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Producing
Quality Oat Hay
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Producing
Quality Oat Hay
The market for oat hay,
whether for export or domestic use
is driven by quality.
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Acknowledgements
Authors
Pamela Zwer, SARDI, National Oat Breeding
Program
Mick Faulkner, Agrilink Agricultural
Consultants Pty Ltd
© 2006 Rural Industries Research and
Development Corporation
All rights reserved
Publication Number is 06/002
ISBN 74151 277 8
Editor
Emma Leonard, AgriKnowHow
ISSN 1440-6845
Contributors
John Black, CSIRO
Robert Di Cristoforo, ARRB Group, formerly
Roaduser Systems Pty Ltd
Pat Guerin, Gilmac
Sue Hoppo, SARDI, National Oat Breeding Program
San Jolly, Applied Ruminant Nutrition
Peter McCormack, SARDI
Alan McKay, SARDI
Frank Mickan, Victorian Department of
Primary Industries
Colin Peace, Australian Fodder Industry Association
Barrie Purser, BSC Nominees
Lyall Schultz, hay grower, Australian Field crop
Association, AEXCO committee
Gavin Schuster, hay grower
Disclaimer
The information contained in this publication
is intended for general use to assist public
knowledge and discussion and to help improve
the development of sustainable industries.
The information should not be relied upon for
the purpose of a particular matter. Specialist
and/or appropriate legal advice should be
obtained before any action or decision is taken
on the basis of any material in this document.
The Commonwealth of Australia, Rural
Industries Research and Development
Corporation, the authors or contributors do
not assume liability of any kind whatsoever
resulting from any person's use or reliance
upon the content of this document.
This publication is copyright. However,
RIRDC encourages wide dissemination of its
research, providing the Corporation is clearly
acknowledged. For any other enquiries
concerning reproduction, contact the
Publications Manager on phone 02 6272 3186.
Murray Smith, Balco Australia
Graham Thomson, hay grower
Published in July 2006
Hugh Wallwork, SARDI
Printed by Union Offset Printers, Canberra
Charlie Williams, hay grower, AFIA
The authors would like to acknowledge the
contribution of Pat Guerin, Gilmac in the
development of the research program that
underpins the new information presented in
this publication.
Design and layout
Lightening Designs
2
P R O D U C I N G Q U A L I T Y O AT H AY
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Contents
The oat hay year planner
Between crops
In Crop
Hay making
Foreword
4
4
4
7
9
Chapter 1 Why grow oat hay?
Opportunities
Risk reduction
11
11
11
Chapter 2 Is oat hay a viable crop choice?
15
Chapter 3 What the market wants?
Domestic hay industry
Hay for export
17
17
19
Chapter 4 Diseases of oats
Disease management and control
Leaf and stem diseases - fungi
Leaf and stem diseases - bacteria
Leaf and stem diseases - viruses
Root diseases - nematodes
Root and crown diseases
25
26
27
31
32
33
36
Chapter 5 Variety selection for hay production
Plant Breeders Rights (PBR)
39
42
Chapter 6 Growing the crop
Paddock selection
The seedbed for oat hay
Sowing date
Seeding rate
Seeding direction
Fertiliser
Annual Ryegrass Toxicity (ARGT)
Insect control
47
47
48
48
49
51
53
57
60
Chapter 7 Making oat hay
Cutting
Curing
Baling
Sampling and tagging
61
61
68
73
76
Chapter 8 Storage and transport
Storing export hay
Storing domestic hay
Hay transport
79
79
80
82
Useful resources
84
P R O D U C I N G Q U A L I T Y O AT H AY
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The oat hay year planner
Between crops
4
Month
Activity
Chapter
November/
December
Consult hay buyers for preferred varieties and potential hay demand
Select variety based on disease constraints and maturity category
Preliminary paddock selection
Order new seed
3,4 & 5
January
Soil test for root disease
Plan stubble management
4
February/March
Enquire about pre-season contract
Deep soil N test and top soil nutrient test
Produce fertiliser budget
Implement repairs and maintenance to storage and hay
making equipment
6
April
Finalise paddock plans
Prepare equipment for sowing
4&6
May/June
Allow volunteer cereals and weeds to germinate
Apply herbicide to prepare paddock for sowing
Calculate 1000 grain weight and seeding rates
Ideally sow before mid June
6
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In crop
Stage
Germination
& emergence
Seedling
Tillering
Zadoks
Growth Code Activity
Stage
Seeding
00
Paddock selection
Seedbed preparation
Pre-emergent herbicide applied
Chapter
6
Coleoptile
emerges
from seed
Coleoptile
through
soil surface
07
First leaf
appears
First true
leaf
unfolded
2 true
leaves
unfolded
until
4 true
leaves
unfolded
until
9 or more
leaves
unfolded
10
Monitor for weed emergence
11
Monitor for red legged earth mite and lucerne
flea; spray if required
6
12
Monitor for post sowing herbicide application
6
14
Apply post sowing N if required
6
Apply post sowing N if required
6
Main shoot
only
First tiller
visible
2 tillers
visible until
9 or more
tillers
visible
09
19
20
21
22
29
Stem elongation 1 node
detectable
31
Monitor and identify leaf diseases
2 nodes
detectable
until
32
Preventative fungicide, if required
Consider withholding periods
9 or more
nodes
detectable
39
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4
5
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Stage
Booting
Panicle
emergence
Flowering
Seed
development
Ripening
6
Page 6
Zadoks
Growth Code Activity
Stage
Early boot
Mid boot
Late boot
Flag leaf
sheath
opening
First
awnlets
visible
41
43
45
47
Panicle
emergence
begins
30% of
panicle
emerged
50% of
panicle
emerged
until
Panicle
fully
emerged
First
anthers
visible
Full
flowering
End of
flowering
61
Continue monitoring for cutting to meet
quality standards
65
Optimum cutting time for premium quality
69
Optimum cutting time for premium quality
Watery
ripe
71
Optimum cutting time for premium quality
Early milk
73
Decreasing likelihood of meeting premium
quality standards
Milky ripe
75
Late milk
77
Early
dough
83
Soft dough
85
Hard dough
87
Grain hard
89
Chapter
4
Prepare hay equipment
Check with contractor
7
51
Commence regular monitoring for cutting
7
53
Check if flowering has comenced
49
55
59
Quality reducing rapidly. Too late to cut to meet
premium quality standards
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Hay making
Month
Activity
Chapter
October/
November
Cut and condition hay
Super condition hay if desired
Monitor moisture levels in windrows
Bale hay when optimum moisture level reached
Cart hay to shed for storage immediately after baling
Develop list of repairs & maintenance
Clean & store machinery
7&8
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Foreword
Growing Oat Hay was first published in 1996 as a
guide to help reduce the risk of growing quality
oat hay. However, this book no longer provides a
source of current information regarding oat hay
production. Information presented in the book
dates from 1983 to 1994. New developments
including varieties, fertility, sowing rates, quality
requirements, and machinery have occurred since
the publication of the first book.
The updated version Producing Quality Oat Hay
has been completely restructured and rewritten to
include the latest developments and research
findings on how to grow, make and deliver high
quality oat hay. The new book provides growers
and processors with a comprehensive guide to all
aspects of quality oat hay production.
The book is the result of collaboration between
agronomic consultants, plant breeders, livestock
consultants, export and domestic hay processors,
and growers. Information presented in the
book is based on research conducted over the
last 10 years.
Four major areas requiring additional research
have been identified: control of diseases by
chemical means, capability to predict yield
and quality early in the growing season, the
development of variety specific agronomic
management packages and how to bale dry hay.
This project was funded from industry revenue
which is matched by funds provided by the
Australian Government.
This report is an addition to RIRDC’s diverse
range of over 1500 research publications.
It forms part of our Fodder R&D sub-program
which aims to facilitate the development of a
sustainable and profitable Australian fodder
industry.
Most of our publications are available for
viewing, downloading or purchasing online
through our website:
• downloads at
www.rirdc.gov.au/fullreports/index.html
• purchases at www.rirdc.gov.au/eshop
Peter O’Brien
Managing Director
Rural Industries Research Development Corporation
P R O D U C I N G Q U A L I T Y O AT H AY
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Executive summary
Annually, Australian farmers’ produce between
5.5 and 6.5 million tonnes of fodder. Most of
this is used on farm or traded domestically,
however a growing proportion is exported, of
which the majority is oat hay. The export oat
hay industry has grown from about 100 000t in
1993 to over 600 000t in 2005 and is worth at
least $150m annually.
The market for oat hay, whether for export or
domestic use is driven by quality. High quality
hay demands high prices and depending on the
year growers can increase income by $50 to $100
a tonne for high quality hay. A consistent supply
of high quality hay is essential for the industry to
meet the challenges of increasing competition
from North America, expansion into new
markets and maintenance of current markets.
As the oat hay industry has grown and
developed, factors affecting hay quality have
been identified and many of these are influenced
by management. An understanding of those
factors that can be managed by the grower will
help to reduce the risk involved with producing
premium quality hay.
The purpose of the book Producing Quality
Oat Hay is to provide growers with a practical
management guide to produce high quality,
profitable hay crops. The information is based
on new developments and current research on
growing high quality oat hay.
Producing Quality Oat Hay contains details that will
help novice and experienced growers evaluate the
viability of oat hay in their system. Oat hay is
often grown for ryegrass control but with good
management it can become a profitable cropping
option in its own right. One of the great challenges
is to achieve high yield while maintaining or
improving hay quality. The book contains
information on all aspects of growing, making,
storing and transporting oat hay to meet these
challenges. It explains quality requirements by
market and how these are measured. Chapters
include the latest details on variety selection
especially in relation to disease; row spacing and
seeding issues; fertiliser management; cutting,
curing and baling hay; and storage and transport.
10
While preparing the material for the book, several
research areas that require further investigation
became apparent.
1. The development of variety specific
agronomic management packages at the
time of new variety releases. The data
presented in the book clearly show that
varieties’ quality traits react differently to
nitrogen management. Variety specific
management packages would ensure that
growers achieve optimum quality for
each new variety.
2. The control of foliar disease using
fungicides. Although genetic resistance is
the preferred option for controlling diseases,
varieties with combinations of the desired
resistances are not always available. Currently
most information about fungicide use is
from data collected from other cereals.
More information is needed for fungicide
application in oat hay especially relating to
withholding periods in oat hay production.
In addition research on protective or
preventative chemical control is required.
This is where fungicides are applied at earlier
growth stages to prevent foliar diseases later
in the plant lifecycle.
3. Yield and quality prediction. Development
of a model to predict oat hay yield and quality
early in the growing season, such a model
would help growers modify management to
optimise these parameters. Currently, oat
crops with high dry matter yields are more
likely to produce poorer quality hay. Better
prediction of yield and quality will assist in
producing high hay yield while maintaining
good quality.
4. How to bale dry hay. Currently when hay
becomes too dry it will not produce a good
bale and baling must stop. This results in
substantial lost time and increased potential
for weather damage.
Dr Pamela Zwer,
SARDI, National Oat Breeding Program
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Chapter 1
Why grow oat hay?
Growing oats for hay offers graingrowers a
combination of opportunity and risk reduction.
Many growers have introduced oat hay into the
rotation as a tool to control herbicide resistant
ryegrass or to slow the development of herbicide
resistant weeds. However, oat hay can provide a
profitable breakcrop that optimises the use of
machinery and labour and introduces diversity
into the timing of crop maturity and payment.
Of course, growing oat hay has a risk profile of
its own, for example capital and/or operating
costs can be substantial.
The application of agronomy that focuses on
hay quality and market requirements can help
minimise the risks associated with oat hay
production. This book offers guidelines on
how to produce quality oat hay for the domestic
and export markets.
Opportunities
Financial contribution
Oat hay production can produce a substantial
gross margin and contribute to improved cash
flow and total farm profit (Table 1.1 and 1.2).
Labour and machinery resources
A hay making enterprise can provide on-going
work for employees or casual labour at times
when other farm enterprises may have low labour
requirements, therefore allowing continuous
employment. Existing farm machinery such as
tractors, loaders and trucks often can be used in
the hay enterprise. The provision of contract
services using cutting, conditioning, super
conditioning, raking, baling and carting
equipment and providing storage can add
substantially to income.
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Figure 1.1 Annual changes in weed seed-bank – source Dr Gurjeet Gill, Adelaide University.
A significant reduction in ryegrass seeds was recorded following an oat hay crop compared to cereal, oilseed and
legume crops harvested at grain maturity. n= number of samples surveyed.
Livestock enterprises
The production of hay can allow livestock
enterprises to be maintained or expanded
particularly when green feed is not available.
Risk reduction
Markets and price
Hay markets and prices are largely independent
of grain markets and prices. Therefore, quality
hay can reduce the risk of poor returns from
cropping due to commodity prices or market
restrictions. Additionally, hay can be stored
when market conditions are poor and sold when
they improve. Oat hay has a well established
market compared to the demand for hay from
other cereals.
Seasonal risk for grain growers
Cereal crops grown for grain are at greater risk
from poor seasonal conditions such as excessive
heat, low subsoil moisture levels or frost
impacting on grain fill. Hay is cut before grain
fill, shortening the growing season and the
potential for damage from these risks.
12
Soil moisture
The production of hay reduces the soil
moisture loss normally associated with maturing
grain crops. On suitable soil types, generally
heavier soils, this moisture can be stored for
subsequent crops.
Soil nutrients
Hay making removes significant nutrients from
the soil (Table 6.4a & b) but late season uptake
of nutrients is reduced. Therefore hay can be
less depleting than: 1) harvesting grain and
cutting straw, and 2) harvesting grain and
burning stubble.
Weeds
Cutting hay can reduce weed seed set by
desiccating later maturing weed species before
viable seed is set. With care, viable weed seeds
can be removed from paddocks in the baled hay.
Hay production is a particularly successful tool in
an integrated approach to managing herbicide
resistance, with particular emphasis on ryegrass
and some broadleaf weeds (Figure 1.1).
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Table 1.1 Gross margin in dollars per hectare for oat hay based on average production
costs, at the time of publication, for the medium and high rainfall regions –
source Agrilink Agricultural Consultants.
Yield (t/ha)
8
Expenditure
Inputs
Dressed seed
Fertiliser
18:20:00
urea
pre-emergent
post-emergent
spray topping regrowth
Herbicide
Insecticides
Subtotal
$/ha
$38.40
$36.00
$36.00
$22.00
$6.00
$8.00
$3.00
$149.00
Operations costed at contract rates
Seeding
Spraying
Rolling
Fertiliser
Mowing/conditioning
Super conditioning
Raking/tedding
Baling
Handling
Transport
Storage
Insurance
pre-emergent
post-emergent
spray topping regrowth
Top dressing
(100km)
including depreciation
$/ha
$30.00
$8.00
$5.00
$5.00
$4.00
$7.00
$35.00
$20.00
$7.00
$160.00
$40.00
$120.00
$80.00
$10.00
Subtotal
$531.00
TOTAL
Expenditure
$680.00
Income
$/t
Premium hay
Second grade hay
Weather damaged/low quality
Gross Margin
per hectare
$135.00
$105.00
$80.00
Premium hay
Second grade hay
Weather damaged/low quality
$/ha
$1,080.00
$840.00
$640.00
$399.60
$159.60
-$40.40
See Table 1.2 for a variance analysis of the impact of yield and price on income.
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Annual Ryegrass Toxicity (ARGT)
Pest and disease
Hay production can offer another breakcrop
opportunity, especially where continuous cropping
is practiced. This may be due to the hay crop
being a non host to a particular pest or disease,
the hay making operation being destructive of
the organism or its habitat, or the production of
hay actually removing the organism from the
paddock. See Chapters 4 and 5.
The timely production of hay can reduce
ARGT by:
• removing ryegrass (and other hosts) prior to
toxin formation;
• interrupting the lifecycle of the causal agents;
• reducing the ryegrass population.
Table 1.2 The impact of yield and price variance on income ($/hectare).
Yield t/ha
14
Price $/t
$50
$75
$100
$125
$150
$175
$200
$225
$250
4t
200
300
400
500
600
700
800
900
1000
6t
300
450
600
750
900
1050
1200
1350
1500
8t
400
600
800
1000
1200
1400
1600
1800
2000
10t
500
750
1000
1250
1500
1750
2000
2250
2500
12t
600
900
1200
1500
1800
2100
2400
2700
3000
14t
700
1050
1400
1750
2100
2450
2800
3150
3500
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Chapter 2
Is oat hay a viable choice?
Before producing oat hay it is useful to answer
some key questions. This methodology is
useful for the potential first time grower or to
determine what area of the farm should be
devoted to hay production each year. The
following chapters contain information that
assists in addressing these questions.
Current information on the domestic or
export market should be sought from hay
purchasers. Hay buyers and the Australian
Fodder Industry Association (AFIA) are useful
sources of information on domestic and export
hay markets.
Market requirements
Yes/No Note
Which market are you producing hay for? - on-farm consumption, domestic
or export market.
Is there a guarantee or high likelihood of sale?
What quality is required, how is quality determined and how are variations in
quality accounted for in the sale price?
What bale size, density, weight and moisture content is preferred and/
or rejected?
What feedback mechanisms exist between the buyer and the potential market
Are freight rates acceptable and is reliable freight available?
What are the storage, delivery and payment arrangements?
Market demand
Yes/No Note
How does demand for hay vary from year to year or at different times of
the year?
Does the domestic industry have ample supplies of:
1) paddock feed,
2) hay or silage on hand and
3) alternative cost effective sources of protein, energy and fibre?
Does the export industry have carryover stocks or are export markets being
over or under supplied?
Does either market have a particular requirement for your hay and are you in a
position to be a reliable supplier?
Do you have a need for increased supplies of hay on farm?
Are livestock enterprises expanding or intensifying?
Financial contribution
Yes/No Note
Can sufficient nett income be generated from the oat hay crop to have a positive
influence on farm profitability and/or cash flow?
Will the production of oat hay impact on the paddock’s future
production potential?
How does the gross margin for hay compare to other crop and livestock options?
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Paddock restrictions
Yes/No Note
Does the paddock have excessive burdens of weeds that can not be or are too
expensive to control? If yes, how will these impact on hay quality?
Are there stones, animal carcasses, sticks, parts of machinery, previous stubbles,
old fences or other debris in the paddock that could be picked up at baling?
Is there a history of ARGT or other toxins in the paddock?
Will the paddock be suitable to cut, rake (if necessary), bale and cart hay
without contamination, risk to machinery or severe degradation of the paddock?
Is the previous cropping history likely to have resulted in a high carryover of
soil or stubble borne diseases that could seriously affect hay yield or quality?
Climate risk
Yes/No Note
Does the climate at the farm location allow for
1) timely seeding of a hay crop
2) economically viable hay yields, in comparison to returns from other
cropping enterprises
3) managing risk of rainfall and humidity from cutting to baling to allow hay
to be baled and stored in good to excellent conditions in most years?
If there is a high risk of substantial rainfall on curing hay would this rainfall be
more profitably turned into grain crops? It has often been stated by grain
growers that “the rain that ruined my hay made my grain crops”.
Infrastructure requirements
Do you own, need to purchase or are able to contract the following to ensure a
reasonable chance of successfully producing a quality hay product?
The following are considered the preferred items for hay making:
• a mower conditioner (or all in one mower; conditioner/super conditioner);
• super conditioner;
• rake;
• baler;
• front-end or telescopic loader;
• flat top or drop deck trucks or trailers;
• hay storage sheds.
Other items that may be required in some circumstances are rubber tyred or
flat roller, suitable seeder, spray unit, additional loader or loaders.
Do you have storage facilities so that potential low prices do not have to be
accepted if hay quality is below current market requirements?
16
P R O D U C I N G Q U A L I T Y O AT H AY
Yes/No Note
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Chapter 3
What the market wants?
Domestic hay industry
Interest in oat hay for the dairy, feedlot and horse
industries has grown in recent years. This is
mainly due to improvements in oat hay quality
brought about by higher quality standards
demanded by the export hay market.
Customer demands’ change from year to year
depending on the availability of home produced
forage and other feeds. Demand in the equine
industry is especially variable.
The domestic market is regarded as loyal to
suppliers who: provide the right product, have
continuity of supply throughout the year, can
deliver on time and load without time constraints.
Each sector differs in their demand for bale size
and shape (Table 3.2). Round bales are primarily
used on farm due to transportation difficulties
and are generally preferred by farmers, who have
limited on-farm storage for large and medium
squares. Small bales are still popular with some
buyers such as hobby farmers but production
is declining, as they are more labour intensive
to handle.
Table 3.1 An example of hay quality
parameters for the domestic market.
Annual quality requirements will
depend on the price of alternate
ingredients used in livestock rations –
source Applied Ruminant Nutrition.
Quality parameter
Level
Dry matter (DM)
83-90%
Crude protein (CP)
At least 8%
Neutral detergent fibre
(NDF)
Less than 60%
Digestibility (IVD)
More than 60%
Metabolisable energy (ME)
MJ/kg DM
More than 8
Potassium (K+)
Less than 2%
Water soluble carbohydrates
(WSC)
More than 14%
Nitrates (NO3)
Less than
500ppm
Figure 3.1 Historical makeup of Australian fodder production – source Australian Bureau of Statistics.
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Table 3.2 Demand and requirements for hay by the domestic market.
Hobby
farmers
Market
Dairy
Feedlots
Horses
Demand for
oat hay
Increased interest
in oat hay due to
improved hay
quality.
Some increased
demand for oat
hay as lucerne
and maize
production has
reduced due to
water restrictions.
Varies from year
to year depending
on availability of
pasture hay.
Low demand for
pure oat hay.
Meadow hay
containing a
mix of grasses,
pasture legumes,
and oats is
preferred.
Fed to animals
for bulk.
Customers are
fussy.
Prefer hay with
no grain.
Hay price is more
important than
hay quality
for cattle.
Hay must be free
from dirt, dust,
mould, and rust
diseases.
Wide variation
in desired hay
quality.
High energy
sought for milk
production.
Cut at early milk
stage – no grain,
no vermin.
Fine stems and
good colour are
demanded.
Green colour and
thin stems are
desired quality
characters.
For sheep
feedlots hay
needs to be finely
chopped and
good quality is
imperative.
Wide variation
in desired hay
quality.
Dairy farmers
are prepared to
compete on price
with export hay.
Hay that does
Quality
requirements not make export
grade is
acceptable.
Palatability is
paramount.
Rust and
mould are not
acceptable.
Customer
preference ranges
from: 1) no grain
development to
some grain, 2)
minimal flag leaf
to plenty of leaf.
Generally do not
cut hay before
milky dough.
Horses seem
to prefer
unconditioned
hay.
Storage and
handling
Preference for
round and
3ftx4ftx8ft bales,
although
4ftx4ftx8ft
becoming more
accepted.
Large square
bales generally
preferred.
Oats may also be
used as silage.
Preference is
generally for hay
to be in small
square bales.
Buy as needed –
lack of long term
storage.
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Low density small
bales preferred
over large bales.
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Hay for export
Over the past five years (1999/00 to 2004/05)
Australia has exported an average of 500 000
tonnes of cereal hay each year (Figure 3.2);
exports increased annually during this period.
The majority of these exports are oat hay of
which 40 to 50% is for the premium, dairy
market. The remainder is sold into mid to low
quality markets, primarily purchased for beef
production and dry cow feed.
Japan, Korea, Taiwan and the Middle East are
currently Australia’s major markets for export hay
and straw. This market is dominated by Japan
that buys at least 85% of the cereal hay exported
from Australia each year (Figure 3.3). These
markets have several common factors that
drive the importation of high quality forage; a
market to which Australia is a relative newcomer.
These factors are:
Image 3.1
For export, bales are
repacked into high density
bales approximately
500mm square and each
weighing 50kg.
At the time of writing the USA and Canada are
Australia’s main competitors in the export hay
market. These countries produce premium hay
products from Timothy, Alfalfa (lucerne) and
Sudan grass. They also produce lower quality hay
from ryegrass and fescue (Figure 3.4).
From the perspective of the Australian producer,
the export hay market and consequently hay price
is driven by:
• large populations, a large proportion of which
has a substantial disposable income;
• supply from Australia and of competitive
products from overseas;
• insufficient land to produce enough quality
feed to meet demand;
• hay quality;
• governments that wish to increase the level of
self sufficiency in dairy and meat production.
• the value of the Australian dollar on the
exchange markets;
• competition from the domestic market.
Figure 3.2 Australian hay and straw exports 2001 to 2005 –
source Australian Bureau of Statistics.
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Figure 3.3 Australian cereal hay exports by destination - source Australian Bureau of Statistics.
The Japanese market
The Japanese market buys on price and quality.
It is looking for forage with high intake qualities.
About 80% of hay goes to the dairy market and the majority of cows are hand fed.
In 2005 there were 1.75 million dairy cows in Japan.
Herd size and the use of mechanised feeding of Total Mixed Rations (TMR) are increasing; this is
resulting in a growing demand for hay where fine stems are less essential for high quality.
Figure 3.4 Japanese imports of baled hay and straw products - source Japanese Quarantine records.
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Figure 3.5 Overview of the Australian fodder industry by market based on several years
data – source AFIA.
What is quality export hay?
In a nutshell the export market demands:
Quality is imperative for export hay. Oat hay
quality is determined by a combination of factors
that can be grouped under three headings:
• hay that animals want to eat, even when their
nutritional requirements have been met;
• visual and sensory appearance;
• objective measurement, including feed analysis;
• product safety.
Hay buyers differ in their methods of quality
determination and the importance they place on
visual, sensory and objective assessment.
Therefore, it is important to have a good
understanding of what the buyer wants in terms
of hay quality and how this is determined.
• hay that animals do not have to continuously
regurgitate to break the particles down to
pieces small enough to be digested, as
regurgitation takes energy and reduces intake;
• hay that provides appropriate levels of
nutrients for the animal to perform.
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Visual, sensory and safety assessments
Colour
The primary visual criterion is an appealing colour. The industry no longer
has the key objective of sourcing hay with a vivid green colour. This is
due to a perceived association of vivid green coloured hay with high nitrate
levels, which can result in nitrate poisoning.
There appears little evidence that animals prefer hay due to its colour but
there may be aromatic compounds that have an influence.
Staining, moulds and dust
The main market inhibitors are yellow staining, brown leaf, high dust levels
and the development of mould. Hay containing one or more of these will
be downgraded.
Moulds can be smelt and buyers want to source sweet, clean smelling hay as
offensive odours deter hay intake.
Stem diameter
Thin stems (bottom left) are preferred as these contain less fibre in the cell
walls. Coarser stems (bottom right) are acceptable in total mixed rations.
Impurities and foreign objects
The inclusion of certain weeds such as Cape weed or Salvation Jane,
animal carcases or faeces can all cause undesirable black patches in the bale,
resulting in discolouration and downgrading.
Hay must be free from foreign material, such as metal objects, glass, sticks
and fencing wire that can injure farm animals, their handlers or equipment.
Freedom from toxins
The industry can not afford livestock deaths due to ARGT or poisoning
from other corynetoxins. Export hay markets are demanding hay free from
the risk of toxicity and increasingly test for toxins or their precursors.
Twelve bales per paddock or 15% of bales in every paddock whichever is
the greater must be sampled for ARGT.
Hay must have chemical residues lower than stautory maximum
residue levels (MRL).
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Objective measurement and
chemical feed analysis
Intake and preference
Hay nutritive value and feeding value should not
be confused. Nutritive value is determined by
digestibility and efficiency of utilisation of
nutrients, whereas feeding value, termed
voluntary feed intake is determined by a
combination of nutritive value and how much an
animal consumes. Hays of similar nutritive value
can differ in feeding value.
Another component of voluntary feed intake is
the preference an animal will have for the hay.
There has been much research on odours that
deter intake, such as must and mould odours.
Research on attractive odours is being carried
out by the University of Adelaide but was not
completed at the time of publication.
Moisture
Moisture will generally be measured in the
paddock by the grower and is reported as part of
the feed test. Most exporters specify maximum
bale moisture of 14% at delivery to ensure hay
does not degrade or spoil during storage. High
moisture hay for the export market will be
rejected at delivery. (Refer to Baling – testing
moisture content).
Feed testing
The feed test measures digestibility, fibre and
water soluble carbohydrate content as well as
crude protein and nitrate nitrogen levels
(Table 3.3). For export hay the feed test is
generally organised by the hay buyer.
For forty years CSIRO has researched ‘what
drives voluntary feed intake?’ This work led to
the development of a measurement for shear
energy. The shear energy measurement reflects
the time and energy taken by a ruminant animal
to breakdown feed into particles of a size that
can be easily digested.
Shear energy is a measure of the difficulty to
shear feed during chewing and rumination. In
trials, typical values for oat hay ranged from
6KJ/m2 to 20KJ/m2. In general, voluntary feed
intake for hay with lower shear energy is more
than for hay with higher shear energy.
Near Infrared Reflectance Spectroscopy (NIR) is
an inexpensive, rapid and accurate test for shear
energy, fibre, water soluble carbohydrate and
protein content.
For information on the availability of NIR
calibration standards, contact [email protected],
and on shear measurements of hay samples
contact [email protected].
Table 3.3 Typical feed test specifications for
export oat hay – source AFIA.
Quality parameter
Dry matter (DM)
Crude Protein (CP)
Level
Greater than 58%
4-10%
Neutral detergent fibre
(NDF)
Less than 57%
Acid detergent fibre
(ADF)
Less than 32%
Digestibility (IVD)
Greater than 58%
Metabolisable energy
(ME)
Greater than
9.5 MJ/kg DM
Water soluble
carbohydrates (WSC)
Greater than 18%
Nitrates (NO3)
Less than 500ppm
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Fibre and digestibility
Digestibility estimates the percentage of forage
that can be readily broken down in the rumen. If
hay is being fed exclusively, digestibility must be
above 58% otherwise animals will lose condition.
Two measurements are used for fibre. Neutral
detergent fibre (NDF) measures how much of
the hay is plant cell wall, the structural part of the
plant that provides ‘bulk’ rather than nutrients in
the diet. A proportion of bulk is required for the
proper functioning of the rumen but too much
will limit intake. The other measure is acid
detergent fibre (ADF) this primarily measures
cellulose, lignin, silica, insoluble crude protein
and ash, which together are the least digestible
parts of the plant. The level of ADF is inversely
proportional to digestibility and it can be used to
calculate energy values.
Water soluble carbohydrates
Water soluble carbohydrates are sugars that can
be readily absorbed into the blood stream to
provide energy. High quality oat hay will have a
water soluble carbohydrate content of about
19%. Water soluble carbohydrates, in particular
fructose, influence palatability but may not be
strongly correlated with preference. Current and
future projects may isolate specific carbohydrates
and other compounds that attract animals to eat
one hay in preference to another.
Minerals
Oat hay is generally low in sodium but potassium
and nitrate levels can vary depending on crop
nutrition and availability in the soil. If dry cows
are fed hay with a potassium level in excess of
2%, within three weeks of calving, the potential
risk of milk fever is increased. However, this
will also be influenced by the level of sodium,
chloride and sulphur in the total diet.
Many of the above factors can be manipulated by
crop agronomy and by the way hay is made and
stored. These are discussed in more detail in
Chapters 6, 7 and 8.
Image 3.2 Three examples of premium quality export hay but with increasing stem diameter from left to right.
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Chapter 4
Disease of oats
A wide range of fungi, bacteria, viruses,
nematodes and insects, can affect all stages
of plant growth and result in reduced hay
production and quality.
The effect of diseases on hay digestibility, fibre
content and water soluble carbohydrates, the key
chemical determinants of hay quality, are not
known at this time. However, diseases reduce the
desirable green colour to yellow, red, and brown,
reducing visual quality. The smell of hay is
adversely affected by crops heavily infected with
stem and leaf rust spores.
Disease and pest control measures include:
genetic resistance, chemical control and
agronomy practices. However, genetic resistance
is the most desirable and sometimes the only
means of disease control (Chapter 5 Variety
selection). When selecting a variety it is
important to understand the dominant disease
constraints in a region.
Figure 4.1 Disease constraints by State. Diseases that cause significant production
constraints for a state are at the top of the columns. The larger the band the more
significant that disease is in that State – source SARDI, National Oat Breeding Program.
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Disease importance varies between production
areas (see Figure 4.1). Varieties with the best
combination of resistance to key diseases should
be selected, if available (Table 5.3 a & b). For
example, a septoria resistant variety is essential in
most regions of WA. However, if a variety is
available with septoria, leaf rust, and barley
yellow dwarf virus (BYDV) resistance it would
be the best variety to select for hay production in
much of WA. Although cereal cyst nematode
(CCN) resistance and tolerance are not indicated
in WA and NSW, if CCN is identified as a
constraint, this should be the first criteria for
variety selection.
Disease management
and control
The potential for damage by key root and crown
diseases can be tested by a single soil test. Soil
samples for the Predicta B soil tests are collected
in summer/early autumn. The tests are
coordinated by local agronomists and resellers
and provide a DNA prediction of soil inoculum
levels for Rhizoctonia, take-all, cereal cyst
nematode, Pratylenchus, stem nematode and
crown rot.
During the growing season, regular paddock
inspections should be carried out for disease.
Care should be taken to avoid spreading foliar
diseases during such inspection; this is especially
26
important if bacterial blight is present. After
Zadok’s growth stage 32 (GS32), aerial fungicide
applications are preferable in order to minimise
crop damage from wheel traffic. The export
market is concerned about the residual nature
of some fungicides and the requirement for
withholding periods. Therefore, it is advisable
to check with your hay buyer before fungicides
are applied.
Table 4.1 Details of common diseases of
oat hay by Zadok’s growth stage –
source SARDI, National Oat Breeding Program. For more
information on growth stages see ‘The oat hay year planner’.
Growth Stage (GS) Disease
GS0-25
Root diseases - stem
nematode, CCN,
Pratylenchus, take-all
and Rhizoctonia.
Foliar disease – barley
yellow dwarf virus
(BYDV)
GS25-30
Septoria, bacterial blight,
BYDV and Pyrenophora
leaf blotch
GS30+
Septoria, bacterial blight,
BYDV, red leather leaf,
stem and leaf rust
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Leaf and stem diseases - fungi
Stem Rust, Puccinia graminis f. sp. avenae
Severity
Stem rust is one of the most devastating diseases of oats. It occurs in
all oat growing regions of Australia. Because the pathogen has the
ability to produce multiple cycles of spores, early infection of the plant
can result in complete crop failure.
Source and spread
Volunteers, spread by wind.
Main hosts
Oats, wild oats.
Plant part attacked
Leaves, stems and heads.
Symptoms
Stems and leaves have dark reddish-brown powdery spores.
Spore pustules are elongated.
Similar to leaf rust but darker and seen on stems and upper leaves first.
Control methods
rotations &
variety choice
Avoid most susceptible varieties. Resistance tends to be short lived.
weed control
Tillage, burning, grazing and spraying to control volunteers.
fungicides
Foliar fungicides provide limited control. Repeat applications may be
necessary if infection occurs early. Withholding periods must
be considered.
Other comments
Infection requires temperatures between 15°C to 30°C and
humid conditions.
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Leaf Rust, Puccinia coronata f.sp. avenae
Severity
Leaf rust occurs in all oat growing regions in Australia. Similar to stem
rust, leaf rust produces multiple cycles of spores, but generally will not
result in complete crop failure. Early infection in a very susceptible variety
can result in crop failure.
Source and spread
Weeds, volunteers, spread by wind.
Main hosts
Oats, wild oats.
Plant part attacked
Leaves.
Symptoms
Circular to oblong pustules on the upper leaf surface that produce orange,
powdery spores. As the crop matures the spores become black, forming a
dark edge to the pustules.
Control methods
rotations &
variety choice
Sow resistant or moderately resistant varieties.
weed control
Control volunteers and wild oats.
fungicides
Disease may be controlled for up to four weeks with use of foliar
fungicides. Repeat applications may be necessary if infection occurs early.
Withholding periods must be considered.
Other comments
28
Disease promoted if temperature is 15°C to 22°C and conditions are moist.
Leaf and stem rust in oats look similar. Leaf rust pustules are smaller and
rarely found on stems but do move to leaf sheath later in the season.
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Septoria Leaf Blotch, Septoria avenae
Severity
Septoria causes leaves, and in severe cases panicles, to turn reddish brown,
reducing visual quality. The spores are splash dispersed and continue to
move up the plant if climatic conditions are conducive.
Source and spread
Stubble, wind, rain splash.
Main hosts
Oats.
Plant part attacked
Leaves and stem.
Symptoms
Leaves have dark, elongated spots with a yellow surround.
Entire leaf can die.
Stem can be infected and lodging may result.
Control methods
rotations &
variety choice
Sow partially or resistant varieties resistant varieties.
Avoid sowing into or near infected stubbles.
Do not grow oats continuously.
time of sowing
In high rainfall areas, do not sow early.
stubble
management
Burn or bury infected stubbles.
fungicides
Propiconazole is a fungicide registered to suppress Septoria in oats.
Withholding periods must be considered.
Other comments
Early infections of Septoria can be confused with Pyrenophora leaf blotch.
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Pyrenophora Leaf Blotch, Pyrenophora avenae
Severity
Source and spread
Main hosts
Plant part attacked
Symptoms
Control methods
Other comments
Seedlings have purple irregular spots that can spread to the upper leaf
canopy when cool moist conditions persist.
Infected seed.
Oats.
Leaves.
Pyrenophora symptoms are small reddish purple oval lesions. Cold wet
conditions favour the development of this disease. As the season
progresses, the crop generally recovers with the upper leaf canopy free of
disease. Hence visual hay colour is not usually affected.
Seed treatment, sanitation, rotation, and cultural methods to promote rapid
seedling development.
This disease is a minor problem in oats and generally does not require
control. Symptoms may be confused with Septoria.
Red Leather Leaf, Spermospora avenae
Severity
Source and spread
Main hosts
Plant part attacked
Symptoms
Control methods
rotations &
variety choice
stubble
management
Other comments
30
Very little is known about this disease but it is known to be favoured by
cool, moist conditions.
Stubble, spread by rain splash.
Oats.
Leaves.
Leaf symptoms begin with yellow circular areas.
Red/brown areas that may cover the majority of the leaf area
surround lesions.
Plants may be stunted.
Avoid susceptible varieties in areas where the risk is high.
Burn or bury infected stubbles.
Disease more likely to occur in high rainfall areas.
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Leaf and stem diseases - bacteria
Fungicides are not effective in controlling bacterial diseases such as halo and stripe blight,
collectively referred to as bacterial blight; genetic resistance is the only option to provide plant
protection to this disease.
Bacterial Blight, Pseudomonas syringae
Halo blight
Pseudomonas syringae
pv. coronafaciens
Stripe blight
(Bacterial stripe)
Pseudomonas syringae
pv. striafaciens
Symptoms - leaves will
have light green oval
spots up to 10mm,
surrounded by yellow
areas, which can join
together to form
blotches on the leaf.
Symptoms - leaves
have brown stripes
surrounded by narrow
yellow edges.
Leaves wither and die.
Severity
Bacterial blight is prevalent early in the growing season when conditions are
cool and moist. Two forms, halo and stripe, are collectively known as
bacterial blight. Symptoms can either be brown oval lesions or brown
stripes on the leaves. Eventually the brown areas disintegrate to form
‘windows’. Symptoms often become apparent after a frost. As the growing
season progresses, plants generally grow away from this disease.
Source and spread
Transfers on tyres, stubble, seed, spread by rain splash and insects.
Main hosts
Oats.
Plant part attacked
Leaves.
Control methods
rotations &
variety choice
Avoid susceptible varieties. Genetic resistance is an option for
plant protection.
Avoid sowing into infected stubbles.
stubble
management
Burn or bury infected stubbles.
clean seed
Do not use seed from infected crops.
Other comments
Common early in the season when conditions are wet and cool.
Paddock hygiene is important.
To prevent disease spread paddock operations should be avoided after frost
or when leaves are wet.
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Leaf and stem diseases - viruses
Barley Yellow Dwarf Virus
Severity
Barley yellow dwarf virus (BYDV) is prevalent in high rainfall areas.
Aphids introduce and spread the virus in the crop.
Source and spread
Volunteers, spread by aphids.
Main hosts
All cereals, many grass weeds.
Plant part attacked
Leaves.
Symptoms
Yellowing of leaves begins at the tips, yellow stripes extend to the base,
and leaves turn red.
Symptoms may not be evident until sometime after the initial infection.
More commonly seen in patches, especially at paddock margins.
Early infection results in dwarfing of the plant and sterile panicles.
Control methods
rotations &
variety choice
Sow resistant or tolerant varieties.
time of sowing
Avoid early growth coinciding with periods of peak aphid activity.
weed control
Tillage, grazing and chemical controls of weeds and volunteers over
summer to reduce aphid build up.
control of insects
Chemical control of aphids.
Other comments
32
Disease transmitted by aphids.
More prevalent following an early break in the season.
Can be confused with nutrient deficiencies, red leather leaf
and waterlogging.
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Root Diseases - nematodes
Nematodes that infect oats are small and usually about 0.2 mm long. They cause major soil-borne
diseases limiting dry matter production and grain yield in certain areas throughout Australia.
Oat varieties differ in their ability to host nematodes. Resistant varieties act as excellent breakcrops
limiting nematode multiplication, while susceptible varieties increase the severity of the disease.
However, varieties also differ in their ability to develop normally and produce hay in the presence of
the nematode. Tolerant varieties will develop normally in the presence of high nematode populations
but in the same situation intolerant varieties would have poor growth or could even die.
Therefore, if nematodes are a problem it is advisable to select a variety with both resistance and tolerance.
Cereal Cyst Nematode, Heterodera avenae
Severity
Source and spread
Main hosts
Plant part attacked
Symptoms
Control methods
rotations &
variety choice
time of sowing
weed control
soil fertility
Other comments
Cereal cyst nematode (CCN) causes stunted root systems, resulting in
reduced plant growth and yellowed leaves.
Oat varieties can be resistant or susceptible to CCN (a variety’s ability to
control nematode numbers). They are also tolerant or intolerant to CCN
(relating to the variety’s ability to yield when nematodes are present).
Severe infestations cause seedling death in intolerant oat varieties.
Soil, weeds, volunteers. Spread by cultivation.
Susceptible cereals - wheat, barley, oats, wild oats.
Roots.
Yellow or pale green patches appear in crops in early winter.
Stunted plants.
Fewer tillers.
Patches 1m to over 100m in diameter.
Shallower root systems.
Oats have thickened roots but no knotting.
White cysts, about 1mm in diameter, appear on roots 11 to 13 weeks
after sowing.
Disease break - at least 1 out of every 2 years with non cereals or
resistant cereals.
Resistant varieties prevent CCN build-up.
Tolerant varieties have a lower yield loss when CCN is present.
Both resistance and tolerance reactions are reported for all oat varieties
released in Australia from the National Oat Breeding Program.
Early sowing helps reduce yield loss by allowing good crop establishment
before large numbers of nematodes hatch.
Tillage, grazing and chemical control of host plants in breakcrops
and pastures.
In fertile soils, plants with well established roots obtain nutrients and have a
better recovery.
CCN can be more of a problem in alkaline, sandy or less fertile soils.
Reduced soil disturbance decreases CCN numbers.
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Stem Nematode, Ditylenchus dipsaci
Severity
Limited in its distribution but devastating to oat crops when present. This
nematode causes multi-tillering and swelling at the base of the seedling,
leaf crinkling, and severe dwarfing of plants. An intolerant variety affected
by stem nematode could result in crop failure.
Source and spread
Soil, stubble, seed.
Main hosts
Oats, wild oats, faba beans, peas, chickpeas, vetch, three horned bed straw
and some other broadleaf weeds.
Plant part attacked
Crown/stem base.
Symptoms
Multiple, stunted tillers.
Poor emergence in soils where nematode numbers are high.
Often seedlings of intolerant varieties do not survive and plants that
survive frequently do not produce panicles.
Control methods
rotations &
variety choice
Disease break - avoid successive susceptible hosts especially prior to oat
crops. Where damage has been severe, avoid a susceptible and intolerant
crop for three or more years, growing resistant oats or other cereals.
Field peas and chickpeas will prevent nematode numbers increasing, but
are very intolerant and can suffer significant losses.
Faba beans are more tolerant than peas but are susceptible allowing
populations to multiply.
weed control
Control susceptible host plants in breakcrops and pastures.
hygiene
Avoid spreading infested plant material by cleaning equipment before
leaving infested paddocks and by minimising soil movement and erosion.
Other comments
34
Stem nematode prefers heavy soils.
Dry years favour survival in the absence of a host.
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Root Lesion Nematode, Pratylenchus thornei, Pratylenchus neglectus
Severity
Root lesion nematode (RLN) prunes the plant’s root system resulting in
thin stands of yellowing plants. Less is known about the resistance and
tolerance reactions to RLN in oat varieties than for CCN and stem
nematode, but differences have been demonstrated between varieties.
Source and spread
Soil, weeds, volunteers.
Main hosts
Wheat, barley, canola, vetch, medic, chickpeas, corn, oats, many grass and
broadleaf weeds.
Plant part attacked
Roots.
Symptoms
Different species of Pratylenchus have similar symptoms.
Stunted plants.
Plants prone to wilting.
Yellow lower leaves in some varieties.
Fewer lateral roots.
Black or brown lesions on roots.
Control methods
rotations &
variety choice
weed control
tillage
soil fertility
Other comments
Disease break – avoid successive susceptible hosts.
In the year before growing oat hay grow resistant cereals, lupins, field peas
and faba beans (moderately susceptible to P. thornei but resistant to
P. neglectus).
Grow cereal varieties with resistance and tolerance where nematode
numbers are high.
Control susceptible weed species and volunteers in pastures or
non-host crops.
Nematode survival is greatly reduced where soils are cultivated dry but the
risk of soil erosion should be evaluated.
Application of ammonium based fertiliser reduces root invasion by
nematodes, as ammonium compounds are toxic to nematodes.
Good nutrition encourages healthy plants with greater tolerance to
root damage.
Root lesion nematodes multiply most rapidly in plant roots growing in
warm soils and can produce three to four generations in a year.
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Root and crown diseases
Rhizoctonia Root Rot, Rhizoctonia solani
Severity
An on-going concern in many areas as it is difficult to predict its
occurrence and severity. Control options are limited and may only provide
partial reduction in disease expression and yield loss.
Source and spread
Soil, plant roots.
Main hosts
All plants are hosts to some degree.
Plant part attacked
Roots.
Symptoms
Bare patches in crops.
Stunted growth.
Root rotting, causing ‘speared tips’.
Pale plants.
Shorter root systems.
Oats are marginally more tolerant than triticale and wheat. While barley is
the most susceptible of all the cereals.
Control methods
weed control
Grass weed control is essential before cereals.
At least two weeks prior to sowing, remove all green growth.
tillage
Minimise time between cultivation and seeding.
The ability of the fungus to cause infection is greatly reduced by deep
cultivation prior to or at sowing.
soil fertility
Improving soil fertility will help plants tolerate root damage.
Other comments
36
Rhizoctonia is most common in low fertility soils such as calcareous or
slightly acid sands.
Direct drilling can increase the risk of rhizoctonia.
Sulfonylurea herbicides should be avoided on alkaline soils as this can
result in increased rhizoctonia in barley sown in the following year.
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Take-all, Gaeumannomyces graminis var. avenae
Severity
Wet springs in the year prior to sowing tend to increase inoculum levels
so severity is seasonally dependent. Only the oat attacking strain
Gaeumannomyces graminis var. avenae causes significant yield reduction
in oats.
Source and spread
Soil, stubble, weeds, volunteers.
Main hosts
Wheat, barley, oats, triticale, barley grass, brome grass, silver grass.
Plant part attacked
Roots.
Symptoms
Early in the season plants can be stunted and pale.
Reduced tillering.
White heads.
Black lesions in centre of root; seen when snapped open.
Blackening of crowns and lower stems in severely infected plants.
Control methods
rotations &
variety choice
A one year disease break before sowing oats for hay. Breakcrops include
pulse crops, oilseeds, oats (for non-oat attacking strain), grass-free pasture
or fallow, cereal rye.
Systems that increase microbial activity can suppress the take-all fungus.
After liming, non-hosts should be considered.
time of sowing
Delayed sowing helps to reduce the impact of the disease.
stubble
management
Encourage decomposition of stubble prior to sowing susceptible cereals.
weed control
Grass hosts and volunteer cereals should be removed early in the break year.
seed dressing
Seed dressings offer some degree of protection.
soil fertility
Plants low in phosphorus, nitrogen and manganese are more susceptible
to take-all.
Take-all is suppressed in soils with low pH (acid soils)
fungicides
Fungicides can be used in furrow and on seed.
Other comments
Moist but well-drained alkaline soils favour growth of the fungus.
Wet springs cause the disease to build-up, while summer rains reduce it.
Take-all can be confused with crown rot and common root rot, which also
causing white heads.
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Crown Rot, Fusarium pseudograminearum, Fusarium culmorum
Severity
Oats are susceptible but tolerant so do not display any symptoms of this
disease; however, they can result in a small carryover of inoculum.
Source and spread
Soil, stubble.
Main hosts
Wheat, barley, oats, triticale, barley grass, other grass weeds.
Other comments
Crown rot only needs to be considered in the terms of the whole rotation.
Most commonly observed to cause severe damage following dry conditions
in spring.
Initial infection of plants is favoured by wet conditions, but the fungus
grows rapidly when plants are moisture stressed.
Damage may occur on all soil types, but is more severe on heavy soils.
Image 4.1 Severe Septoria infection in a susceptible oat variety grown in WA.
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Chapter 5
Variety selection for
hay production
Choice of variety has a major influence on hay
quality. Disease resistance or susceptibility in
relation to the growing regions’ disease pressures
need to be considered when selecting a variety.
Other considerations are time of maturity, yield
and market objectives as these factors can also
impact on hay quality.
The following information provides a brief
summary of the characteristics of oat varieties
most suited to hay production and commercially
available in Australia at the time of publication.
It is based on varieties that have been tested as
part of the National Oat Breeding Program
funded by RIRDC and GRDC. Information
on each variety is available on release from the
respective breeding programs, licensee or seed
companies. A more comprehensive variety
guide is published annually on the SARDI
website www.sardi.sa.gov.au (search in
publications for Oats – sowing guide).
Oat varieties that have been bred for grazing
or grain production may also be made into
hay; these include varieties such as Bulban,
Coolabah, some of the Graza varieties
and Volta.
Quality and yield sit on either end of the see-saw.
In terms of variety selection, if a balance
between these characteristics is to be achieved,
then variety maturity in relation to rainfall needs
to be considered. Generally, early maturing
varieties are more suited to hay production in
low rainfall areas, while late maturing varieties
perform well in higher rainfall areas with a longer
growing season, (Table 5.2). However, late
season varieties generally have poorer early vigour
and competition with weeds such as ryegrass is
reduced. If sown late they can suffer yield loss
from an early spring cut-off and they generally
mature later than key grass weeds, allowing
ryegrass, wild oats, barley and brome grasses to
set seed. In favourable seasons late maturing
varieties can produce higher yields and better feed
test results than early and mid season varieties.
BassA
Bass was released by the Tasmanian Department
of Agriculture in 1998 as a grazing variety. It has
also been used to produce hay in high rainfall
regions. Bass is a very late maturing with poor
early vigour. It was released as a replacement
for Esk.
Image 5.1 Oat variety trials are run across the western and southern region of Australia by the National Oat Breeding Program.
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Bettong
Bettong was developed by Texas A&M University
and jointly released in Australia. It is a tall
mid-season variety with poor early vigour. It
has good resistance to a wide spectrum of foliar
diseases. Although Bettong maintains good
colour, hay produced from the variety was found
to be unpalatable in the export market.
Glider
Glider was a joint release by SARDI and Texas
A&M University in 1999. It is a late maturing
hay variety adapted to high rainfall (>500mm)
areas. Glider has poor early vigour and heads
about two weeks later than mid season varieties.
It has excellent foliar disease resistance and
plant colour.
BrusherA
Brusher is a hay variety developed by SA
Research and Development Institute (SARDI)
and commercialised by AEXCO in 2004.
Brusher is a tall line, heading about three to four
days earlier than Wintaroo, with good early
vigour. Brusher is moderately intolerant to
CCN. When there are high levels of the
nematode in the soil and favourable seasonal
conditions Brusher will have significantly lower
hay yield than tolerant varieties. Brusher has
consistently higher digestibility than current
early to mid season oat varieties and is adapted
to low, medium, and high rainfall areas. It has
moderately low grain hull lignin.
Graza 50A
Originally commercialised by Pioneer Seeds,
Graza 50 is a tall, late maturing variety released
for grazing. It has also been used for hay
production where a late variety was needed.
Graza 50 produces coarse stems when grown
for hay.
CarrolupA
Carrolup was released as a milling variety in 1993
by the Department of Agriculture Western
Australia. It is a medium tall early to mid season
variety that has been widely grown in Western
Australia (WA) for hay production. Although
Carrolup was developed as a grain variety, its
hay quality is similar to other early to mid season
hay varieties. Carrolup is very susceptible to
leaf rust.
Eurabbie
Eurabbie is a dual purpose dwarf oat variety
released by New South Wales Department of
Primary Industries for grazing and feed grain
production. It is a mid season hay variety but a
mid to late grain variety. Eurabbie has potential
for hay production in high rainfall areas,
particularly New South Wales (NSW). Eurabbie
has excellent hay quality characters.
40
KangarooA
Kangaroo is a hay variety commercialised from
the SARDI Oat Breeding Program by AEXCO in
2006. It is a tall, mid to late season variety with
good early vigour, heading about four days later
than mid season varieties. Kangaroo has good
foliar disease resistance combined with good
nematode resistance and moderate tolerance.
It has high grain hull lignin. Hay cut from this
variety tends to be high in neutral detergent fibre
(NDF) and lower in water soluble carbohydrates
(WSC), therefore careful management is required.
Lampton
Lampton is an old, very tall, late maturing variety
grown in Victoria. It has good stem colour and
quality. It will lodge in some seasons, particularly
if sown early.
Marloo
Marloo was released by the Department of
Agriculture, South Australia in 1987 as a CCN
resistant and tolerant hay variety. It is a tall, mid
season variety with good early vigour. Marloo is
sensitive to dry, hot northerly winds resulting in
leaf browning.
RielA
Riel was developed in Canada and released by the
Department of Primary Industries Queensland in
1993 for grazing. It is a tall, late maturing variety
with reasonable early vigour and fine stems when
grown for hay production.
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Swan
Swan is a tall mid season variety, released in 1967
by Department of Agriculture, Western Australia.
Swan has excellent early vigour and high hay
yield. It produces coarse stems and often lodges
in high rainfall regions. Swan is very susceptible
to stem rust.
VasseA
Vasse was released by Department of Agriculture
Western Australia in 1997 as a hay variety. It is a
‘tall dwarf ’, late maturing variety adapted to high
rainfall, long season areas of WA. Because its
stem diameter tends to be coarse, it is not sought
after for the export market.
TargaA
Targa was released by the Tasmanian Department
of Agriculture in 1999 as a grazing variety. It has
been used for hay production in high rainfall
regions, but has a tendency to lodge. Targa is a
very late maturing variety with poor early vigour.
It was released as a replacement
for Esk.
Wallaroo
Wallaroo was released by the Department of
Agriculture, South Australia in 1987 as a CCN
resistant and tolerant hay variety. It is an early
variety suited to the low to medium rainfall areas.
Wallaroo is a tall variety with good early vigour.
WanderingA
Wandering was released by Department of
Agriculture Western Australia in 1999 as a feed
variety. It is a mid season, dwarf variety adapted
to medium and high rainfall regions of WA.
It has been used to produce hay, but often
produces thick stems.
Winjardie
Winjardie was released by Department of
Agriculture Western Australia in 1985 as a hay
and feed grain variety. It is a tall, early to mid
season variety adapted to low, medium, and
high rainfall regions of WA. It was commonly
grown in northern WA, but susceptibility to
septoria has reduced the use of this variety for
hay production.
WintarooA
Wintaroo is a hay variety developed by SARDI
and commercialised by AEXCO in 2002. It was
released as a replacement for Marloo. Wintaroo
is a tall, mid season oat with good early vigour. It
resists brown leaf tipping by hot northerly winds
better than other varieties and is adapted to low,
medium, and high rainfall locations. Wintaroo
also has low grain hull lignin making it an option
for feed grain. Wintaroo maintains good colour
longer than most varieties, so care is needed to
assess the crop for optimum cutting time to
ensure good quality.
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Plant breeders rights
(PBR)A
Plant Breeder’s Rights (PBR) were introduced to
stimulate private investment in plant breeding by
conferring ownership rights to varieties and
thereby the potential to market those rights as
part of a commercialisation process.
The Plant Breeder’s Rights Act 1994 as amended
Act No:148 2002 gives an owner of PBR the
exclusive right to sell, produce or reproduce,
import, export, stock or condition the seed of
a variety protected by PBR (or license another
person or organisation to undertake
these activities).
PBR protection can last up to 20 years for
broadacre crops and guarantees ownership of a
variety but does not specify how the variety
should be commercialised or whether or where
royalties should be charged.
Royalties
The concept generally referred to as ‘end-point
royalty’ (EPR) collection gives the licensee the
right to collect royalties on the production of hay
from oat varieties protected by PBR.
When purchasing seed farmers should read
carefully any documentation provided to be fully
aware of the conditions of sale. While the
restrictions in the use of seed under the PBR
Act are clearly defined, other contractual
arrangements may have been imposed by the
licensee following agreement by the owners.
An example of royalties applied to oat hay is
reported on the section on AEXCO.
Australian Exporters Company Pty
Ltd (AEXCO)
Established in 2000 Australian Exporters
Company Pty Ltd (AEXCO) is a consortium of
hay exporters in Southern Australia that is able
to tender for the commercialisation rights of
specialist hay varieties being developed by the
42
South Australian Research & Development
Institute (SARDI) Oat Breeding Program. At
present AEXCO consists of 14 shareholders
situated in SA, WA, Victoria and Southern NSW.
AEXCO has successfully tendered for the
commercialisation rights to three varieties Wintaroo, Brusher and Kangaroo.
AEXCO has an agreement with the Australian
Field Crop Association (AFCA) for the seed
production of these cultivars, whereby ‘Basic
Seed’ is supplied to one grower who produces
‘Certified Seed’. The Certified Seed is then
distributed to other AFCA members who grow
‘Commercial Seed’ from fields that have been
independently inspected and approved for the
production of Commercial Seed. Before being
offered for sale Commercial Seed is cleaned and
then each seed-lot tested for germination
and purity.
As the varieties, Wintaroo, Brusher and
Kangaroo are marketed under a Plant Breeders
Rights (PBR) system, they are subject to the
royalties on the following page.
It is important to note that varieties with PBR
protection can only be bought from the owner,
commercial partner/licensee or an agent (seed
merchant) authorized by the owner.
Growers cannot sell, trade or give away the
variety for seed. Penalties for breaches of the
PBR Act are $50,000 for an individual and
$250,000 for a company.
From the $1.00/tonne collected by AEXCO a
50 cent royalty is paid to the variety owners
SARDI and RIRDC to further the breeding
program whilst the other $0.50 is retained for
administration costs.
AEXCO is a “not for profit” organisation. As
tonnages of hay delivered and seed sold increase,
funding grants could be made to enhance the
work of the National Oat Breeding Program to
improve the oat hay industry.
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Seed purchased for sowing to produce export hay under contract
No Royalty charge.
Seed purchased for domestic use
Royalty charge $55.00 per tonne
including GST. No further
charges are applicable.
Export hay delivered to hay processing plant
Royalty charge $1.10 per tonne
including GST.
Sunset Clause: Seed purchased for domestic use (with royalty
paid) but delivered as export hay in the second year will attract
the end point royalty of $1.10 per tonne.
Table 5.1 Average predicted hay yield for selected varieties in Western Australia (WA),
South Australia (SA) and Victoria (VIC) from 1998-2004 – source SARDI, National Oat Breeding Program.
Variety
Bettong
Brusher
Carrolup
Eurabbie
Glider
Kangaroo
Marloo
WA
9.2
9.8
9.7
9.1
9.2
9.7
9.3
Hay yield - t/ha
SA
9.1
9.5
9.1
9.3
9.6
9.2
VIC
10.5
10.7
10.4
10.6
10.8
10.4
Variety
Riel
Swan
Vasse
Wallaroo
Wandering
Winjardie
Wintaroo
WA
9.6
9.6
9.6
9.6
9.6
9.7
9.9
Hay yield - t/ha
SA
9.8
9.4
9.3
9.8
VIC
10.5
10.5
11.0
Table 5.2 Predicted hay yield for selected varieties grown in Western Australia, South
Australia and Victoria, 1998-2004, by rainfall and maturity. The number of observations
is in italics – source SARDI, National Oat Breeding Program.
Variety
Bettong
Brusher
Carrolup
Eurabbie
Glider
Kangaroo
Marloo
Riel
Swan
Vasse
Wallaroo
Wandering
Winjardie
Wintaroo
<375mm
6.1
18
6.5
25
6.4
1
6.0
23
6.2
25
6.5
21
6.1
25
6.3
25
6.3
1
6.3
25
6.3
1
6.4
1
6.7
25
Hay yield - t/ha
375-500mm
8.9
21
9.3
25
9.3
2
8.8
23
8.9
25
9.1
22
9.4
25
9.0
2
9.2
25
9.2
2
9.2
25
9.2
2
9.3
2
9.6
25
>500 mm
12.3
23
12.7
35
12.1
34
12.2
35
12.4
29
12.7
35
12.3
1
12.5
35
12.5
35
12.9
35
Maturity
M
EM
EM
M
L
ML
M
L
M
L
E
M
M
M
Key to Maturity scores: E - early, EM - early to midseason, M - midseason, ML - mid to late season and L – late.
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Table 5.3a Disease reactions for oat varieties used for hay production.
Where no data is available for a disease a dash is used.
Disease reactions may be different depending on the region.
Colours associated with varieties indicated the highest level of resistance available
for the priority diseases in different regions as illustrated in figure 4.1 –
source SARDI, National Oat Breeding Program.
Variety
Bass
Bettong
Brusher
Carrolup
Eurabbie
Glider
Graza 50
Kangaroo
Lampton
Marloo
Riel
Swan
Targa
Vasse
Wallaroo
Wandering
Winjardie
Wintaroo
CCN
Stem
R
T
rust
VS
I
S
R
VI
MS
R MI
MS
S
I
MS
MS MI
S
MS
I
R
VS MI
S
R MT MR
MR I
MS
R MT
S
MR I
R
MR I
S
MR I
S
VS MI
S
R MT
S
VS
I
S
S
I
S
R MT
S
Leaf
Bacterial
Stem
BYDV
Septoria
rust
blight nematode
VS
MS
I
R
MR
MR
T
MS-MR
R
MS
MS
I
MS-MR
VS
MI
MS
I
S
S
MS
S
MI
MS
R
MS
R
T
MR
S
MR
I
MR
MR
MR
MS
MT
MR
MR
R
S
MS
VS
MI
S
R
I
S
MR
MS
I
MS
S
MS
MT
MS
MR
MS
MI
MS
S
MS
MS
MI
S
S
MR
MR
MI
MR
VS MS/MR
I
S
MS
MR
MR
T
MR
Red leather
leaf
MS
S
R
MR
S
S
S
MS
Table 5.3b Disease reactions for oat varieties bred for grazing or grain but possibly used
for oat hay production – source SARDI, National Oat Breeding Program.
Variety
CCN
R
T
Bulban
Coolabah
Esk
Graza 68
Gwydir
Warrego
S
S
R
R
S
S
VI
VI
I
I
I
I
Stem
rust
Leaf
rust
BYDV
MS
S
S
S
R
R
S
S
S
S
R
R
MS
MR
R
R
Bacterial
Stem
Septoria
blight nematode
-
MI
I
VI
VI
MS
S
-
Red leather
leaf
-
Key to Tables 5.3 a & b:
Disease names: CCN - cereal cyst nematode, BYDV - barley yellow dwarf virus
Disease reactions: R - resistant, MR - moderately resistant, MS - moderately susceptible, S - susceptible, VS - very susceptible, T - tolerant, MT moderately tolerant, MI - moderately intolerant, I - intolerant, and VI - very intolerant.
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Table 5.4a Agronomic and hay quality characters for oat varieties grown for hay –
source SARDI, National Oat Breeding Program.
Variety
Bass
Bettong
Brusher
Carrolup
Eurabbie
Glider
Graza 50
Kangaroo
Lampton
Marloo
Riel
Swan
Targa
Vasse
Wallaroo
Wandering
Winjardie
Wintaroo
Height
Early
vigour
T
MT
T
T
D
T
T
MT
VT
T
T
T
T
D
T
D
T
T
9
7
3
3
7
8
7
3
7
3
5
2
8
4
3
1
6
3
Maturity Digestibility
L
M
M
M
EM
MH
EM
M
M
H
L
H
L
MH
ML
M
L
M
M
L
MH
M
M
VL
M
L
M
E
M
EM
M
M
M
M
M
Hay quality
Crude
WSC protein ADF
ML
L
M
MH
MH
M
M
M
M
M
H
M
L
H
M
ML
ML
ML
M
MH
M
M
M
H
M
L
M
ML
M
ML
H
M
M
M
M
M
M
M
M
MH
M
M
M
M
M
Stem
Hull
NDF diameter lignin
MH
M
M
L
ML
MH
M
L
M
M
M
M
M
M
C
F
F
F
F
F
C
F
F
F
F/C
F
C
F
C
C
F
H
ML
H
ML
ML
H
M
segregating
M
H
H
L
H
L
L
Table 5.4b Agronomic and hay quality characters for oat varieties bred for grazing or
grain production but sometimes grown for hay – source SARDI, National Oat Breeding Program.
Variety
Bulban
Coolabah
Esk
Graza 68
Gwydir
Warrego
Height
Early
vigour
T
T
T
T
T
T
3
8
8
6
6
4
Hay quality
Stem
Hull
Maturity DigestCrude
diameter lignin
ibility WSC protein ADF NDF
L
M
VL
L
L
L
M
M
M
M
-
ML
M
ML
M
-
-
C
C
F
C
C
C
L
MH
L
L
MH
H
Key to Tables 5.4 a & b:
Height: T - tall, MT - medium tall, D - dwarf;
Early vigour scores: 1 - excellent early vigour and 9 - poor;
Maturity scores: E - early, EM - early to midseason, M - midseason, ML - mid to late season, L - late, and VL - very late;
Hay quality: WSC - water soluble carbohydrate, ADF - acid detergent fibre, NDF - neutral detergent fibre;
Hay quality scores: H - high, MH - medium high, M - medium, ML - medium low, and L - low; Stem diameters: F - fine and C - coarse;
Hull lignin - the amount of lignin found in the hull of the grain: L - low, M - medium, and H - high.
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Chapter 6
Growing the crop
Paddock selection
Impact on hay quality
• Feed test
• Colour
• Contamination
• Toxins
Nutrient status
Paddocks with high nutrient status soils tend
to produce bulk rather than quality hay. In
nutritional terms the criteria for paddock
selection are moderate fertility of less than
80kg/ha of available nitrogen in the top 60cm
at seeding; similar fertility for a crop of malting
barley. Where possible avoid soils that are
expected to have high nett mineralisation rates,
such as paddocks containing pulse and pasture
legume stubbles.
Water soluble carbohydrates will be suppressed in
oat crops that have too ready access to nitrogen,
especially during early growth. The components
of the feed test are expressed as a percentage
(Table 3.3). Therefore, as the percentage of
water soluble carbohydrates falls the percentage
of fibre rises, both of which have a negative
impact on hay quality, especially for the export
market. At stem elongation, lush crops that often
occur due to early sowing, high nitrogen nutrition
or warm winters, have an increased internode
length, which tends to favour the accumulation of
fibre and lignin. In these tall crops sunlight has
difficulty penetrating the canopy resulting in
senescence of lower leaves and the destruction of
chlorophyll in stems, often resulting in hay with
poor colour. Lodging is more likely to occur.
Slope/orientation
Maturity differences and wind damage can occur
between north south or west east facing slopes.
North facing slopes receive more solar radiation,
so crops will mature faster, while in some regions
crops grown on western slopes suffer more rain
damage. Where practical changing variety or
adjusting cutting time may be beneficial. For
example, bacterial blight is usually more severe
where frosts or wind borne rain occur.
Prevailing winds
Paddocks prone to regular warm to hot winds
during spring can result in levels of brown leaf
that are unacceptable to the premium hay
market. Varieties differ in their response to
hot wind damage, so variety selection should be
considered. For example, Wintaroo, Glider,
Kangaroo and Riel are varieties that are less
susceptible to brown leaf tipping due to hot
winds, while Marloo and Potoroo are more
susceptible. As variety selection for hay end
use continues it is expected that most of
these varieties will be able to hold green leaf
better than those selected primarily for grain
production.
Image 6.1 Varieties differ in their response to hot wind
damage, so variety selection should be considered.
Browning of the flag leaf can result in hay with
poor visual quality.
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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).
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
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.
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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.
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Sowing date needs to be matched to variety
maturity for the different rainfall zones and to the
likelihood of rainfall at the potential cutting date.
Early maturing varieties (see Table 5.2) will be
compromised in a high rainfall area due to the
increased risk of weather damage on the cut hay.
Conversely late maturing varieties in low rainfall
districts are more prone to damage by heat and
moisture stress.
If varieties with different maturities are being
sown in districts with the same rainfall late
maturing varieties will usually be sown first. In a
500mm rainfall district delaying seeding by 7 days
will generally delay cutting by 1 to 1.5 days.
Maturity differences between varieties are greater
than maturity differences for the same variety
sown at different times.
Diseases such as bacterial blight and septoria can
cause leaf damage, especially in higher rainfall
regions, with earlier sowing.
A relationship between sowing date and nitrogen
rate has been established (Figure 6.2).
Hay needs to be clean and weed free, so seeding
date may be dictated by the need to wait for
weeds and volunteers, especially barley and
wheat, to germinate.
Seeding rate
Impact on hay quality
Image 6.3 Examples of different variety seed sizes.
Low plant populations can produce hay crops
with thicker stems that are more susceptible to
weed competition. The former increases the
fibre content, whilst the latter increases the
potential for spoilage and contamination.
Modest nitrogen regimes have a negative impact
on yield compared to higher nitrogen regimes.
However, this can be counteracted by increasing
plant populations without being detrimental to
hay quality (Table 6.2). High plant populations,
especially in combination with high levels of
nitrogen, are more prone to: lodging, bleaching
of lower stems producing poor visual
characteristics, wind scorch of leaves in spring
and suppressed water soluble carbohydrates.
Table 6.1 Target plants per square metre
by rainfall (winter and spring rainfall
dominant regions) and soil fertility –
• Stem diameter
• Weed competition
source Agrilink Agricultural Consultants.
• Colour
Generally seeding rates for hay are 30 to 50%
higher than for grain crops grown in the same
rainfall district. This is because hay is cut before
grain fill and generally will be harvested before
moisture stress occurs; also because denser crops
have thinner stems that are more desirable to the
export market. Seed size varies between varieties
(Image 6.3), so it is important to calculate seeding
rates based on the seed 1000 grain weight. For
example in the experiments reported in Table 6.2
the 1000 grain weight for Brusher was
32.8g/1000 grains, for Wintaroo 36.8g and for
Graza 50 only 26.0g.
Rainfall
Soil nitrogen fertility
High
Average
Low
<350mm
120-160
150-180
150-200
350-425mm
160-200
180-220
200-240
425-500 mm
200-220
220-250
240-280
>500 mm
210-230
250-280
250-300
When varieties with poor early vigour are grown
(Table 5.4) seeding rates can be increased by
20 to 30% to compensate. This recommendation
should be tempered in soils with high fertility.
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Higher plant populations produce higher yield
but plant populations need to be matched to
rainfall and soil fertility (Table 6.1).
A relationship between seeding rate, nitrogen rate
and variety has been established. Trials were
sown at Mintaro, SA (450mm rainfall) in 1999
and 2000 to compare the early to mid maturity
variety Brusher with the late maturing variety
Graza 50. Both varieties were sown at 200, 300
and 400 seeds per square meter, so differences
in seed size were eliminated. Seven nitrogen
treatments were applied at seeding either by
broadcasting or deep banding (0, 25, 50, 75, 100,
125, and 150kg/ha). In both years these seeding
rates, which are considered to be high to very
high did not result in a change in feed test results.
However, in 1999 as seeding rate increased shear
energy was reduced.
Where row spacing is wider than 22.5cm
(9 inches) the risk of reducing hay quality
increases due to:
• high concentrations of plant nitrogen;
• increased weed competition and contamination
in the cut hay;
• cut hay hitting the ground and becoming
contaminated with soil.
Where seeding equipment has 30cm (12 inch)
spacing some growers cross-seed to produce a
row spacing of 15cm (6 inches). However,
considerations about row orientation, (see
Seeding direction) must be taken into account.
The use of high accuracy (2cm) GPS autosteer
systems may allow a second pass to be sown
between the rows of the first pass to produce a
15cm spacing.
Further research is required to help develop
variety specific management recommendations.
Row spacing
Impact on hay quality
• Weed competition
• Feed tests
• Colour
• Staining and moulds
To optimise hay yield and quality, a row spacing
of 7.5cm (3 inches) was found to be ideal.
At this row spacing plants have better weed
competition and better access to nutrients. The
density of stems across the paddock is high and
when cut these stems better support the cut hay
off the ground minimising the risk of soil
contamination and uneven curing.
Image 6.4 A row spacing of 7.5cm (3 inches) was found
to be ideal to optimise hay yield and quality. Where
equipment has 30cm (12 inch) spacing cross-seeding,
as pictured, or the use of 2cm accuracy auotsteer to inter
row seed are methods of reducing row spacing to 15cm
(6 inches).
In many situations a row spacing of 7.5cm is
impractical due to existing machinery set-up,
reduced emergence due to seed mixing with
pre-sowing herbicide and greater weed seed
germination due to an increased proportion of
the paddock being cultivated.
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Table 6.2 The impact of seed and fertiliser spread and row spacing on plant spacing and
theoretical nitrogen concentration in the plant – source Agrilink Agricultural Consultants.
Lateral seed spread
Tyne spacing
1
2
2.5cm (1 inch)
5cm (2 inches)
7.5cm (3 inches)
17.5cm 22.5cm 30cm 17.5cm 22.5cm 30cm 17.5cm 22.5cm 30cm
7”
9”
12”
7”
9”
12”
7”
9”
12”
% of surface covered
with stems1
17%
Theoretical change in
plant nitrogen status
from the base2
Base
0%
11%
8%
+28% +71%
33%
-10%
22%
17%
+14% +36%
50%
-25%
33%
25%
+10% +22%
The higher the percentage the lower the risk of hay hitting the ground and being weather damaged.
The greater the negative deviation from the base the better the hay quality.
Seeding direction
Impact on hay quality
• Staining and moulds
• Colour
• Contamination
When cutting the crop it is desirable to use
the remaining stubble to support the hay
off the ground (Image 6.5). This helps hay
cure evenly and contamination at baling is
minimised. Therefore, choice of seeding
direction should take into consideration the
direction that the crop will be cut.
Oat crops can be sown round and round, up
and back or diagonally. If sown round and
round the ideal is to mow the hay at 90
degrees to the longest paddock length.
Those sown up and back should be cut at
90 degrees to the direction of sowing, while
diagonally sown crops can be harvested
round and round or up and back as cutting
will always be at 45 degrees to the seeding
row (Figures 6.1a, b, c & d).
Image 6.5 Cut stubble should support hay off
the ground to improve curing and minimise soil
contamination; the choice of seeding direction to
cutting direction influences how successfully
this is achieved.
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Figure 6.1a Sown round and round – cut
round and round
With this combination more cut hay is likely to
fall between the seeding rows resulting in uneven
curing, as hay on the ground takes longer to cure
than that supported on the stubble. It also means
windrowers and rakes have to be set lower
increasing the opportunity for contaminants to
be picked up with the hay. Super conditioners
struggle to pick up hay that has fallen to the
ground. Another problem is that seed and
fertiliser rates are double on the headlands,
therefore plants in this area are likely to lodge,
have bleached stems and poorer feed test
results due to lower levels of water soluble
carbohydrates. (Figure 6.1a)
Figure 6.1b Sown up and back – cut up and
back at 90 degrees
Self propelled or swinging arm mowers allow hay
to be cut up and back. This combination of
seeding and mowing direction should ensure the
majority of hay remains off the ground.
Headland areas are minimised and bales made on
the headlands can easily be separated.
Figure 6.1c Sown up and back – cut round
and round
Off-set, ‘PTO’ driven mowers can only be used
round and round. Therefore to minimise hay
damage sowing should be done on the shortest
run and mowing round and round. (Figure 6.1b).
Figure 6.1d Sown diagonally – cut up and
back or round and round
Cutting round and round will still result in
damage on the headlands. However, sowing
diagonally minimises the risk of hay damage as
seeding and cutting operations are never in the
same direction.
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Fertiliser
Impact on hay quality
• Feed test
• Colour
Traditionally hay production used high inputs of
nitrogen to produce yield. Today’s export markets
are driven by quality, so it is recommended that
nitrogen inputs are limited and matched to
available soil nitrogen levels at seeding and the
length of the growing season.
Under low nitrogen regimes yield potential is
optimised by correct seeding rate (Table 6.3). In
low rainfall regions, where early growth is limited
due to lack of soil moisture, high levels of
nitrogen in the soil or as fertiliser have a less
negative impact on hay quality than in medium
and high rainfall regions.
A nutrient balance is one way of calculating
nutrient requirements as oat hay removes
significant quantities of all the major elements nitrogen, phosphorus, sulphur and especially
potassium. Zinc and manganese levels should
also be considered. The starting point for a
nutrient balance is the current soil nutrient status
and the predicted hay yield (Tables 6.3a & b).
Oat hay production can result in lower nitrogen
removal as uptake of nitrogen ceases when the
crop is cut (assuming there is little or no
regrowth). Highly productive cereal crops for
grain have a large uptake of soil nitrogen from
flowering to grain maturity (Table 6.3a).
Oat growth is strongly influenced by temperature
and early sown crops can generally make
adequate growth with low to moderate fertiliser
inputs at seeding. If seeding is delayed oat crops
become far more responsive to applied fertiliser
as root and aerial growth slows in response to
colder conditions.
For best results phosphorus, potassium and trace
elements required during early growth should be
applied in or under the seed row. More mobile
nutrients such as nitrogen and sulphur can be
applied during the growing season by a range
of methods. Some trace elements, such as
manganese can be rapidly immobilised in the soil,
so foliar application may be the most appropriate.
Image 6.6 The starting point for a nutrient balance is the
current soil nutrient status and the predicted hay yield. Deep
nutrient tests should be carried out in late summer to assess
levels of available nitrogen in the soil profile.
Nitrogen
At seeding nitrogen application should be
moderate (Figures 6.2, 6.3 & 6.4). Oat crops that
have ready access to nitrogen, especially during
early growth result in hay with lower levels of
water soluble carbohydrate and proportionally
higher fibre content. Both of these factors are
negative in terms of hay quality, especially for the
export market.
Research has shown that both early and late
sown crops will have lower levels of water
soluble carbohydrate when they receive over
100kg/ha of nitrogen at seeding (Figure 6.2).
In these experiments the fertiliser was either
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broadcast or deep banded at seeding. Higher
levels of seedbed nitrogen increased fibre levels,
especially in early sown crops (Figure 6.3). In
other trials high levels of seedbed nitrogen
negatively affected quality criteria, especially
ADF levels, to different degrees depending on
variety maturity (Figure 6.4). The latter results
suggest there is a need to develop specific
nitrogen management packages for varieties
with different maturities.
seedbed utilisation (SBU). It also depends on soil
type, soil moisture, fertiliser product and method
of application.
If applied in close proximity to the seed, high
rates of nitrogen at seeding increase the risk of
damage to germinating seedlings by ammonia
toxicity. The degree of damage depends on
row spacing and the lateral spread of seed and
fertiliser within a row; this is referred to as
• broadcasting after seeding with incorporation
by rainfall.
If significant nitrogen is applied at seeding,
especially as urea that converts to ammonia gas,
it should be placed away from the seed by:
• deep or side banding;
• broadcasting prior to seeding with
incorporation by seeding or rainfall; or
In the growing crop nitrogen rate and timing in
relation to crop development are important.
Table 6.3a Major nutrients removed per tonne of commodity removed kg/tonne.
Commodity
Removed
Nitrogen
Phosphorus Potassium
Sulphur
Calcium
Magnesium
Ave Range Ave Range Ave Range Ave Range Ave Range Ave Range
Oats Hay
11
8-13.5
2
1.2-2.2
20
15-30
2
1-3.5
8
5-11
8
5-11
Medic Hay
30
18-32
3
2.5-3.5
25
20-30
2
1-3.5
9
7-12
9
7-12
Wheat Grain
23
14-28
3
2-5.5
5
2.0-7
2
1-3.5
0.4 0.2-0.7 0.4 0.2-0.7
Barley Grain
20
13-28
2.7
2-5.1
5
2.0-7
2
1-3.5
0.4 0.2-0.7 0.4 0.2-0.7
Field Pea
Grain
41
35-45
4.5
3.5-7
10
8-15
4
3-6
1
0.7-2
1
0.7-2
Table 6.3b Minor nutrients removed per tonne of commodity removed grams/tonne.
Copper
Zinc
Manganese Molybdenum
Iron
Boron
Oats Hay
4
2-20
20
6-40
9
7-15
1
Medic Hay
5
2-20
20
7-40
15
10-20
1.2
Wheat Grain
3
1-30
15
7-40
30
15-80
1.8
Barley Grain
3
1-30
15
7-40
25
15-80
1.8
Field Pea
Grain
6
1.5-50
25
8-40
9
7-15
2
Little comparative
information available
Ave Range Ave Range Ave Range Ave Range Ave Range Ave Range
Range unknown
Commodity
Removed
4
2-80
25 10-100
2
1-100
2
1-100
10
2-100
Note: the figures are average removals published for southern Australian conditions.
The range represents the extremes of variation that are encountered due to soil type and nutrient level, the length of growing season and the
total yield.
Examples: 1) removals are likely to be greater where soil levels are high and conversely removals may be low where soil levels are low.
2) removals are generally higher where the growing season is longer, as significant root uptake occurs while there is adequate
soil moisture.
3) removals may be lower where yields are extremely high and dilution occurs.
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Growth stages should be used to determine
the appropriate timing for additional nitrogen
applications (see year planner). To maximise
quality any late nitrogen should be applied
between GS25 and 31. Before this stage the
nitrogen increases yield, but after this point it can
accumulate as nitrates and reduce quality.
Figure 6.3 Impact of increasing seedbed
nitrogen on neutral detergent fibre (NDF)
content of early and late sown crops source Agrilink Agricultural Consultants.
If growth rates decline or nitrogen deficiency
symptoms are observed applicaions of 25kg/ha
of nitrogen can be sufficient.
Where soil fertility is high hay crops are prone to
lodging. This causes the lower stem to be shaded
and become bleached resulting in a poor feed test
and visual assessment.
Excess nitrogen applied to the crop can
occasionally result in hay with nitrate nitrogen
levels greater than 500ppm, which is
unacceptable to many hay markets.
Phosphorus
Response of oat hay to phosphorus is similar
to cereal crops grown for grain; therefore
application rates are the same as for other
grain crops.
Figure 6.4 Interaction between variety
maturity and fibre content under increasing
regimes of seedbed nitrogen. The impact
on quality was more negative in early and
mid season varieties source Agrilink Agricultural Consultants.
Potassium
Cutting hay removes greater levels of potassium
than cereals harvested for grain. Particular
attention should be given to potassium in the
nutrient budget.
Figure 6.2 Impact of increasing seedbed
nitrogen on water soluble carbohydrate
(WSC) content of early and late sown crops
- source Agrilink Agricultural Consultants.
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Weed control
Impact on hay quality
• Contamination
• Colour
• Taints
• Toxins
Pre-seeding weed control is vital, as in-crop weed
control options are limited. Weeds not only
impact on yield but also on quality. Exporters
will have standards for acceptable inclusion of
weeds and admixture; generally it is 5% of the
hay by weight.
Non-selective knockdown herbicides are the
most economic option for pre-seeding weed
control. At the time of writing there are few
on-label herbicide recommendations for weed
control in oats or for soil active weed control
when sowing oats. Some states such as South
Australia have supplementary lists for herbicide
use in oats. Advice should be sought from your
herbicide reseller. Some herbicides used for weed
control in oat hay crops are listed in Table 6.5.
In-crop weed control should be carried out
when weeds are small and easily killed and before
GS32 to minimise the impact of crop damage in
wheel tracks.
Broadleaf and grass weeds can reduce hay quality
due to contamination and reduced visual and
sensory characteristics.
Grass weeds
Wild oats cause yield loss, increase CCN levels,
are a source of rust inoculum and have a
detrimental effect on quality due to early maturity.
Hay paddocks containing wild oats should be cut
as near as practical to the flowering stage of the
wild oats to prevent a build-up of wild oats in the
paddock and to decrease their detrimental effect
on quality. For most oat hay varieties this means
cutting the oats before flowering as wild oats
generally flower before commercial oat varieties.
Some of the early maturing varieties may
coincide with wild oats. Very late maturing
varieties should be avoided where wild oats are
expected. There is no safe chemical option for
the control of wild oats in oat hay although the
use of trifluralin applied in no-till systems has
given partial control.
Ryegrass is a particular issue for oat hay
production because hay is often included in the
rotation to provide a non chemical control of
ryegrass. However, ryegrass hosts the ARGT
complex that can poison animals fed hay
containing ryegrass infected with the toxin.
Initially the export market limited the ryegrass
level in oat hay to 5% but as ryegrass itself makes
very good quality hay often higher levels can be
marketed as long as the hay is free from ARGT.
Good ryegrass control can be difficult to
achieve in oat hay with herbicides but trifluralin
(especially in no-till systems), metolachlor
(pre-seeding or post sowing pre-emergent)
and chlorsulfuron (for Group B susceptible
populations) have been used.
Grass weeds such as barley grass, silvergrass
and brome grass reduce palatability and
visual quality.
After cutting, regrowth of oats and other
grass weeds can be controlled with paraquat
or glyphosate.
Image 6.7 Oat hay is often included in the
rotation to provide a non chemical control of
ryegrass. To achieve this hay must be cut before
ryegrass sets seed. However, ryegrass hosts the
ARGT complex that can poison animals fed hay
containing ryegrass infected with the toxin.
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Broadleaf weeds
Weeds with a thick stem such as Salvation Jane
and Small-flowered mallow/Marshmallow
(Malva parviflora) cause visual down grading and
cure at a different rate to oats. Dark, unsightly
patches or mouldy hot spots can result from the
inclusion of broadleaf weeds. Cape weed is a
particular problem as it causes yield loss and
has a detrimental effect on quality by causing
unsightly dark and low nutrient patches in bales.
Brassica weeds and Bifora can result in
unacceptable taints to the hay that will reduce
livestock intake. Some weeds, such as Melilotus
can impart taints to milk.
Sharp, spiky weeds such as thistles can cause
intake problems as well as impact on handling.
80% of cows in Japan are fed by hand and the
presence of thistles is easily noticed.
Annual ryegrass toxicity
(ARGT)
ARGT is caused by toxins produced by the
bacterium Rathayibacter toxicus that infect the seed
heads of ryegrass. These toxins can prove fatal
if ingested by livestock. The bacterium is
transferred to ryegrass seedheads by a nematode
(Aguina spp.). The nematode, which only has one
lifecycle each year, invades the ryegrass during
the winter and in spring produces a gall that
replaces a developing seed in the immature
seedhead. If the bacterium is present, it quickly
multiples during early spring, swamping the
nematode and takes over the gall. After ryegrass
flowers the bacterium begins to produce potent
toxins called corynetoxins. Toxin production
increases rapidly just before the grass hays-off.
The toxin is very stable and persists in dry
pasture or hay.
Circumstances that favour development of
ARGT are:
• paddocks with moderate to high frequency
of cropping;
• poor ryegrass control in previous year often
associated with herbicide resistance;
• poor ryegrass control in-crop;
• ryegrass seedheads are cut or spray-topped
after flowering has commenced allowing
nematodes to complete its lifecycle;
• successive short growing seasons; favours
nematode multiplication;
• spread of galls from infected areas within or
surrounding the paddock;
• pasture phase under grazed during spring,
allowing infected ryegrass seedheads to mature
and continue infection cycle.
Infected seedheads usually show no visual signs
of infection. Sometimes excessive bacterial
growth causes the emerging seedheads to become
twisted and deformed. In this case the bacterium
will appear as a yellow exudate. When dry the
exudate turns orange and becomes brittle and
transparent. Close inspection of the spikelets will
often reveal that individual seeds have been
replaced by nematode galls, most of which will
be colonised by the bacterium.
The twist fungus (Dilophospora alopecuri) also
causes ryegrass seedheads to become distorted.
Twist is a plant parasitic fungus, but it needs the
nematode to carry its spores into the plant. The
spores quickly colonise the galls produced by
nematode. Excessive infection can cause the
seedhead to become deformed and ‘twisted’.
The twist fungus is a useful biological control for
the nematode and is now established in many
areas affected by ARGT. However, symptoms of
the fungus indicate the nematode is present in the
paddock, and that the bacterium may also be
present. Presence of significant levels of the
fungus reduces but does not eliminate the risk of
poisoning to stock. The fungus can be purchased
from Biological and Resource Technology Pty
Ltd who distribute the twist fungus under license.
The orders must be received before the end of
February and an order form can by downloaded
from Biology and Resource Technology's website
at www.argt.com.au
Testing for ARGT bacterial contamination in
export hay and straw is compulsory. Local
hay buyers may also require test results. The
reputation of Australian oat hay depends on
the constant sampling and testing of export
hay to minimise the likelihood of toxicity
reaching animals.
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Image 6.8 Pre seeding weed control is vital as in-crop options are limited.
The Australian Quarantine Inspection Service
(AQIS) has produced a set of standards for
minimising the risk of corynetoxin contamination
in export hay and straw. For the most up to date
information on sampling protocols check the
AQIS website (www.aqis.gov.au). At the time of
publication the approved method of sampling
for ARGT contamination while bales are in the
paddock is as follows:
• in the paddock, sample the greater of 12 bales
or 15% of bales in the paddock;
• samples should be taken from all bales on the
perimeter of the paddock and then taken from
bales that fall within the lines of a ‘W’ pattern
across the rest of the paddock; or
Two laboratories are accredited to test export hay
samples for ARGT contamination.
In Western Australia contact the Department of
Agriculture, Immunology Laboratory, Animal
Health Laboratories, 3 Baron-Hay Court South
Perth, WA 6151 (08 9368 3491).
In all other states of Australia contact the SARDI
Crop Pathology Diagnostics Laboratory at the
Plant Research Centre, Urrbrae, SA 5064,
(08 8303 9668 or 9360).
Processors intending to submit samples for
testing should first register with the laboratories
and obtain appropriate sample kits.
• samples should be taken from each bale that is
produced every seventh lap of the baler and
every bale in the perimeter lap; or
• starting from the first bale in the paddock
every ‘x’ bale should be sampled, following the
path of the baler to ensure that the greater of
12 or 15% of bales are sampled; or
• any similar systematic plan used for the
selection of bales sampled.
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Table 6.5 Herbicides for weed control in oat hay crops - source Agrilink Agricultural Consultants.
Herbicide
group
Active
ingredient
Example of
brand name
B
metosulam
Eclipse®
B
flumetsulam
Broadstrike®
B
chlorsulfuron
Glean®, Siege®
B
Ally®
C
metsulfuron
methyl
bromoxynil
C
diuron
Diuron,
Diurex®
D
trifluralin
TriflurX
F
diflufenican
Brodal®
G
carfentrazone
Affinity®
I
dicamba
I
Cadence®,
Banvel®
MCPA LVE
MCPA Ester
MCPA LVE
MCPA Amine MCPA 500
Apply before
GS25.
Apply between
GS13 and GS37.
Rate dependent at
differing growth
stages.
I
24-D Amine
24-D Ester
Amicide®
Estercide®
I
clopyralid
Lontrel®,
Archer®
Apply between
GS13 and GS37.
Rate dependent at
differing growth
stages.
Apply at any
growth stage.
K
metolachlor
Dual®,
Dual Gold®
Buctril®,
Bromicide®
Comments
Apply late post
emergent.
Apply late post
emergent.
Apply post
emergent.
Apply after GS15.
Apply after GS13.
Avoid spraying in
warm conditions.
Apply pre-seeding,
post seeding/preemergent or early
post emergent.
Apply pre-seeding
or post seeding
pre-emergent.
Apply post
emergent.
Apply after GS14
but before GS31.
Apply pre-seeding
or post seeding
pre-emergent.
Post emergent broadleaf
weed control.
Post emergent broadleaf
weed control.
Used post emergent for Group
B susceptible weeds.
Used without the addition of
wetter on certain weeds.
Can be used in a tank mix with
diflufenican (Group F).
Used as a residual herbicide
before emergence or as a tank
mix partner early post
emergent.
Only at low rates pre-seeding
in no-till situations or before
emergence and incorporated
by seeding. Seeding depth is
critical to avoid oat damage.
Usually applied as a tank mix
partner with a Group I product.
Particularly good as a tank mix
partner to control bifora and
bedstraw.
Common mixing partner for
wireweed and legume control.
Can be used in a tank mix with
diflufenican to broaden
spectrum.
Appears to be less damaging
than equivalent rates of
2,4-D products.
Only at low rates as scorching
and yield loss can occur at
high spraying rates.
Good for thistles and legumes
with some short term soil
residual. Can be residual in hay.
Usually applied as post sowing
pre-emergent, often in
combination with diuron.
Highly soluble so damage can
occur in sandy soils or shallow
sown crops.
Note – some of the above chemicals are not covered by label registrations but only by supplementary registrations that may only relate to certain States.
Always check the label and with your reseller or adviser before use.
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Insect control
Oat hay crops are damaged by certain insects and
provide a habitat for insects to multiply and
survive; thus endangering future crops and
pastures grown in a paddock. Diligent crop
monitoring is required throughout the
growing season.
Lucerne flea
Oats are particularly palatable to lucerne flea
(Sminthurus viridis). Heavy infections prior to
GS25 can cause very high levels of damage and
result in plant death. Left unchecked low initial
infestations can complete several lifecycles in oats
and produce many over-summering eggs. These
can cause crop damage when they hatch the
following year.
Aphids
Aphids can occasionally cause yield loss in oats
when their numbers are very high in early spring.
In some situations control is warranted. Of
more importance is that aphids transmit viruses,
particularly barley yellow dwarf virus (BYDV)
that can cause high yield losses, in favourable
years, in hay crops. Therefore, most aphid
control is aimed at reducing or preventing BYDV.
For this reason control needs to be achieved
early in the season. This can be by using seed
treatments or by spraying insecticides (usually
synthetic pyrethroids) at the early growth stages
often as a preventative application.
Contact your local reseller or adviser about insect
control products.
Control can be achieved cheaply with a range
of insecticides. Prior to crop emergence soil
residual insecticides are useful but when there is
plant material available to spray after emergence
the systemic products such as dimethoate and
omethoate give outstanding results. Once
lucerne flea is controlled plant recovery is rapid.
Red-legged earth mite and
Blue oat mite
Red-legged earth mite (Halotydeus destructor) and
Blue oat mite (Penthaleus major) also cause severe
and rapid damage to oats as well as
allowing lifecycles to be completed to cause
problems for the following year. Control is
similar to lucerne flea although the results
achieved with soil residual products are usually
greater. Some control is achieved at all stages
with a range of synthetic pyrethroids, which are
generally weak on lucerne flea. The response to
dimethoate and omethoate is rapid when foliage
is sprayed. Once again when the mites are
controlled plant recovery is rapid.
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Chapter 7
Making oat hay
Cutting
Cutting is the first stage of the hay making
operation. The objectives of the cutting
operation are to:
• cut the hay so that it sits on the cut stems to
promote rapid drying;
• produce a gently domed windrow that
sheds water;
• have a windrow wide enough to fill the full
width of the bale pick-up. This may be
achieved by tedding or raking rows into one
just before baling.
Cutting, conditioning and the formation of a
suitable windrow may be achieved in a single
operation using an all-in-one mower conditioner
or super conditioner. However, where disc or
knife cutting mower conditioners are used a
super conditioner may be required to reduce
curing time.
The time of cutting in relation to plant growth
stage, cutting height and direction, all impact on
hay quality.
Cutting time
Choice of cutting time is based on achieving a
balance between yield and quality. Optimum
cutting time is determined by the growth stage
of the plant (Figure 7.1). Research has shown
that the ideal time for cutting high quality hay is
from flowering (GS60), when the top floret has
anthers protruding, to the watery ripe stage
(GS71), when the ‘grain’ in the top floret is
squashed it releases a clear greenish fluid
(Figure 7.2).
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Figure 7.1
The change in
digestibility (IVD),
fibre (NDF and ADF)
and water soluble
carbohydrates as
oat crops mature
from the swollen
boot stage (GS45)
to milky dough
(GS73), for the
late maturing
variety Riel under
a high and low
nitrogen regime.
In commercial hay
crops the change
may not be as
extreme as the
starting point may
be lower.
The selected time of
cutting based on the
trade-off between
yield and quality must
also take into account
the likelihood of
rainfall, and the curing
conditions being
favourable. For
example, in most of
southern Australia
later cutting times
coincide with
lower soil moisture,
lower atmospheric
humidity and higher
temperature, all
of which reduce
curing times.
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The impact of growth stage on hay
quality and quantity
The following information explains how the oat
crop changes during the growing, maturing and
grain fill periods. All growth stages relate to the
Zadok’s scale.
GS30 to 39 – stem elongation to flag
leaf emergence
As the plant extends during stem elongation
(GS30 to 39) photosynthate is used for the
formation of cellular structures such as lipids,
hemicellulose, cellulose and lignin. The more
mature an internode the greater the proportions
of lignin and cellulose and the lower the
proportions of hemicellulose and lipids.
Carbohydrate can be mobilised from older nodal
and internodal tissue to support the demand
of new growth. This is greatest if soil moisture
is limiting and temperatures are too high for
efficient photosynthesis.
GS39 to 60 – flag leaf emergence
to flowering
The most rapid period of growth, as measured
by dry matter accumulation on a daily basis,
occurs from flag leaf emergence (GS39) until the
end of boot stage (GS49). There is a slight
decline in growth before flowering (GS60). From
GS39 to GS60 it is not uncommon for oat hay
crops to accumulate dry matter at 0.5 to 2% of
the previous days weight, for any particular 24
hour period. Dry matter accumulation can reach
a maximum of 200kg/ha/day, for high yielding
crops with adequate soil moisture, good fertility
and mild temperatures.
Daily growth rates are reduced as temperatures
exceed 30°C or in very cool conditions. Hay
crops can lose weight during hot weather or
when under moisture stress, as respiration and
transpiration losses exceed photosynthetic gains.
From the time the panicle is fully extended
(GS59) there is little addition of new
photosynthate to the stems as it is partitioned
to the head structures and ultimately to the
developing grain. If flowering heads are
sterilised the plant retains the carbohydrate
fractions of the stems and the conversion of
soluble and partially soluble material to cellulose
and lignin is reduced.
Assuming that oat hay is not cut before the
swollen boot stage (GS45), then maximum
digestibility and lowest fibre deposition will occur
between the boot to head extended stage (GS59).
In hot dry conditions water soluble carbohydrates
can sometimes begin declining by head extension.
Conversely in good growing conditions water
soluble carbohydrates can increase to the end of
the watery ripe stage.
Oats can flower before emerging from the boot,
especially in moisture stress conditions or if a
dwarf oat variety is grown. This situation
results in GS60 occurring before GS50 to 59
is complete.
GS60 to 73 - flowering to milky dough including the ideal cutting period
The first three to seven days of grain formation
culminates at the watery ripe stage (GS71) where
the grain is fully extended but only contains clear,
greenish liquid (Figure 7.2) and is not drawing
heavily on carbohydrate from photosynthesis or
storage. However, this changes rapidly as solids
start to accumulate at the start of the milky
dough stage (GS73).
As stems become more mature they absorb water
more quickly from rainfall. Hay cut after GS71
can deteriorate more rapidly after rainfall than
hay cut at or around flowering.
GS73 onwards
After GS73 carbohydrate requirements for the
developing grain is extreme and lignification of
older stem material is accelerating. This results in
an increase in the fibre fractions (as measured by
NDF and ADF) and a reduction in water soluble
carbohydrate, which together result in lower
digestibility (IVD). ADF and NDF content
increase from the panicle to the base of the stem
but there may not always be a similar pattern
with WSC.
From flowering to soft dough (GS85) growth
rates of 0.5 to 1.7% to a maximum
175kg/ha/day have been recorded, so yield
continues to accumulate.
As grain starts to ripen (GS90) overall digestibility
of the plant increases and fibre fractions decrease
because of the high starch content of the grain
itself. If this grain is removed the remaining
plant material has poor quality as mainly fibre
fractions remain.
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Ripe grain in hay is undesirable to hay buyers
because if grain is lost during conditioning, super
conditioning or processing at a hay plant then the
remaining hay is likely to be poor quality. The
presence of grains also makes hay more attractive
to rodents.
Curing time can be increased if the crop is cut
wet. This is because moisture evaporates more
quickly from the standing crop than from within
the windrow. Ideally, allow dew or rain to
evaporate before cutting.
After flowering the flag leaf will gradually
senesce resulting in leaf discolouration.
Senescence is likely to have started to occur
in the F-1 and F-2 leaves, those directly below
the flag leaf, several days earlier. If senescing
leaves remain in the hay they result in hay
discolouration. Additionally, fully extended flag
leaves are prone to wind scorch although there
are varietal interactions and invariably thick lush
crops are more damaged. If scorching occurs on
the flag leaf it can look unsightly and hay can be
downgraded. Scorching can occur on earlier
emerging leaves but the presence of clean flag
leaves is usually enough to overcome visual
discolouration in the bale.
Cutting height
Ideally, if there were no quality issues, cutting
height would be as low as possible to maximise
yield. This height would be determined by the
ability of super conditioners, rakes, tedders and
balers to move or pick-up all the hay without
contacting the soil.
Impact of hour of cutting
Hay quality traits peak in the afternoon on cool
to mild days and mid morning on hot days.
This fact is important for research scientists but
is usually not significant enough to alter the time
of hay cutting at the farm level.
Cutting higher reduces yield but can have a
marked influence on quality. A rule of thumb is
to cut at 15cm, the height of a drink can. High
yielding crops and lodged crops may be cut
slightly higher to ensure the weight of the
windrow is supported off the ground. However,
the following factors need to be considered when
determining cutting height.
Fibre content
The bottom of the plant has higher proportions
of lignin (largely indigestible) and cellulose (lower
digestibility) compared to the top, which has
more hemicellulose (reasonably digestible), lipids
(highly digestible) and soluble carbohydrate
products (highly digestible) but still considerable
Figure 7.2 Identifying when to cut – GS71 is the ideal time to cut for high quality oat hay.
Select the top floret
The white anthers indicate
the crop is flowering (GS61)
Squeeze the top grain to
check the growth stage
GS71
Watery dough
GS75
Milky dough
GS85
Dough
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cellulose. When hay is cut too low NIR feed
tests will have higher NDF and ADF values and
lower digestibility (IVD).
Poor colour
The lower part of the stem has poorer colour
due to:
1) high fibre content;
2) discolouration probably due to
oxidation reactions;
Lodging
Lodged plants do not support the weight of a
windrow because of the low angle of stems to
the horizontal soil surface. Invariably, lodged
plants are cut at differing heights depending on
the direction of cut, the type of cutter used and
the speed of operation. If weather is going
to be fine from cutting to baling lodged crops
can be cut low, although feed test parameters
would be expected to be poorer. However, if
there is a risk of rainfall lodged crops should be
cut higher.
3) early cessation of photosynthesis due
to shading;
4) reduction in water soluble carbohydrates when
moisture stress occurs during stem elongation.
Stem thickness
Stem thickness is greatest at the bottom of the
plant and can impact on the visual appearance of
the hay. Nodes are very highly digestible and are
storage areas for water soluble carbohydrates.
Conversely internodes contain the lowest level
of water soluble carbohydrates and are highest
in lignin and cellulose. Between the node and
the mid point of the internode there is a
gradation from water soluble carbohydrates, to
hemicellulose, to cellulose to lignin. Therefore,
if possible, it is best to cut to include a node.
Image 7.2 When row spacing is greater than 12.5cm
cutting direction should be across the seeding direction to
keep hay off the ground, improve air circulation, limit
spoilage and assist in efficient pick up by super conditioners
and balers.
Direction
In crops that may be leaning or lodged cutting
height needs to accommodate the direction of
travel of cutter, super conditioners and balers.
Image 7.1 Oats at cutting time showing a range of
stem diameters (thin to thick L to R) and different levels of
stem bleaching. Stem diameter and colour both impact on
hay quality.
Cutting direction should be across the seeding
direction, when the distance between plants in
adjacent rows is greater than 12.5cm. This will
keep hay off the ground, improve air circulation,
limit spoilage and assist in efficient pick up by
super conditioners and balers (Chapter 6 Seeding
direction and Figures 6.1a,b,c & d). When
cutting across seeding rows cutting height may
be slightly lower than when cutting in the same
direction as seeding rows.
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Plants leaning at different angles may need to
be cut at different heights. Therefore, choice of
cutting height needs to be adjusted for the
direction of travel to ensure the crop is cut with
a sufficient stubble length to allow hay to be
picked up by super conditioners and balers
without contaminants.
Super conditioners with roller pick-ups need the
windrowed hay to be presented clear of the
ground to allow efficient pickup of all cut hay.
However, excessive length of the remaining
uncut stubble can result in wrapping around the
pick-up rollers causing blockages and lumpiness
in the windrow. This can also result in plants
with soil attached being pulled out of the ground
and deposited in the windrow.
Contamination
Cutting height must be sufficient to prevent
contamination from previous stubbles, soil,
manure and other contaminants that may be on
the soil surface. The aim is to present a windrow
where the rake (if used) or the baler pick-up can
clear the soil surface by 25 to 50mm. This
generally requires a minimum cutting height of
12cm and preferably 15cm above the highest
point between seeding rows. On high yielding,
lodged crops cutting height may need to be
raised to 20cm.
Cutting equipment
There are basically five types of hay cutting
equipment. Some purely cut the crop while
others cut and condition to reduce the curing
time. The types are listed in Table 7.1, together
with details of the drive options available.
Additional equipment that may be required for
the cutting/curing operation includes super
conditioners, tedders and rakes; these are
discussed in the section on curing.
Self propelled versus PTO equipment
PTO driven equipment can only cut round and
round, so this must be taken into consideration
when selecting seeding direction (Figures 6.1a,b,c
& d). When cutting and conditioning with PTO
machines the drawbar and differential of the
tractor must be able to clear the previous
windrow; dragging equipment through a windrow
can undo a good operation. Similarly, the tractor
operating the mower conditioner should not run
over any of the previous windrow. Therefore,
windrow size and shape may be dictated by
tractor configurations when using PTO driven
machines to avoid these issues.
Swinging arm, hydraulic cutters offer the
ability to cut up and back and reduce damage on
headlands.
Self propelled mower conditioners largely
overcome these problems of disturbing or
running over the previous windrow. Self
propelled conditioners can be used more easily
to cut across or at an angle to the seeding rows,
which helps keep the windrow off the ground.
This is especially important as seeding row
spacing increases. The greatest downside of
self propelled mower conditioners is the capital
and annual depreciation costs.
Table 7.1 Types of mowers and conditioners and available drive options
Self
propelled
Offset PTO
or hydraulic
✔
Rotary or flail slasher
66
Swinging arm
hydraulic
Windrower
✔
✔
Rotary/disc cutting mower conditioner
✔
✔
✔
Knife cutting mower conditioner
✔
✔
✔
All in one mower conditioner/
super conditioner – knife or disc
✔
✔
✔
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Knife versus disc cutters
There is always great discussion over the virtues
of disc and knife cutting machinery. Disc cutters
have a greater cutting capacity than knife cutters
and can be operated at greater speeds. Working
speeds for disc cutters are stated as 20 to 30%
higher than knife cutters, which can convert into
cutting time efficiencies. This is often the reason
for their widespread use. However, excess speed
is one of the most common reasons for poor
cutting and windrow presentation with both types
of cutters.
Image 7.3 Disc cutters have a greater cutting capacity than
knife cutters and can be operated at faster speeds.
Disc cutters produce excellent results providing
cutting blades are sharp and working speeds are
not excessive (8 to 12 km/hr) for crops of 7 to
10 tonnes per hectare. Some operators have a
preference for disc cutters when cutting lodged
crops, because the discs have a lifting action on
the cut hay. This may be an advantage but can
result in variable cutting height depending on the
direction of travel and the direction the crop is
leaning. The best direction of travel in lodged
crops often is determined by trial and error.
Knife cutters must be sharp and when they are
driven at moderate speeds the cut and windrow
formation is excellent. Operating speed is
particularly important in lodged crops where
poor results are the most obvious.
Rotary or flail slashers
Flail slashers are not used to cut cereal hay
and while rotary slashers can be used the
performance thus far has been inferior to disc or
knife mowers. The cut hay is not conditioned
and windrow presentation can be poor.
Windrowers
Windrowers are a compromise for hay cutting, as
they do not condition hay. They are most suited
to cutting straw after grain has been harvested.
Windrowers are sometimes used when hay yields
are low and the extra width of a windrower is
utilised to produce a windrow of suitable size for
baling. Windrowers have high capacity but as hay
is cut onto a belt front and deposited either into
the centre (central discharge draper fronts) or on
one side (honeybee front) the cut stems of hay
are usually predominantly presented lying in the
same direction as cutting. This can result in more
hay falling between the cut stalks and contacting
the soil surface, making it difficult for super
conditioner or baler pick-ups to retrieve all the
cut material. Even if hay remains supported on
the cut stems the direction in which the cut
stems are leaning can make pick up difficult by a
normal baler pick-up. Raking windrows or the
use of mixing belts can help overcome this
problem but invariably produces inferior
windrows to those produced by a mower
conditioner. As windrowed hay is not
conditioned at cutting it takes longer to cure.
All in one mower conditioner/
super conditioners
All in one mower conditioners/super
conditioners are a relatively new innovation and
are still being developed and commercialised.
They execute two operations in one, reducing
the number of passes required to convert the
standing crop to curing hay.
Evidence so far shows these machines to be very
good when soil and atmospheric moisture are
low (dry springs or late cuts), as hay is rapidly cut
and cured in one pass. However, cutting lush
crops with an all-in-one machine when the soil
surface is moist and humidity is high, can create
dense windrows and promote mould formation.
In this situation additional removal of free
moisture from the crop by raking, tedding or
super conditioning may be required.
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Curing
For every one tonne of hay baled approximately
three tonnes of water needs to be removed by
evaporation. Dew can add an additional one to
two tonnes of water per hectare.
Curing speed is affected by environmental,
management and mechanical factors (Table 7.2).
An understanding of each of these factors can
help improve the quality of hay that is baled,
stored and eventually fed out.
Environmental factors
Solar radiation, temperature and wind combine to
drive the speed of the curing process (Figure
7.3). However, the speed of curing is also
influenced by humidity and rain.
The faster the curing process generally the better
as hay quality continues to decline during the
curing process. This is because the cut plants
respire while their moisture content is above
30%. Respiration is an important part of the
drying process but at the same time plant sugars
Table 7.2 Factors that affect the curing of hay.
Environmental factors
Management factors
Mechanical factors
Solar radiation
Crop maturity
Tedders
Temperature
Leaves versus stems
Mower conditioners
Humidity
Time of mowing
Super conditioners
Wind speed
Windrow formation
Windrow inverters
Rakes
Figure 7.3 Influence of solar radiation and airspeed on evaporation rate of water source W. Dernedde (1980).
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Image 7.4 A wide, evenly domed windrow (L) allows more penetration of wind and sunlight and sheds rain to maximise the
speed of curing and minimise weather damage. Excess cutting speed is often characterised by bunching in the windrows or
the formation of a V or U shape in the centre of the top of the windrow (R). The presence of this windrow shape channels
water from rainfall into the centre of the windrow rather than allowing it to be shed to the sides of the windrow.
are broken down resulting in a loss of quality and
dry matter. Respiration losses increase rapidly
when temperatures are above 20°C and can result
in dry matter losses of over 15%, compared to
dry matter losses of between 2 to 8% when
curing occurs in cooler conditions.
Long curing periods make the hay crop more
vulnerable to weather damage resulting in loss of
soluble nutrients, bleaching and the development
of moulds, stains and taints; all of which impact
on hay quality. After heavy rainfall leaching can
cause dry matter to reduce by 20% of the original
crop dry matter. Rain can also cause leaf shatter
and regrowth to occur in the windrow (Image 7.5).
The latter not only increases the curing
time but the potential for green matter to be
included in the bales increasing their moisture
and likelihood of moulds developing and even
self-combustion.
Generally, the greater the amount of rain, the
longer its duration, the lower its intensity and the
later in the curing period, the greater the loss of
dry matter and hay quality (Figure 7.4).
Cutting hay on to wet ground should be avoided
as the moisture from the ground will move up
through the drying hay increasing curing time.
Image 7.5 Long curing periods caused by rain can result in regrowth occurring in the windrow, this in turn slows the curing
process and increases the potential for green material to be included in the bales increasing their moisture and likelihood of
moulds developing and even self-combustion.
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Figure 7.4 The impact of rainfall amount and intensity (rate) on retention of water by
mown plants - source Pitt and McGechan (1989).
Management factors
Of all the management factors, windrow
formation has the greatest influence on the
curing time. Younger plants cure faster than
older plants and leaves dry faster than stems
but these factors are determined by
crop management.
Cutting after dew has dried helps reduce curing
times but overall the impact of temperature and
wind conditions drives the curing process rather
than the hour of cutting.
Windrow shape is a compromise between
minimising drying time and minimising weather
damage and water entering from moist soil.
A wide, evenly domed windrow allows more
penetration of wind and sunlight and sheds rain
to maximise the speed of curing and minimise
weather damage (Image 7.4).
Windrow dimensions may vary between export
and domestic hay. A less dense windrow cures
more quickly as the proportion of air to cut
material is greater. However, a less dense
windrow usually has a greater surface area that
can result in more sun bleaching and colour loss.
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For this reason it is better to have narrower
formed windrows for the export market where
colour is a determining factor in the price paid
for hay. A broader flatter windrow is suitable for
hay produced for the domestic market.
The windrow width should be closely matched
to the width of the bale pick-up to ensure all
material is picked up and the accumulation
chamber in the baler is evenly filled. If windrows
are narrow, then the baler operator needs to
swerve the baler from side to side as it travels
along the windrow to keep the chamber
evenly loaded.
Excess cutting speed is often characterised by
bunching in the windrows or the formation of a
V or U shape in the centre of the top of the
windrow (Image 7.4). The presence of this
windrow shape channels water from rainfall into
the centre of the windrow rather than allowing it
to be shed to the sides of the windrow. Where
higher operating speeds are required, care should
be taken with the shape of the windrow and
adjustments must be made to the delivery chute
to avoid poor windrow presentation.
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Mechanical factors
Tedders
Tedders are commonly used for pasture hay,
sometimes used for domestic hay and less
commonly used for export hay. Tedders increase
the surface area of the hay by spreading a
windrow in a thin layer thereby speeding up the
drying process. However the increased surface
area may result in higher levels of sun bleaching.
Tedding hay to improve drying times is less
recommended for export hay as it increases
the opportunity to pick up soil and other
contaminants, but this must be balanced against
the opportunity to reduce curing time and
maintain feed test quality. Their use for export
hay has usually been to spread windrows that
have been rained on, to aid the drying process
and reduce spoilage.
Super conditioners
Approximately 30% of stem water is lost through
the leaf, leaving 70% to be lost through the stem.
The use of conditioning and super conditioning
helps accelerate the loss of stem water by
cracking the stems and crushing nodes (Image
7.6). Water evaporates at 100 litres per tonne
per hour, from open stomata on the leaf surface.
Squashing stems and abrading leaves by
conditioning increases the rate of water loss to
between 150 to 180 litres per tonne per hour.
As a general rule of thumb super conditioners
can reduce drying time by around 50% compared
to normally conditioned hay. Super conditioners
can be used successfully to dry hay that has
received rain after cutting. The best results are
achieved when rain occurs shortly after cutting
and no further rain falls. Subsequent rainfall has
been reported to be more damaging to hay that
has been super conditioned, but there is no trial
data to support the claim.
In good drying conditions super conditioning can
result in hay becoming too dry resulting in poorer
bale formation. Therefore, drying conditions and
baling equipment must be considered before
super conditioning (refer to Bale formation).
Super conditioners operate at much higher roller
pressures than mower conditioners and provide
continuous squeezing pressure for all the hay
rather than a crimping effect.
Image 7.6 A trailed super conditioner, the conditioning
rollers and super conditioned hay showing crimping and
squashed nodes, both of which help to reduce curing time.
Super conditioners can have roller or finger
pick-ups, large or small high pressure rollers,
finely fluted or flat rollers. The top and bottom
rollers can be the same or different sizes and can
operate at the same speed or have the rollers
operating at differing speeds. The discharge can
have a windrow forming chute or wings.
Generally, roller pick-ups can be operated at
higher speeds than finger pick-ups but they
cannot pick up hay close to the soil surface
(approximately 10 to 20mm). Where hay is
lying close to the soil surface finger pick-ups
are favoured.
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Image 7.7 The windrow before (L) and after (R) super conditioning.
Finger pick-up machines are the preferred option
for crops on wider row spacings, although the
‘all–in-one mower conditioner, super conditioner’
usually produces superior results on crops with
wide row spacing.
Super conditioners with rollers operating at
different speeds or fluted rollers should not be
used on drier hay as they can cause ‘chaffing’.
This type of super conditioner should probably
be used closer to cutting time. Conversely, high
pressure roller super conditioners can cause
excess moisture loss and subsequent mould
formation if used too soon behind the mower.
As with all the cutting and curing operations it is
important that super conditioning avoids running
over windrows with tractor or conditioner tyres
and forms a windrow that enhances drying
and curing. The windrow formed by a super
conditioner should have the same basic
fundamentals as a mower formed windrow
(refer to Management factors).
Windrow inverters
These gently lift and invert the windrow on to
dry ground but are generally not found to be as
effective as tedders or super conditioners.
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Rakes
Raking can be used to speed up the drying
process. Turning exposes hay from the centre
of the windrow to lower humidity, higher
temperatures and sunlight on the outside of the
windrow. A rough rule of thumb is that each
raking reduces the time from cutting to baling
by 10 to 15%. Raking can also be used to aid in
drying after rainfall but it appears the results are
best if the rainfall is relatively light.
The downside of raking is some physical damage
to the hay and each raking progressively removes
more leaf material. While raking helps reduce
curing time this may come at the expense of
some sun bleaching. The commercial impact
of this will depend on customer preferences.
Additionally there is an increased risk of
introducing contaminants.
Raking is widely used to create a windrow
suitable for baling and to reduce inactive baling
time. It is cheaper to rake hay than operate a
baler with the front only partially filled. Using
powered or finger driven rakes to combine two,
three or four windrows into one, just before the
baler, is common practice.
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Baling
Baling hay is a crucial part of the hay making
operation. Attention to detail is required when
assessing hay moisture, atmospheric conditions
and checking machinery performance. Bales
must be dense and well formed if they are going
to be transported or stored.
Choice of baler
The choice of baler will firstly be dictated by
market requirements and secondly by the storage,
handling and cartage needs. Differences in baler
performance usually fall into third place.
Medium and large square bales are preferred by
the export industry, as they are easily stacked
without loss of space in storage or transport.
Bales for export are repacked into small, high
density bales at the hay plant. Medium and large
squares are more suited to this as string can be
easily removed and biscuits of hay are readily
teased or guillotined from these bales.
The domestic market is often restricted by the
capability of handling and feeding machinery.
Therefore, it has a preference for round and
medium square bales, although there is a trend to
larger square bales, due to savings in freight.
Small square bales are used by hobby farmers,
recreational users and occasionally by other
domestic users.
Moisture content
The moisture content of baled hay is critical and
baling high moisture hay should be avoided at all
costs. Hay baled at over 18% moisture is at risk
from damage by mould developing in the bale
and spontaneous combustion. Export markets
prefer baled hay with a moisture content less
than 14%; some exporters standards are as low
as 12% moisture. At these low moistures
the risk of spontaneous combustion during
storage is minimised, and there is a lower risk
of condensation occurring during transit that
ultimately drips off the container roof back onto
the hay, creating wet patches and encouraging
mould formation.
High density bales do not dry readily because of
low air exchange rates and the insulating qualities
of hay. Consequently bales of 18% moisture
may take many months to dry to an acceptable
moisture content.
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Testing moisture content
A moisture meter can adequately measure
moisture in a tightly bound handful of hay.
The most reliable test is to squash the nodes
on a dark, metal surface with a hammer. Check
for moisture underneath a squashed node uncured, nearly cured, fully cured (L to R).
The same handful of hay can be wound rapidly
in a circular motion to produce shearing. If by
three turns the hay does not break it may not
be sufficiently cured.
Test bales with a moisture meter. If higher
moisture bales exist these are best stored
separately and the moisture monitored.
Open a stem above and below the node. The
inner most leaf inside the stalk can still be
moist when the outer stalk appears totally dry.
If there is still concern over hay moisture content
then it is suggested that about 10 bales are made
and left over night. The moisture should be
tested the next day and if it remains under 14%,
or a target moisture content, then the hay is ready
for baling.
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Bale formation
Poorly made bales will collapse resulting in
handling difficulties and wastage. Balers must be
set-up to produce dense bales and twine should
be matched to bale densities as bales with broken
strings are unacceptable to the market. The
increasing trend towards net wrap for round bales
helps overcome this problem. Matching the
width of the windrow and bale pick-up helps in
the production of evenly shaped bales.
When the accumulation chamber is full the hay is
discharged into the bale chamber as a distinct
wad or biscuit of hay. For well formed dense
8’x4’x4’ bales, successful baler operators indicate
setting machines to produce 38 to 40 of these
wads per bale, while other industry participants
suggest 32 is satisfactory. Any less and the bale
can lack density and be poorly shaped. Any more
exerts excess pressure on strings, increasing the
chance of breakage.
If hay is baled too dry it has lower density in the
accumulation chamber and does not retain its
shape in the bale chamber. This can result in
poorly shaped, light bales with excess pressure on
strings. Innovations such as the use of metal
wedges in the bale chamber, extended bale
chambers or water sprayed on to the sides of
the bale in the chamber to increase the friction
between the bale and the chamber, allow the
baling of drier hay or baling when atmospheric
conditions would normally stop baling.
Image 7.8 Well made, dense square bales retain their
shape which is crucial for ease of transport and storage.
If hay is too damp it feeds unevenly and creates
areas of high density. Excess moisture can
not be released from the bale and wet patches
can occur.
For large square bales, hay is picked up and fed
by finger tines into the accumulation chamber.
The aim is to maintain the uniformity and density
of hay in the accumulation chamber, so that it
packs evenly into the bale chamber. Slower
ground speeds result in the hay being more
densely packed in the accumulation chamber,
which can help overall bale density.
Square bales can be discharged directly from the
rear of the baler or can be turned 90 degrees
(Image 7.10) so when discharged the bale rests on
the cut side, rather than on the strings. This
offers the advantage that the less dense part of
the bale, which dries more quickly, is exposed to
soil moisture and rain. If this face is damaged by
moisture it can be removed by a guillotine.
Image 7.9
Balers fitted with water
tanks to spray water on
to the sides of the bale
in the chamber allows
drier hay to be baled.
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Handling can be easier if the bale is not sitting on
the strings.
Making round hay bales is generally more
forgiving than for large squares as bale density
is lower. This allows hay to be baled at higher
moisture with lower risk of spontaneous
combustion and a much greater ability to dry
due to air movement and evaporation within and
between bales. However, bales should still be
robust and should not lose their round shape
after being discharged from the baler.
Image 7.10 Square bales can be discharged directly from
the rear of the baler or can be turned 90 degrees so when
discharged the bale rests on the cut side, rather than on the
strings. This can make handling easier.
Sampling and tagging
The accuracy of nutrient content depends on the
sample sent to the laboratory. It is critical that
the sample represents the average composition of
the hay ‘lot’ sampled, otherwise the laboratory
tests will not be useful.
A ‘lot’ is defined as hay taken from the same
cutting, at the same stage of maturity, the same
species (pure or mixed) and variety, the same
paddock, and harvested within 48 hours. Other
factors influencing the definition of a ‘lot’ include
rain damage, weed content, soil type, treatment
after cutting and storage implications. A ‘lot’ of
baled hay should not exceed 200 tonnes.
Sampling hay
Representative hay samples can only be obtained
with a probe or core sampling device (Image
7.12). A couple of handfuls or a ‘flake’ from one
bale are not adequate. Corers are commercially
available in Australia (for details visit the AFIA
website www.afia.org.au). Alternatively, corers
can be made using 32mm steel tubing, and
should be at least 450 to 500mm long with a
slightly scalloped, sharp cutting edge. Corers are
driven by a hand brace or an electric drill (where
practicable). Some cordless drills may not be
suitable if they lack power or turn too fast. A
portable generator is useful and can be justified
if many samples are taken.
Sample size should be confirmed with the hay
buyer or testing laboratory.
Small square bales
Sample between 10 and 20 small square bales,
selected at random from the ‘lot’. Take one core
from each bale selected, probing near the centre
end bale (small face), at right angles to the
surface. Ensure that the corer does not become
hot. Combine all cores into a single sample in a
bucket, and mix thoroughly. The whole sample
should be kept intact and not subdivided.
Image 7.11 The use of net wrap is common to produce
round bales.
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Large round or square bales
Sample between 5 and 10 large bales, selected at
random. Take one core from each side of all
bales selected, probing at right angles to the
surface at different heights. Combine all cores
into a single sample in a bucket, and mix
thoroughly. The whole sample should be kept
intact and not subdivided.
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instructions for labelling samples are closely
followed and all the required details on the
sample submission sheet are completed.
Details of sampling for ARGT are found in the
section on ARGT, Chapter 6.
Image 7.12 A ute mounted hay sampler as used by many
export hay buyers.
Sample handling
Immediately after sampling and mixing, the
final hay sample should be placed in a robust
(preferably ‘press-seal’) plastic bag and tightly
sealed to exclude air. This is to ensure that the
laboratory report of dry matter will approximate
the dry matter content of the ‘lot’ when it was
sampled, and is also to minimise aerobic spoilage.
Samples must be delivered to the laboratory as
quickly as possible after being taken. Avoid mail
delays over the weekend by posting samples
early in the week. Ensure that the laboratory's
Identification and traceability
Hay exporters are already required to
demonstrate sampling, testing and tracking of
hay in the export pathway. Most exporters use a
bar coded tag so each bale can easily be identified
(Image 7.13). All export bales must be tagged
before going into storage. Tags are currently
manually attached in the paddock to one of the
bale strings on the side opposite the knot.
The hay industry is considering a national bale
identification scheme for domestic and export
hay. AFIA is coordinating a project to introduce
hay bale tags that provide both a visible and
scannable number. This number could
distinguish both a property and paddock.
To save time fixing tags to bales AFIA is
developing an automated attachment device
that would fasten the tags to large square bales as
they leave the baling chamber. At the time of
writing, funding was being sought to complete
this project.
Image 7.13 Bar coded tags allow for easy identification of bale supplier and in future may identify property and paddock of
origin. Labels are located on the outside of loaded bales for ease of checking at the hay plant.
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Chapter 8
Storage and transport
Hay can be stored for long periods of time with
little reduction in quality, providing the hay is in
dense, well formed bales and remains dry and
free from damage by vermin.
Left outside and unprotected, hay will degrade
and a substantial proportion of the bale can be
wasted due to the formation of moulds. For
example, 33% of the total volume of a 2m round
bale is in the outside 15cm and nearly 60% is in
the outside 30cm.
into the bales. Rubble floors should be avoided
as they allow moisture to penetrate bales and
stones and dirt can become lodged in the bales.
The shed’s gutters and down pipes must divert
water away from the shed and water must be
prevented from flowing back to the base of the
stored bales.
Bales from the perimeter of the paddock should
be stored together as these may be tested
separately by the export hay buyer.
Storing export hay
For short periods of time, especially if rain is
anticipated, large square bales for export can be
stored on their flat end in the paddock, in order
to minimise weather damage (Image 8.1).
Otherwise export hay must be stored so that it is
protected from sunlight, rain and wind. Ideally
export hay should be stored in a fully clad shed.
Any openings should be away from the prevailing
weather and the roof and walls must be secure
and leak free. The floor should either be
concrete, bitumen or covered with heavy duty
black plastic sheeting to prevent moisture rising
Image 8.1 For short periods of time, especially if rain
is anticipated, large square bales for export can be stored
on their flat end in the paddock, in order to minimise
weather damage.
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Storing domestic hay
The criteria for storing export hay will also
maintain the best hay quality for the domestic
market. However, hay for the domestic market
may be baled at a higher moisture content
therefore, care must be taken to avoid conditions
that promote the potential for self combustion
during storage, (Figure 8.1).
For a hay stack to combust it must undergo a
process of self heating that even now is not fully
understood. However, it is known that several
sources of heat can contribute to the process.
Biological
For vegetable material to continue heating it is
generally due to a biological process reliant on
oxygen and living microorganisms. If the hay
is well cured it will not allow this destructive
fermentation to occur. Conversely if too wet,
not enough oxygen can diffuse into the mass
and no fire will occur.
It would appear that partially cured hay (moisture
content between 12 to 21%) is the most prone to
fire due to biological heating. This will heat the
hay to the thermal death point of the organisms
involved; that is in the vicinity of 70°C.
Regardless of how well the heated hay is
insulated, temperatures of 70°C fall far short of
the ignition point of hay, which is in the vicinity
of 280°C (Figure 8.1).
Secondary heating
Exothermic
Once hay reaches the limit of the primary heating
(70°C), the exothermic process can be initiated to
raise the temperature much higher.
Many theories can explain this process including
the production of pyrophoric carbon, pyrophoric
iron, heat from enzyme action, and even the
auto-oxydation of the oils contained in seeds.
What is known is that this process is generally
accompanied by the production of much acid in
the early stages and is accompanied by a marked
browning of the hay.
Image 8.2 High moisture bales may need to be stored
outside until the moisture content and temperature
has dropped.
Primary heating
Respiration
Respiration of freshly cut plants and subsequent
bacterial action causes bale temperature to
increase to a maximum of between 48 to 70°C.
If the heating hay is located on the outside of the
stack, where the heat can dissipate, the process
may very well stop here.
However, if the heating is located at the
bottom or inside of the stack then the heat may
continue to build. This would appear to be the
time that the moisture content of the hay may
be most critical.
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If insulated, this process can progressively raise
the temperature inside the stack to 240 to 280°C
at which point the slightest introduction of
oxygen will result in the ignition of the stack.
Some research has shown that hay does not
need to reach such high temperatures to ignite
spontaneously. If hay is subjected to long
periods of heating at temperatures as low as 88°C
and remains in the presence of volatile gases
produced by oxidation, it may ignite when
introduced to air. In other words a relatively
low temperature for long periods may have the
same effect on hay as high temperatures for
short periods.
Combustion can therefore occur in two different
ways, in a hot pocket of carbonised hay or in a
larger volume surrounding the hot pocket.
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Time line
Spontaneous fires in stacked hay do not usually
occur in less than 10 to 14 days after stacking,
and generally require five to 10 weeks. Under
ideal conditions of moisture and high ambient
temperatures ignition has been observed in
six to seven days.
Figure 8.2 Testing the temperature of hay
within the stack – source Victorian Department of
Primary Industries.
Monitoring - a simple test
The temperature of a stack may be checked by
the use of a ‘temperature probe’, a crow bar or
other piece of steel. The bar should be left in
place and checked regularly (Figure 8.2). A pipe
or tubing should not be used as this may entrain
air into the stack and cause ignition to occur.
Any stack that is known to be heating should be
checked even more regularly to determine if
temperature is rising or falling. If the stack
continues to heat the only solution is to pull it
apart. Water and fire fighting equipment should
always be on hand to extinguish a possible
fire. Bales that have reached a high enough
temperature may spontaneously combust as they
are introduced to a more available oxygen supply.
Figure 8.2 provides information on a simple
method of estimating the temperature of hay in
the stack.
Figure 8.1 Causes of heating in hay – source C Sheaffer & N Martin.
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Hay transport
It is the responsibility of the vehicle owner,
manufacturer or operator to ensure the safe
performance, fitness for purpose and regulatory
compliance of any vehicle.
At the time of writing each state and territory
has its own regulations regarding the transport
of hay. AFIA is working to develop a set of
national standards for the transport of hay.
RIRDC continues to invest into research on
hay transport to support the development of
national standards.
Each state has legislation covering the loading,
restraint and dimensions of hay loads. The
industry, through AFIA, is addressing concerns
regarding load height and width as well as time of
travel, warning signs, lights and flags. Based on
current bale sizes and allowable load widths and
height, the hay transport industry anticipates a
minimum of 27% improvement in productivity
(30 square bales per load compared to 22) could
be achieved through proper reform of the hay
transport regulations Australia-wide.
Bale orientation
Round bales are less dense than squares, so
properly stacked and restrained loads of round
bales tend to be more stable than square bales
stacked to the same height.
The load stability of large square bales (nominally
4’x4’x8’) can be improved if they are stacked with
the strings around the sides and the knots to the
centre. This is because the bales tend to lean into
the centre of the trailer due to a natural thickness
bias in bales being thinner near the knots. This
method of loading also means bales are loaded in
the same orientation as they were stored on farm,
so any compression or settling of the bales over
time is not disturbed by loading on their sides.
For export hay, the tags attached to bale strings
can be readily inspected on the laden vehicle,
when stacked in this manner.
Load restraint
The method of load restraint has been shown to
have a measurable effect on vehicle stability. The
importance of load restraint is more than simply
keeping the load on the vehicle. The shift of a
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Image 8.3 The load stability of large square bales
(nominally 4’x4’x8’) can be improved if they are stacked with
the strings around the sides and the knots to the centre. For
export hay, the tags attached to bale strings can be readily
inspected on the laden vehicle, when stacked in this manner.
load’s centre-of-gravity that results from the
movement of poorly restrained loads (either in
the fore-aft or lateral directions) impacts on
vehicle performance, because it causes a change
in the load distribution between all tyres of the
vehicle. Lateral load shift brings about a small
amount of load transfer from the tyres on one
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side of the vehicle to the other, while fore-aft
(or longitudinal) load shift brings about a change
in load distribution between axle groups, which
can affect roll stability and braking performance.
A commonly accepted threshold for safe lateral
load shift is 100mm. Research conducted by
Roaduser Systems Ltd and funded by RIRDC,
showed that the maximum lateral movement for
all of the properly restrained loads tested is less
than 100mm. The load shift at the centre-ofgravity is less than 50mm, which represents a
movement of around 3% of the axle track width.
Longitudinally, this equates to an effective
centre-of-gravity shift of around 300mm based
on trailer wheelbase.
Information in this section is based on research
by Roaduser Systems Pty Ltd executed on behalf
of RIRDC. The full report references are:
Di Cristoforo, R. & Sweatman, P.F. (2003),
Testing and simulation of hay bale loading on
semi-trailers, Rural Industries Research and
Development Corporation Publication
03/120 Project ROA-1A.
Di Cristoforo, R. & Sweatman, P.F. (2004),
Further testing and simulation of hay bale
loading on semi-trailers, Rural Industries
Research and Development Corporation
Publication 04/124 Project ROA-2A.
This research also found that there are small
but worthwhile benefits gained by using more
effective load restraint methods such as
double-strapping or “double-dogging” of
single straps (one load binder on each side of
the load for a single strap).
It was found that the use of a diagonal bracing
strap provided an enormous improvement on
load stability. The research recommends that
diagonal bracing straps are used for securing all
groups of bales on a semi-trailer, two per group
of bales, at opposing angles (Image 8.4).
Fore-aft load restraint is sufficient when bales
are restrained by two individual straps, each
tensioned at one end by an under-floor winch.
The straps should be placed at an angle to the
vertical (except for the foremost and rearmost
straps, and straps on bales running across the
bed of the trailer). This method satisfies both
lateral and fore-aft load restraint requirements.
Image 8.4 Fore-aft load restraint is
sufficient when bales are restrained by
two individual straps, each tensioned at
one end by an under-floor winch. The
straps should be placed at an angle to
the vertical except for the foremost and
rearmost straps, and straps on bales
running across the bed of the trailer –
source Roaduser Systems Pty. Ltd.
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Useful resources
Australian Fodder Industry (AFIA)
www.afia.org.au
Latest variety information SARDI www.sardi.sa.gov.au
Department of Agriculture and Food WA
www.agric.wa.gov.au
Other state department websites
Seed company websites
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Plant Breeders Rights
www.affa.gov.au/content/pbr_database/search.cfm
RIRDC
www.rirdc.gov.au/fullreports/index.html
ARGT Testing
www.argt.com.au
Hay sampling for export
www.aqis.gov.au
Shear test calibration standards contact
[email protected],
Shear measurements of hay samples contact
[email protected]
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Producing Quality Oat Hay
By Pamela Zwer and Mick Faulkner
RIRDC Publiction No. 06/002
The market for oat hay, whether for export or
domestic use is driven by quality. High quality
hay demands high prices and depending on the
year growers can increase income by $50 to $100
a tonne for high quality hay. A consistent supply
of high quality hay is essential for the industry to
meet the challenges of increasing competition
from North America, expansion into new
markets and maintenance of current markets.
The purpose of the book Producing Quality Oat
Hay is to provide growers with a practical
management guide to produce high quality,
profitable hay crops. The information is based
on new developments and current research on
growing high quality oat hay.
This publication can be downloaded from our website –
www.rirdc.gov.au
All RIRDC books can be purchased from
www.rirdc.gov.au/eshop
Producing Quality Oat Hay contains details that
will help novice and experienced growers evaluate
the viability of oat hay in their system. Oat hay is
often grown for ryegrass control but with good
management it can become a profitable cropping
option. One of the great challenges is to achieve
high yield while maintaining or improving hay
quality. The book contains information on
all aspects of growing, making, storing and
transporting oat hay to meet these challenges.
It explains quality requirements by market and
how these are measured. Chapters include the
latest details on variety selection especially in
relation to disease; row spacing and seeding
issues; fertiliser management; cutting, curing
and baling hay; and storage and transport.
Contact RIRDC:
Level 2
15 National Circuit
Barton ACT 2000
PO Box 4776 Kingston ACT 2604