Pastures 1 Flashcards
(16 cards)
Understand why pastures are relevant to livestock and society
(Define pasture, types, food chain, & influence)
- A pasture is a population of herbaceous (non-woody) plants with short growth habitat and continuous ground cover
- Grasses, legumes, herbs (forbs/broad leaf plants)
- Tropical or temperature
- Annual (dies and germinates every year) or perennial
- Plants enter the food chain through their consumption and utilisation by herbivores, primarily ruminants
- Pasture characteristics influence what animals eat
- Animals grow faster when on better/more pasture
- thus greater profit is obtained from animals provided larger amounts of better quality pasture
Understand why pastures are relevant to livestock and society
(Herbivores)
- Herbivores have the capacity to digest the fibrous tissue of plants (primarily cellulose) and convert it into animal products
- Herbivores have digestive systems that contain large cellulose-digesting “fermentation-vats” (plant material is digested by “cellulose” enzymes produce by bacteria)
Describe how pastures have changed since settlement and what has influenced these changes
(Since 1788 - settlement)
- Cleared most of the land of native vegetation
- cleared trees, brought water table closer to the surface resulting in salinization
- Ruined lots of land
- Introduced sheep and cattle grazing
- Fencing and overgrazing
- Introduction of various annual grasses and forbs
- New diseases, insects and pests
Describe how pastures have changed since settlement and what has influenced these changes
(Restoration phase)
- Land care and ‘sustainability movement’
- More conservative stocking rates
- Tackling erosion, acidification, compaction and salinization problems
- Alternative crops to cereals
- Greater focus on perennial pastures
Describe where and how pastures are used for animal production in Australia
- Environmental factors influence the growth and persistence of pastures
- Soil moisture
- amount and distribution of rainfall
- Seasonal temperatures
- Solarradiation
- Different pastures have different levels of adaptation to factors influencing growth
- Interactions between seasonal rainfall and temperatures delineate the tropical, arid and temperate zone
List key pasture zones across southern Australia
- Major zones in WA
- Orange – Mediterranean annual pasture zone
- Light blue – temperate perennial grass – annual legume pasture zone
- High rainfall areas
- Green/blue – temperate perennial pasture zone (mainly legumes) – high rainfall
Know which pastures dominate in each zone
Sown temperate pastures
- Temperate perennial zone
- Temperate perennial grass – annual legume zone
- Mediterranean annual temperate pasture zone
- Lucerne (a special case)
Know which pastures dominate in each zone
(Sown temperate pastures)
-Temperate perennial zone
- Perennial ryegrass and white clover
- High production and well adapted to defoliation by livestock
- Compete well for resources such as nutrients and light
- Confined to coast and tablelands of South-Eastern Australia
- Annual rainfall around 700mm-750mm
- Phalaris, cocksfoot and tall fescue are also grown in this zone
Know which pastures dominate in each zone
(Sown temperate pastures)
-Temperate perennial grass – annual legume zone
- Phalaris and subterranean clover
- Annual rainfall around 500mm
- Phalaris is the most drought tolerant temperate grass sown in Australia
Know which pastures dominate in each zone
(Sown temperate pastures)
-Mediterranean annual temperate pasture zone
- Annual legumes such as subterranean clover and annual medics
- Annual rainfall above 400mm in Southern NSW and 300mm in Victoria, SA and WA
- Subclover suited to well drained acid sandy loam soils (pH 4.5 to 6.5) whereas medics prefer clay loams and pH >6.5
Know which pastures dominate in each zone
(Sown temperate pastures)
-Lucerne (a special case)
- Deep-rooted (>5m – can extract water from great depths) perennial legume adapted to several zones
- Persists on suitable soils where rainfall exceeds$400mm
- Sown as mixtures with other grasses and annual legumes
Know which pastures dominate in each zone
Native grasslands of northern Australia
- Greater reliance on native pastures to support the northerncattle industry
- Highly variable with coastal and wet/dry tropics dominated by tall perennial grasses
- Mitchell grass and acacia scrublands dominate more inland arid areas
Know which pastures dominate in each zone
Sown tropical pastures of northern Aus
- Infrequent sowing of grasses such as buffel grass
- Leucaena is well known legume scrub
- Rhodes grass, panic grass and kikuyu are prominent in more inland areas
Know which pastures dominate in each zone
Native grasslands of southern Australia
- Exist in a variety of states after history of grazing, fertilisation and sowing legumes
- Examples include wallaby grass, weeping grass and redgrass
- Common companions include silver grass, barley and capeweed
- Low levels of productivity but used for grazing on NSW slopes and tablelands
List pasture characteristics which influence their suitability for different farming systems
(Farming systems)
- Permanent pasture
- constant pasture
- Ley farming
- pastures are used in rotation with crops
- Phase farming
- several year of pasture, followed by several years of crop (cycle)
List pasture characteristics which influence their suitability for different farming systems
(Different farming systems require pastures with different attributes)
- Adaptation to ‘environment’
- High water use efficiency
- High production
- Persistence and tolerance to grazing
- Ability to combine with other pastures
- High seed production and small seeds
- more seeds means more growth and small seeds allow them to survive digestion
- Disease and insect resistance
- High nutritional value
- need energy and high protein
- No adverse effects on animals
- don’t want toxins and such
