Stocking rate affects plant community structure and reproductive strategies of a desirable and an undesirable grass species in an alpine steppe, Qilian Mountains, China

2020 ◽  
Vol 42 (1) ◽  
pp. 63
Author(s):  
Yarong Guo ◽  
Xiong Z. He ◽  
Fujiang Hou ◽  
Jizhou Ren
Keyword(s):  
Plant Community ◽  
Reproductive Strategies ◽  
Plant Density ◽  
Dry Weight ◽  
Grassland Management ◽  
Grass Species ◽  
Stocking Rate ◽  
Weight Changes ◽  
Alpine Steppe ◽  
Stocking Rates

The effects of grazing on species reproduction is a fundamental issue of grassland management. We investigated plant density and dry weight changes at community and species levels, and the reproductive strategies of the dominant desirable Stipa purpurea and the undesirable Achnatherum inebrians grass species in response to stocking rate in an alpine steppe with a 10-year grazing history. Results showed complex patterns of plant community and reproductive strategy. Overall plant density increased with increasing stocking rate and dry weight was significantly higher at light and high stocking rates. Plant density and dry weight of A. inebrians peaked at moderate stocking rates. Higher stocking rate had little impact on S. purpurea density but significantly reduced its dry weight. Both species displayed linearly increasing/decreasing or unimodal/bimodal reproductive effort in response to increased stocking rate. The discrepancies in plant reproductive characteristics between S. purpurea and A. inebrians indicated that: (1) light and moderate grazing may promote an adaption strategy of reproduction by desirable species, which may then contribute to their maintenance in grasslands, and (2) undesirable species presence did not lead to the replacement of desirable species in the grasslands. Therefore, light and moderate stocking rates are recommended to maintain the grasslands and to increase the reproductive outputs of desirable species.

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.

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 systems of grassland management and winter feeding on the productivity of an 18-month grass-cereal beef system

1978 ◽  
Vol 27 (1) ◽  
pp. 99-107
Author(s):  
J. B. Moran ◽  
W. Holmes
Keyword(s):  
Weight Gain ◽  
Grassland Management ◽  
Metabolizable Energy ◽  
Stocking Rate ◽  
Field System ◽  
Grass Silage ◽  
Grazing System ◽  
Grazing Systems ◽  
Ad Libitum ◽  
Stocking Rates

ABSTRACTExperiments in two successive years with 24 cattle compared a six-paddock grazing system with a simpler two-field system. In each system the whole area was cut for conservation once during the season. The two systems were stocked each at 3·9 or 6·5 cattle/ha. In the following winters the cattle were offered grass silage (1974) or dried lucerne pellets (1975) ad libitum with two levels of barley.Daily gains on pasture were depressed by the higher stocking rate but there was no difference between grazing systems. The yield of conserved grass was least on the high stocking rate two-field system. The estimated output of utilized metabolizable energy per hectare was highest on the high stocking rate paddock grazing system but the output from the low stocking rate two-field system was almost as high. It was concluded that the latter system was valuable in many practical situations. Cattle that had been grazed at low stocking rates finished earlier in winter. There was some evidence of winter compensation in cattle weight gain on diets with dried lucerne pellets but not on grass silage diets.

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 stocking rate and fertilizer on the performance of steers grazing Townsville stylo-based pasture in north Queensland

1974 ◽  
Vol 14 (67) ◽  
pp. 146 ◽  
Author(s):  
L Winks ◽  
FC Lamberth ◽  
KW Moir ◽  
PM Pepper
Keyword(s):  
Grass Species ◽  
Stocking Rate ◽  
Native Grass ◽  
Dry Tropics ◽  
Yield And Quality ◽  
Stylosanthes Humilis ◽  
Native Pasture ◽  
Townsville Stylo ◽  
Stocking Rates

The performance of steers grazing Townsville stylo (Stylosanthes humilis)-native grass pasture, with and without superphosphate fertilizer, was studied at two stocking rate (0.41 and 0.82 beasts ha-1) on the sub-coastal spear grass region of the dry tropics of north Queensland over a period of three and a half years. Fertilizer increased yield and quality of pasture, but invasion of the fertilized areas by annual grass species was occurring by the end of the study. Liveweight gains on fertilized Townsville stylo pastures were greater than on unfertilized Townsville stylo, where performance was similar to that recorded on untreated native pasture at stocking rates of 0.25 and 0.41 beasts ha-1. Liveweight gains at the lighter stocking rate were greater than at the higher level on the Townsville stylo-native grass pasture, but at the stocking rates applied to native pasture there was no significant effect of stocking rate. A stocking rate of 0.41 beast ha-1 on fertilized Townsville stylo was safe in all years. Wastage of material was high owing to mould development on the Townsville stylo which remained as standing hay during the winter.

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.

Lucerne persistence and the productivity of ewes and lambs grazed at two stocking rates within different management systems

1975 ◽  
Vol 15 (77) ◽  
pp. 747 ◽  
Author(s):  
OR Southwood ◽  
GE Robards
Keyword(s):  
Plant Density ◽  
Agricultural Research ◽  
New South ◽  
Research Station ◽  
Stocking Rate ◽  
South Wales ◽  
Continuous Grazing ◽  
Rotational Systems ◽  
Stocking Rates ◽  
Lamb Growth

From 1967 to 1971 a grazing experiment was conducted at the Agricultural Research Station, Temora, New South Wales with Merino ewes and first cross spring lambs on lucerne pastures. Set stocking was compared with a number of rotational systems at twice replicated stocking rates of five and ten ewes ha-1. The rotational systems consisted of either five or seven paddocks each grazed to give a constant pasture recovery time of 36 days year round, or 36 days mid-summer to mid-winter and 24 days when lambs were present. Stocking rate was the only variable affecting ewe wool production and body weight. During the driest year the constant rotation was the best treatment, whereas in the wetter year ewes managed in a variable rotation grew most wool. The number of lambs born and their birth weight did not vary among treatments. Growth rate was slower at the higher stocking rate but the management treatments had no effect on lamb growth. Lucerne plant density decreased by half during the first three years of the experiment. Thereafter plant density was maintained in the rotationally grazed systems. Under continuous grazing at the high stocking rate no lucerne survived after four months but at the low stocking rate most remaining plants died after a spring drought in 1971.

scholarly journals Competitive Interaction ofAxonopus compressusandAsystasia gangeticaunder Contrasting Sunlight Intensity

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
B. Samedani ◽  
A. S. Juraimi ◽  
M. P. Anwar ◽  
M. Y. Rafii ◽  
S. H. Sheikh Awadz ◽  
...  
Keyword(s):  
Cover Crops ◽  
Oil Palm ◽  
Cover Crop ◽  
Plant Density ◽  
Relative Yield ◽  
Dry Weight ◽  
High Density ◽  
Grass Species ◽  
Full Sunlight ◽  
Sunlight Intensity

Axonopus compressusis one of the native soft grass species in oil palm in Malaysia which can be used as a cover crop. The competitive ability ofA. compressusto overcomeA. gangeticawas studied using multiple-density, multiple-proportion replacements series under a glasshouse and full sunlight conditions in a poly bag for 10 weeks.A. compressusproduced more dry weight and leaf area when competing againstA. gangeticathan in monoculture at both densities in the full sunlight and at high density in the shade. Moreover, the relative yield and relative crowding coefficients also indicatedA. compressusis a stronger competitor thanA. gangeticaat both densities in the full sunlight and high density in the shade. It seemed thatA. gangeticaplants in the shade did not compete with each other and were more competitive againstA. compressusas could influenceA. compressusheight in the shade. It is concluded that although suppression ofA. gangeticabyA. compressusoccurred under full sunlight, irrespective of plant density, this ability reduced under shade asA. compressusdensity decreased. The result suggests thatA. compressusin high density could be considered as a candidate for cover crops under oil palm canopy.

Performance of sheep and cattle grazed separately and together

1970 ◽  
Vol 10 (42) ◽  
pp. 19 ◽  
Author(s):  
D/Bath JG Hamilton
Keyword(s):  
Annual Production ◽  
Stocking Rate ◽  
Weight Changes ◽  
One Year ◽  
Stocking Rates

Groups of two young steers and eight autumn lambing ewes, mated for prime lamb production and each rearing a single lamb, grazed together at three stocking rates and separately each at five stocking rates on annual pasture. Results were rejected for animals fed a supplement. In most instances when pasture conditions were fairly good throughout the year, mixed stocking increased production. In one year when pasture was very poor during winter, mixed stocking resulted in little or no increase in production. The weight changes of the animals suggest that most of the benefit from mixed stocking occurred during winter. The effect of mixed stocking on production varied with stocking rate only in the first pear. In general, the competition between sheep and cattle, as measured by annual production, did not vary with stocking rate. The sheep appeared to benefit more than the steers from mixed stocking, but this may have been a consequence of the stocking ratio selected.

Balancing animal, pasture and environmental outcomes in grazing management experiments

2017 ◽  
Vol 57 (9) ◽  
pp. 1775 ◽  
Author(s):  
D. L. Michalk ◽  
W. B. Badgery ◽  
D. R. Kemp
Keyword(s):  
Grassland Management ◽  
Environmental Benefits ◽  
Grazing Management ◽  
Stocking Rate ◽  
Commercial Practice ◽  
Large Plot ◽  
Grazing Systems ◽  
Landscape Variability ◽  
Native Pastures ◽  
Stocking Rates

About 60% of the gross value of Australia’s agriculture (AU$49 billion) is produced from the 85 million ha of temperate grasslands of southern Australia. A large part of this production comes from grazing livestock in the high-rainfall zone (HRZ) where 40% of the area has been retained as native and naturalised pastures, located in variable landscapes. These native pastures have seen a decline in productivity and increasing environmental problems, such as erosion, due to a loss of productive perennial species over recent decades. Grazing management systems have been advocated to not only balance the quality and quantity of forage with the nutritional demands of grazing animals, but also to manage the degradation caused by grazing. There has been an evolution of grazing management research through national projects from Temperate Pasture Sustainability Key Program to Sustainable Grazing Systems and then EverGraze, which has shifted from a focus on small plots and fixed stocking rates, to large-plot and farmlet experiments that include landscape variability and flexible grazing systems that more closely resemble commercial practice. These experiments generate reliable plant and animal response data that can be used to validate system models needed to assess the spatial and temporal challenges of grassland management. The present paper introduces the research conducted at the Orange proof site as part of the national EverGraze program. The research investigated the interactions between landscape variability and grazing method (1-, 4- and 20-paddock grazing management treatments) with flexible stocking rates. The following three key questions were addressed: (1) does increasing the number of paddocks and implementing rotational grazing result in a higher stocking rate, higher per hectare production and better economic outcomes; (2) which is the most appropriate combination of grazing method and stocking rate to achieve a higher and more stable perennial component to improve production and environmental benefits in different parts of the landscape; and (3) can landscape variability be identified, mapped and effectively managed on HRZ native grassland properties? This special edition of Animal Production Science answers these questions and provides recommendations for managing HRZ native pastures.

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