizing individual animal performance and/or gain per hectare on alfalfa grass pastures, however differences in the effect of continuous and rotational stocking on pasture productivity were minimal. Key words: Alfalfa, grazing, stocker cattle, production

Response of skeleton weed (Chondrilla juncea) to applied superphosphate and grazing management

1975 ◽  
Vol 15 (72) ◽  
pp. 102 ◽  
Author(s):  
GD Kohn ◽  
EG Cuthbertson
Keyword(s):  
New South ◽  
Trifolium Subterraneum ◽  
Wagga Wagga ◽  
Stocking Rate ◽  
Lolium Rigidum ◽  
Fertilizer Rate ◽  
South Wales ◽  
Continuous Grazing ◽  
Grazing Systems ◽  
Stocking Rates

The influence of pasture topdressing with superphosphate and of stocking rate on the Chondrilla uncea population in a clover-ryegrass (Trifolium subterraneum-Lolium rigidum) pasture was measured in a grazing experiment at Wagga Wagga, New South Wales, over the period 1962 to 1966. Superphosphate application reduced final weed populations at all stocking rates. Continuous grazing maintained skeleton weed populations at a low level, but increasing the stocking rate from 5 to 15 sheep ha-1 had little influence on weed numbers. A management comparison at a high stocking rate-high fertilizer rate showed that rotational grazing increased the weed population compared with continuous grazing systems.

The productivity of pastures sown with Phalaris tuberosa or Lolium perenne. 1. Pasture growth and composition

1974 ◽  
Vol 14 (70) ◽  
pp. 640 ◽  
Author(s):  
KFM Reed
Keyword(s):  
Lolium Perenne ◽  
Dry Matter ◽  
Protein Concentration ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Stocking Rate ◽  
Basal Cover ◽  
Western Victoria ◽  
Cutting Height ◽  
Stocking Rates

Pastures at Glenormiston in western Victoria, sown with Phalaris tuberosa cv. Australian (phalaris) or Lolium perenne cv. Victorian (ryegrass) each with Trifolium subterraneum (subterranean clover), were grazed continuously by wethers at six rates of stocking over the range 19.8 to 32.1 sheep ha-1 from October 1966 to March 1971. Pasture growth was measured at three rates of stocking. During a four-year period, the phalaris and ryegrass pastures produced average annual yields of 10.4 and 8.0 t dry matter ha-1 respectively. The growth of phalaris pasture was usually greater in winter when it produced approximately 30 per cent more dry matter than ryegrass pasture. The effect of rate of stocking on pasture growth was rarely significant except in the final six months of the experiment when there was a reduction in growth rate as stocking rate increased. The basal cover of phalaris declined in the two years after a drought in 1967-68 to about 20 per cent irrespective of stocking rate. The basal cover of ryegrass also declined during this period, to a greater extent than phalaris, but in 1969 and 1970 there was some recovery at the lower stocking rates when the ryegrass was able to set seed. The basal cover of subterranean clover was about 20 per cent at 19.8 sheep ha-1 in most years and usually less at the higher stocking rates. The main species that replaced the sown species were Poa annua, Trifolium cernuum, Trifolium glomerata, Arctotheca calendula and Holcus lanatus. The amount of pasture present above a cutting height of 1.5 cm was less than 2 t ha-1 during most of the experiment and decreased as rate of stocking increased. The crude protein concentration of pasture present was always greater than 11 per cent except during the drought in 1967-68, when it fell as low as 5.2 per cent on the ryegrass pastures and to half this level on the phalaris pastures.

Management of grazing systems

1989 ◽  
pp. 117-122 ◽  
Author(s):  
J. Hodgson
Keyword(s):  
Management Practices ◽  
Management Control ◽  
Grazing Management ◽  
Relative Importance ◽  
Stocking Rate ◽  
Pastoral Systems ◽  
Starting Point ◽  
Alternative Means ◽  
Grazing Systems ◽  
Stocking Rates

Recent assessments of the relative importance of stocking rate. stocking policy and grazing management on the output from pastoral systems are used as a starting point to argue the need for objective pasture assessments to aid control of livestock enterprises to meet production targets. Variations in stocking rates, stocking policy and other management practices all provide alternative means of control of pasture conditions which are the major determinants of pasture and animal performance. Understanding of the influence of pasture conditions on systems performance should provide a better basis for management control and for Communication between farmers, extension officers and researchers. Keywords: Stocking rate, pasture condition, pasture cover

Pasture management in semi-arid tropical woodlands: dynamics of perennial grasses

2007 ◽  
Vol 29 (1) ◽  
pp. 87 ◽  
Author(s):  
John G. McIvor
Keyword(s):  
Perennial Grasses ◽  
Individual Species ◽  
Stocking Rate ◽  
Pasture Management ◽  
Management Options ◽  
Exotic Grasses ◽  
Heteropogon Contortus ◽  
Basal Cover ◽  
Growing Seasons ◽  
North East

The effects of a range of pasture management options (introduced legumes and grasses, superphosphate, timber treatment, cultivation before sowing and stocking rate) on the basal cover of perennial grasses were measured from 1982 to 1991 at two sites, ‘Hillgrove’ and ‘Cardigan’, near Charters Towers, in north-east Queensland. Colonisation and survival of eight native and exotic grasses were followed in permanent quadrats in a subset of treatments. Overall, there were significant changes in total basal cover of plots between years and with tree killing, but no significant differences in sown pastures, fertiliser or stocking rate. Basal cover increased when defoliation levels were less than 40% but increases were smaller at higher levels of defoliation and basal cover often declined when defoliation was greater than 60%. Basal cover declined when growing seasons were <10 weeks, remained static with 10–15 weeks growth, and increased when growing seasons were 16 weeks or longer. There was some colonisation in all years but large differences between years. The differences in colonisation between systems were generally small but there was a general trend for higher colonisation at higher stocking rates. Bothriochloa ewartiana (Domin) C.E.Hubb. and Chrysopogon fallax S.T.Blake had low, Heteropogon contortus (L.) P.Beauv. ex Roem.&Schult., Cenchrus ciliaris L. and Aristida spp. had intermediate, and Bothriochloa pertusa (L.) A.Camus and Urochloa mosambicensis (Hack.) Dandy had high colonising ability. Survival of individual species was generally similar at both sites except for Urochloa mosambicensis. Heteropogon contortus and U. mosambicensis at ‘Hillgrove’ were short-lived (<10% survival after 4 years), B. ewartiana, Themeda triandra Forssk. and Aristida spp. had intermediate survival (10–50%), and C. ciliaris, C. fallax, B. pertusa and U. mosambicensis at ‘Cardigan’ were long-lived (>50% survival). Annual survival rates increased with plant age, were higher in good growing seasons than in poor seasons, were higher for large plants than small plants, and were lower at high defoliation levels than where defoliation was less severe. The differences between species in ability to colonise and survive, and the small influence of management compared to seasonal effects on survival, are discussed to explain species performance in pastures.

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

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.

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.

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.

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