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

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).

scholarly journals Impact of Climate Change on Livestock Returns and Rangeland Ecosystem Sustainability in the Southwest

2018 ◽  
Vol 47 (2) ◽  
pp. 336-356 ◽  
Author(s):  
Gregory L. Torell ◽  
Katherine D. Lee
Keyword(s):  
Climate Change ◽  
Current Method ◽  
Adaptive Methods ◽  
Livestock Grazing ◽  
Climate Projections ◽  
Stocking Rate ◽  
Forage Production ◽  
Temperature And Precipitation ◽  
Stocking Rates

Climate change will increase variability in temperature and precipitation on rangelands, impacting ecosystem services including livestock grazing. Facing uncertainty about future climate, managers must know if current practices will maintain rangeland sustainability. Herein, the future density of an invasive species, broom snakeweed, is estimated using a long-term ecological dataset and climate projections. We find that livestock stocking rates determined using a current method result in lower forage production, allowable stocking rate, and grazing value than an economically efficient stocking rate. Results indicate that using ecology and adaptive methods in management are critical to the sustainability of rangelands.

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.

The inter-relationships of grazing method and stocking rate in the efficiency of pasture utilization by dairy cattle

1963 ◽  
Vol 61 (2) ◽  
pp. 147-166 ◽  
Author(s):  
C. P. McMeekan ◽  
M. J. Walshe
Keyword(s):  
Dairy Cows ◽  
Large Scale ◽  
Age Distribution ◽  
Grazing Management ◽  
Vanishing Point ◽  
Stocking Rate ◽  
Rotational Grazing ◽  
Continuous Grazing ◽  
Grazing System ◽  
Stocking Rates

1. A large-scale grazing management study comparing rotational grazing and continuous grazing with dairy cows at two stocking rates over four complete production seasons is described.2. The four treatments were: (i) controlled grazing, light stocking rate; (ii) controlled grazing, heavy stocking rate; (iii) uncontrolled grazing, light stocking rate; (iv) uncontrolled grazing, heavy stocking rate.Each treatment involved 40 cows for a first 2-year phase and 42 cows for the following 2 years. Each herd had a normal age distribution pattern and seven 2-year-old first lactation heifers (17% of total herd) were introduced each year to maintain this pattern.3. Stocking rate was the more important factor affecting the efficiency of pasture utilization as measured by per acre output of milk and butterfat. In general, high stocking was associated with higher outputs per acre despite lower yields per animal.4. Grazing method was of less importance. In general, controlled rotational grazing was superior to uncontrolled continuous grazing, both per animal and per acre, but the average influence even of these extremes of management was only half that of stocking rate.5. Significant interactions between stocking rate and grazing method existed. Under continuous grazing a point was reached where production per acre declined to the vanishing point with increased stocking rate due to excessive depression of per cow yield: this point was not reached under rotational grazing at the same high stocking levels.6. The results suggest that optimum stocking rate under rotational grazing occurs at a level some 5–10% higher than under continuous grazing. A depression of 10–12% in per cow yield, compared with more lenient grazing, corresponds with optimum stocking level irrespective of the grazing system. This estimate is suggested as a guide line in applying the principles involved.

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

Levels of total nitrogen and total volatile fatty acids in the rumen fluid of sheep under different grazing management systems

1967 ◽  
Vol 7 (28) ◽  
pp. 434
Author(s):  
WR McManus
Keyword(s):  
Fatty Acids ◽  
Total Nitrogen ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Subterranean Clover ◽  
Grazing Management ◽  
Stocking Rate ◽  
Continuous Grazing ◽  
Grazing System ◽  
Stocking Rates

Concentrations of total nitrogen and total volatile fatty acids in the rumen fluid of sheep grazing improved pastures were measured for ten months in a dry year on the southern tablelands of New South Wales, and the concentrations of nitrogen and volatile fatty acids (V.F.A.) were related to season, wool production, and grazing management. The observations were made during two long-term grazing management experiments. In the first experiment four groups of breeding Merino ewes grazed a Wimmera ryegrass-subterranean clover (Lolium rigidum Gaud.-Trifolium subterraneum L.) pasture. A deferred grazing system (autumn saving) of pasture management was compared with continuous grazing at stocking rate treatments equivalent to 7.0 and 3.5 ewes to the acre. In the second experiment two groups of Merino weaners grazed a Phalaris tuberosa-subterranean clover pasture at a stocking rate equivalent to 8.6 sheep to the acre. One group received a hay supplement, the other did not. In both experiments nitrogen values were low between late autumn and mid-winter and again between late spring and summer, and high in early autumn and again in spring (P<0.05). The low levels were about 55 per cent of peak autumn and spring levels in (experiment 1) and 60 per cent of peak autumn and spring levels in (experiment 2). Total V.F.A. did not vary significantly between seasons in either experiment. At the higher stocking rate the ewes had lower levels of rumen total nitrogen than at the lower stocking rate. V.F.A. did not vary consistently between stocking rates. At both stocking rates ewes on the autumn saving system of grazing management had more nitrogen in the rumen fluid during late pregnancy and early lactation than did those on the continuous grazing system (P<0.001). After the ewes had access to the saved pasture, autumn saving resulted in a higher concentration of volatile fatty acids than continuous grazing (P< 0.05). Although feeding a hay supplement benefited the weaners the concentrations of total nitrogen in the rumen fluid of the two groups of sheep were similar. There was a fairly consistent tendency for the group receiving hay to have lower concentrations of volatile fatty acids in their rumen fluid. Possible reasons for these effects are discussed.

Influence of stocking rate and mixed grazing of Angora goats and Merino sheep on animal and pasture production in southern Australia. 1. Botanical composition, sward characteristics and availability of components of annual temperate pastures

2010 ◽  
Vol 50 (2) ◽  
pp. 138 ◽  
Author(s):  
B. A. McGregor
Keyword(s):  
Subterranean Clover ◽  
Botanical Composition ◽  
Stocking Rate ◽  
Bare Ground ◽  
Pasture Production ◽  
Weed Invasion ◽  
Merino Sheep ◽  
Grazed Pastures ◽  
Temperate Pastures ◽  
Angora Goats

The effects of animal species (AS; Angora goats, Merino sheep or goats and sheep mixed grazed together at ratio 1 : 1) and stocking rate (SR; 7.5, 10 and 12.5 animals/ha) on the availability, botanical composition and sward characteristics of annual temperate pastures under continuous grazing were determined in a replicated experiment from 1981 to 1984. AS and SR had significant effects on pasture availability and composition and many AS × SR interactions were detected. The pastures grazed by sheep had significantly reduced content and proportion of subterranean clover and more undesirable grasses compared with those grazed by goats. There were no differences in dry matter availabilities between goat- and sheep-grazed pastures at 7.5/ha, but at 10 and 12.5/ha goat pastures had significantly increased availabilities of green grass, dead and green clover and less weeds compared with sheep pastures. There was a significant AS × SR interaction for the density of seedlings in May following pasture germination. Between July and January, the height of pastures was greater under goats than sheep but from January to March pasture height declined more on goat-grazed than on sheep-grazed pastures. There was an AS × SR interaction for incidence of bare ground. Increasing the SR increased bare ground in pastures grazed by sheep but no change occurred on pastures grazed by goats. Changes in pasture characteristics due to increased SR were minimised on pastures grazed by goats but the grazing of sheep caused larger and faster changes and the pastures were damaged at the highest SR. Goats did not always select the same herbage material as sheep, changed their selection between seasons and were not less selective than sheep. Angora goats were flexible grazers and continually adapted their grazing behaviour to changing herbage conditions. Goat grazing led to an increase in subterranean clover, an accumulation of dead herbage at the base of the sward, reduced bare ground, taller pastures in spring and a more stable botanical composition. Mixed-grazed pasture characteristics were altered with SR. With careful management Angora goats on sheep farms may be used to manipulate pasture composition, to speed up establishment of subterranean clover, to decrease soil erosion and to reduce weed invasion.

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.

Sign in / Sign up

Export Citation Format

Share Document