Safe pasture utilisation rates as a grazing management tool in extensively grazed tropical savannas of northern Australia

2008 ◽  
Vol 30 (3) ◽  
pp. 305 ◽  
Author(s):  
L. P. Hunt
Keyword(s):  
Perennial Grass ◽  
Grazing Intensity ◽  
Growing Season ◽  
Perennial Grasses ◽  
Management Tool ◽  
Management Approach ◽  
Tropical Savannas ◽  
Forage Production ◽  
Stocking Rates

The concept of safe pasture utilisation rates is frequently promoted as a tool for use in setting livestock numbers in perennial grass pastures in northern Australia’s tropical savannas to achieve a grazing intensity that is ecologically and economically sustainable. However, recommended pasture utilisation rates have been defined and applied in several ways, and this has led to some confusion among managers, researchers and advisers about their appropriate use. In order to reduce this confusion, this paper reviews the ecological basis and use of safe pasture utilisation rates as a management tool, concentrating on two common ways (i.e. strategic and tactical) in which they are applied. The main objective of both approaches is to limit the intensity of grazing of perennial grasses during the growing season when they are most sensitive to defoliation. When used in a strategic way, safe pasture utilisation rates provide an indication of long-term safe stocking rates that will avoid pasture deterioration in most years. Alternatively, they are used in a tactical sense to adjust stocking rates to track forage production, usually on an annual basis. Using the tactical approach, stocking rates are set at the end of the growing season in order to use a ‘safe’ proportion of the standing forage available at that time during the subsequent 12 months. Thus, stocking rates for one growing season are based on the quantity of forage available at the end of the previous growing season. In areas with high year-to-year variability in pasture growth this may lead to overgrazing during the growing season. This paper concludes by suggesting several strategies to better manage pasture utilisation levels under a tactical management approach to ensure that palatable perennial grass populations persist in the long term. A call is also made for researchers and land management advisers to be clear in the way recommended safe pasture utilisation rates are defined and intended to be used.

SGS Pasture Theme: effect of climate, soil factors and management onpasture production and stability across the high rainfall zone of southern Australia

2003 ◽  
Vol 43 (8) ◽  
pp. 945 ◽  
Author(s):  
P. Sanford ◽  
B. R. Cullen ◽  
P. M. Dowling ◽  
D. F. Chapman ◽  
D. L. Garden ◽  
...  
Keyword(s):  
Soil Ph ◽  
Perennial Grass ◽  
Growing Season ◽  
Perennial Grasses ◽  
Annual Rainfall ◽  
Stocking Rate ◽  
Rotational Grazing ◽  
Soil P ◽  
High Rainfall ◽  
Stocking Rates

The Sustainable Grazing Systems (SGS) National Experiment (NE) Pasture Theme explored factors that influenced annual herbage accumulation and perennial grass and legume content across the NE sites, in the high rainfall zone (HRZ, >600 mm/year annual rainfall) of southern Australia using multi-variate analysis and the SGS Pasture Model. Annual rainfall was a poor predictor of annual herbage accumulation. The length of growing season accounted for 30% of the variation in annual herbage accumulation. Much of the remaining 70% of variation in annual herbage accumulation was explained by soil Olsen P, the proportion of native species in the pasture and stocking rate, together with interactions among other factors including legume content. Simulated effects of set stocking and rotational grazing on herbage accumulation using the SGS Pasture Model, predicted that rotational grazing was unlikely to result in large increases in herbage accumulation. In contrast, it was predicted that the adoption of deep-rooted C3 and C4 perennial grasses could provide useful increases in herbage accumulation. Perennial grass content and basal cover were both significantly influenced by growing season length (P<0.001), grazing method (P<0.001) and an interaction between stocking rate and soil pH (P = 0.002). These analyses suggested that to maintain or improve the perennial grass component of a pasture at medium–high stocking rates, it was crucial to adopt grazing strategies that included rotation or resting. Perennial grass percent also significantly (P<0.001) increased in response to ameliorating the soil pH. Legume content of pastures significantly (P<0.001) increased in response to set stocking and increased stocking rate.To be botanically stable and productive, sown pastures based on perennial grasses in the HRZ of southern Australia will need to be grazed at high stocking rates (15–23 DSE/ha) in combination with rotational grazing or resting, and with adequate soil P. Additional gains in production and stability could be obtained by ensuring an adequate legume component, including a C4 perennial grass and ameliorating soil acidity. Pastures based on native perennial grasses may require lower soil P and more conservative stocking rates, depending on species.

scholarly journals How Long Before a Second Defoliation of Actively Growing Grass Plants in the Desert Grassland?

2020 ◽  
Vol 7 ◽  
Author(s):  
Sarah Noelle ◽  
Timothy Lyons ◽  
Alessandra Gorlier ◽  
Mitchel P. McClaran ◽  
Mary Nichols ◽  
...  
Keyword(s):  
Plant Height ◽  
Perennial Grass ◽  
Growing Season ◽  
Perennial Grasses ◽  
Desert Grassland ◽  
Winter Grazing ◽  
Grazing Period ◽  
Animal Diet ◽  
Stocking Rates ◽  
Reduced Time

In the Desert Grassland, second and subsequent defoliations on perennial grasses during the active growing season can have substantial impacts on grass recovery and reproduction following herbivory. Land managers implement tactics to avoid multiple defoliations on plants by way of rotational grazing, reduced stocking rates, and/or reduced time spent within a given pasture. We explored frequency and rate of defoliation by cattle on perennial bunchgrasses within an 11-day grazing period in three pastures including distance to water (300 and 600 m) and plant height to determine their influence on animal diet selection. Results indicate that 32% of all marked plants were defoliated by cattle and only 5% of defoliated plants were defoliated a second time by day 10 of the grazing period. Defoliation patterns in the studied pastures did not differ between two distances from water, or in relation to plant height. However, at the second defoliation cattle grazed plants that were shorter than at the first defoliation suggesting a selection for high quality re-growth over larger forage on offer. The results of this study show that a 10-day grazing period during the growing season of the Desert Grassland is an effective strategy to avoid second defoliations on individual perennial grass plants while maintaining sufficient forage for use during the dormant winter grazing season.

A survey of the natural pastures of the Trangie District, New South Wales, with particular reference to the grazing factor.

1953 ◽  
Vol 4 (1) ◽  
pp. 1 ◽  
Author(s):  
EF Biddiscombe
Keyword(s):  
Perennial Grass ◽  
Grazing Intensity ◽  
Basal Area ◽  
Grazing Pressure ◽  
Perennial Grasses ◽  
Forage Production ◽  
South Wales ◽  
Wide Range ◽  
Grazing Intensities ◽  
Summer Maximum

The Trangie district has a rainfall of 1,750 points with a slight summer maximum, a high relative variability of rainfall, and high summer temperatures. Disclimax pasture communities produced by a range of sheep grazing intensities operative during the past 20-30 years are described. On light soils ungrazed pasture comprises a wide range of perennial grasses. Light grazing (1 sheep per 2 acres) gives increased dominance by Stipa fulcata. With successive increases in grazing pressure Chloris acicdaris and Stipa setacea become conspicuous in turn, only to be virtually replaced by Chloris trumata as grazing intensity reaches 1 sheep per 0.5 acre. On heavy soils Stipa aristiglumis is dominant under light grazing. With increased rate of stocking, first Sporobolus caroli and then Stipa setacea gain dominance. At the highest stocking rates all these species are largely replaced by Chloris truncata. Throughout the sere the number of species is far more restricted than on the light soils. The striking feature of these results is that though botanical composition of the perennial grass component on light and heavy soils respectively is vastly different under light grazing, it becomes similar under heavy grazing and almost identical under severe grazing. Degenerative changes common to pastures of both soil groups under increasing grazing pressure are the decline in density and basal area of the perennial grass component, the greater population of winter and summer annuals, and the declining contribution of perennial grasses to green forage production in the spring. The basis of these findings is firstly the measurement of basal area, density and yield of perennial grasses, and density and yield of annual species in pastures of varying stocking history, and secondly, the measurement of pasture composition in relation to increasing distance from watering points.

Sources of valuable traits for perennial grass breeding

2021 ◽  
pp. 78-89
Author(s):  
LZ Baistruk-Hlodan ◽  
MM Кhomiak ◽  
HZ Zhapaleu
Keyword(s):  
Festuca Arundinacea ◽  
Trifolium Pratense ◽  
Perennial Grass ◽  
High Energy ◽  
Phleum Pratense ◽  
Perennial Grasses ◽  
Starting Material ◽  
Forage Production ◽  
Daily Growth ◽  
Galega Orientalis

Aim. The purpose was to identify collection accessions – sources of valuable traits to use as starting material for creating varieties of perennial grasses in Western Ukraine. Results and Discussion. Perennial grasses play an essential role in improving the efficiency of forage production. They produce a fodder mass that contains major macro- and micronutrients, minerals, vitamins, amino acids, and other nutrients in available forms, with a high energy protein saturation. Practice shows that due to the introduction of varietal crops into production in combination with optimal technologies of their cultivation, which allows revealing the potential of each variety, it is possible to additionally obtain 20-30% higher yields of fodder mass annually and harvest 2 to 3-fold seed yields. In 2016-2020, a search was carried out and 570 new accessions of perennial grasses were recruited, of which 201 were legumes and 369 were graminaceous grasses. The collection contains 1,319 accessions, of which 232 are Trifolium pratense L., 115 are Trifolium repens L., 49 are Trifolium hybridum L., 107 are Lotus corniculatus L., 80 belong to other legume species (Medicago, Galega orientalis L. Galega orientalis L. and Trifolium species), 131 are Phleum pratense L., 187 are Dactylis glomerata L., 146 are Lolium perenne L., 53 are Arrhenatherum elatius (L.) J. et C.Presl., 67 are Festuca rubra L., 28 are Festuca trachyphylla L., 32 are Bromopsis inermis (Leyss.) Holub, 92 belong to other species of other types of graminaceous grasses (Festuca pratensis Huds., Festuca arundinacea Schreb., Agrostis alba L. etc.). Accessions that enter the Department are registered and sown for propagation in the field. After examination, valuable accessions are transferred to the National Depository and registered in the National Catalogue; the rest of the obtained seeds are used in working collections. Conclusions. The best collection accessions were identified by a set of economically valuable traits: sources of daily growth of shoots (30), winter hardiness (28), plant height (22), yield of green mass upon haymaking (28) and pasture (19) use, forage productivity (15), seed productivity (25), foliage (21), and disease resistance (23). They can be recommended as starting material to create varieties of perennial grasses with high yields of forage mass and seeds for various applications.

Growth, seed production and effect of defoliation in an early flowering perennial grass, Alloteropsis semialata (Poaceae), on Cape York Peninsula, Australia

2001 ◽  
Vol 49 (6) ◽  
pp. 735 ◽  
Author(s):  
Gabriel M. Crowley ◽  
Stephen T. Garnett
Keyword(s):  
Plant Growth ◽  
Seed Production ◽  
Perennial Grass ◽  
Soil Surface ◽  
Plant Size ◽  
Perennial Grasses ◽  
Wet Season ◽  
Cape York ◽  
Seed Dynamics

Alloteropsis semialata (R.Br.) A.Hitchc. is one of the first perennial grasses in monsoonal Australia to produce seed at the start of the wet season. Patterns of growth and seed production and seed dynamics of Alloteropsis semialata were examined in this study, along with the effects of partial defoliation. Growth of Alloteropsis semialata tussocks started with the first pre-wet-season rains, and was then interrupted during a period with little rain. Growth ceased before the end of the wet season, indicating that factors other than moisture availability were limiting. Seeds of Alloteropsis semialata were germinable on production, but did not remain viable or persist on the soil surface through the dry season. Most seeds and young seedlings were harvested and no seedlings were recruited. Inflorescence production increased with plant size. Moderate defoliation in the early wet season had no impact on plant growth, but reduced inflorescence and seed production for at least 2 years. Absence of a seed bank and early wet-season flowering mean that Alloteropsis semialata is likely to be sensitive to long-term over-grazing.

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.

Short-lived intercrop forages affect long-term yields of alfalfa and wildrye grass mixtures

2002 ◽  
Vol 82 (1) ◽  
pp. 67-74
Author(s):  
A. J. Leyshon ◽  
P. G. Jefferson ◽  
J. Waddington
Keyword(s):  
Medicago Sativa ◽  
Avena Sativa ◽  
Forage Yield ◽  
Perennial Grasses ◽  
Forage Production ◽  
Elymus Trachycaulus ◽  
Psathyrostachys Juncea ◽  
Russian Wildrye ◽  
Slender Wheatgrass

Widely seeded rows (>60 cm) of perennial grasses have exhibited greater long-term yield stability, but allow weed invasion in the first years after establishment. A 9-yr study was conducted at a semiarid site at Swift Current, Saskatchewan, Canada, to determine the effects of intercropping oats (Avena sativa L.) and slender wheatgrass [Elymus trachycaulus (Link) Gould ex Shinners] between rows of Russian wildrye [Psathyrostachys juncea (Fisch.) Nevski], and Altai wildrye [Leymus angustus (Trin) Pilger] seeded in 90-cm spacings either alone or in alternate rows with alfalfa (Medicago sativa L.). Two rows of oats depressed grass forage production in the year following establishment. Slender wheatgrass intercrops reduced grass forage yield and alfalfa forage yield. However, slender wheatgrass contributed to increased total forage yields while it persisted in the mixture. By the fifth year, it had disappeared from the Russian wildrye plots but persisted 2 more years when intercropped with Altai wildrye. Interseeded companion crops, either annual or short-lived perennials, for forage will give short-term yield gains, but long-lived perennial forages may not recover from the competition in the long-term. Key words: Avena sativa, Elymus trachycaulus, Psathyrostachys juncea, Leymus angustus, Medicago sativa, forage yield

scholarly journals Review of trap-and-haul for managing Pacific salmonids (Oncorhynchus spp.) in impounded river systems

2020 ◽  
Author(s):  
Tobias J. Kock ◽  
John W. Ferguson ◽  
Matthew L. Keefer ◽  
Carl B. Schreck
Keyword(s):  
Pacific Salmon ◽  
Biological Effects ◽  
Management Tool ◽  
Management Approach ◽  
Facility Design ◽  
River Systems ◽  
Management Actions ◽  
High Head ◽  
Pacific Salmonids

AbstractHigh-head dams are migration barriers for Pacific salmon Oncorhynchus spp. in many river systems and recovery measures for impacted stocks are limited. Trap-and-haul has been widely used in attempts to facilitate recovery but information from existing programs has not been synthesized to inform improvements to aid recovery of salmonids in systems with high-head dams. We reviewed 17 trap-and-haul programs regarding Pacific salmon to: (1) summarize information about facility design, operation and biological effects; (2) identify critical knowledge gaps; and (3) evaluate trap-and-haul as a current and future management tool. Existing programs are operated to address a range of management goals including restoring access to historical habitats, temporarily reducing exposure to dangerous in-river conditions, and reintroducing ecological processes upstream from dams. Information gathered from decades of operation on facility design criteria and fish handling protocols, and robust literature on fish collection and passage are available. While many aspects of trap-and-haul have been evaluated, effects on population productivity and sustainability remain poorly understood. Long-term and systematic studies of trap-and-haul outcomes are rare, and assessments can be confounded by concurrent management actions and broad ecological and climatic effects. Existing data suggest that performance and effectiveness vary among programs and over various time scales within programs. Although critical information gaps exist, trap-and-haul is an important management and conservation tool for providing Pacific salmonids access to historical habitats. Successful application of trap-and-haul programs requires long-term commitment and an adaptive management approach by dam owners and stakeholders, and careful planning of new programs.

Evaluation of natural annual pasture at Trangie in central western New South Wales. 3. Effect of stocking rate on annual-dominated and perennial-dominated natural pastures

1978 ◽  
Vol 18 (92) ◽  
pp. 361 ◽  
Author(s):  
GE Robards ◽  
DL Michalk ◽  
RJ Pither
Keyword(s):  
New South ◽  
Perennial Grass ◽  
New South Wales ◽  
Perennial Grasses ◽  
Stocking Rate ◽  
Wool Production ◽  
South Wales ◽  
Natural Pasture ◽  
Ewe Lamb ◽  
Stocking Rates

A four year experiment is reported during which breeding Merino ewes grazed two natural pasture types at three stocking rates at Trangie in central-western New South Wales. Initially, the pasture on a red brown soil was dominated by cool season annual species, particularly Hordeum leporinum, Erodium species and Medicago species. The pasture on a heavier grey soil was dominated by the perennial grasses Chloris acicularis, C. truncata and Stipa variabilis. Clean wool production of ewes grazing the annual-dominated pasture was significantly (P< 0.05) higher than that of ewes grazing the perennial grass-dominated pasture even though the wool of the ewes grazing perennial pasture had a higher percentage clean yield (P < 0.05). The ewes on the annual-dominated pasture were significantly heavier in autumn and winter, and had a faster rate of wool growth in each season except spring, than ewes grazing perennial pasture. Number of lambs born per ewe, lamb birth weight and lamb growth rate were not affected by pasture type or stocking rate. Stocking rate had a small but statistically significant effect on clean wool production and only small effects on ewe liveweight, regardless of pasture type. When hand feeding of the pregnant ewes became necessary in the poor winters of 1971 and 1972 all stocking rates had to be commenced simultaneously. The significance of perennial grasses in these natural pastures is discussed in relationship to animal production, stocking rate, pasture and soil stability, and regeneration of grasses following favourable seasons.

scholarly journals The productivity of agrocoenosis in the steppe zone of Khakasia according to Terra Modis

2020 ◽  
Vol 149 ◽  
pp. 03002
Author(s):  
Elena Zhukova ◽  
Natalya Kutkina ◽  
Alexander Zhukov
Keyword(s):  
Gross Primary Production ◽  
Growing Season ◽  
Steppe Zone ◽  
Perennial Grasses ◽  
Hydrothermal Coefficient ◽  
Arable Fields ◽  
Increase In Productivity ◽  
Terra Modis ◽  
Integral Productivity

The article presents the results of a quantitative assessment of the productivity of agrocoenosis according to Terra MODIS within the steppe zone of Khakasia. The gross primary production of various agrocoenosis during the growing season ranges from 3.42 to 7.41 kg/m2. On average, the integral productivity for the growing season of 2018 was for wheat – 5.01 ± 1.04 kg / m2, oats – 4.86 ± 1.12 kg / m2, barley – 4.52 ± 0.42 kg / m2, buckwheat – 5.25 kg / m2, hayfields – 4.86 ± 0.45 kg / m2, deposits – 4.39 ± 0.40 kg / m2. Least of all phytomass were some arable fields and low-yielding crops of wheat and abandoned lands, and most of all perennial grasses and high-yielding wheat and oats. The GPP indicators are associated with the sum of positive temperatures positively (R2×0.673), to a lesser extent (R2×0.333) with a hydrothermal coefficient for the examined agrocoenosis. The most productive crops and fertile territories were determined based on the seasonal and long-term dynamics of gross productivity. An increase in productivity for some agrocenoses was noted in 2018 according to satellite data.

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