Native pastures can be managed through a number of grazing strategies including:
- Continuous grazing and set stocking
- Rotational grazing
- Cell grazing
- Time control grazing
- Spell grazing
Continuous grazing is a management system where livestock run in a paddock continuously over time with no, or only infrequent, spells from grazing. Continuous set stocking refers to the situation where livestock numbers in a paddock vary little from month to month, or from year to year.
The main benefits of continuous grazing are that it is simple to apply, requires minimal labour and can deliver good production and land condition outcomes if managed well. Disadvantages of set stocked continuous grazing are that pasture utilisation may be above or below the optimal level at any one time. There is also the potential for overgrazing with livestock habitually revisiting preferred areas.
For good production and land class outcomes, set stocked continuous grazing systems should be conservatively stocked to minimise the decline of preferred native pasture species and land types. Risks to land condition and production can be minimised in a continuous grazing system by:
- Preparing a forage budget and adjusting stocking rate accordingly.
- Spelling the paddock during the growing season once every 3-4 years to allow full pasture recovery.
- Rotational burning to minimise patch grazing.
Rotational grazing, cell grazing and time control grazing
Rotational grazing involves moving livestock through a series of paddocks so when they have finished grazing the last paddock in the series, the first paddock has recovered to allow the rotation to recommence. Rotations are often organised around the plant growth cycles and aim to optimise pasture utilisation.
Cell grazing and time control grazing are similar to rotational grazing, but are more intensive and involve more paddocks or 'cells'. In time control grazing, paddock moves are determined by plant growth - the faster the growth, the more moves and vice versa.
The main benefits of rotational grazing stem from a focus on plant growth phase. Plants are grazed in their vegetative state for relatively short periods, compared with continuous grazing, which reduces the tendency for preferred species to be grazed out. Grazing is then followed by a rest period, which allows perennials to replenish their root reserves and better withstand dry periods, benefiting both soil structure and land condition.
A well designed rotational grazing system can also prevent uneven grazing across the paddock.
Rotational grazing does, however require increased infrastructure and labour and may not be practical when plants are not growing, sheep and cattle are lambing and / or calving. The reduced opportunity to selectively graze in a rotational grazing program can also lead to a decline in per head animal production due to livestock being forced to graze less nutritious plant species.
Spell grazing involves locking up pastures at critical times in their growth cycle to allow plants to replenish root reserves and set seed. This reduces the risk of over grazing and encourages pasture plant recruitment through seed set.
An example of spell grazing is wet season spell grazing in northern cattle production systems which involves destocking paddocks during the wet season to allow plant recovery and new native pasture plant recruitment through seed set.
Spell grazing can cause possible overgrazing if livestock are bought together at higher than optimal stocking rates while other paddocks are being spelled.
Successful grazing systems
Regardless of the strategy used, a successful system will:
- Manage pasture utilisation effectively (carrying capacity and timing of spelling).
- Reduce uneven grazing that is either wasteful or harmful.
- Match stocking rate to the diet quality required by the animal production targets.
Strategic grazing can also play an important role in hazard reduction and weed management.
- Module 2: Tactical stock control and Module 4: Pasture utilisation from the More Beef from Pastures: The producer's manual
- Module 7: Grow More Pasture and Module 8: Turn Pasture into Product from the Making More From Sheep manual
- Grazing land management: Sustainable and productive natural resource management
- MLA Tips & Tools: