Topdressing your pastures for autumn
In southern Australia, most graziers topdress their pastures in late
summer or early autumn to boost pasture growth and maintain
soil fertility.
Pastures need access to readily available nutrients such as
phosphorus and sulphur when the autumn break occurs for strong
growth.
This is an important time of year to lift pasture growth before it
naturally slows during the cooler months.
For best responses, pasture fertilisers should be applied before
the opening rains and before the clover has germinated,
particularly if soil fertility is below optimum levels.
In pastures containing perennial legumes such as lucerne and
white clover and in higher rainfall areas, spring topdressing can
be just as effective as autumn applications.
The fertilisers needed and the rates required will depend on
existing soil fertility and production targets.
Concentration and coverage
For best results from pasture topdressing, it is important to ensure
optimum distribution of the nutrients to the pasture.
Nutrient ratio
The importance of sulphur in pastures is often underestimated.
If a soil test reveals that sulphur fertility is low, it is particularly
important to choose a fertiliser that contains at least 30% of its
sulphur as plant available sulphate sulphur.
In situations where potassium responses are likely, potassium
may be included as a blend ingredient with the autumn
topdressing or applied in a spring application.
In most soils, phosphorus will only diffuse distances of up to 5 cm
from the fertiliser granule. It is only used by plants when their
roots contact the soil zone immediately surrounding the fertiliser
granule.
Lower analysis fertilisers, such as SuPerfect, allow graziers to
apply more granules per square metre than higher analysis
fertilisers, to feed pastures more evenly.
This can be particularly important when phosphorus is applied
at low rates and when phosphorus is applied to soils with lower
phosphorus fertility.
Fertilisers for autumn
Fertiliser
Analysis
8.8% phosphorus,
Fertilisers for autumn
SuPerfect
SuPerfect Mo
11% sulphate sulphur,
19% calcium
8.8% phosphorus,
11% sulphate sulphur,
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