4. RUMINANT LIVESTOCK PRODUCTION SYSTEMS

4.1 Australian livestock production
An historical overview of Australian agriculture, with chapters devoted to ‘beef and dairy products’ and ‘sheep and wool’, can be found in Henzell (2007). As stated earlier, winter temperatures in 99% of Australia are relatively mild, enabling livestock to graze year-round on native pastures, improved pastures, forages and crop stubbles/residues. Dairy cattle occur mainly in coastal and irrigated areas. European breeds of cattle (Bos taurus) are pastured in southern Australia up to the Tropic (Figure 7). Bos indicus cattle such as the Brahman breed and its crosses are better adapted in several ways (thermoregulation, pest tolerance) to the more tropical environments of northern Australia, and these crosses are also popular in herds below the Tropic. Sheep are pastured from the southern tip of Tasmania up to latitude 20^oS in northern Australia, avoiding the humid, wet tropical coast of Queensland.

In temperate Australia, year-round stocking rates of about 0.5-2 dry sheep equivalents (dse) per hectare (or the equivalent in cattle) are carried on non-degraded native pastures, with about 8-10 dse on good quality improved pastures. In northern Australia, one beef animal or its equivalent in sheep (8 dse) can be carried per ha on well-improved pastures or on 3 ha of the best native pastures, compared with more than 50 hectares being needed to carry the same animal on the least productive pastures.

Domestically, Australians annually consume 37 kg beef and veal (steady trend), 13 kg of sheep meat per capita (steady), along with 25 kg pig meat (↑) and 38 kg poultry (↑) (Australian Bureau of Statistics). Livestock production is geared both to this domestic demand and to export markets for livestock products and livestock.

Photo 1. Dairying areas.
a. Dairying, Upper Murray, NSW.	b. Dairying, South Coast, NSW.

4.2 Dairy cattle
The Australian dairy industry [Photo 1.] has undergone substantial restructuring over the past few years. This process has contributed to the continuing long-term decline in Australian dairy farm numbers, from 118,000 farms in 1960 to 15,600 in 1990 and less than 10,000 today. Victoria is Australia’s largest milk producing state, accounting for more than 60% of the national milk production and more than 70% of manufacturing milk production. The average herd size in Victoria has increased from 150 head in the late 1970s to around 250+ head.

Figure 8. Map of the area of modified pastures (predominantly sown and fertilized) in Australia 2001 (green pixels) Also shown is the area of irrigated pastures, the largest area of which is either side of the border of southern NSW and Victoria (red pixels). Each pixel (cell) represents about 1000 ha (i.e. a total of 22.1 M ha of dryland sown pastures and 1.2 M ha irrigated sown pastures). This map was used to define the inland limit of sown pastures (see Figure 12). Note: The Bureau of Resource Sciences is now The Bureau of Rural Sciences (Australian Department of Agriculture, Fisheries and Forestry). [Click to view full map]

4.3 Sheep
Over the last three decades there has been a halving of sheep numbers (Table 1), to 77 million in 2007/08. This decline was due to the unstable marketing and reduced value of wool, and Australian producers responded by severely reducing their numbers of Merino sheep, the medium-fine wool breed. Over the same period, the numbers of crossbred sheep and other meat-producing breeds were stable and receipts from lamb increased. Currently (2007/08), the sheep industry [Photo 2.] is still an important part of Australia’s economy, with production of 510 kt wool, 435 kt lamb and 259 kt mutton, worth $4,777 m ($2,612 m wool, $1,466 m lamb) – about 11% of the gross value of Australia’s agricultural production. In 2007/08, Australia exported 45% of total lamb production, 77% of total mutton production and 4.09 million live sheep, earning about 2% of Australia’s total export earnings.

Photo 2. The sheep industry
a. Sheep country, Victoria.	b. Sheep transport by road.

There are many different breeds of sheep in Australia, each having attributes that suit different conditions and circumstances. Conditions such as climate, soil type, access to markets, economic trends and a variety of social factors affect breed popularity. The Merino breed still constitutes the majority of the total Australian sheep flock, because of their adaptation to the environment, high quality wool, relatively high wool production per head and their value as a component of the fat lamb production system. Dual-purpose breeds such as the Corriedale and Polwarth are declining but meat breeds are needed for the production of sires of fat lambs. The four main types of sheep enterprises in Australia are:

• Self-replacement enterprises for wool: As the name suggests, stock numbers on a farm are maintained using young animals that are born on that same farm. These enterprises are therefore pure breeding enterprises. In these flocks, adult ewes are sold (cast for age - CFA) at five or six years of age after completing four or five lambing cycles. These older ewes and any deaths that have occurred in the flock are replaced each year by 18 month old ewes (maidens or ewe hoggets). The wether (castrated male) portions of the above flocks are sold at 9-12 months of age or used as replacements in a wether wool growing enterprise operating on the farm.
• First Cross Ewe breeding enterprise: In this enterprise, Border Leicester (BL) rams are mated to Merino (M) ewes, and the resultant progeny are BL x M (or first cross) lambs. Wethers are sold when they reach about 35 kg liveweight (7-10 months old). Ewe lambs are sold as first cross breeding ewes when they are 12-15 months old (about 40 kg liveweight).
• Prime lamb production: Producers purchase young first cross (BLM) ewes. These ewes are mated with specialist meat breed rams such as Dorset Horn, Suffolk and other terminal sire breeds. The Dorper, bred in South Africa, is becoming a popular sire as a means of reducing labour inputs and addressing the issue of blowfly strike. The progeny of the above mating are known as second cross lambs or prime lambs. All wether and ewe lambs are sold for slaughter at liveweights ranging from 35-45 kg. Some are sold as ‘suckers’ (straight off their mothers, before weaning, at about 4 months old) and the balance are weaned and sometimes shorn before sale. The distribution of the broadacre lamb-producing farms in Australia is given in Table 2 (Hooper 2009).
  

Table 2. The distribution of broadacre slaughter lamb producing farms, 2001-02 to 2007-08 by number of slaughter lambs sold

The majority of sheep farms are staffed by family members, with occasional contract labour. Most farms are diversified, producing wool, beef and/or grain. In southern Australia, the biological optimum time for joining ewes with rams is from late February with lambing in late July (slopes and plains) to late September (tablelands). In practice, sheep are mated to lamb from March to September, with some flocks split for lambing in different months.

4.4 Beef production
Australian beef producers [see Photo 3.] supply two main market areas; the domestic market and the export markets. Production of beef and veal was 2,155 kt in 2007/08. The domestic market consists of clients such as retail butchers, supermarkets, hotels, restaurants and institutions. The per capita amount of beef consumed by the Australian public (37-38 kg, see above) is now relatively stable. The proportion of production available for export peaked in the 1990s (60%) but this market now comprises 43% to Japan (364 kt in 2007/08), US (238 kt), Republic of Korea (146 kt) and other markets. Feedlot production, mainly to ‘finish’ cattle, accounted for about 40% of the adult cattle slaughtered annually in Australia. The Australian live cattle export trade, 713,000 head in 2007/08, is the largest in the world.  

Photo 3. Beef cattle production
a. Beef cattle on the Southern Tablelands of NSW, grazing a perennial grass and subterranean clover pasture.	b. Cattle grazing Tagasaste (Chamaecytisus palmensis), Western Australia (Photo by B. Cook).

The differentiation into various systems of beef production is due largely to the growth rate of the animal and the degree of finish or fat cover that can be achieved on a particular farm or under a particular environment. Broadly, animals may be raised on the one farm until slaughter or they may be purchased as ‘store cattle’, for finishing on pasture in a more favourable environment or in a feedlot. Adult cattle are slaughtered to produce a carcass weight of 325-350 kg at 2-2.5 years of age in southern Australia and 4-4.5 years (bullocks or culled cows, Figure 9) in northern Australia. Better livestock management and improved pastures have closed the gap between turn-off rates between beef cattle in northern and southern Australia (Figure 10).

Figure 9: The pronounced seasonal changes in liveweight of cattle 1-4 years old, grazing native tropical pastures at Katherine, Northern Territory. (Source: adapted from CSIRO Division of Land Resource Technology, Paper 28).

Figure 10: Hypothetical growth curve (kg liveweight by time in weeks) of a calf born in late-autumn and finished as a yearling in the spring of the following year (Source: Department of Further Education, SA).

On temperate improved pastures in southern Australia, other systems of production include:

• Steer production, castrated male with two or more permanent incisors, with a carcass weight of less than 300 kg. The age ranges from 18-24 months (two permanent incisors) up to about 3-3.5 years (six tooth).
• Yearling beef – an animal of either sex aged 12-16 months weighing between 300-400 kg liveweight with a dressed weight of 170-220 kg. In comparison with vealers, yearlings (Figure 10) do not have the same fast rate of growth;
• ‘Vealer’ production (a fast growing, unweaned or newly weaned animal aged 8-10 months, slaughtered at 165-330 kg liveweight to produce a carcass of 90-180 kg dressed weight); and
• Veal production (mainly dairy calves slaughtered before weaning to produce a carcass <90 kg).

The most popular types of beef cattle are the Angus and Hereford breeds in southern Australia, with Brahman and Brahman-derived crossbreeds such as the Santa Gertrudis, Braford and Droughtmaster in tropical Australia. Other breeds include Charolais, Murray Grey and Shorthorn.

The distribution of broadacre beef cattle farms in Australia is given in Table 3. In northern Australia, many of the farms (stations) also run sheep. In southern Australia, most of the farms also run sheep and many produce crops as well. Up to 400 head or so, the cattle can be managed by one farm family without additional permanent labour.

Table 3. The distribution of broadacre beef cattle farms by numbers of cattle (average between 2001/02 and 2007/08) (Mackinnon, 2009)

4.5 Other livestock production
In retail butcheries and restaurants in major Australian cities and towns, it is possible to purchase a wide range of meat types, including goat, deer, horse, camel, buffalo, kangaroo and crocodile. Information on the organization of these industries and new animal products is available at www.rirdc.gov.au.

5. THE PASTURE RESOURCE

5.1 Native grasslands
Native grasslands are still a significant component of the pasture resource in all Australian agro-ecological zones, even though large areas have been replaced or modified with improved grasses and legumes (exotic species) that were either deliberately or accidentally imported from world temperate and tropical regions. In southern Australia, these modified areas include the higher rainfall areas (coast, tablelands and slopes), where introduced species contribute most to grassland productivity, and the slopes and plains of the wheat-sheep belt, where crops and pasture legumes predominate. In northern Australia, the development and use of introduced species for pastures has occurred mainly in the last half-century, and there is an overall greater reliance on native grasses. Native grasslands, modified by the agencies of grazing, clearing and fire, are the mainstay of the semi-arid grazing areas.

5.1.1 Native grasslands in southern Australia
For the slopes and tablelands of NSW, Moore (1970) described the main botanical changes in pastures in typical Eucalyptus woodland–grassland communities during the first 150 years of clearing and grazing with livestock and rabbits, which accompanied the first white settlers. The original vegetation, dominated by tall warm season perennial tussock grasses such as kangaroo grass (Themeda triandra = T. australis), plains grass (Austrostipa aristiglumis) and poa tussock (Poa labillarderi), was presumably well-adjusted to the ebb and flow of the native herbivores (kangaroos, wallabies, bird life) and occasional fires. Once sheep and cattle were introduced to the tablelands and slopes in the 1830-40s, accompanied by tree-clearing operations, there began a sequential progression (Figure 11) in the botanical composition of the grasslands, toward communities that contained an array of grazing-tolerant, cool- and warm-season native grasses, together with various naturalised annual grasses and forbs that had been introduced into Australia in agricultural seeds and feeds. The main agent of change was presumably continuous defoliation by harder-hoofed animals, with the loss of grazing-susceptible plant species (an early casualty was kangaroo grass) opening the sward to native and exotic invading species. Nutrient redistribution and changes in the seasonal extraction and replenishment of soil water are other processes that presumably influenced these earlier changes in Australian grassland communities (Johnston, 1996).

Garden and Bolger (2001) and Wolfe and Dear (2001) used the state and transition model to update the nature and timing of changes that occurred in grasslands on the tablelands of NSW since 1950 (Figure 11). These changes were rapid, driven by the popular practice of aerially applying legumes and superphosphate (originally 100-125 kg/ha/year) to native pastures to provide higher quality feed and to provide nitrogen for grasses, as well as sowing exotic grasses and legumes into herbicide-treated or prepared seedbeds. Other agents of change were grazing at higher stocking rates (which enhanced the transfer of fixed nitrogen to the associated species), invasion by nitrophilous weeds, a process of soil acidification (due to changes in the cycling and distribution of nitrogen and carbon in the grazed ecosystem), various good and bad management practices, bursts of enthusiasm and apathy towards pasture improvement, and wet/dry years. As a consequence, pastures along the NSW slopes and tablelands exist in an array of states (Figure 11), some even reverting back to native species after a history of fertilization and legumes. Several native grasses, especially perennials like the wallaby grasses (Austrodanthonia spp.) and redgrass (Bothriochloa macra), [see Photo 4.] are currently regarded as useful because of their tolerance of grazing, their adaptation and their lack of spiny awns. Poa tussock and weeping grass (Microlaena stipoides) are persistent on wetter, more fertile sites. The main impediments to resowing larger areas of native pastures are their relatively low productivity in favoured areas compared with exotics and the lack of seed, or its high cost if available.

Photo 4. Redgrass, NSW Tablelands.

Other important components of the degraded grasslands of southern Australia included many grasses, forbs and legumes that became naturalised after their entry to Australia. Sometimes this naturalisation followed their accidental introduction in agricultural produce from various destinations along the sea routes from Europe and the Mediterranean region to Australia (for example, silver grass Vulpia spp.), barley grass (Hordeum leporinum) and capeweed (Arctotheca calendula). In other cases, plants that were introduced deliberately as ornamentals, such as soursob (Oxalis pes-caprae), variegated thistle (Silybum marianum) and Paterson’s curse or ‘Salvation Jane’ (Echium plantagineum), colonised pastures (Michael, 1970). Most of the strains of subterranean clover (Trifolium subterraneum) found in the suburbs of Perth by Gladstones (1966) entered Australia accidentally before 1870, and some annual Medicago spp. were naturalised by the early 1900s (Crawford et al., 1989). Michael (1970) attributed the competitive success of these alien species to their adaptability to disturbed environments and/or the absence of their native pests and competitors. Why they were so successful in competition with the native perennial grasses is open to speculation. A possible reason is that the winter-growing Mediterranean annuals depleted soil water in spring such that the summer-growing perennials were unable to survive the long, dry summers. Another factor may have been selective grazing of the perennials by sheep over summer, reducing the above-ground green material and energy reserves of the perennial grasses, and encouraging invasion by serious weeds such as serrated tussock (Nassella trichotoma).

Figure 11. The application of the state and transition model to the generalised pathways of botanical change that have occurred in permanent pastures in south-eastern Australia. The main agents of change (transitions: G = grazing, F = fertiliser, L= legumes, E = exotic grasses, D = drought) are indicated (after Wolfe and Dear, 2001) [Click to view the full figure]

With some variations, similar patterns of clearing and botanical change occurred throughout the tablelands, slopes and plains of NSW, central and southern Victoria, Tasmania, lower SA and the south-western tip of WA. On parts of the Central and Southern Tablelands of NSW, the aggressive and indigestible serrated tussock (Nassella trichotoma, a native of South America) colonised tracts of non-arable country (Campbell, 1998). On the northern slopes of NSW and on granite soils in southern Queensland, three-awned speargrass or wiregrass (Aristida ramosa), an unpalatable C4 species, became co-dominant with redgrass on extensive areas of lightly grazed grasslands – it has subsequently been shown that A. ramosa is sensitive to defoliation and the balance can be shifted back towards more palatable C3 species by strategic seasonal grazing (Lodge and Whalley, 1985). Towards the 300-350 mm rainfall isohyets (Figure 2) in north-western Victoria, southern SA and south-western WA, extensive areas of mallee shrublands (‘mallee’ is a multi-stemmed, lignotuber form of eucalypt species, a form that occurs in sandy areas of variable rainfall) were cleared for wheat growing, with sheep pastured on the various native and naturalised, annual volunteer species that occurred in fallows. The mallee shrublands that occur along parts of the coast of SA and WA were cleared and used for crops/pastures only in the last 40-60 years, after micronutrient problems were solved and when heavy equipment was available for sowing crops and pastures.

Accurate statistics on current pasture areas in Australia are difficult to obtain due to the nature of the questions asked in the official census that is taken every 5 years. Dear and Ewing (2008), who extracted the area data from the Australian Temperate Pastures database (Hill and Donald, 1998), reported an area (excluding Queensland, NT and tropical WA) of 32 M ha of unimproved native pastures and 6 M ha of improved native pastures (fertilized or fertilized + oversown, mainly in areas with >550 mm average annual rainfall). These values compare with an area of up to 25 M ha of sown pastures in southern Australia. The adaptation of sown species and cultivars in southern Australia is discussed in section 5.2.

5.1.2 Native grasslands in northern Australia
General maps of the vegetation and grassland areas of tropical Australia are available in Moore (1970); a more detailed map of the native pasture communities in Queensland was published in Walker and Weston (1990). Along the tropical eastern coast of Queensland and into the nearby ranges and plateaus, where much of the original rainforest has been cleared, there are extensive areas of grassland, dominated by bunch speargrass (Heteropogon contortus) in the drier areas and blady grass (Imperata cylindrica) in the more humid areas, both interspersed with kangaroo grass and forest bluegrass (Bothriochloa bladhii). In the seasonal wet/dry tropics, taller grasses occur, such as perennial and annual Sorghum species, wild rice (Oryza rufipogon, Northern Territory), fire grass (Schizachrium spp., Cape York Peninsula) and ribbon grass (Chrysopogon spp.). Further inland from the coast, the central sub-humid zone in Queensland is dominated by woodlands and acacia scrublands, with smaller areas of grasslands dominated by bluegrasses (Dichanthium spp., Bothriochloa spp.), plains grass and satintop (Bothriochloa erianthoides). The woodland areas, comprising gums (Eucalyptus spp. and Corymbia spp.), sheoak (Casuarina spp.) and cypress pine (Callitris spp.), produced a grassy Aristida-Bothriochloa understorey once they were cleared for grazing, and the dominance of these grasses was maintained by periodic burning. The sub-humid acacia shrublands, comprising brigalow (A. harpophylla) and/or gidgee (A. cambagei), were cleared primarily for cropping but these shrublands also support good quality native and improved pastures. Further inland towards the semi-arid zone, there are large areas of native perennial grasslands such as those dominated by Mitchell grass (Astrebla spp.) that are prized for cattle grazing, along with areas of mulga grasslands (dense to scattered Acacia aneura trees with an understorey of Aristida and Enneapogon annual grasses), spinifex (Triodia irritans) and bluebush grasslands (Kochia spp., Bassia spp., annual and perennial grasses). Sheep are grazed with beef cattle in the sub-humid and semi-arid areas of Queensland but not in the humid eastern tropics (Queensland) or the northern tropics (Queensland, Northern Territory, Kimberley region of WA), where the climate (wet hot summers, dry winters) and tall tropical grasses are suitable only for beef cattle, especially the adapted Bos indicus breeds.

In 1996 and 1997, Bortolussi et al. (2005a, 2005b, 2005c) comprehensively surveyed 375 producers representing the northern Australian beef industry that is based on these subtropical and tropical native grasslands. In contrast to southern Australia, where cropping and livestock grazing for meat and wool is conducted on properties that are of moderate size (median 2000 ha) with most beef farms having less than 400 head (Table 3), the median size of the survey properties was 1,669 ha (Maranoa and south-west) to 36,310 ha (north-west) in Queensland (range 324-2,133,100 ha), 304,200 ha in the Northern Territory (range 20,000-1,630,433 ha) and 286,216 in northern WA (range 300-914,386 ha). Median herd sizes were from 1,550 head (central coastal Queensland) to 62,000 (Northern Territory). From the survey, the most commonly used native pasture communities (Table 4) were speargrass (high rainfall, near to the coast) and Mitchell grass (inland plains), while improved pastures based on grasses or grasses + legumes were sown mainly in intermediate areas formerly dominated by black speargrass, woodland (Aristida-Bothriochloa association) or acacia scrub (brigalow, gidgee).

Table 4. The frequency of native and sown pasture communities and the average annual liveweight gains of cattle (LWG, kg/head) on 375 surveyed beef properties in northern Australia, 1996/97 (Bortolussi et al., 2005b)

Based on a broad scale assessment of Queensland’s land resources in the late 1980s and expert opinion (Walker and Weston, 1990; J.G. McIvor personal communication), the area of native pastures grazed by livestock in northern Australia is likely to be about 110 M ha, of which an area of around 5 M ha comprises naturalised pastures (occasionally fertilized, oversown and/or naturally spreading improved species) and 4.5 M ha sown pastures. The adaptation of sown species and cultivars in northern Australia is discussed in section 5.3.

5.1.3 Native or exotic?
There is a continuing dialogue in Australia between environmentalists and agricultural scientists, groups that are often opposed on matters such as native grasslands, forest policies and water utilisation/conservation. Australia has replaced huge areas of woodlands and grasslands with crops and with grasslands based on exotic species. The inclusion of superphosphate and exotic pasture species (utilising locally produced seed of adapted or bred cultivars) into farming systems has lifted productivity in a country where soil fertility is limited by weathered soils and by a paucity of useful local legumes. Leaving aside for the moment the difficulty of producing abundant supplies of cheap seed from native species, there is a strong case on sustainability grounds for the use of management options that utilise adapted native grasses, and for the inclusion of a wider range of perennial grasses, particularly C4 species, for pastoral use (Johnston et al., 1999). Johnston et al. (1999) questioned the amount of research and development effort that has gone into replacing indigenous grasses with exotic introductions, many of which fail to persist over the frequent droughts that characterise the Australian climate. They reviewed the evidence for the persistence, productivity and nutritive value of several species of native grasses in grazed pastures, and argued for strategies that utilise adapted, palatable grasses such as wallaby grass in low-input situations and C4 perennials in areas that are prone to hydrologic imbalance. Importantly, however, Johnston et al. (1999) acknowledged the folly of a “one-or-the-other” philosophy, compared with an approach that achieves a complementary fit between a low-input, conservative approach to pasture management and the high-input, exotic species approach to pasture improvement. The high-input approach, at least where sown pastures have been properly managed, has produced notable gains in the productivity of Australian grasslands for wool and red meat production (Smith 2000). The low-input approach is important in lands where restoration is a priority (e.g. on degraded or eroded sites, in national parks or in reference conservancy areas) or where disturbance is unwise. In several States, there are native grassland reference areas that are protected; these areas cannot be modified by oversowing with exotic species, fertilized or cultivated.

5.2 Sown pasture types and species, temperate Australia

5.2.1 Map of zones
Figure 12 depicts a general map of the main tropical and temperate pasture zones in Australia. This map updates the zones in Map 5 of Moore (1970), taking into account the adaptation zones for temperate species mapped by Moore and by Hill (1996), the map of Australian agro-ecological zones (Figure 7) and the actual distribution of sown pasture species (Figure 8).

5.2.2 Temperate pasture zones
The temperate zones are based on the limits to the adaptation of important pasture species, especially the inland limit that is set by moisture, the arid boundary (Donald, 1970) (Figure 13). The arid boundary for each zone is defined mainly by the P/E ratio (Hill, 1996), where P = precipitation and E = potential evaporation (Figure 2). The main pasture zones are:

• Temperate perennial pasture zone. This pasture type, characterised by perennial ryegrass (Lolium perenne) and white clover (Trifolium repens), is restricted by an inland limit of annual P/E >0.55, corresponding with annual median rainfall of 700 mm in Victoria and about 750 mm along the coast and higher tablelands of NSW and the far south of Queensland. Hence, unlike New Zealand, Europe and parts of the USA, ryegrass/white clover is a pasture type of secondary importance in Australia. According to Dear and Ewing (2008) there were 6 M ha of improved pastures containing perennial ryegrass and/or white clover in southern Australia in 1997. In this zone, there also occur smaller areas of phalaris (Phalaris aquatica) and cocksfoot (Dactylis glomerata) in NSW, Victoria and Tasmania, as well as tall fescue (Festuca arundinacea) in NSW.
• Temperate perennial grass – annual legume pasture zone. Phalaris, which is usually sown with subterranean clover, extends the inland limit of perennial grass to about the 500 mm annual rainfall isohyet (Figure 13). By way of comparison, the inland limit of the wheat belt (Figure 14) is about 300 mm in WA, 350 mm in SA and north-western Victoria, 400 mm in southern NSW and 500 mm in northern NSW and southern Queensland. Phalaris is the most persistent (drought tolerant) temperate grass introduced into Australia and is particularly important in NSW and Victoria, where there is a considerable area between the 500 and 750 mm annual rainfall, In 1997, there were 4.75 M ha of improved pastures containing phalaris. Smaller areas of perennial ryegrass, cocksfoot and tall fescue are sown in this zone but they rarely persist after major droughts.

Figure 12. Pastures of Australia based on the limits to the adaptation of tropical and temperate pasture species (after Moore, 1970; Hill, 1996; B. Cook, personal communication). [Click for full map]

Figure 13. Limits to the growth and survival of temperate pasture species, after Moore (1970) and Hill (1996) [Click for full map]

• Lucerne pastures are a special case since, if the soils are suitable, deep-rooted lucerne is adapted (Figure 13) to the climate of several zones, including the lower half of the tropical subhumid/semi-arid zone. Lucerne, lucerne/grass and lucerne/annual mixtures are used for grazing and hay production on alluvial soils and aeolian (windborne) sediments in southern Australia and southern Queensland. Lucerne has a huge area of potential adaptation that is greater than that for any other pasture species (Hill, 1996), persisting inland on suitable soils where summer P/E is >0.5, which corresponds with the 500 mm annual rainfall isohyet in southern Queensland and northern NSW and the 400 mm isohyet in southern NSW, Victoria, SA and WA. In practice, the adoption of lucerne has been constrained by its susceptibility to acid soils (pH CaCl₂ <5.2), the need for a rotational grazing regime to ensure its survival, the incidence of insect pests and disease, and by the attitudes of those farmers and graziers who perceive lucerne to be a special-purpose pasture rather than an all-rounder. There were 3.5 M ha of lucerne pastures in 1997 (Dear and Ewing, 2008). In recent years there has been strong advocacy of lucerne as a component of permanent or ley pastures to enhance livestock production, N fixation and/or water extraction from the soil profile.
• Annual temperate pasture zone. Annual legumes, principally subterranean clover and annual medics, were the basis for the legume ley pasture system in the Australian wheat belt (Figure 14 and Photo 5), where there are about 22 M ha cropped each year plus a further 11 M ha in the pasture phase. Annual legumes persist where winter P/E >0.5, equivalent to the 400 mm isohyet in southern NSW and 350 mm in Victoria, SA and WA. There is a wide range of cultivars available of both subclover (used in temperate croplands, slopes and tablelands) and medics (croplands and plains) to suit a range of seasonal durations, soil types and crop/pasture systems. Subterranean clover and annual medics also are restricted by a northern warm boundary, since most cultivars require a daylength or cool temperature trigger for floral initiation (Archer et al., 1987), as well as by a cold boundary in alpine areas where cold temperatures may arrest growth and flower/seed development (Donald, 1970). The survival of medics is further limited on soils of low surface pH (pH CaCl₂ <5.2-5.8, depending on the species). There are a number of sown annual grasses (chiefly Wimmera ryegrass Lolium rigidum) as well as an array of volunteer annual grasses (e.g. Vulpia spp.) and forbs that are well adapted in this zone (Rossiter, 1966, Wolfe and Dear 2001) but their use is restricted by their status as important crop weeds.

Figure 14. The Australian wheat belt, where annual legumes are used in pasture leys and phases, in relation to annual rainfall isohyets

a. Wheat belt pastures and crops, Wagga Wagga, NSW	b. Wheat-sheep belt 1 – Birchip, Victoria.
c. Wheat-sheep belt 2 – Birchip, Victoria.	d. Wheat belt Junee, NSW
Photo 5. Wheat-sheep belt.

5.2.3 Perennial temperate species
Both perennial ryegrass and white clover are well-adapted to defoliation by livestock and both compete well for available resources such as nutrients and light. However, the relatively dry environments and lighter textured soils of Australia confine these species to a favourable fringe along the coast and tablelands of south-eastern Australia, with smaller areas of irrigated pastures occurring inland. The coastal fringe contains the major population centres of Brisbane, Sydney, Melbourne and Hobart. Perennial ryegrass/white clover pastures along with Kikuyu (Pennisetum clandestinum) pastures (see section 5.3) have underpinned much of the Australian dairy industry. The link of these species to dairying remains strong but now the system of milk production is more decentralised towards areas that are closer to fodder and water resources due to the encroachment of the urban fringe on agricultural lands, the scarcity of water and better transport services. Attempts to improve the productivity and reliability of the perennial ryegrass/white clover pasture type, either by breeding/selecting for persistence in ryegrass (Blumenthal et al., 1996, Oram and Lodge, 2003) and white clover (Lane et al., 2000; Jahufer et al., 2002) or by using alternative species such as cocksfoot or tall fescue (Nie et al., 2008), have met with limited success. Tall fescue (cv. Demeter) is useful alone or in combination with other grasses where summer growth is required for production or bloat avoidance, while a number of summer-dormant cultivars offer better persistence where summer rainfall is unreliable. Similarly, both phalaris and cocksfoot possess some desirable agronomic attributes but there are negative aspects of their nutritive value compared with ryegrass (Oram and Lodge, 2003).

Phalaris, grown on 4.5 M ha, is second to perennial ryegrass in total pasture sowings and is the dominant temperate sown grass where perennial ryegrass will not persist. It characterises important sheep and cattle meat-producing areas in NSW, Victoria, SA and Tasmania. A deep-rooted, prostrate habit, dense tillering, partial summer dormancy and the presence of a large underground rhizome are features associated with the outstanding persistence of the ‘Australian Commercial’ cultivar. This cultivar possesses important deficiencies such as poor seed production due to shattering, slow seedling establishment, a susceptibility to acidic soils and several anti-nutritional components, factors that have been addressed, at least in part, by breeding (Oram and Lodge, 2003; Oram et al., 2009). However, the presence of phalaris in grazed pastures is generally prized, conferring both stable productivity and sustainability (soil protection, competitive ability with weeds, reduction in groundwater accessions).

Lucerne, sown either alone or in mixture with other species, is currently grown on more than 3.5 M ha (Dear and Ewing, 2008), with most of this area occurring in the wheat belt. During the 1980s, after the dominant Hunter River cultivar succumbed to the spotted alfalfa aphid and the blue-green aphid, successful breeding programs were developed to produce several aphid-resistant, Australian-adapted lucerne cultivars with boosted winter activity (Williams, 1998; Humphries and Auricht, 2001). A beneficial spin-off from this effort was the improved tolerance of Australian cultivars to diseases such as phytophthora root rot (Phytophthora medicaginis) and colletotrichum crown rot (Colletotrichum trifolii) (Irwin et al., 2001). These diseases limited lucerne survival in humid summer environments found in northern NSW and Queensland, the zone where lucerne is most needed to restore soil fertility. During the 1990s and into the new millennium, a continuing investment in lucerne improvement was justified, at least in part, by the stronger focus on soil health and agricultural sustainability in the main pasturelands and croplands (Cocks, 2001). Several Australian studies (Turner and Asseng, 2005) have confirmed the value of lucerne in utilising water spared by annual crops and annual pastures, thereby reducing the potential of groundwater recharge both directly (water extraction) and indirectly (creating extra water storage capacity prior to winter).

Dear and Ewing (2008) outlined the rationale for a targeted effort to increase the available deep-rooted perennial pasture species for the control of dryland salinity in Australia. Hughes et al. (2008) described the systematic process, including the development of a database of priority species (nearly 700); their screening for weed risk; securing the needed germplasm from Australian and overseas collections or by direct collecting; quarantine; nursery and plot evaluation; and species characterisation and multiplication. A preliminary review of the results of this program was given by Dear et al. (2008) who, among other species, mentioned cullen or tall verbine (Cullen australasicum, an Australian native, leguminous shrub), lotononis (Lotononis bainseii, already available from prior work done in subtropical Australia), several available temperate and tropical perennial grasses and, for discharge (salty) environments, certain legumes (e.g. Melilotus siculus, M. sulcatus) and grasses (e.g. Puccinellia ciliata). This program, restricted somewhat by inadequate funding, is an example of what can be done when experienced, committed professionals work towards a clear objective.

Finally in this section, mention needs to be made of the potential of subtropical and tropical perennial C4 species such as Kikuyu, Rhodes grass (Chloris gayana), buffel grass and lotononis in temperate areas, especially in the temperate/subtropical transition zone along the NSW-Queensland coast (Figure 8), the border slopes/plains (Boschma et al., 2009) and for specific purposes such as the management of groundwater accessions in southern Australia (Nie et al., 2008).

5.2.4 New temperate annual legumes for pastures
Annual pasture legume options were once largely confined to cultivars of subterranean clover and annual medics. The life cycle and dynamics of these species were outlined by Wolfe and Dear (2001). Subterranean clover, in particular, is well adapted to continuous grazing with livestock. During summer, the pool of hard (impermeable) seed is partially protected from grazing by burr (pod) burial. After germination, the emerging seedlings are unattractive to livestock. In winter, when grazing pressure is high, the continued close grazing of the prostrate herbage stimulates seed production and burr burial in spring. During spring, low grazing pressure (growth exceeds consumption) and burr burial protect the developing inflorescences. Compared with subterranean clover, annual medics are more susceptible to grazing but they produce an abundance of flowers and the seed pods are better adapted to drought.

During the 1980s, the release of cultivars of yellow serradella (Ornithopus compressus, tolerant of acidic, sandy soils), Medicago murex (tolerant of acid soils) and balansa clover (Trifolium michelianum, suitable for waterlogged, heavy–textured soils) extended annual legumes into specific niches. From 1990, the changing nature of farming systems and a recognised lack of legume biodiversity triggered a new emphasis on annual pasture legume breeding and selection (Loi et al., 2005). A national effort (Nichols et al., 2007) was directed towards producing annual legumes to deal with particular problems and opportunities, such as legume adaptation on difficult soils (acid, waterlogged or saline), weed and insect threats, longer pasture and cropping phases, deeper-rooted plants to reduce groundwater accessions, and the need for easily harvested and sown seed. As a result, a wide range of species and cultivars are now available for the wheat belt in WA and other States (Table 5).

Cultivars of pink or French serradella (Ornithopus sativus), gland clover (Trifolium glanduliferum) and biserrula (Biserrula pelicinus) [see Photo 6.] are the most successful outputs from this recent, well-executed program (Loi et al., 2005; Nichols et al., 2007). Yellow and pink serradella are the only species that are well-adapted to the sandy soils of coastal WA. New cultivars of yellow serradella (cvs. Yelbini, Charano, Santorini and King) and French serradella (cvs. Cadiz, Margurita [Photo 6], Erica) were selected for the combination of pod retention and straight (non-segmenting) pods, which allowed direct heading and reduced the need for seed processing. Gland clover (cv. Prima) has resistance to redlegged earth mite and aphids. Biserrula, which can be harvested with commercial headers, is a successful alternative to subterranean clover, which is difficult to harvest. Biserrula (cvs. Casbah, Mauro) offers a high level of hard seeds with a delayed seed softening pattern, a deep-rooted habit and a potential for herbicide-free weed management (Loi et al., 2005). Another legume species that is of particular interest is eastern star clover (Trifolium dasyurum) [Photo 6]. Following the normal break of season (late autumn), eastern star clover germinates several weeks after other pasture legumes and weeds (Loi et al., 2005), a pattern that can be combined with strategic grazing or herbicide application to control crop weeds during the pasture phase. In addition to the recent release of cultivars of these and other new annual legume species (e.g. T. spumosum , bladder clover), new cultivars have also revitalised the use of traditional subterranean clover and annual medic as well as less popular species such as rose clover (T. hirtum) and arrowleaf clover (T. vesiculosum) (Nichols et al. 2007). This program is a further example that illustrates Australian ingenuity in assembling temperate germplasm, ingenuity that also applies to the domestication of a range of genera and species for subtropical and tropical Australia (Section 5.3).

a. Biserrula pelecinus. Biserrula has been released as a new aerial seeding hard-seeded annual legume for acid and light textured soil (B. Dear )	b. Trifolium glanduliferum. Gland clover is a new red-legged earth mite resistant annual legume suited to poorly drained soils. (B. Dear )
c. Trifolium michelianum. Balansa clover is a winter growing annual suited to poorly drained acid to neutral soils with rainfall of 275-600 mm. (B. Dear)	d. Ornithopus sativus. French serradella cv. Margurita. (A. Loi)
e. Trifolium dasyurum. Eastern star clover cv. AgWest Sothis. (A. Loi)	f. Trifolium spumosum Bladder clover cv. AgWest Bartolo. (A. Loi)
Photo 6. New annual legumes for Australian pastures (Photos by B. Dear and A. Loi).

Table 5. The effects of soil type and the length of the pasture phase on the choice of legume species used in pastures in the wheat belt of southern Australia. In each zone, the areas of the legumes in parenthesis are subdominant.

There has been little recent research into annual pasture grasses for the cropping zone because of the potential of these grasses to become important crop weeds. Such is the case with Wimmera ryegrass, which has become resistant to a wide range of herbicides (Broster and Pratley, 2006). However, cereals sown for grazing and grain (Hacker et al., 2009), oats sown with vetch (Vicia sativa) or peas (Pisum sativum) (Coventry et al., 1998; Kaiser et al., 2007) and an array of annual and biennial grasses marketed by commercial companies are potentially valuable as short-term forages.

5.3 Sown pasture species, subtropical and tropical Australia

5.3.1 Pasture zones in the subtropics and tropics
An expanded range of subtropical and tropical pasture species for use around the world has come from a sustained effort to collect, introduce and manage species for subtropical and tropical pastures in Australia. This effort was mounted during most of the 20th century by the Commonwealth Scientific and Industrial Research Organisation (CSIRO and its antecedent CSIR, initially through the Division of Tropical Pastures and subsequently the Division of Tropical Crops and Pastures), along with three State/Territory Departments of Agriculture (now NSW Industry & Investment; Queensland Primary Industries and Fisheries in the Department of Employment, Economic Development and Innovation, and the Northern Territory Department of Regional Development, Primary Industry, Fisheries and Resources). Eyles et al. (1985) and ‘t Mannetje (2003) outlined the history of this effort, including a pioneering phase up to 1952, a growth spurt towards the creation of a separate CSIRO Division of Tropical Pastures (1959) and a productive period into the 1980s. Although research activity peaked in the 1970s, work has continued on a range of pasture research issues, expanding and characterising tropical pasture resources (e.g., Cook et al., 2005). Directly and indirectly, the Australian work has assisted the development of pastures in a range of tropical countries (e.g. China, Liu et al., 2009; Uruguay, Real et al., 2005).

Early successful introductions were Rhodes grass, Kikuyu, lucerne, white clover and various annual forages. As well, experience was gained with a range of tropical grasses and legumes, but pasture improvement was limited until the complex major and trace element deficiencies of the coastal soils were sorted out and corrected during the 1950s. Then, it was clear that certain trailing/climbing legumes, such as centro (Centrosema molle) and puero (Pueraria phaseoloides) in the north, and Desmodium spp., Macroptilium spp. and glycine (Neonotonia wightii) in the south, grew well once their rhizobiology limitations were resolved. Several grass species, belonging to genera including Digitaria, Panicum, Setaria and Paspalum, which were productive and persistent in plots, were adopted commercially.

At this time (1960s-70s), constraints to research funding and the declining importance of dairying relative to beef production shifted the emphasis to tropical pastures further north and west of south-eastern Queensland. Concurrently, the emphasis in the main program shifted from species agronomy to pasture utilisation by cattle. It was realised that the impressive growth of tropical species that were tall (grasses) and/or climbing/twining (e.g. legumes such as siratro, Macroptilium atropurpureum) did not necessarily translate well into cattle production. The poorer production from pastures based on tall or climbing species versus shorter, denser pastures occurred both at low stocking rates, where the open sward structure resulted in cattle grazing for relatively long periods to harvest sufficient forage to meet their requirements (Stobbs, 1973), and at moderate to high stocking rates, where twining species persisted poorly under heavy cattle grazing (Jones and Jones, 1978).

Hence, subsequent emphasis was on expanding the list of shorter, denser species that were likely to be tolerant of heavy grazing (Cameron et al., 1989), on improving disease and insect tolerance in proven species (Cameron et al., 1993 quoted by ‘t Mannetje, 2003), and overcoming anti-nutritional constraints to cattle production (Jones and Megarrity, 1986). Some of the persistent legumes released were lotononis, jointvetch (Aeschynomene americana, A. falcata and A. villosa) and creeping vigna (Vigna parkeri). The highly persistent and productive, rhizomatous legume Arachis glabrata was released as an option for intensively grazed dairy pastures, but it proved commercially unacceptable since it required vegetative propagation. Pinto peanut (A. pintoi) is now recommended widely.

Relatively recently, forage resources in the form of a forage selection tool (SoFT) supplemented with fact sheets in CD-ROM (world database) and online (Australian database) versions have been made available (Cook et al., 2005 – see www.tropicalforages.info). Examples of the output of potentially suitable tropical species from the CD-ROM database are given in Table 6, for perennial grasses and legumes that tolerate heavy grazing on relatively dry sites (500-750 mm annual rainfall) and wet sites (1800-2500 mm). The species that are suitable for intermediate rainfall (800-1500 mm) areas can be inferred from this table. [Details of grass and legume species, with photographs, are also available in the FAO Grassland Species database < /www.fao.org/ag/AGP/AGPC/doc/GBASE/Default.htm >].

In Figure 12 are shown five pasture zones that occur in subtropical and tropical Australia – the subtropical transition zone, the humid coastal perennial pasture zone that is primarily confined to Queensland, the tropical (speargrass) pasture zone in Queensland that was originally colonised by Townsville stylo (Stylosanthes humulis), the wet/dry tropics of northern Australia and an inland, low-moderate rainfall zone (here termed tropical sub-humid/semi-arid perennial pasture zone) in which species must tolerate a long (6+ months) winter drought. These zones, described below, are a convenient simplification of reality. For greater detail concerning tropical pasture species recommended for regions in northern Australia, the reader is referred to the following on-line pasture database: www.tropicalgrasslands.asn.au/pastures/default.htm
Recommendations covering pasture species for all Australian pasture locations, temperate and tropical, can now be found at an interactive website www.pasturepicker.com.au.

5.3.2 Subtropical transition zone
In this coastal zone, which extends either side of the Queensland-NSW border from Maryborough (N) to Taree (S), systematic work to import and evaluate both temperate and subtropical species for coastal dairy pastures dates back to the 1890s, when paspalum (Paspalum dilatatum) was introduced and adopted enthusiastically. In this zone, temperate annuals/biennials (ryegrass, oats, annual clovers) are often sown as seasonal forages, while perennial ryegrass (or tall fescue), white clover, paspalum and Kikuyu are components of permanent pastures. A system is developing wherein base tropical pastures of pinto peanut or Kikuyu (weakened by glyphosate) are oversown with cool season annuals in March/April. For well-drained sites that are grazed leniently to moderately, other tropical species that are recommended include green and Gatton panics (Panicum maximum), glycine and siratro. On less well-drained soils with moderate to intensive grazing, the grasses pangola (Digitaria eriantha), setaria (Setaria sphacelata) and paspalum, and the legumes pinto peanut and creeping vigna, are sown. Creeping vigna is one of the few tropical legumes that is best under intensive grazing and it can combine successfully with competitive species such as Kikuyu and setaria. This zone strictly could include the tropical upland areas of the Eungella Plateau west of Mackay and Atherton Tableland near Cairns but these are not shown in Figure 12.

Table 6. Sown pasture plants suitable for long-term pastures and heavy grazing in Australia’s subtropics and tropics (Cook et al., 2005).

5.3.3 Humid coastal perennial pasture zone
In practice, a long list of grasses and legumes is recommended for the humid tropics of Queensland where there are extremes in latitude, soil fertility and landscape (from hilly to flood-susceptible flats). In the northern part of the zone (former rainforest), the most popular grasses, which may be sown without a legume, are signal grass (Brachiaria decumbens) and guinea grass (Panicum maximum = Megathyrsus maximus) but nitrogen fertilizer is required for maintenance and production. Guinea grass combines well with centro, puero or hetero (Desmodium heterophyllum) in less intensively managed pastures, and signal grass with pinto peanut in intensive pastures. In the central parts of this zone, Kazungula setaria, tall finger grass (Digitaria milanjiana), pangola grass and Rhodes grass are sown with American jointvetch, hairy jointvetch, siratro or centro.

If the soil fertility is relatively low and the grazing system is intensive, Indian bluegrass (Bothriochloa pertusa), creeping bluegrass (Bothriochloa insculpta), Caribbean stylo (Stylosanthes hamata) and shrubby stylo (Stylosanthes scabra) are preferred. Several grasses are suitable for seasonally wet areas in this zone, such as para grass (Brachiaria mutica = Urochloa mutica), aleman grass (Echinochloa polystachya) and humidicola (Brachiaria humidicola = Urochloa humidicola).

5.3.4 Tropical (speargrass) pasture zone
A notable early introduction into this perennial/annual zone was the free-seeding annual Stylosanthes humilis, Townsville stylo. This accidental introduction, which came into the country at the turn of the 20th century, was spread along the network of stock routes in north-eastern Queensland and northern Australia by animals and stockmen. According to Gillard and Fisher (1978), it was best adapted to land between the 800 and 1200 mm annual rainfall isohyets on most soils except saline coastal soils and heavy cracking clays. Townsville stylo could survive on soils of low fertility but it responded well to phosphatic fertilizers. It was compatible with the native speargrass. While it was often sown with setaria, it fixed insufficient N to maintain the vigour of that grass. Unfortunately, Townsville stylo succumbed to the disease anthracnose caused by Colletotrichum gloeosporioides (Davis et al., 1987) in the 1970s, by which time a number of alternative Stylosanthes species, hybrids and cultivars had been released or were in the pipeline. The Townsville stylo alternatives that are currently popular include shrubby stylo, caatinga stylo (Stylosanthes seabrana), Caribbean stylo and fine stem stylo (Stylosanthes guianensis var. intermedia). While stylos are sometimes used in sown pasture mixtures with less competitive grasses such as sabi grass (Urochloa mosambicensis), their main application is in native pasture amelioration. They are oversown into grassy woodland with minimal intervention, sometimes only after fire or tyne ripping.

Walker and Weston (1990) mentioned the replacement of black speargrass with volunteer Indian bluegrass on 0.8 M ha in parts of coastal and sub-coastal north Queensland, as a result of heavy grazing that followed the anthracnose-induced collapse of the Townsville stylo component. When the stylo population “crashed”, leading to near denudation of catchments, the already naturalised Indian bluegrass was fortuitously able to revegetate the bare landscapes, thereby minimising the potentially catastrophic erosion problems that would have otherwise occurred.

The current species that are suitable for sowing on sites in this zone include:

• For the northern parts of the zone – creeping bluegrass, Indian bluegrass, sabi grass, caribbean stylo, shrubby stylo and leucaena (Leucaena leucocephala) [see Photo 7.], and
• For the southern parts – creeping bluegrass [Photo 8.], forest bluegrass (Bothriochloa bladhii ssp. glabra), buffel grass (primarily cv. Gayndah, which performs best on sandy soils), the digit grasses (D. milanjiana, D. eriantha), finestem stylo, shrubby stylo, leucaena, roundleaf cassia (Chamaecrista rotundifolia), lotononis and Bargoo jointvetch

When grown in pure stands, many grasses experience N rundown, requiring legumes such as leucaena, caatinga stylo and desmanthus (D. virgatus). Creeping bluegrass, which is often sown on the better forest soils, tends to be too competitive with the legume component.

Photo 7. Cattle grazing leucaena and mature grass, Central Queensland (Photo by B. Cook).

Photo 8. Charolais cattle grazing Bisset Creeping Bluegrass, SE Queensland (Photo by B. Cook).

5.3.5 Wet/dry tropics
A successful coloniser in this zone has been Cloncurry buffel grass (Cenchrus pennisetiformis), which occurs widely in the watershed around the bottom of the Gulf of Carpentaria in north-western Queensland – an area of 1.2 M ha was involved by the late 1980s (Walker and Weston, 1990). According to Bortolussi et al. (2005c), sown grasses include birdwood grass (Cenchrus setigerus), buffel grass, para grass, Rhodes grass and sabi grass; sown legumes include Caribbean stylo, American jointvetch, shrubby stylo and roundleaf cassia. However, there have been few large-scale pasture sowings in the wet/dry tropics of northern Australia (Figure 8). Part of this lack is related to the monsoonal nature (wet summers, dry winters) of the local climate. Local farmers have adopted a cautious approach of trialling new species and mixtures, initially on a small scale. However, there are other important factors operating, such as the traditionally extensive nature of cattle production in northern WA and ‘the Territory’, the allocation of tracts of land as homelands for Aboriginal people, mining leases, defence areas and national reserves/parks.

Some potentially useful species for permanent pastures in seasonally flooded areas in the monsoonal Northern Territory include Brazilian centro (Centrosema brasilianum), aleman grass (which can only be established from cuttings), green/Gatton panic and perennial forage sorghum (sorghum hybrid). Shrubby stylo is worth introducing into grassy pastures in inland, drier areas. Centrosema pascuorum is an important legume on the floodplain country and Digitaria milanjiana is also finding application. Andropogon gayanus and the water grass, Hymenachne amplexicaulis, which are very useful forages in their respective habitats, have both become environmental weeds in the region.

5.3.6 Tropical sub-humid/semi-arid zone
This zone takes in the subhumid and semiarid agro-ecological zones (Figure 7). Mitchell grass, a prized native grass, grows well on extensive areas of vertosols (Figure 4) in this zone. Sown grass pastures, principally buffel grass, Rhodes grass, purple pigeon grass and bambatsi panic (Panicum coloratum), occur at sites in central and southern Queensland on the fertile brigalow clay soils and gidgee clay loams; the latter two grasses are suitable for seasonally flooded sites in the ‘channel’ (watercourse) country. About 70% of these sown pastures, the most extensive in area in Queensland, were sown to grasses without legumes. These grasses depend on the relatively high N status of the former acacia (legume) shrublands for production but this status and grass productivity are declining. It is hoped that Caatinga stylo, desmanthus and leucaena, recommended as legumes for this zone, will arrest or reverse these declines.

On the plains of this zone, there are each year 1-2 M ha of winter and summer crops in northern NSW and southern/central Queensland, principally wheat and sorghum. The cropped areas are grazed after harvest. There has been work done to develop legumes that may be used either in short pasture phases of tropical cropping systems or as a component of a perennial pasture for areas where grazing intensity can be controlled (Cameron, 1996). This legume research was a response to declining grain yields and grain protein levels of cereal crops. Butterfly pea (Clitoria ternatea), burgundy bean (Macroptilium bracteatum) and lab lab (Lablab purpureus) are recommended as ley legumes in central Queensland, and burgundy bean has potential in southern Queensland also (Pengelly and Conway, 2000). Currently, about 1.2 M ha of lucerne pastures are grown to restore soil fertility after several years of cereal crops. These lucerne pastures also are grazed or cut for hay. According to Walker and Weston (1990), annual medics are naturalised on about 1.7 M ha of inland pastures and dry watercourses in southern Queensland. The interface between the temperate and subtropical areas that are either side of the inland NSW-Queensland border poses particular problems for pasture systems, requiring the selection and utilisation of temperate grasses that are either deep-rooted or summer dormant, or subtropical species that are frost tolerant (Boschma et al., 2009).

6. OPPORTUNITIES FOR IMPROVEMENT OF PASTURE RESOURCES

6.1 Research outcomes
In Australia, as in many countries, the emphasis of research into pastures and grazing has evolved from a singular focus on factors limiting production to one that encompasses the effect of practices on environmental parameters such as soil pH (Box 1), soil erosion, nitrate leaching, pollution of groundwater by nutrients and chemicals, and the absorption/release of greenhouse gases. Often, broader systemic dimensions are considered, such as the impact of management practices and systems on the changes in the financial capital, social capital and even the political aspects of pasture/animal systems (Kemp and Michalk, 2007). This evolution is a follow-on to ideas on sustainable development espoused by authors such as Gordon Conway (productivity, stability, sustainability and equity – Conway, 1986) and Jules Pretty (external costs of agriculture – Pretty et al., 2000). A recent Australian example of this broad approach was the Sustainable Grazing Systems (SGS) program, which operated across the high rainfall zone (>600 mm/year) of southern Australia (Mason et al., 2003). The SGS program involved researchers and producers working together (the participative approach) in a program that explored natural capital (environmental issues), financial capital (the impact of grazing management or stocking rate on profit and risk) and social capital (adoption, personal growth and satisfaction, networking). In the program, there was a major focus on grazing management. This focus did not resolve the benefits or otherwise of different grazing methods on animal production and sustainability but benefits flowed from the co-learning component of the project, thereby contributing to the producers’ understanding of their grazing systems [Photo 9]. Similar participative approaches have been successfully used in subsequent programs that have explored the management of pasture systems to reduce salinisation in agricultural landscapes (Masters et al., 2006) and the integration of grazing and grain systems (Hacker et al., 2009). A broad approach is now being taken by most of the agencies that are helping Australian farmers adjust to the impact of climate change.

Photo 9. Field Day, NSW.

Some of the past highlights from animal production research have included the adoption by the sheep industry of the system of crossing Merino x Border Leicester ewes to Dorset Horn sires (and alternatives) for prime lamb production, the introduction of Bos indicus bloodlines into tropical cattle, the exploitation of novel exotic pasture legumes, successful strategies to substantially reduce the impact of rabbits on Australian pastures, the eradication of tuberculosis and brucellosis in Australian cattle, and the recognition and management of soil acidity in southern Australia (Scott et al., 2000). The last-mentioned topic (Box 1) exemplifies win-win benefits for both production agriculture and the environment. Current Australian research priorities reflect the production-environmental approach, such as the management of agricultural systems and catchments to avoid soil erosion, species losses and salinisation, the abatement of greenhouse gas emissions from agriculture, the ongoing need to achieve improvements in water efficiency and conservation, and the adjustment of local agriculture to climate change.

In recent years, the research agenda has broadened to include environmental, financial and social issues on the farm (Mason et al., 2003). Unfortunately, past research into on-farm business management and off-farm supply chains has often not been relevant to farm profits (McCown and Parton, 2006) and, while the need for social indicators in agriculture is acknowledged, there are as yet no agreed protocols for the routine collection of indicators that define the social capital of farm families.

From the research and development pool of knowledge accumulated so far, there are a number of aspects of pasture management that are now part of industry best practice in Australia. An example is the widespread use of soil and plant tissue testing services in order to plan fertilizer applications, especially for the major nutrients P and S (soil tests) and trace elements (tissue tests) which are needed by legumes. These aspects are discussed further below.

6.2 Pasture management for productivity and sustainability

6.2.1 Fertilizer rates
With the dependence on legumes, nitrogen fertilizer applications to sheep and beef cattle pastures are relatively uncommon in Australia. Hence, the emphasis is on the selection of an appropriate legume, the introduction of appropriate rhizobia (species- or cultivar-specific if needed), the application of fertilizers to correct major and minor element deficiencies that limit the growth of legumes and monitoring soil pH (Box 1).

Box 1. Soil acidification in temperate Australia (see also Scott et al. 2000) The problem of soil acidity on Australian soils, most of which are poorly buffered with respect to pH change, is an interesting agricultural case study. By the late 1990s, it was estimated that 13.7 m ha of agricultural land in Australia were affected by soil acidification, and a further 6 m ha would develop serious acid soil problems if agricultural practices were not changed. Estimates of the total cost of soil acidity to the NSW economy ranged between $90 m and $225 m per year. In NSW, Victoria and WA, the three states most affected, the genesis of the problem goes back to the period between 1950 and 1970. Then, the area of sown improved pastures more than quadrupled, and the area of pastures fertilized with superphosphate more than doubled, driven by high wool prices and the advent of aerial agriculture. During the 1960s, in districts that had enthusiastically adopted pasture improvement, there emerged a decline in the productivity of pastures and crops that appeared to be related to soil fertility. This decline was evident in high quality grazing and farming districts in southern NSW, especially around Albury, Holbrook, Tumut, Yass and Goulburn. The main symptoms of the decline were poorer productivity of well-fertilized improved pastures, seasonal yellowing, difficulty in establishing or re-establishing perennial grasses, and poor growth of wheat and barley crops. In parts of NSW, Victoria and WA, the insidious effects of the problem had a devastating impact on the economy of communities and the well being of individual farm families. Most landowners were poorly prepared for the setback to their pasture improvement program, which had appeared easy in its initial stages. In agribusiness circles, there was concern and consternation. The productivity decline coincided with an economic downturn in the grazing industries. Land values fell and farm workers were laid off as formerly profitable landowners tried to cope with the changed pasture environment. From the mid-1970s, an expanded research effort by the then NSW Agriculture, through a multidisciplinary team at Wagga and support from a soil chemistry team in Sydney, together with a team from Agriculture Victoria at Rutherglen, unravelled the nature of the problem. Experiments and observations explored the chemistry of soil acidity, and confirmed that manganese toxicity, aluminium toxicity and molybdenum deficiency were all manifestations of soil acidity, which became limiting to the growth of many plants in soils more acid than pHCa < 4.5-5.0. It was demonstrated that both plant breeding, to produce plants that were tolerant of soil acidity, and liming to raise soil pH, were complementary approaches to restoring the productivity of the affected soils. The work also explained, at least in part, how soils became more acid due to imbalances in the nitrogen and carbon cycles induced by agricultural production. Rates of acidification were estimated for some different agricultural systems, and strategies were put in place for managing soil acidity in the areas at risk. Subsequently, the recommendations were successful in overcoming soil acidity at the paddock level, especially in cropping districts. The economic benefits from healthier crops and pastures on limed soil were considerable. Both canola, a crop that was known to be sensitive to aluminium toxicity, and lucerne, another sensitive plant especially during the establishment phase, became more popular and valuable in agricultural rotations. On most affected farms, lime is now applied or reapplied at the common rate of 2.5 tonnes/ha to acid soils as soon as the soil pH has reached pH 4.5 (calcium chloride) or pH 5.2 (water) – farmers now are advised to manage actively to avoid the accretion of acid in farming systems due to imbalances in the N-cycle (caused by nitrate leaching or the addition of ammonia-containing fertilizers) or the C-cycle. In recent years, agriculturalists and the community at large have become increasingly concerned about the environmental management of agricultural systems. These communities have recognised that soil acidification is more than just an issue of soil degradation. Dryland salinity, nitrate pollution of ground water, soil erosion, and damage to roads and buildings from rising water tables are all regarded as problems that are linked with acidification.

Phosphorus (P) is widely deficient and deficiencies of sulphur (S) are common. Superphosphate (9% P, 11% S) and sulphur-fortified superphosphate (e.g. Pasture SF 5.5% P, 40 % S) are the main fertilizers applied to pastures, by aircraft in non-arable areas. Rates of P are usually 20-30 kg P/ha if the soil is deficient and new pastures are being established, with maintenance applications of 10-15 kg P/ha. These rates may be applied less frequently on land that is of lower potential productivity. On many tableland soils, molybdenum is required as a trace element (50 g/ha per application, mixed in superphosphate). In the wheat belt, rather than topdressing pastures with superphosphate, extra P- and S-containing fertilizer may be applied with the last one or two crops for the subsequent pasture phase. Soil pH is monitored routinely as a guide to the need for lime amendment every few years. On susceptible soils the common rate of lime for each application is 2.5 t/ha.

6.2.2 Grazing management
There are several principles relevant to grazing management systems in Australian systems and world agriculture. In spite of frequent advocacy, the majority of studies on temperate and tropical pastures indicate no advantage in animal production from rotational grazing systems compared to continuous grazing (Humphreys, 1997). However, there are some exceptions to this general rule:

• Pastures containing lucerne must be rotationally grazed by sheep or otherwise the population of lucerne plants declines steeply. For lucerne survival, the length of spelling is more important than the length of grazing (McKinney, 1974), the minimum time between each grazing being 5-6 weeks. With cattle, the requirement for rotational grazing need not be as strict. In fact, there are advantages in continuous grazing by cattle during spring because the bloat risk is reduced and barley grass invasion is reduced. Chicory is another pasture species that apparently requires rotational grazing for it to survive.
• In temperate pastures, a seasonal rest enhances the production and competitiveness of the perennial grass component of pastures. However, this enhanced perennial grass content neither translates into extra animal production nor may it be sufficient to improve sustainability by reducing deep drainage and nitrate leaching (Kemp et al., 2000).
• A strategic grazing approach is warranted in certain situations, such as reducing the content of undesirable weeds like wiregrass by heavy grazing at certain times (mob stocking – see Lodge and Whalley, 1985), spelling pasture to make hay or silage, allocating forage crops to dairy cows (strip grazing) or to avoid grazing damage to certain soils when they are soil wet.
• In tropical pastures, the persistence of climbing or twining legumes such as siratro is reduced by heavy stocking rates (Jones and Jones, 1978). This issue is addressed either by adjusting the stocking rate or by using alternative species.

From the research evidence available, it appears that cattle and sheep are complementary rather than competitive. A management approach that combines sheep and cattle, grazing either together or sequentially, produces several benefits, including a more even utilization of pasture and the management of certain weeds that are avoided by one livestock group. For example, Paterson’s curse, a well-known weed in south-eastern Australia, is grazed by sheep and avoided by cattle and horses.

6.2.3 Weed management
Australia has a thorough system of screening and quarantining plants before they are allowed into Australia. The Future Farm Industries CRC (one of a network of Australian Cooperative Research Centres) has developed an ‘environmental weed risk protocol’ that is available on their website (http://www.futurefarmcrc.com.au). There is an Australian Weeds Strategy at www.weeds.gov.au/publications/strategies/pubs/weed-strategy.pdf, which defines the roles and responsibilities of the Australian government, the governments of States and Territories, local government and individuals in the management of weeds. Following the development of weeds that are resistant to herbicides, integrated weed management strategies are advocated, especially in mixed farming areas (Sindell, 2000).

6.3 Future opportunities

6.3.1 Research capacity (also see Section 7.)
A constructive critique of the agricultural R&D system in Australia was made by Hamblin (2004). She acknowledged progress in terms of production research, but was less positive about the levels of investment into or benefits from research into issues of ecological sustainability, innovation beyond the farm gate (processing, distribution, promotion) or improving the budget sheet of farms and the well-being of rural communities. In recent years, these issues continue to provide a challenge for research institutions and funders. So too do shifts in the policies of governments who, noting the decline in the proportion (2.5%) of gross national product contributed by agriculture, lower receipts from production levies due to ongoing droughts and the declines in sheep and dairy cattle numbers, are spending less on agricultural research. Government departments, bureaus and universities also are offering contract rather than tenured employment to scientists and other professional researchers. These trends may limit future gains from agricultural research in Australia.

More optimistically, the negative trends could be balanced by better communication between scientists around the world and by improved collaboration between production scientists and environmental scientists. Another issue, the slow adoption of research findings, especially complex technologies that are aligned with sustainable production, is being addressed through the adoption by the livestock industries of participatory extension methodologies (e.g. Pannell et al., 2006; Friend et al., 2009; Hacker et al., 2009) rather than employing the diffusion (trickle down) approach that is effective with simple technologies.

6.3.2 Molecular biology applications for pasture species improvement
Spangenberg et al. (2001) outlined a number of opportunities and approaches for the application of transgenic and genomic technologies for the improvement of forage plants. Examples were given on how the genes controlling metabolic pathways might be manipulated to enhance forage quality, transgenic approaches to enhancing resistance to diseases and pests, the deconstruction and reconstruction of plant development, and the use of molecular markers.

Biotechnology is justifiable on the basis that it has the potential to achieve what conventional plant breeding might never achieve. However, there are two issues that are likely to ensure that most of the ideas for projects may fail to produce an outcome. First, the pathway from the cell to the ecosystem level is difficult (Giampietro, 1994). The scientific understanding of the plant genome is still poor – substantial effort will be needed to assign function to genes, particularly when protein function is context dependent. There is a complex sequence of steps necessary to insert a gene, alter its level of expression and utilize it (Oram and Lodge, 2003). Biotechnologists have a track record of unrealistic optimism in terms of achieving, on-time and on-budget, the targets that they or their backers have set (e.g. the search for a bloat-resistant lucerne). Second, there is the matter of unintended consequences. The experience of Dear et al. (2003) with transgenic subterranean clover is revealing. A gene for tolerance to bromoxynil herbicide (bxn) was isolated from a soil bacterium and inserted successfully into a range of agricultural plants, among them subterranean clover. Dear and his colleagues explored some of the potential changes that a random insertion of the bxn gene might cause. The inclusion of the bxn gene did not change the agronomic characteristics of one of the three resultant lines, but the gene or transformation process did have unintended effects (reduced seed production, lower levels of hard seed, and changes to the levels of phyto-oestrogens) on the other two transgenic lines. Third, the ongoing, unresolved conflict about GM organisms is another negative complication. However, there are some Australian plant breeding groups, working with a major species for the world market (e.g. lucerne, cotton), that possess sufficient expertise and experience for success at the genome, plant and industry levels. Such groups will utilize molecular marker technologies that are useful in exploring plant genomes and in building up genetic combinations for heterosis and disease resistance (Irwin et al., 2001).

6.3.3 Pasture monitoring and decision support systems
Pasture monitoring protocols such as PROGRAZE (Bell and Allan, 2000) and pasture-livestock models such as GrassGro (Clark et al., 2000) and DairyMod (Johnson et al., 2007) have been assembled and used to monitor progress and set targets in Australian pasture-livestock enterprises. Simple pasture-monitoring tools have been tested (Wolfe et al., 2006) to collect basic information on pasture parameters such as cover (%), botanical composition (%), biomass (kg/ha), growth (kg/ha.d) and plant populations (numbers/m²). However, there is as yet no complete and accepted protocol for pasture management on farms, and acceptance of an agreed industry protocol is an important industry need. It could be used to predict and monitor pasture production, environmental parameters and systemic stress. Individual parameters such as botanical composition are useful to assess pastures in terms of the risk of metabolic disorders (grass tetany, bloat) or the benefits likely from procedures such as winter-cleaning, which is the removal of grasses from pastures before the cropping phase to overcome cereal root pathogens and/or boost nitrogen supply. When linked to weather forecasting models, modelling could improve tactical and strategic decision-making, such as predicting periods that are favourable for destocking and restocking at the farm and regional levels.

6.3.5 The impact of global factors on pasture and livestock production in Australia
In a global economy, there are several influences that will determine the capacity of Australia to grow pastures and produce livestock. On the demand side is world population and the increasing numbers of relatively affluent consumers, factors that will positively affect the global market for red meat. On the supply side are potentially negative impacts such as the political environment, climate change, and the availability of essential agricultural inputs such as fertilizer, chemicals and energy. Schiere et al. (2006) highlighted the importance of processes that interact rather than behave in a straightforward manner, such as the post-World War II boom in pasture improvement in Australia and economic reforms in China, that produced rapid rather than incremental advances or failures in agricultural systems. Future perturbations to world agriculture arising from climate change or fuel shortages may interact with agro-ecosystem types or government policies, and trigger major changes to agricultural industries.

Australian agricultural producers, who receive mild benefits from government policies such as investment and research incentives, have so far adjusted to the realities of free markets. However, there are signs (increasing age of farmers, increasing indebtedness, difficulties in attracting skilled labour on farms) of market failure. One example is the plight of local dairy farmers who run large (250+ cow), multi-million dollar enterprises that do not produce a satisfactory return.

Predictions of a hotter continent, a more erratic climate and a drier south-eastern Australia (McKeon et al., 2009) may bring greater operational diversity in Australian agriculture, at least at the regional level (Harle et al., 2007). Resource limitations and other constraints may encourage many livestock producers to seek a lower input, more ecologically-focused production system rather than one that operates at a higher level of production risk. Other graziers will respond to the expanded array of useful pasture species for tropical and temperate areas (Section 5); they will make greater use of perennial species, supplemented strategically with annuals, to convert rainfall to fodder and meat and to protect the soil resource. In the wheat belt, risky crop production areas may be turned over to meat and wool production (Kopke et al., 2008), while crops may extend further into suitable high-rainfall areas (Harle et al., 2007). Before the recent improvement in prices for livestock, extension officers acknowledged the social rather than technical difficulties of improving or expanding livestock production in the wheat belt, where many crop specialists reluctantly tolerate the presence of livestock (Robertson and Wimalasuriya, 2004) as a means of capturing some of the synergies of mixed farming.

The strong demand for food may lead to a greater number of larger, specialised farms that achieve synergy through integration with complementary businesses. In Australia, the complexity of managing large, mixed farms may be offset through innovative business partnerships that not only retain mixed farming (diversification) but also encourage simultaneous specialisation, essentially by separating the management of crops and livestock and placing each enterprise into the hands of enthusiasts. For example, a well-organised sheep specialist could run flocks on several farms. Greater benefits may come from innovation in the economic and social aspects of agriculture, rather than by refining the technology of production. During the last two decades, while the Australian agribusiness sector has accepted a need to employ graduate agronomists to supplement the reduced advisory services provided by government, few agricultural specialists have been employed in commercial livestock production, either extensive or intensive. Hence, at least in Australia, there is an opportunity to overcome the lag in technology applied to grazing livestock production, technology that is behind the level applied to crop management or to intensive livestock. The need to manage greenhouse gas emissions, with livestock farms seen as part of the solution rather than as part of the problem (Howden and Reyenga, 1999; Howden et al., 2008), is another factor that may lead to an exciting future.

7. RESEARCH AND DEVELOPMENT ORGANIZATIONS AND PERSONNEL

7.1 The current landscape
For the agricultural industries, Australia has pursued a strong policy of publicly-funded R&D, but private research investment has been relatively low. R&D support occurs in several forms. The Australian Government provides funding to CSIRO, the universities, the Australian Centre for International Agricultural Research, and Cooperative Research Centres that link several agricultural industries with public institutions and private companies. State Governments invest in their network of agricultural research centres and stations as well as into strategic partnerships. Finally there is a national system of Rural Industry Research Corporations (including Meat and Livestock Australia, Australian Wool International and the Grains Research and Development Corporation), which evolved from ad hoc industry funds. These corporations manage industry production levies that are matched with a $ for $ contribution from the Australian Government; increasingly, co-investment occurs with public and private entities. However, the overall investment into pasture research and development is declining.

The main pasture/livestock research centres are located at Perth (WA); Katherine (NT); Townsville, Toowoomba and Brisbane (Qld); Armidale, Tamworth, Orange and Wagga Wagga (NSW); Canberra (ACT); Hamilton and Melbourne (Vic.); Hobart (Tas.); Adelaide (SA) (Figure 12). Pasture plant genetic resource centres are located in Biloela (Qld, tropical species), Adelaide (Medicago spp. and other legumes) and Perth (Trifolium spp. and other legumes).

7.2 List of selected personnel/organizations involved in pasture R&D

Archer, K.A., Wolfe, E.C. & Cullis, B.R. (1987) Flowering time of cultivars of subterranean clover in New South Wales. Australian Journal of Experimental Agriculture 27, 791-797.

Barr, N.F. & Cary, J.W. (1992) Greening a Brown Land, an Australian Search for Sustainable Land Use (MacMillan, Melbourne).

Bell, A.K. & Allan, C.J. (2000) PROGRAZE – an extension package in grazing and pasture management. Australian Journal of Experimental Agriculture 40, 325-330.

Blumenthal, M.J., Prakash, K., Leonforte, A., Cunningham, P.J. & Nicol, H.I. (1996) Characterization of the Kangaroo Valley ecotype of perennial ryegrass (Lolium perenne). Australian Journal of Agricultural Research, 47, 1131-1142.

Bortolussi, G., McIvor, J.G., Hodgkinson, J.J., Coffey, S.G. & Holmes, C.R. (2005a) The northern Australian beef industry, a snapshot. 1. Regional enterprise activity and structure. Australian Journal of Experimental Agriculture, 45, 1057-1073.

Bortolussi, G., McIvor, J.G., Hodgkinson, J.J., Coffey, S.G. & Holmes, C.R. (2005b) The northern Australian beef industry, a snapshot. 3. Annual liveweight gains from pasture based systems. Australian Journal of Experimental Agriculture, 45, 1093-1108.

Bortolussi, G., McIvor, J.G., Hodgkinson, J.J., Coffey, S.G. & Holmes, C.R. (2005c) The northern Australian beef industry, a snapshot. 5. Land and pasture development practices. Australian Journal of Experimental Agriculture, 45, 1121-1129.

Broster, J.C. & Pratley, J.E. (2006) A decade of monitoring herbicide resistance in Lolium rigidum in Australia. Australian Journal of Experimental Agriculture, 46, 1151-1160.

Boschma, S.P., Lodge, G.M. & Harden, S. (2009) Establishment and persistence of perennial grass and herb cultivars in a recharge area, North-West Slopes, New South Wales. Crop and Pasture Science, 60, 753-767.

Cameron, A. (1996) Evaluation of tropical pasture species as leys in the semi-arid tropics of northern Australia. Australian Journal of Experimental Agriculture, 36, 929-935.

Cameron, D.G., Jones, R.M., Wilson, G.P.M., Bishop, H.G., Cook, B.G., Lee, G.R. & Lowe, K.F. (1989) Legumes for heavy grazing on coastal subtropical Australia. Tropical Grasslands 23, 153-161.

Campbell, M.H. (1998) Biological and ecological impact of serrated tussock (Nassella trichotoma (Nees) Arech.) on pastures in Australia. Plant Protection Quarterly, 13, 80-86.

Clark, S.G., Donnelly, J.R. & Moore, A.D. (2000) The GrassGro decision support tool: its effectiveness in simulating pasture and animal production and value in determining research priorities. Australian Journal of Experimental Agriculture, 40, 247-256.

Cocks, P.S. (2001) Ecology of herbaceous perennial legumes: a review of characteristics that may provide management options for the control of salinity and waterlogging in dryland cropping environments. Australian Journal of Agricultural Research, 52, 137-151.

Conway, G.R. (1986) Agroecosystem Analysis for Research and Development (Winrock International, Bangkok).

Cook, B.G., Pengelly, B.C., Brown, S.D., Donnelly, J.L., Eagles, D.A., Franco, M.A., Hanson, J., Mullen, B.F., Partridge, I.J., Peters, M. & Schultze-Kraft, R. (2005) Tropical Forages: an interactive selection tool., (CD-ROM), (CSIRO, QDPI&F, CIAT and ILRI, Brisbane).

Coventry, D.R., Holloway, R.E. & Cummins, J.A. (1998) Farming fragile environments: low rainfall and difficult soils in South Australia. Proceedings of the 9th Australian Agronomy Conference, Wagga Wagga, www.regional.org.au/au/asa/1998/plenary/coventry.htm

Crawford, E.J., Lake, A.W.H. & Boyce, K.G. (1989) Breeding annual Medicago species for semiarid conditions in southern Australia. Advances in Agronomy, 42, 399-437.

Davis, R.D., Irwin, J.A.G., Cameron, D.F. & Shepherd, R.K. (1987) Epidemiological studies on the anthracnose diseases caused by Colletotrichum gloeosporoides in north Queensland and pathogenic specialization within the natural fungal populations. Australian Journal of Agricultural Research, 38, 1019-1032.

Dear, B.S., Sandral, G.A., Spencer, D., Khan, M.R.I. & Higgins, T.J.V. (2003) The tolerance of three transgenic subterranean clover (Trifolium subterraneum L.) lines with the bxn gene to herbicides containing bromoxynil. Australian Journal of Agricultural Research, 54, 203-210.

Dear, B.S. & Ewing, M.A. (2008) The search for new pasture plants to achieve more sustainable production systems in southern Australia. Australian Journal of Experimental Agriculture, 48, 387-396.

Dear, B.S., Reed, K.F.M. & Craig, A.D. (2008) Outcomes of the search for new perennial and salt tolerant pasture plants for southern Australia. Australian Journal of Experimental Agriculture 48, 578-588.

Donald, C.M. (1970) Temperate pasture species. (In) Moore, R.M. (ed.) Australian Grasslands (ANU Press, Canberra), pp. 303-320.

Eyles, A.G., Cameron, D.G. & Hacker, J.B. (1985) Pasture research in northern Australia – its history, achievements and future emphasis. Research Report No. 4 (CSIRO Division of Tropical Crops and Pastures, Brisbane).

Friend, M.A., Dunn, A.M. & Jennings, J. (2009) Lessons learned about effectively applying participatory action research: a case study from the New South Wales dairy industry. Animal Production Science 49, 1007-1014.

Garden, D. & Bolger, T. (2001) Interaction of competition and management in regulating composition and sustainability of native pasture. (In) Tow, P.G., Lazenby, Alec (eds) Competition and Succession in Pastures (CABI Publishing, Wallingford), pp. 213-232.

Giampietro, M. (1994) Sustainability and technological development in agriculture. BioScience, 44, 677-689.

Gillard, P. & Fisher, M.J. (1978) The ecology of Townsville stylo-based pastures in Northern Australia. (In) Wilson, J.R. (ed.) Plant Relations in Pastures (CSIRO, Melbourne), pp. 340-352.

Gladstones, J.S. (1966) Naturalised subterranean clover (Trifolium subterraneum L.) in Western Australia: the strains, their distributions, characteristics and possible origins. Australian Journal of Botany, 14, 329-354.

Hacker, R.B., Robertson, M.J., Price, R.J. & Bowman, A.M. (2009) Evolution of mixed farming systems for the delivery of triple bottom line outcomes: a synthesis of the Grain & Graze program. Animal Production Science, 49, 966-974.

Hamblin, A. (2004) The imperatives for research implementation and delivery in Australia. Proceedings of the 4th International Crop Science Congress (International Crop Science Society, Brisbane). Verified online 8th December 2009 www.cropscience.org.au/icsc2004/symposia/6/4/1324_hamblina.htm

Harle, K.J., Howden, S.M., Hunt, L.P. & Dunlop, M. (2007) The potential impact of climate change on the Australian wool industry by 2030. Agricultural Systems, 93, 61-89.

Henzell, Ted (2007) Australian Agriculture. Its History and Challenges (CSIRO, Melbourne).

Hill, M.J. (1996) Potential adaptation zones for temperate pasture species as constrained by climate: a knowledge-based logical modelling approach. Australian Journal of Agricultural Research, 47, 1095-1107.

Hill, M.J. & Donald, G.E. (1998) ‘Australian temperate pasture database’. (CD-ROM) (CSIRO Division of Animal Production, Sydney).

Hooper, S. (2009) Australian lamb 09.1 – Financial performance of slaughter lamb producing farms 2006-07 to 2008-09 (Australian Bureau of Agricultural Resource Economics, Canberra). Verified on-line 10th September 2009 www.abare.gov.au/publications_html/livestock/livestock_09/9_1_lamb.pdf

Howden, S.M. & Reyenga, P.J. (1999) Methane emissions from Australian livestock. Australian Journal of Agricultural Research, 50, 1285-1291.

Howden, S.M., Crimp, S.J. & Stokes, C.J. (2008) Climate change and Australian livestock systems. Australian Journal of Experimental Agriculture, 48, 780-788.

Humphreys, L.R. (1997) The Evolving Science of Grassland Improvement (Cambridge University Press, UK).

Humphries, A.W. & Auricht, G.C. (2001) Breeding lucernes for Australia’s dryland cropping environments. Australian Journal of Agricultural Research, 52, 153-169.

Hughes, S.J., Snowball, R., Reed, K.F.M., Cohen, B., Gajda, K., Williams, A.R. & Groeneweg, S.L. (2008) The systematic collection and characterisation of herbaceous forage species for recharge and discharge environments in southern Australia. Australian Journal of Experimental Agriculture, 48, 397-408.

Irwin, J.A.G., Lloyd, D.L. & Lowe, K.F. (2001) Lucerne biology and genetic improvement – an analysis of past activities and future goals in Australia. Australian Journal of Agricultural Research, 52, 699-712.

Isbell, R.F. (1992) A brief history of national soil classification in Australia since the 1920s. Australian Journal of Soil Research, 30, 825-842.

Jahufer, M.Z.Z., Cooper, M., Ayres, J.F. & Bray, R.A. (2002) Identification of strategies to improve the efficiency of breeding strategies for white clover in Australia – a review. Australian Journal of Agricultural Research, 53, 239-257.

Johnston, W.H. (1996) The place of C4 grasses in temperate pastures in Australia. New Zealand Journal of Agricultural Research, 39, 527-540.

Johnson, I.R., Chapman, D.F., Snow, V.O., Eckard, R.J., Parsons, A.J., Lambert, M.G. & Cullen, B.R. (2007) DairyMod and EcoMod: biophysical pasture-simulation models for Australia and New Zealand. Australian Journal of Experimental Agriculture, 48, 621-631.

Johnston, W.H., Clifton, C.A., Cole, I.A., Koen, T.B., Mitchell, M.L. & Waterhouse, D.B. (1999) Low input grasses useful in limiting environments (LIGULE). Australian Journal of Agricultural Research, 50, 29-53.

Jones, R.J. & Jones, R.M. (1978) The ecology of Siratro pastures. (In) Wilson, J.R. (ed.) Plant Relations in Pastures (CSIRO, Melbourne), pp. 353-367.

Jones, R.J. & Megarrity, R.G. (1986) Successful transfer of DHP-degrading bacteria from Hawaiian goats to Australian ruminants to overcome the toxicity of Leucaena. Australian Veterinary Journal, 63, 259-262.

Kaiser, A.G., Dear, B.S. & Morris, S.G. (2007) An evaluation of the yield and quality of oat-legume and ryegrass-legume mixtures and legume monocultures harvested at three stages of growth for silage. Australian Journal of Experimental Agriculture, 47, 25-38.

Kemp, D.R., Michalk, D.L. & Virgona, J.M. (2000) Towards more sustainable pastures: lessons learnt. Australian Journal of Experimental Agriculture 40, 343-356.

Kemp, D.R. & Michalk, D.L. (2007) Towards sustainable grassland and livestock management. Journal of Agricultural Science, Cambridge 145, 543-564.

Kopke, E., Young, J. & Kingwell, R. (2008) The relative profitability and environmental impacts of different sheep systems in a Mediterranean environment. Agricultural Systems, 96, 85-94.

Lane, L.A., Ayres, J.F. & Lovett, J.V. (2000) The pastoral significance, adaptive characteristics, and grazing value of white clover (Trifolium repens L.) in dryland environments in Australia: a review. Australian Journal of Experimental Agriculture 40, 1033-1046.

Liu, G.D., Michalk, D.L., Bai, C.J., Yu, D.G. & Chen, Z.Q. (2009) Grassland development in tropical and subtropical southern China. The Rangeland Journal 30, 255-270.

Lodge, G.M. & Whalley, R.D.B. (1985) The manipulation of species composition of natural pastures by grazing management on the northern slopes of New South Wales. The Australian Rangeland Journal, 7, 6-16.

Loi, A., Howieson, J.G., Nutt, B.J. & Carr, S.J. (2005) A second generation of annual pasture legumes and their potential for inclusion in Mediterranean-type farming systems. Australian Journal of Experimental Agriculture 45, 289-299.

‘t Mannetje, L. (2003) Advances in grassland science. NJAS – Wageningen Journal of Life Sciences, 50, 195-221.

Mason, W.K., Lodge, G.M., Allan, C.J., Andrew, M.H., Johnson, T., Russell, B. & Simpson, I.H. (2003) An appraisal of sustainable grazing systems: the program, the triple bottom line impacts and the sustainability of grazing systems. Australian Journal of Experimental Agriculture 43, 1061-1082.

Masters, D., Edwards, N., Sillence, M., Avery, A., Revell, D., Friend, M., Sanford, P., Saul, G., Beverly, C. & Young, J. (2006) The role of livestock in the management of dryland salinity. Australian Journal of Experimental Agriculture 46, 733-741.

Mackinnon, D. (2009) Australian beef 09.1 – Financial performance of beef farms 2006-07 to 2008-09 (Australian Bureau of Agricultural and Resource Economics, Canberra). Verified on-line 10th September 2009 www.abare.gov.au/publications_html/livestock/livestock_09/9_1_beef.pdf

McCown, R.L. & Parton, K.A. (2006) Learning from the historical failure of farm management models to aid management practice. Part 2. Three systems approaches. Australian Journal of Agricultural Research, 57, 157-172.

McKeon, G.M., Stone, G.S., Syktus, J.I., Carter, J.O., Flood, N.R., Ahrens, D.G., Bruget, D.N., Chilcott, C.R., Cobon, D.H., Cowley, R.A., Crimp, S.J., Fraser, G.W., Howden, S.M., Johnston, P.W., Ryan, J.G., Stokes, C.J. & Day, K.A. (2009) Climate change impacts on northern Australian rangeland livestock carrying capacity: a review of issues. The Rangeland Journal, 31, 1-29.

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This profile was prepared in September-December 2009 by Emeritus Professor Ted Wolfe , who is a member of the E.H. Graham Centre for Agricultural Innovation (Charles Sturt University and NSW Industry & Investment) at Wagga Wagga in southern NSW. His home office details are: 58 Henwood Avenue, Wagga Wagga NSW 2650 AUSTRALIA, +61 2 6922 4347, twolfe@csu.edu.au. Professor Wolfe acknowledges in particular the technical inputs into this profile from Bruce Cook, a tropical forage specialist who was formerly with Queensland Department of Primary Industries & Fisheries and who is now self-employed. Thanks to Gail Fuller and Craig Poynter of CSU’s Spatial Analysis Unit for assistance in locating and/or redrawing several of the Figures, and to the acknowledged organizations for several Tables and Figures. Australian climate maps, additional to those reproduced by permission of the Australian Bureau of Meteorology (Figures 2, 5 and 6) are available on the Bureau website < http://www.bom.gov.au/climate/ > ; Figure 3 is reproduced from the Geosience Australia website < http://www.ga.gov.au/ >; Figure 9 from CSIRO Publishing < http://www.publish.csiro.au/ > and Figure 8 from the Bureau of Rural Sciences website < http://www.daff.gov.au/brs > . Parts of section 4 were adapted from subject notes compiled by animal production academics at CSU. Valuable editorial and technical suggestions were made by the team of reviewers, who were Bruce Cook (ex Queensland DPI&F), Dr Brian Dear (NSW Industry & Investment), Dr Bob Clements (former Chief, CSIRO Division of Tropical Pastures), Arthur Cameron (Principal Pastures and Extension Agronomist, Division of Resources, NT), Professor Alec Lazenby (former Director, Grassland Research Institute, UK) and Professor David Kemp (Charles Sturt University, Orange). Photos are by Ted Wolfe with additional photos by Bruce Cook, Brian Dear and Angelo Loi. Comments, contributions and updates from readers of this profile are welcome, to be incorporated into future updates.

[The profile was drafted in the period September to December 2009 and edited by S.G Reynolds and J.M. Suttie in December 2009].