Producing Quality Oat Hay

Herbicide residues
Some herbicide residues can severely reduce early
growth of oat crops grown on susceptible soil
types, especially after sub optimal rainfall. The
amount of rainfall, soil pH and the biological
activity of soils impact on herbicide breakdown.
On high pH soils sulfonylurea herbicide
residues can be damaging, with triasulfuron
generally more damaging than chlorsulfuron
or metsulfuron methyl. Group B herbicides
used on Clearfield wheats and Clearfield canolas
can have residual effects on oat crops but
damage is usually less than seen in barley. The
imidazolanones are usually more residual in acidic
soils. Always check product labels for residue risk.
Contaminants
Paddocks with potential contaminants such as
animal carcasses, old fencing wire and rocks
should be avoided, unless these contaminants are
removed or rocks are rolled into the soil.
ARGT
Paddocks with a history of ARGT should either
be avoided or cut prior to ryegrass flowering,
(refer to ARGT, page57).
Image 6.2
Furrows formed by press wheel can cause a large amount of
machinery vibration at mowing and baling and can result in
herbicide injury if herbicide is washed into the furrow.
Rolling prior to applying post emergent herbicide can reduce
both of these problems.
48 PRODUCING QUALITY OAT HAY
The seedbed for oat hay
Impact on hay quality
• Contamination
Seedbed preparation for hay crops should result
in a paddock surface that minimises the potential
for hay contamination from weeds, rocks and
soil. Carcasses of dead animals and other debris
that could become a contaminant of the hay
must be removed before or soon after seeding.
It is suggested that crop residues that could be a
source of contamination are burnt but care must
be taken to avoid soil erosion.
Rolling
Press wheel furrows can be problematic to some
hay making machinery due to the vibrations
caused if the machinery is used at right angles to
the furrows. Rolling paddocks after seeding but
before the start of tillering (GS24) reduces the
severe ridge/furrow effects. After this growth
stage, rolling can cause long term damage and
reduce yield. Paddocks should not be rolled after
a frost or when leaves are wet as this increases
the chance of spreading bacterial blight.
The seedbed should be left in a state that does
not cause herbicide injury. The most common
injury is where post sowing pre-emergent soluble
herbicides are washed into furrows by rainfall.
Rolling prior to applying post sowing
pre-emergent herbicide can reduce this risk.
Sowing date
Impact on hay quality
• Feed test
• Staining and moulds
• Colour
Oats are a spring cereal sown in autumn.
Generally higher yields are associated with
early sown crops but quality may be adversely
affected, especially if early sowing results in
rapid, prolonged early growth. This tends to
lead to rank, fibrous crops and bleaching of
the lower stem.