lucerne
prospects
2006
Michael Robertson
CRC FOR PLANT-BASED MANAGEMENT
DRYLAND SALINITY
OF
Drivers for widespread
adoption of lucerne
for profit and salinity
management
© Cooperative Research Centre for Plant-based Management of Dryland Salinity, 2006.
ISBN 0–9775865–0–2
This work is copyright. The Copyright Act 1968 permits fair dealing for study, research, news reporting,
criticism or review. Selected passages, tables or diagrams may be reproduced for such purposes provided
acknowledgement of the source is included. Major extracts of the entire document may not be reproduced
by any process.
Published by the Cooperative Research Centre for Plant-based Management of Dryland Salinity (CRC Salinity)
www.crcsalinity.com.au
Further copies may be requested from:
The Cooperative Research Centre for Plant-based Management of Dryland Salinity
The University of Western Australia (M081)
35 Stirling Highway
Crawley WA 6009
T: (08) 6488 2505
This publication should be cited as:
Robertson M (2006) Lucerne prospects: Drivers for widespread adoption of lucerne for profit and salinity
management. Cooperative Research Centre for Plant-based Management of Dryland Salinity, Perth.
Case studies described in this publication do not represent endorsement of specific practices or business models
and are used for illustrative purposes only. Maps showing lucerne prospect zones are also only illustrative and
should not be interpreted as indicating that the prospects for lucerne are uniform across a zone.
While reasonable efforts have been made to ensure that the contents of this publication are factually correct, the
CRC Salinity and its partners do not accept responsibility for the accuracy or the completeness of the contents, and
shall not be liable for any loss or damage that might be occasioned directly or indirectly through the use of, or
reliance on, the contents of this publication.
Editor: Kondinin Group
Graphic design: Kondinin Group
Cover photograph: Kondinin Group
Core partners of the CRC for Plant-based Management of Dryland Salinity:
Established and supported under the Australian
Government’s Cooperative Research Centres Program.
lucerne
prospects
Michael Robertson
CRC FOR PLANT-BASED MANAGEMENT
OF DRYLAND SALINITY
Drivers for widespread
adoption of lucerne for
profit and salinity
management
foreword
In the quest to manage dryland salinity we often look to plants for the answer. After all, it was the vast expanse of deeprooted native vegetation that maintained groundwater equilibrium for thousands of years of indigenous land use. And it
was the salt-tolerant scrub — grasses, sedges, herbs and shrubs — that adapted to the naturally saline land.
The CRC for Plant-based Management of Dryland Salinity is leading the national research effort to find and develop longterm, economically and socially acceptable agricultural systems that help manage salinity. Farms occupy approximately 60
per cent of Australia’s land mass, so the plant-based approach makes a lot of sense since growing plants is exactly what
farmers do.
Regarded as ‘the king of fodders’, lucerne travelled from Iran to Asia via the Silk Road about 2000 years ago, valued for
its high feed value and, unknowingly, for its ability to fix nitrogen. It is now dispersed as a significant pasture plant
throughout most countries with a temperate or Mediterranean climate, with Australia still a relatively minor player.
Lucerne is a widely adapted perennial plant with good productive value, persistence, and such effective water use that in
many situations it allows little or no leakage past its root zone. Clearly this makes it one of the most economically viable
options for emulating the role of native vegetation in reducing recharge and hence the spread of dryland salinity.
And yet there remain challenges — challenges to extend the range of lucerne into more stressful settings associated with
low rainfall and drought, acid and acidifying soil, heavy and uncontrolled grazing, and frequent cropping in systems facing
challenges such as herbicide-tolerant weeds. In tackling such challenges we are now finding lucerne performing
effectively in situations most would have previously thought improbable.
The area planted to lucerne in Australia is still far short of its potential, so there is no shortage of growth prospects for
the industry. However farmers will not grow lucerne just because it is possible. It must be profitable and practical, and
generally speaking it should be more profitable than other options.
Lucerne prospects provides what most land managers are looking for — an indication of the economic prospects of
integrating lucerne into their farming system.
Grazing industries have been resurgent in recent years and there are signs that this is well entrenched. Add to this a very
large national fodder industry and it is clear that there will continue to be a great demand for lucerne in Australian
farming systems. However for most farms in the wheatbelts of Australia, dryland cropping is still the best economic option
most of the time, so for these farmers a key issue is the extent of their lucerne use and how best to fit it into their crop
dominated systems.
The benefits that lucerne brings to the farm system include risk management — avoiding the risk of frost damage in lowlying areas by replacing crop with lucerne; a grass-free phase that helps manage cereal root disease and the development
of herbicide resistance; and of course an opportunity to significantly lower water tables in areas experiencing or at risk
from salinity.
The case studies introduced here cover a range of agro-climatic conditions across southern Australia and a range of
different farming enterprises. They give us a revealing snapshot of farmers who have taken on the lucerne option,
surmounted the challenges, and so often captured the benefit.
The CRC’s Lucerne prospects provides an essential insight into just how far we have come with lucerne as an important
component of farming systems and a realistic assessment of its future.
Lucerne prospects is one of five CRC prospect statements planned for 2006/07, one for each key farming technology that
synthesises existing knowledge across a range of projects. The statements address the case for current investment in
each farming technology, the limits and risks of current applications, and future development opportunities. The five
farming technology areas are:
•
•
•
•
•
Lucerne in crop and livestock systems
Sustainable production from saline lands
Livestock production from perennials in recharge areas
Integrated forestry in salt-source catchments
New industries from perennials in low rainfall environments.
Kevin Goss
CHIEF EXECUTIVE OFFICER
CRC FOR PLANT-BASED MANAGEMENT
OF
DRYLAND SALINITY
contents
introduction
Lucerne — growing towards a sustainable future
............................................................................
5
prospects
Prospects for lucerne in the Australian wheatbelt
.........................................................................
6
integration
Lucerne — the second wave ................................................................................................................. 8
Integrating lucerne with crops — principles, practices and prospects .................................... 12
region-by-region
Prospects region-by-region
.................................................................................................................
20
State-by-State
Assessment of areas suitable for lucerne production State-by-State ...................................... 25
Companions can get along well together ....................................................................................... 28
outlook
Regional outlook
...................................................................................................................................
29
Central Wheatbelt Western Australia .............................................................................................. 31
Case study: Lucerne proves timely opportunist ......................................................................... 33
South West Western Australia ........................................................................................................... 34
Case study: Lucerne repairs waterlogging damage ................................................................... 36
South Coast Western Australia .......................................................................................................... 37
Case study: Lucerne protects farm sustainability ..................................................................... 39
Wimmera/Mallee South Australia, Victoria and New South Wales ........................................... 40
Case study: Drought-proofing with lucerne ................................................................................ 42
Mid-north and Yorke Peninsula South Australia ............................................................................ 43
Case study: Profits rise as water table falls ............................................................................... 44
Case study: Boosting profits and managing salt ........................................................................ 46
South-West Slopes New South Wales and Riverine Plains NSW and Victoria ......................... 47
Case study: Nitrogen boost lifts grain quality ............................................................................ 50
Central West New South Wales ......................................................................................................... 51
Case study: Lucerne maintains productivity levels ................................................................... 53
influences
..................................................................................................................................
54
breeding
..........................................................................................................
56
.....................................................................................................................................
58
Breeding for wider adaptation
further reading
Further reading
3
2006
Global influences
lucerne prospects
regions at a glance
PHOTOS: K Fisher & C Nicholls
Acknowledgements
This document was prepared for the Cooperative Research
Centre for Plant-based Management of Dryland Salinity.
Thanks go to:
lucerne prospects
4
Felicity Byrne, Mike Krause and Andrew Bathgate for whole-farm economic analyses; Don Gaydon
for APSIM simulations; Michael O’Connor for regional maps; Doug Crawford, Mark Imhof, David
Maschmedt, Dennis van Gool and Ian McGowen for spatial analyses of potential lucerne area; Anna
Ridley, Roy Latta, Mike Ewing, Richard George, Tim Clune, Perry Dolling, Peter Regan, David
Pannell, Ted Lefroy, Gary Patterson, Kevin Graham and Alan Humphries for comments on drafts of
this document; Adrian Driden for comments on the seed industry; Neil Fettell, Bill Bellotti, Brett
Honeysett, Rob Harris, Jeff Hirth, Soheila Mokhtari and Christopher Loo for farmer case studies,
comments and rating of constraints; Geoff Auricht and Alan Humphries for information on lucerne
breeding; Tim Clune for permission to use results from project DAV253; Michele John for
information on climate change; and Bruce Munday and Georgina Wilson for editorial advice.
About the author
2006
Michael Robertson is group leader of CSIRO Sustainable Ecosystems in Western Australia, based at the
Centre for Environment and Life Sciences. He has published extensively in farming systems research,
crop and pasture agronomy and physiology, and simulation modelling. His involvement in the CRC
Salinity has been through integrating perennial pastures, including lucerne, into cropping systems.
Mike’s current research interests include salinity management in the WA wheatbelt, nutrient
management in cropping systems, management of climate variability in farming, and integrating
nature conservation with production in agricultural landscapes.
introduction
Lucerne — growing towards a
sustainable future
L
There are significant opportunities for greater areas
to be sown to lucerne in the Australian wheatbelt
due to recovery of commodity prices for livestock
products, potential market demands for ‘clean and
green’ and the need for more profitable enterprises
with declining terms of trade for grain production.
Regions with the best prospects for high
percentages of the farm under lucerne are those in
medium to high rainfall agro-ecological zones, with
a high percentage of suitable soils and with only
minor technical constraints. Producers who will
benefit most from the greater adoption of lucerne
are those who adapt their existing livestock systems
to lucerne’s specific grazing management
requirements. Even in low rainfall regions lucerne
provides an opportunity to reduce the level of risk
associated with annual cropping systems.
The current area under lucerne in Australia is
3.2 million hectares (about 7 per cent of farm area
in the regions considered here), compared with the
30 Mha potentially suitable in biophysical terms.
But given economic constraints, a realistic upper
limit for adoption might be about 7 Mha (15% of
farm area in low rainfall regions and up to 60% of
some farms in high rainfall regions).
Producers can close the gap between actual and
potential lucerne areas by adopting profitable
livestock systems and meeting some of the challenges
associated with integrating lucerne and crops. These
challenges include successful lucerne establishment
and removal, seasonal workloads, and minimising any
potential reduction in grain yields.
The aim of this document
This publication brings together existing
knowledge about lucerne as a basis for spelling
out its prospects as a profitable part of future
farming systems. It concentrates on the mixed
crop/livestock systems associated with the
Australian ‘wheatbelt’ and draws out the
implications for managing dryland salinity.
The discussion aims to inform and influence the
investment decisions of leading farmers, farmer
groups and their advisers, agribusiness, investors
in perennials, and natural resource management
groups interested in sustainable agriculture.
5
2006
As lucerne-based systems are almost leak-proof, the
local impact on salinity can be immediate where
large parts of the farm are planted.
lucerne prospects
PHOTO: C Nicholls
ucerne, one of the most nutritious pasture
species available, is also one of the most
economically attractive herbaceous perennials for
the management of dryland salinity. It is suitable
and widely adapted for use on mixed farms in the
medium to high rainfall areas of the Australian
wheatbelt, where it offers additional advantages for
the control of herbicide-resistant weeds and
provides resilience and diversity to mixed-farm
enterprises.
Prospects for lucerne in the
Australian wheatbelt
L
ucerne is a unique perennial legume in
terms of its scale of application, flexibility
and pattern of regional use in farming systems.
Among its considerable array of benefits is lucerne’s
capacity to contribute to the management of
dryland salinity, one of the most important but
challenging problems facing many farm managers.
This capacity derives from the ability of its deep
roots to use a high proportion of rainfall and of the
plant to respond to rainfall occurring outside the
winter growing period.
lucerne prospects
6
Lucerne is currently grown across 3.2 million
hectares of the Australian landscape, but a further
27 Mha has potential for lucerne production (see
pages 20–27).
2006
Ultimately it will be economic factors that drive the
wider adoption of lucerne in the Australian
wheatbelt. These drivers include the recovery of
prices for livestock products, potential market
demands for clean and green products and the need
for enterprise diversity on mixed crop/livestock
farms.
Lucerne has been widely grown as a permanent
pasture for many years, but by far its largest
potential for expansion is its integration within a
cropping rotation.
key features of lucerne
• summer-active perennial
• performs best with an annual rainfall
exceeding 350 mm
• prefers neutral to alkaline non-sodic soils
• prefers well-drained soils and is sensitive
to waterlogging
• frost-tolerant
• requires short spells of rotational grazing
for successful persistence and production
Successful use of lucerne in an integrated cropping
system requires producers to:
• maximise the use and benefits of the lucerne
pasture phase to livestock enterprises
• optimise the positive benefits flowing from the
pasture phase to subsequent crops (for
example, nitrogen fixation, weed and disease
management)
• manage the potential costs and impacts of
lucerne on following crops (for example,
effective establishment and removal strategies
and competition for water)
• manage additional workload and lifestyle
preferences.
prospects
Lucerne is currently the most important and readily
available plant for salinity management in southern
Australia. Knowing and understanding its
capabilities is important for maximising successful
low risk investment opportunities and defining the
target environments for alternative options.
The extent to which perennial plants, such as
lucerne, can reduce salinity or even limit its further
spread is closely linked to their scale of application
in farming systems. The highest lucerne use to date
has been achieved in medium to high rainfall
wheatbelt regions where lucerne grows well and
where livestock are critical to farm profitability.
Lucerne adoption in Australian farming systems
might be expected to expand to at least 7 Mha in
the medium term, but this remains well short of
the area currently regarded as suitable for
production. This is partly due to the limited use of
lucerne in phase rotations (rarely more than 50% of
years as lucerne), which is in turn partly explained
by the needs of livestock enterprises for a range of
pasture types providing year-round production.
Existing livestock production systems need
modifying to better exploit the opportunities
presented by lucerne. Genetic improvements to
overcome existing challenges (such as acidity and
grazing tolerance, and drought persistence) will
also facilitate additional expansion.
•
attributes of lucerne that make it the most
widely-grown herbaceous perennial
suitable for mixed farming systems in the
wheatbelt (Lucerne — the second wave,
pages 8–11)
•
principles, practices and prospects
involved in integrating lucerne with crops
(Integrating lucerne on farm — principles,
practices and prospects, pages 12–19)
•
prospects for lucerne across seven regions
(Prospects region-by-region, pages 20–24)
•
assessment of areas suitable for lucerne
production (Assessment of areas suitable
for lucerne production State-by-State,
pages 25–27)
•
region-by-region evaluation of lucerne for
the:
•
•
•
•
Central Wheatbelt WA (pages 31–33)
South West WA (pages 34–37)
South Coast WA (pages 37–39)
Wimmera/Mallee SA, Victoria and NSW
(pages 40–42)
• Mid-north and Yorke Peninsula SA
(pages 43–47)
• South-West Slopes NSW and Riverine
Plains NSW and Victoria (pages 47–50)
• Central West NSW (pages 51–53)
•
extent to which global factors could
influence uptake (pages 54–55)
•
prospects for improved cultivars for wider
adaptation (pages 56–57)
•
suggestions for further reading
(pages 58–60).
lucerne prospects
Opportunities for expansion
This publication outlines the prospects for
profitable lucerne adoption in the wheatbelt
of southern Australia to help manage dryland
salinity. It covers:
7
2006
PHOTO: K Fisher
How this Prospects Statement helps
PHOTO: Kondinin Group
Lucerne — the second wave
L
ucerne is currently experiencing its second
wave of adoption by Australian producers,
having been introduced to New South Wales in 1806.
By 1833 some 800 hectares were growing as
permanent specialist pastures, valued for their
combination of productivity and pasture quality.
lucerne prospects
8
Gradual expansion occurred until 1976 when there
were more than 200,000 ha in pure lucerne stands,
dominated by the local Hunter River cultivar. This
cultivar proved to be highly susceptible to attack by
several exotic aphid species, which arrived in
Australia during 1977 and spread rapidly.
Consequently, stands were devastated, plantings
ceased, lucerne hay production fell dramatically
and seed production became insignificant.
State Departments of Agriculture and commercial
seed companies reacted promptly and started to
evaluate cultivars from the USA to identify adapted
and productive aphid-resistant germplasm for use
and incorporation into breeding programs.
2006
The second wave of lucerne interest emerged as it
became clear new cultivars could resist aphid
predation. By 1999 the area sown to lucerne, both
pure and mixed stands, had recovered to their
current levels of about 3.2 Mha.
Historically lucerne was grown as a permanent
pasture, even on cropping farms, but there is a
growing momentum to increase the integration of
lucerne into cropping systems in the wheatbelt.
While the primary objective has been to produce
profitable and stable systems, integrated lucerne
rotations also offer the opportunity to manage
dryland salinity and other farming system challenges
such as herbicide resistance and waterlogging.
Embracing this new role for lucerne in cropping
systems sets Australian producers apart from those
in most other countries and regions where lucerne is
used mainly as a permanent pasture for forage
(silage, hay or cut and carry) or grazed directly,
usually with intensive rotational grazing strategies.
The distinctive farming system context linked to
expanded lucerne use in Australia means unique
management strategies are required along with
cultivars that meet the demands of our systems.
Some of the benefits of cropping rotations based on
lucerne versus annual pastures are summarised in
Table 1.
Wide-ranging suitability
Currently grown in a wide range of environments
from sub-tropical southern Queensland to cool,
temperate Tasmania, lucerne is also productive and
persistent throughout much of the wheatbelt in
southern and western Australia, even in regions
receiving as little as 300 millimetres of average
annual rainfall. It can be a more valuable forage
crop than shallow-rooted annual pasture legumes
due to its perennial habit, responsiveness to summer
rain, and ability to survive long drought periods.
integration
TABLE 1: Comparison of crops grown in phase with lucerne or with annual pastures
Impact
Cropping operations
Pasture termination
In-crop weed control
Grain yield
Summer weeds
Pasture establishment
Livestock operations
Stocking rates
Grazing management
Ewe joining dates
Lambing dates
Weaning dates
Shearing dates
Supplementary feeding
Farm economics
Livestock returns
Cropping returns
Crops growing in phase with
annual pastures
Crops growing in phase
with lucerne
Not required
More herbicide-resistant
grass weeds
Soil water supply less likely
to limit grain yields
More opportunity for summer
weed invasion
Less costly
Required
Fewer herbicide-resistant
grass weeds
Soil water supply more likely to
limit first year crop yields
Less opportunity for summer
weed invasion
More costly
Lower, especially in drier
environments
Set-stocking
Higher, especially in drier
environments
Rotational with infrastructure costs
(fencing/watering)
Late summer to mid-autumn
Winter/spring
Late spring/early summer
Summer
Less summer/autumn feeding
but less winter feed supply
Early to mid-summer
Autumn/winter
Early spring/mid-spring
Spring
More summer/autumn feeding
but greater winter feed supply
Lower supply of lambs to oversupplied markets; grass seed
penalties
Slightly higher — less impact on
subsequent crops
Increased supply of late
season lambs
Slightly lower in first year after
lucerne if dry conditions
Source: R Harris, DPI Victoria
lucerne prospects
In frost-prone situations, such as valleys in the
wheatbelt of Western Australia, lucerne can be a
lower risk land use than cropping.
Lucerne is more amenable to adoption than other
perennials such as trees or woody shrubs because
it provides a more immediate return on investment
and is more easily integrated into a farming system
with crops and other pastures.
In South Australia and Victoria, lucerne paddocks
often provide a bushfire buffer.
PHOTO: R Ballard
Field trial for acid-tolerant lucerne rhizobia
2006
9
While best adapted to neutral and alkaline soils,
lucerne will grow on mildly acid soils but is sensitive
to moderately acidic soils containing aluminium and
manganese. It is intolerant of waterlogging but can
be used to help manage waterlogged sites.
Profit and sustainability prove key drivers
Lucerne can be a profitable enterprise in its own
right, but the key to its ability to contribute to
whole-farm profit and sustainability lies in increased
integration into the whole farming system.
lucerne prospects
10
PHOTO: K Fisher
Modelling predicts that lucerne can increase wholefarm profitability by as much as $80,000 annually for
some enterprises in optimum agro-ecological zones,
on a 1000 ha property. In other agro-ecological
zones the increased profit per hectare is less, but
properties in these zones are generally larger.
Case studies presented in the following pages show
that for any given farming system there is a broadly
defined optimum area for lucerne that maximises
whole-farm profit. The size of this area varies from
region-to-region, due to differences in rainfall,
climate and soils. It also varies from farm-to-farm
depending on soil types, the livestock enterprise
mix, occurrence of herbicide-resistant weeds and
management expertise.
The beneficial buffer against recharge
In marginal areas, lucerne can increase farm profit
slightly, but in many cases not enough to warrant
adoption, particularly given the management
considerations and costs of transition to livestock
infrastructure. But in other cases, if lucerne can
ameliorate soils previously unsuitable for cropping
(for example, by reducing deep drainage and
therefore waterlogging or salinity) then increases in
profit, through improved crop production, will
justify greater lucerne areas. In some low rainfall
environments lucerne can provide an important risk
management tool even if it does not improve
overall profitability.
When integrated into annual cropping systems
lucerne can create a dry soil buffer (the maximum
additional soil water storage available after lucerne,
compared with storage available after an annual crop
or pasture) equivalent to at least 100 mm of rainfall.
It can thus prevent or significantly reduce leakage in
most pasture years and reduce and delay leakage
during following crops. In some cases this can have
an immediate and significant effect on groundwater
levels (see Figure 1).
2006
Environmental benefits, and hence farm
sustainability, are enhanced by the ability of
lucerne roots to penetrate difficult subsoils,
improving soil structure, recycling deep soil
nitrogen and increasing soil microbial populations.
Lucerne also reduces the risk of soil acidification
and soil erosion, particularly if grown with
companion species.
Cattle grazing lucerne in April, Marcollat (SA)
As a summer-active perennial, lucerne can
significantly reduce groundwater recharge with a root
system that grows deeper into the soil, creating a
zone of dry soil beyond the penetration depth of
annuals during a single growing season.
The extent to which lucerne can create a dry soil
buffer varies, but in general the buffer increases with
lucerne age and is greater for heavier-textured soils.
integration
FIGURE 1: Dry soil buffers for storing excess winter rainfall under lucerne compared with annual
crops/pastures
1m
3m
Lucerne
Annual
High quality feed and fodder
Management the key to success
Well-managed lucerne pastures can deliver high
quality grazing (energy and protein) at all stages of
plant growth and high quality fodder for conservation
as silage or hay. Compared with annual pastures,
lucerne production and quality is superior during
summer and autumn, depending on rainfall, but is
likely to be less productive during winter.
Like most changes to existing farming systems,
lucerne integration has potential implications for
farm management and workload.
Superior summer and autumn productivity and
quality overcome a major constraint to livestock
production from annual pastures and even modest
areas of lucerne can allow useful and profitable
stocking rate increases.
Lucerne is ideal for finishing prime lambs and
yearling cattle, and for putting weight on ewes
during summer, leading to improved lambing
percentages. Lucerne can also increase wool
quality and tensile strength and reduce the risk of
internal parasites in sheep.
It follows that livestock production systems that
take full advantage of the benefits of lucerne and
manage the challenges can significantly improve
profitability.
The challenges are most evident in a pure lucerne
stand and can include animal health issues such as
bloat and red gut. Productivity challenges are
mainly the low level of production during winter
and leaf drop in extreme summer conditions.
Some producers see lucerne as offering an
equivalent stocking rate but at a lower cost and
with less time committed to supplementary
feeding, particularly during the summer/autumn
feed gap.
For others it is a pathway to higher stocking rates
and profits but with possible increased workloads
around livestock management.
In addition to the benefits to livestock enterprises,
integrating lucerne into a cropping rotation can
provide opportunities to control weeds and reduce
the risk of herbicide resistance. This will have
flow-on benefits in lowering the costs of cropping
through reduced weed burdens and by providing a
disease break in cropping rotations.
Management changes needed to maximise the
benefits of lucerne largely centre on the need for
rotational grazing. This can require increased
fencing and stock water supply, particularly where
these have been removed to allow for
uninterrupted use of cropping machinery.
lucerne prospects
Source: R Harris, DPI Victoria
11
2006
Larger zone of
dry soil creating
a greater buffer
to store excess
winter rainfall
resulting in less
leakage
Smaller zone of dry
soil resulting in a
smaller buffer and
more leakage
Integrating lucerne with crops —
principles, practices and prospects
I
ntegrating lucerne into whole farming
systems offers opportunities to
simultaneously increase farm profits and reduce
leakage to groundwater.
Optimising these outcomes requires strategic
management decisions that in turn will vary with
regional conditions and farm enterprise mixes.
This is illustrated in Figure 2 where, for a typical
farming system, modelling shows that profits
increase until 20% of the farm is under lucerne,
but beyond this point profits start to decline.
The outputs from this model (MIDAS or Model of an
Integrated Dryland Agricultural System), being
sensitive to enterprise mix and regional conditions,
will generate unique curve profiles and achievable
profits for each farm situation. See Table 7 on
page 30 for its application to regions.
lucerne prospects
Whole-farm profit ($ per year)
A phase or rotational cropping system allows lucerne
to be successfully integrated with crops. Typically
the lucerne phase (of two to five years duration) is
followed by a phase of crop production, usually of
similar duration.
The many advantages to this system include its
potential flexibility in phase length, improved soil
structure and reduced rates of leakage to
groundwater, along with the benefits for cereal
crops following lucerne (such as increased yields
and grain protein levels).
Lucerne can improve soil structure, encouraging
better root penetration by crops after lucerne
compared with a continuous annual system. This
can reduce crop leakage rates after lucerne and
increase root growth during the lucerne phases.
Grain yields following lucerne can increase, but in
drier seasons or locations they may decrease in the
initial crop.
FIGURE 2: The optimum area for lucerne on a
representative farm
12
Phase cropping
Grain protein contents for crops grown after the
lucerne phase also tend to be higher than those
grown after other crops or pastures, but again
results vary depending on soil conditions and
lucerne’s own demand for nitrogen.
140,000
120,000
100,000
80,000
60,000
40,000
20,000
0
0
10
20
30
40
Area of lucerne on farm (%)
50
When planning a phase system that incorporates
lucerne, producers need to weigh up their options
regarding phase length, establishment tactics,
maintenance of plant density during the lucerne
phase and the transition from lucerne to crop
production.
2006
The optimum length of the lucerne and cropping
phases to minimise leakage varies according to soil
type, paddock management and rainfall patterns.
These are the factors that influence the persistence
of the soil water buffer created during the lucerne
phase.
integration
Managing soil water buffers
The development of a buffer of drier soil is central
to lucerne’s role in reducing groundwater recharge
and possible waterlogging and salinity.
There is generally little leakage reduction to be
gained through extended phases of lucerne, but
whole-farm benefits are possible with increased
areas of lucerne.
Depth of water extraction (m)
FIGURE 3: Depth of extraction by lucerne roots in
three contrasting soils in WA
0
200
Days since sowing
400
800
600
1000
1
2
In wet environments with soils of low plantavailable water capacity (PAWC), such as shallow
duplex soils in medium to high rainfall Western
Australia, buffers last on average, two years. On
the other hand, in medium rainfall environments
with uniform rainfall throughout the year and soils
of reasonable PAWC, such as the Riverine Plains of
New South Wales and Victoria, the leakage may not
return to levels like those under annual cropping
for an average of five to six years. In environments
with a run of dry seasons the buffer could last for
up to 10 or even 20 years.
A key element of phase design for leakage control
is the ability of the system to cope with rainfall
variability. For instance, although lucerne can
generally reduce leakage in subsequent cropping
years, a small proportion of very wet years will
result in high and unacceptable leakage during the
cropping phase.
3
4
5
Duplex, sodic subsoil
Duplex, acid subsoil
Source: Dolling et al. (2005a)
Deep sand
This variability invites a tactical approach, with
phase changes between cropping and lucerne
prompted by a measurement or estimate of soil
water below the crop root zone, groundwater
measurements if the system is responsive, or
rainfall measurements, as there is a direct
relationship between cumulative rainfall and the
filling of the profile.
lucerne prospects
In hostile subsoils lucerne roots can penetrate,
albeit slowly, to considerable depth (see Figure 3),
while on deep soils with no subsoil constraints roots
can reach 4 metres within one year. On duplex
soils with acid or sodic subsoils roots eventually
reach 2 m during three years of growth.
Lucerne roots can penetrate several metres in
some soils
13
2006
In many situations the buffer develops to its
maximum two to three years into the lucerne phase
and longer phases do not reduce leakage any
further. Typically, the buffer reaches a maximum
equivalent to 100–150 mm of rainfall, although
deep, heavy clay soils have recorded buffers greater
than 200 mm. Leakage will not occur again until
the buffer is offset by rainfall greater than that
used by the following annual cropping phase.
PHOTO: Y Oliver
The nature of the established buffer, which is
influenced by soil type, rainfall and the density and
vigour of the lucerne stand, is significant when
making decisions about the length of the subsequent
cropping phase.
Indications of soil wetting up at
depth could signal the need to
switch to lucerne, whereas the
absence of further drying at
depth may indicate it is time to
return to cropping. Simulations
support this flexible approach to
phase periods rather than fixed
rotations.
Researchers are currently
exploring the use of simple,
inexpensive soil water potential
sensors that can indicate
initiation of wetting and drying
deep in the soil profile.
The costs associated with
lucerne establishment need to
be recovered during the
following pasture and crop
phases, so successful low-cost
establishment leading to a
maximum period of productivity
is essential.
lucerne prospects
14
A number of general establishment strategies are
in wide use and this diversity reflects regional and
farm-to-farm differences. Lucerne establishment in
low rainfall regions offers the greatest challenges
and ignoring the possibility of some climate-related
failure is over-optimistic. Lucerne can establish in
such regions, but it often only persists at low
density and requires intensive management.
The two main establishment options in a phase
system involve sowing lucerne as a monoculture or
with a cover crop (often canola or barley).
2006
The timing of monoculture sowings can vary from
winter through to spring, and is often influenced by
the need for effective pre-sowing weed control.
Cover crop establishment usually involves reduced
crop density, often with increased crop row spacing.
PHOTO: E Madden
Successful lucerne
establishment
Bruce Whitby, Narrandera (NSW) — lucerne
established with wheat cover crop
Either strategy requires suitable site selection and
pre-sowing preparation. In general, lucerne
establishes successfully and grows productively in a
wide range of soil types and conditions. However it
requires a relatively weed-free seed bed with no
history of Group A herbicide use during the past 12
months and adequate levels of phosphorus,
potassium and sulphur.
Recommended practices for successful lucerne
establishment are well documented in publications
such as Success with Lucerne (Stanley et al. 2002).
integration
FIGURE 4: Long-term APSIM simulations for the
Riverine Plains (NSW) indicate that early
removal of lucerne benefits grain yield
Timing and methods of lucerne removal
Timing lucerne removal is a delicate balance
between maximising potential crop yield and
achieving the groundwater benefits of a soil
water buffer.
Continuous cropping
Autumn removal
Spring removal
Reduced crop yields in the first or second year after
lucerne are often due to the greater extraction of
soil water by lucerne, particularly on heavier soils
in low to medium rainfall regions where the wet-up
period is longer.
Delaying lucerne removal until autumn can reduce
crop yields due to the reduced soil moisture levels
going into the cropping phase, but compared with
spring removal it also reduces deep leakage for one
to three years following. Producers often report
difficulty in removing lucerne during autumn, but
modelling suggests the benefit to less leakage
through late removal could equate to about
10 mm/yr.
Removing lucerne earlier (during spring) leaves
more time for soil water to accumulate and
nitrogen to mineralise before sowing a crop (see
Figure 4), the benefit to crop yields being greatest
in dry environments. The down-side is the potential
for wind erosion during summer, loss of summer
lucerne production and the risk of filling the soil
water buffer earlier.
Wheat yield (t/ha)
6.0
5.5
5.0
4.5
4.0
3.5
3.0
1st
3rd
2nd
Wheat crop after lucerne
Herbicide removal or heavy set stocking during
spring, rather than tillage, can be used to retain
groundcover. But research shows the reliability of
removing lucerne with herbicides is greatest when
it has been allowed to regrow for four to five weeks
following complete defoliation, coinciding with the
downward movement of sap sugars and proteins
from the shoots to the taproot (see Figure 5).
Herbicide efficacy also is reduced if lucerne is
grazed, mown or cultivated in the two weeks
following application.
lucerne prospects
FIGURE 5: Growth stage determines the direction of carbohydrate movement and herbicide efficacy when
attempting to remove lucerne
Spraying window for maximum herbicide efficacy
Direction of assimilate
movement
1 week
2 weeks
Utilisation phase
Source: M Peoples, CSIRO
3 weeks
4 weeks
Storage phase
5 weeks
Budding
6–7 weeks
Flowering
Reproduction phase
2006
15
Companion cropping
Companion cropping (also known as intercropping or
overcropping) is another way to integrate lucerne
with crops without the cost and risk of both
establishing the lucerne and removing it at the end
of each phase.
Direct-drilling crops into existing lucerne pastures,
takes advantage of the different seasonal growth
patterns of the two plant types (see Figure 6), crops
growing fastest during spring, lucerne being more
summer active. This offers the advantage of
increased cropping intensity, while maintaining the
perennial component for leakage and waterlogging
control, summer forage and groundcover, and
reduced weed competition.
Companion cropping systems potentially provide
similar levels of soil water control to a lucerne-only
phase, but with an extended period of protection,
while still allowing grain production.
These benefits, along with pasture production,
must be offset against likely crop yield reductions
due to lucerne competition.
Lucerne stands generally deteriorate with time,
leaving an opportunity for a companion crop in the
low density lucerne stand during the transition to
the pure cropping phase, when lucerne is
completely removed (see Table 2).
FIGURE 6: Activities undertaken when farmers companion crop lucerne
1 Rotational
graze
2 Pre-crop lucerne
suppression and
weed control
3 Sow crop
4 In-crop lucerne
suppression
5 Harvest crop
6 Wean prime
7 Rotational
lambs onto
companion
crop stubble
graze
TIME
lucerne prospects
Summer
Autumn
Winter
Spring
Summer
Source: R Harris, DPI Victoria
TABLE 2: Comparison of phase and companion systems for grain yield, lucerne production and leakage
below the root zone (after Ward et al. 2004)
Year
1
2
3
4
5
6
TOTAL
0.0
2.0
30
0.0
3.0
0
0.0
3.0
0
3.0
0.0
0
3.0
0.0
30
3.0
0.0
30
9.0
8.0
90
0.0
2.0
30
0.0
3.0
0
1.5
1.0
0
2.0
0.6
0
2.7
0.3
0
3.0
0.0
30
9.2
6.9
60
Phase
16
2006
Grain (t/ha)
Lucerne (t DM/ha)
Leakage (mm)
Companion
Grain (t/ha)
Lucerne (t DM/ha)
Leakage (mm)
PHOTO: J Patterson
integration
Canola harvest with lucerne, Dumbleyung (WA)
Managing competition between crops
and lucerne
80
70
60
40
30
200
250
300
350
400
450
Mean annual rainfall (mm)
TABLE 3: Suppression of lucerne with herbicides increases grain yield in companion cropping and reduces
grain contamination in northern Victoria
Treatment
Companion cropping
Companion cropping + suppression
Cereal only
Courtesy of R Harris, DPI Victoria
Grain yield
(t/ha)
5.02
5.34
5.66
Grain contamination
(per hectolitre)
53
2
0
Grain protein
(%)
9.6
9.5
10.6
lucerne prospects
50
17
2006
Three seasons of experiments in southern NSW
and trials in SA have shown in-crop suppression of
lucerne growth with herbicides significantly
increases grain yield and reduces risk of grain
contamination from lucerne leaf curls and seed
pods (see Table 3).
FIGURE 7: Long-term APSIM modelling suggests
competition for water between crops and
lucerne is a significant factor in
companion cropping
Yield loss in companion
cropping compared to
crop monoculture (%)
Competition for water between crops and lucerne
in a companion cropping situation is more critical
in drier years or locations, whereas in wetter
circumstances competition for nitrogen is the main
crop yield constraint (see Figure 7). As nitrogen is
easily added, companion cropping is generally best
adapted to wetter regions of the cereal-growing
areas. But in drier regions, opportunistic
companion cropping into low-density lucerne
stands (less than three plants per square metre) in
response to positive seasonal forecasts can optimise
crop yield potential and increase long-term
economic returns.
PHOTO: K Fisher
Best results come from rotational grazing
Maximising grazing opportunities
Lucerne in alleys
Where integrating lucerne into grazing enterprises,
producers need different management strategies to
those used for grazing annual pastures to optimise
the production benefits from both livestock and
pasture.
Alley cropping, in which strips of lucerne alternate
with crop, is a variation on companion cropping.
Spacing between strips depends on the amount of
leakage occurring under annual crops and the
extent to which lucerne can dry out the soil
laterally into the crop.
Experience has shown short spells of rotational
grazing is the most effective strategy for grazing
lucerne, to maximise pasture persistence and
quality.
Experiments in WA and NSW have shown the
influence of lucerne on soil water content under
adjacent crops varies between 0.5 and 1.5 m
depending upon soil type. An alley design of 0.5 m
lucerne and 2 m crop can limit leakage to 10% of
annual rainfall, but competition between lucerne
and crop reduces grain yield by 40–50%.
lucerne prospects
Sheep mostly graze close to watering points and
shade, leading to uneven pasture removal in large
paddocks. This can be avoided with higher stocking
densities on smaller paddocks, temporary electric
fencing or, where possible, grazing with cattle.
Wider strip cropping design can reduce crop
competition, but lessens the effectiveness of
leakage management. Alley systems are unlikely to
have practical application based on the information
currently available.
To maximise profit from the lucerne phase,
producers can increase stocking rates, focus on
higher value products (for example, prime lambs or
vealers instead of medium-wool or store lambs),
reassess the time of lambing or calving and reduce
supplementary feeding (see Figure 8).
The aim is to convert lucerne pasture into profit
and manage livestock effectively to optimise the
use of the highly digestible, high protein legumedominant pasture.
18
PHOTO: Y Oliver
2006
Alley trial at Dumbleyung (WA)
integration
Lucerne-annual legume mixtures
Including perennial grasses, such as phalaris or
cocksfoot, with lucerne as part of the pasture
mixture reduces the risk of bloat and red gut.
Perennial grasses can be more productive during
autumn/winter, helping offset the winter feed gap
common in pure lucerne pastures and reducing the
need for supplementary feeding.
Perennial grasses act as a sink for any excess
nitrogen produced by lucerne, increasing their
productivity and ensuring the lucerne maintains a
high nitrogen fixation rate. Perennial grasses also
inhibit the invasion of lucerne swards by unwanted
annual grasses.
When using perennial grasses in lucerne mixtures,
the lucerne density needs to be reduced to ensure
the available rainfall can support the total number
of perennials per unit area.
Perennial grasses are removed along with the
lucerne, when returning to the cropping phase.
FIGURE 8: Optimum lucerne area for a mixed crop
and livestock enterprise increases with
rainfall. Modelled ‘current’ system (selfreplacing ewe flock) compared with ‘new’
system (prime lamb production) and grass
mixtures where applicable.
Results from four regional whole-farm
economic models in WA
60
Current
New
50
40
30
Decreasing the lucerne density, increasing the
lucerne row spacing and selecting appropriate
cultivars are effective strategies to increase
subclover persistence in lucerne swards.
Maintaining adequate plant density
Lucerne stands can vary in density from few to
more than 100 plants per square metre. Plant
density generally declines with time, influencing
decisions about re-sowing or cropping.
While low lucerne densities can take longer to dry
soil profiles, they compensate by becoming large
individual plants with more stems, leaves and roots,
compared with smaller plants found in denser
stands. Nevertheless, stands with initial densities
of less than six plants per square metre are
generally less effective in drying soils than denser
stands. Research in WA on relatively hostile soils
showed higher densities were required than in
eastern Australia to achieve similar outcomes.
20
19
10
0
200
300
400
500
600
Mean annual rainfall (mm)
Source: Modified from Lefroy et al. (2005)
700
2006
Optimum area of farm
under lucerne (%)
70
Mixtures of lucerne and annual legumes, such as
subterranean clover, are common in NSW and
Victoria. The subclover helps fill the winter feed
gap and provides groundcover between the lucerne
plants. Where lucerne fails to persist due to
drought, waterlogging or overgrazing, swards revert
to an annual legume pasture that can still be highly
productive but lacks the capacity to provide a soil
water buffer. High lucerne densities can inhibit
subclover germination during autumn, particularly
when autumn rains are light or not followed by
further rain.
lucerne prospects
Lucerne-grass mixtures
PHOTO: R Bennett
Lucerne in wheat at Katanning (WA)
Prospects region-by-region
T
he prospects for widespread adoption of
lucerne for profit and salinity management
vary markedly from region to region.
The following section investigates seven regions
within the Australian wheatbelt, based on CRC
Salinity research indicating they represent the most
promising prospects for lucerne (see Figure 9).
lucerne prospects
20
The prospects for lucerne in each of these regions
have been evaluated against the following criteria:
• profitability — how different areas of lucerne
on mixed farms affect whole-farm profit
• leakiness and productivity of different phase
and companion systems
• impact on salinity
• suitability of soils and climate
• drivers and constraints to adoption.
2006
A case study then follows for each region examining
how leading producers successfully use lucerne for
profit and salinity management.
Profitability
Producers are most likely to adopt lucerne if it is
profitable. Case studies and modelling described
here highlight the economic opportunities for
lucerne in the wheatbelt to encourage further
widespread adoption.
Producers are generally aware of the role lucerne
and other perennials can play in managing salinity,
but are often deterred by the economic costs
compared with what appear to be limited benefits.
This caution towards lucerne is not helped by the
difficulties of trialling the various options, the long
time needed to gather definitive results, and
uncertainty about how lucerne can impact on other
aspects of the farm system including farm labour.
Where possible the regional evaluation uses wholefarm models, configured to represent a typical farm
within a region, with its soils, crop and pasture
sequences, livestock production, costs, prices and
availability of labour and capital. In regions where
a suitable whole-farm model was unavailable
simpler methods were used, such as farm budgeting
approaches and case studies.
While results are representative of the various
regions with typical farm system configurations,
there will naturally be variations from farm-to-farm
within each region.
region-by-region
FIGURE 9: Seven regions where lucerne prospects have been evaluated
NORTHERN
TERRITORY
QUEENSLAND
WESTERN
AUSTRALIA
SOUTH AUSTRALIA
NEW SOUTH
WALES
Northam
Perth
Katanning
Esperance
Albany
Renmark
Griffith
Mildura
Adelaide
Goolwa
Bordertown
South Coast WA
Mid-north and Yorke Peninsula SA
Wimmera/Mallee SA, Victoria & NSW
South-West Slopes NSW & Riverine Plains NSW & Victoria
Sydney
Young
Wagga Wagga
Wangaratta
Melbourne
Prospect regions
South West WA
Cowra
VICTORIA
Ararat
Bendigo
Central Wheatbelt WA
Nyngan
Dubbo
TASMANIA
lucerne prospects
Port Pirie
21
2006
Central West NSW
Profitability being the
driver for widespread
lucerne adoption, the
whole-farm economic
analyses presented here
highlight some key
messages:
For a given farming system there is an optimum
area of lucerne that maximises whole-farm profit.
The size of this area varies from region-to-region,
due to differences in rainfall, climate and soils. It
also varies from farm-to-farm depending on the soiltype mix, animal enterprise, occurrence of
herbicide-resistant weeds and producer expertise.
lucerne prospects
22
Beyond this optimum area, profit decreases with
each additional hectare of lucerne, because the
opportunity cost of not growing something else
exceeds the benefit from the additional hectare.
So, while some lucerne is good, more is not
necessarily better. In some cases the decrease in
profit is small, meaning lucerne beyond the
optimum might be grown if improved leakage
control is a priority.
2006
Optimum lucerne area and profitability depend on
livestock enterprises. Whole-farm modelling and
farm budgets show that changes in livestock
enterprise from wool to prime lambs deliver the full
economic benefit from increased lucerne. Changes
to lambing date, a higher lambing percentage and
the use of crossbreds are all characteristic of more
profitable systems. The demand for supplementary
feeding varies, in some cases increasing, while in
others decreasing.
In some regions (including South Coast WA)
companion grass species promote a greater
percentage of the farm under perennials.
PHOTO: G Gates
Key messages
High quality fodder can be a profitable enterprise
Targeting soil types is important. Moving to
lucerne is not a process of simple substitution for
annual pastures. Crop rotations and the soil types
upon which they occur often need to change also.
Small changes in lucerne production or
profitability per hectare will have minimal impact
on the optimum area. This is because the fixed
costs of lucerne production are closely related to
the area planted, and generally much greater than
any variation in profit due to changes in
productivity.
In marginal areas the slight increase in farm
profit from lucerne might not warrant adoption.
In some cases management considerations and the
costs of transition involving reduced return on crop
infrastructure and new investment in livestock
infrastructure are too great an impediment. But if
lucerne can ameliorate soils previously unsuitable
for cropping (for example, due to waterlogging or
salinity) then increases in profit from improved
crop production will justify greater areas of
lucerne.
Some producers believe that while lucerne may not
improve overall profitability it forms a risk
management tool in low rainfall environments.
region-by-region
Productivity and leakage
Impact on salinity
Grain and fodder yields in phase and companion
systems compared with cropping and pure lucerne
stands are estimated using simulation modelling.
Lucerne’s impact on salinity by reducing leakage
to groundwater is affected by rainfall, soil type
(mainly the plant available water capacity), length
of the lucerne phase, timing of establishment and
removal, and management and density of the
lucerne stand.
For each region the combination of soils and rainfall
means phase and companion systems differ in
productivity and leakage control.
When used in cropping systems, lucerne reduces
leakage below the root zone to less than 5 mm/yr
in most environments. When grown as part of a
crop rotation there is some risk of leakage during
the cropping phase but permanent lucerne pastures
will reduce leakage to lower levels than in annual
systems. Permanent lucerne pastures and
companion cropping systems are equally effective
at reducing leakage.
The complex interplay between these factors can
be assessed with simulation models.
Whether lucerne has any on-farm impact across a
more sizable area depends on the area planted
within a particular farm or catchment and the
characteristics and stage of development of the
underlying groundwater flow system (see
Figure 10). Several studies as part of the National
Dryland Salinity Program have shown that 50% or
more of some catchments would need to be
managed for recharge reduction with perennials
such as lucerne to prevent or control salinity.
lucerne prospects
FIGURE 10: Distribution of groundwater flow systems in Australia
Scale: 1:22,000,000
Kilometres
0
1000
Projection: Lambert Conformal Conic with standard parallels 18°S and 36°S
Local
Intermediate
Source: National Land and Water Resources Audit
Regional
2006
23
Local groundwater flow systems respond relatively
rapidly to salinity management practices and afford
opportunities for dryland salinity control through
alternative land management practices such as the
use of perennials.
Profitable innovations that prevent or ameliorate
salinity, such as lucerne, are more likely to be
accepted by producers in regions with local
groundwater systems because they will benefit
privately and relatively quickly and need not rely
on the actions of others.
lucerne prospects
24
On the other hand, intermediate and regional
groundwater systems occur on a scale so large as to
make farm-based catchment management options
impractical. Salinity management through the use
of lucerne in these systems requires widespread
community action.
The need for lucerne is greatest in those areas
with forecast large increases in salt-affected land:
Central Wheatbelt WA, South West WA, South Coast
WA, South-West Slopes NSW and Riverine Plains NSW
and Victoria. These areas are also the main
consistent sources of Australian farm profit.
2006
The actual impact of lucerne through reduced
leakage will be greatest where the groundwater
flow systems are predominantly local or
intermediate — most of the WA wheatbelt and parts
of SA, Victorian Wimmera and Mallee and NSW and
Victorian Riverine Plains. On an individual farm
basis reduced leakage under lucerne will have a
local impact regardless of the underlying
groundwater system.
PHOTO: W Bellotti
The actual percentage and rotation
length are partly dictated by local
hydrogeology (groundwater flow
systems). Smaller areas of
perennials can still generate
important salinity-related benefits
through local containment and
delaying impacts, especially in
valley floors of WA where lateral
water movement is low.
Anthony Litster, Stansbury (SA) sowing triticale
into his lucerne
Lucerne’s preference for situations with higher
rainfall, deeper soils, and more neutral soil pH in
the surface and subsoil means large areas of the
wheatbelt have significant prospects. Areas in each
region are assessed in the following section.
Drivers and constraints to adoption
Lucerne can be profitable in its own right, but the
integrated role it can play in the farming system
and the contribution it makes to whole-farm profit
and sustainability are further potential drivers to
adoption. Constraints such as difficulties with
establishment and removal, lack of livestock and
associated infrastructure and seasonal workload can
be difficult to quantify, but represent challenges
even after accounting for profitability
considerations.
Case studies
Many producers in the wheatbelt are making a
success of integrating lucerne into their cropping
systems. Case studies highlighting the experiences
of leading producers who have successfully adopted
lucerne for profit and salinity management in the
listed regions are described in the following pages.
State-by-State
Assessment of areas suitable for
lucerne production State-by-State
K
eeping in mind the optimum conditions for
lucerne (neutral pH, well-drained, arable
non-sodic, non-saline soils and annual rainfall
exceeding 350 mm), its suitability has been assessed
below on a State-by-State basis. In Western
Australia and South Australia the area potentially
suitable was assessed using criteria applied to
existing medium scale land resource information. In
Victoria and New South Wales, where land resource
mapping is incomplete, assessments were made on
available data, mostly small scale land resource
information, using the criteria in Table 4.
PHOTO: M Crosbie
Currently, lucerne is most widely grown in NSW,
SA and Victoria, with smaller areas grown in
Queensland and WA (see Table 5). The table shows
that in all States the area under lucerne is much
less than the area potentially suitable.
Of the 3.2 Mha presently under lucerne, about
two-thirds is in mixed stands with grasses and other
legumes and one-third as pure lucerne stands.
The hay industry accounts for about 200,000 ha
nationally. Survey figures suggest about 16% of the
lucerne stands on average are re-sown each year.
TABLE 4: Suitability criteria for lucerne
High
>5.5
>800
>70
>450
Moderate
5.0–5.5
500–800
35–70
350–450
Low
4.5–5.0
300–500
—
250–350
Very low
<4.5
<300
<35
<250
Source: Kingwell 2003
TABLE 5: Current (from ABS 2002) and potential area of lucerne (‘000 ha) in Australia
Current area
Mixed lucerne
Pure lucerne
Total
Potential area1
25
NSW
Vic
Qld
SA
WA
Other
Total
1476
560
2036
9053
162
124
286
5212
78
40
118
N/a2
506
138
643
8300
87
84
171
7800
113
11
178
N/a
2323
917
3279
30,365
1 moderate-highly suitable for lucerne (see Table 4 for criteria), 2 not available
2006
Criterion
Soil pHCa
Rooting depth (mm)
Soil water storage (mm)
Rainfall (mm/yr)
lucerne prospects
Belinda, Hamish and David MacLure on their
mixed farm at Tarcutta (NSW)
Potential area in
Western Australia
FIGURE 11: Potential for dryland lucerne in WA
For all the agricultural land in WA
the area considered moderately to
highly suitable for lucerne
production is about 7.8 Mha, about
42% of the total. The current area
under lucerne (2002 estimate) in
WA is only 171,000 ha which suggests
a significant potential for expansion,
varying between regions.
Most lucerne is currently grown in
the Central Wheatbelt, South West
and South Coast (see Figure 11),
although many producers also grow
lucerne successfully in lower
rainfall areas.
GRDC Zones not considered here
(the WA Northern and WA Eastern)
are less suitable, mostly due to low
rainfall, but lucerne could play a
niche role in the valley floors.
Potential area in
New South Wales
For the whole of NSW the area considered moderately to highly suitable for lucerne production is about
9.1 Mha, about 50% of the agricultural land (see Figure 12). Little more than 2 Mha is currently under
lucerne and there is a significant opportunity for expansion across the State.
FIGURE 12: Potential for dryland lucerne in NSW
lucerne prospects
26
2006
State-by-State
Potential area in South Australia
The total area considered moderately to highly suitable for lucerne production across SA is about 8.3 Mha
including that covered by native vegetation (see Figure 13). The areas vary from 55 to 85% of the GRDC
SA Midnorth-Lower Yorke Eyre Zone, SA VIC Mallee Zone and SA VIC Bordertown-Wimmera Zone. Given the
current area under lucerne in SA is 643,000 ha, there is considerable potential for increased adoption.
FIGURE 13: Potential for dryland lucerne in SA
FIGURE 14: Potential for dryland lucerne in Victoria
27
2006
For the whole of
Victoria the area
considered
moderately to highly
suitable for lucerne
production is about
5.2 Mha, about 57%
of the total
agricultural land (see
Figure 14), compared
with only 286,000 ha
currently sown to
lucerne, leaving a
significant potential
for expansion given
favourable
conditions.
lucerne prospects
Potential area
in Victoria
snapshot
Companions can get along well together
A
PSIM (Agricultural Production System
Simulator) is a simulation model for crop
and lucerne production and yield on a daily time
step. APSIM ‘feeds on’ data such as daily climate,
soil characteristics, genetic parameters describing
the development and growth of the plants, and
management details like sowing time, seeding and
fertiliser rates, and herbicide applications, among
others.
In return, the model accounts for the key
interactions between these parameters and provides
a wealth of output variables such as crop growth and
grain yield, lucerne biomass, soil water dynamics
including deep drainage, and soil nitrogen.
“What makes APSIM really useful is that it provides
insights into system performance that would not
otherwise be possible,” says CRC Salinity researcher
from The University of Adelaide, Dr Bill Bellotti.
“This model has been so extensively tested against
observed plant and soil data that we are confident
in its capacity for predicting plant growth and soil
water balance and ready to apply it to issues of
agricultural production and sustainability.”
lucerne prospects
Hilltown in the Mid-north of South Australia is typical
of areas where lucerne can be highly profitable and
where localised salinity can be managed and reduced
through its wider adoption in the landscape.
Dr Michael Robertson and Don Gaydon of CSIRO have
used APSIM to evaluate the potential for a range of
different systems of companion cropping in this
region using daily climate data from 1900 to 2003.
Four of these are shown in Table 6.
These simulations illustrate the gains and losses that
are likely under companion cropping systems. Clearly
it is very important to suppress the lucerne to allow
wheat access to water, nutrients and light, and the
data reinforce the significance of whole system
productivity, not just the penalty to grain yield.
An interesting feature of their results is that grain
yields under optimum companion cropping conditions
are comparable with those for phase cropping but
with the added benefit of the lucerne forage crop.
Lessons learned
“Lucerne is very competitive with its deep root
system that can dry the soil out. Although it fixes
nitrogen, it also has a high demand for soil N which
is often low under living lucerne,” says Dr Bellotti.
“So to grow a crop with acceptable grain yield we
need to tip the balance in favour of the crop with
herbicides to suppress the lucerne at key times in
the crop’s development, with fertiliser N at strategic
times to meet crop demand, by manipulating lucerne
and crop density, and with early sowing times.
“Lucerne–wheat systems, including companion
cropping, can be highly productive and profitable if
we look at the whole system productivity rather than
just focus on the grain yield penalty. They also
contribute to the sustainability of cropping systems.”
TABLE 6: Comparison of average annual productivity of wheat and lucerne systems at Hilltown (SA)
1900-2003
28
2006
Continuous wheat
Wheat with companion
lucerne suppressed
Wheat with no suppression
of companion lucerne
Continuous lucerne
Wheat grain
yield (t/ha)
Lucerne biomass
harvested (t/ha)
Total production
(t/ha)
5.7
4.5
0
3.0
5.7
7.5
1.2
5.0
6.2
0
8.5
8.5