A DECADE OF
DIFFERENCE
Waikerie Field Day
Tuesday 1st September, 2009
Principle
Sponsor
Also
Supported By
Mallee Sustainable Farming Inc thanks all supporters and
sponsors of the 2009 Waikerie Field Day
Wishart Transport
Hentschke Transport
National Foods
2
Mallee Sustainable Farming Inc. would like to acknowledge the following sponsors whose support has helped
make the 2008 Waikerie Field Day possible
Principle Corporate Sponsor
Corporate Sponsors
AGT
Ag Bureau of SA
Company Sponsors
ABB Grain
Riverland Farm Machinery
SA MDB NRM Board
Agrichem
Associate Sponsor
AWB
CBA
RW LAP
MM LAP
CBH
Ronco Motors
Men’s Health Pitstop Sponsors
Rabobank
Wishart Transport
Syngenta
Hentschke Transport
National Foods
3
4
CONTENTS
6
1
Session Descriptions
2
Program
7
3
Site Plan
8
4
Men’s Health Pit Stop
9
5
Weeds and Resistance Management
11
6
Wheat Breeding: 10 Years of Change
15
7
Barley Varieties and Agronomy
17
8
The Role of Livestock in a No-Till Farming System—Production Drivers
21
9
The Role of Livestock in a No Till Farming System—Grazing Management
23
10
Farming Systems Trial, 11 Years One
25
11
Predicting and Managing Rhizoctonia Bare Patch
Disease in Cereals
27
12
Evercrop: Exploring The Potential of Perennials in
the Mallee
31
13
Enrich—Potential Woody Perennial Forages
33
14
The Characteristics, Yield Potential and Risk Management of Mallee Soils
35
15
Airborne Multispectral Imagery for Agriculture
37
Disclaimer
This document reflects the understanding of the authors based on research relating to some agricultural systems.
As such it must be considered as representing the current state of knowledge and may be subject to change
resulting from new developments from further research.
Readers who act on this information do so at their own risk.
5
6
7
8
MEN’S HEALTH PIT STOP
In conjunction with Riverland Community Health and Riverland Division of General Practice
Why Men’s Health?
The Field Day Committee is firmly committed to the view that Men’s Health is an important part of
sustainable farming in the Mallee. We have for a number of years wished to invite health professionals to the field day to present the issue of men’s health. We see it as our responsibility under
the whole sustainable farming emphasis to include growers’ health and to ensure that growers gain
the best possible information regarding factors affecting men’s health.
The Pit Stop Program
Men have been described as one of the sickest groups in Australia, second only to Aboriginal people. Australian men are more likely to die of all causes of death and have a life expectancy five
years shorter than women. Only a small proportion of this difference can be attributed to genetic
factors. Far more important are the adverse lifestyle behaviours adopted by males and the effect of
social conditioning.
Research suggests that due to the belief system of men and their interaction with health services,
health promotion should be operated where men gather, (work place / football club etc). Men take
an interest in maintaining their vehicles, with regular tune-ups so why does their body not rate the
same attention? Developed in Western Australia the "Pit Stop" style health check is a strategy to
get men to take an interest in preventative health. It uses the analogy of the male body as a car and
applies the principles of maintaining a car in good working order (ie: using regular preventative
maintenance) to look after health.
Pit Stop consists of a series of brief men's health screening tests, housed within a mechanical
"garage" concept.
Upon entry men are issued with a work order sheet and challenged to haul their body over the pits
to see if they are road worthy. After completing the tests, men are issued with either a yellow sticker,
indicating they need to do some repair work or make some changes to their lifestyle, or a registration sticker to indicate their road worthiness.
The following shows the "garage checks" available at Pit Stop:
Oil Pressure - Blood pressure
Chassis Check - Waist:Hip
ratio
Fuel Additives - Alcohol
Exhaust - Smoking
The Jack - Manual Handling
Shock Absorbers - Stress
management
Spark Plugs - Testicles and
prostate
Fuel Impurities - Diabetes risk
9
The MSF Field Day Committee would like to thank the following organisations for
their support of the Men’s Health Pit Stop Initiative
2009 Waikerie Field Day Drinks Supplied By
10
WEEDS AND RESISTANCE MANAGEMENT
Chris Preston, Peter Boutsalis, Sam Kleeman and Gurjeet Gill
School of Agriculture, Food & Wine, University of Adelaide, PMB1 Glen Osmond SA 5064.
TAKE HOME MESSAGES
• Trifluralin resistance in annual ryegrass is increasing in South Australia
• New pre-emergence herbicides are effective at controlling trifluralin-resistant annual rye
grass
• Management of brome grass requires two consecutive years of excellent control to drive
down seed banks
• Resistance to Group A and Group B herbicides has occurred in brome grass
• Pre-emergent chemistry offers some promise for brome grass, although not enough
control on its own.
SURVEYS OF HERBICIDE RESISTANT ANNUAL RYEGRASS IN
SOUTH AUSTRALIA
Recent surveys of cropping regions in South Australia have indicated that many farms have annual
ryegrass with resistance to Groups A or B herbicides (Table 1). The worst examples of resistance
are occurring in continuously cropped areas where Group A and Group B herbicides have been intensively used for many years. Resistance to DIM herbicides is increasing, including resistance to
Select. Resistance to trifluralin is high in many areas of South Australia.
Table 1. Percentage of paddocks with herbicide resistant annual ryegrass in cropping regions of
South Australia
Region
Year of
survey
Trifluralin
Hoegrass
Glean
Achieve
Axial
Select
Northern Mallee
2007
5
0
75
2
2
2
Southern Mallee
2007
35
12
59
2
2
2
Upper
East
South
2007
43
60
71
50
53
43
Lower
East
South
2007
12
62
58
52
52
29
Mid North
2003
19
74
68
62
53
60
Lower North
2003
44
77
82
30
26
28
Yorke Peninsula
2003
84
77
75
61
43
31
NEW PRE-EMERGENCE HERBICIDES
We have been investigating new pre-emergent herbicides for the control of trifluralin resistant annual ryegrass. The alternative pre-emergence herbicides include: Boxer Gold (Prosulfocarb + SMetolachlor) currently marketed by Syngenta; Sakura (BAY-191) being developed by Bayer CropScience; and NUL-1493 being developed by Nufarm. Field trials with these herbicides show they
provide effective control of annual ryegrass on sites where trifluralin resistance is present (Figure 1).
Sakura looks the most effective herbicide for lower rainfall regions, followed by Boxer Gold and then
NUL 1493. However, all products are highly effective on annual ryegrass.
11
a
a
b
80
c
60
c
40
d
20
e
0
Un
t
re
at
Tr
ed
ifl
ur
X
B
20
ox
Sa
00
er
ku
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15
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i
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lG
0
+
r1
ol
Av
d
50
30
ad
0
0
ex
+
16
Av
00
ad
ex
16
00
Annual ryegrass control
(% )
100
Figure 1. Performance of pre-emergent herbicides on trifluralin-resistant annual ryegrass at Berriwillock, Vic
(low rainfall site) in no-till wheat sown using knife points and press wheels.
PRE-EMERGENT HERBICIDES FOR BROME GRASS CONTROL
a
a
80
60
ab
b
40
20
c
80
60
40
20
U
nt
re
flu ate
Tr
rX d
if l
Sa 20
ur
B
X
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20 xe ura 0
00 r G
11
NU
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8
A ld
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de 00
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Sa 93
U x1
ku 750 L
14 600
ra
+
11 Av 93
7
a
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+ de 50
x
A
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Sa ad 60
ku ex 0
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11 00
8
sp
lit
Tr
i
Av
ad
ex
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+
20
00
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Tr
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16
00
25
00
8
11
B
ox
e
rG
ol
15
00
ur
X
Tr
i fl
re
at
e
Un
t
100
0
d
0
Brome grass control
(% )
100
Sa
ku
ra
Brome grass control
(% )
Figure 2 shows the performance of pre-emergence herbicide products in 2 field trials. Trifluralin
alone provides insufficient control of brome grass. The three new products are being developed for
annual ryegrass control (Boxer Gold, Sakura and NUL 1493) have some activity on brome grass,
but insufficient as stand-alone products. The main problem with pre-emergent chemistry for brome
grass control is that the herbicides have dissipated before all the brome grass has emerged. At this
stage, the best mixture in every trial has been trifluralin (Triflur X) plus triallate (Avadex Xtra). A split
application of Sakura (2/3 pre-emergent and 1/3 post sowing) is also looking promising.
Figure 2: Performance of pre-emergence herbicides on Brome grass at Wokurna, SA in no-till wheat sown
using knife points and press wheels (left), and at Lascelles, Vic in no-till wheat sown using discs (right).
12
Pre-emergent herbicides alone will not provide sufficient control of brome grass to keep weed seed
banks from increasing. Other control options like spray-topping pastures and grass control in break
crops will need to be employed.
This work is funded by GRDC Project UA00098
Further information
Dr. Chris Preston, University of Adelaide
(08) 8303 7237
13
14
WHEAT BREEDING: 10 YEARS OF CHANGE
Haydn Kuchel, Australian Grain Technologies
TAKE HOME MESSAGES
• Wheat breeding has moved from publicly funded, university and state department
based research, to a commercial user-pays system.
• Although the structure and funding system has changed, the breeding aims remain
the same – high yielding varieties, with good quality and resistance to the diseases
encountered in the Mallee.
• New wheat varieties are now available with improved yield and disease resistance
Moving from public to private
Over the last decade, the structure and funding for wheat breeding in Australia has changed dramatically. Previously, wheat breeding occurred either at universities or state departments of agriculture. Funds were largely contributed by state governments and farmer levies (provided to researchers by the Grains Research and Development Corporation). In South Australia, two separate University of Adelaide programmes bred for local wheat growers. One of these was based at the Roseworthy campus and the other at the Waite campus. With the advent of Plant Breeder’s Rights and the
commencement of End Point Royalty collection, funding bodies proposed (and implemented) a new
model, where private breeding programmes would be directly funded by growers.
Various companies have come and gone in a short time, but we are now left with three companies
breeding for the predominant wheat growing districts of Australia. Australian Grain Technologies
(AGT) comprises all of the previous public breeding programmes except for the old West Australian
Dept. of Ag programme. Intergrain has been formed from the West Australian Dept. Ag programme,
while Longreach is a new company, formed in 2002, owned by Pacific Seeds and Syngenta.
Building on the successes of the past
At AGT, a breeding programme dedicated to southern Australia (SA, Vic Mallee and WA neutralalkaline soils) is based at the Roseworthy Campus, and has been formed from the old Waite and
Roseworthy University of Adelaide breeding programmes. Historically, these programmes have released varieties such as Halberd, Aroona, Machete, Spear, Frame and Yitpi amongst others. In the
Mallee (both SA and Vic), Frame and Yitpi have been particularly important over the last decade.
Frame, and its daughter Yitpi, are a combination of the Aroona and Spear families, uniting the quality and CCN resistance of Molineux (a niece of Aroona) with the high yield and broad adaptation of
Dagger (a Spear sister). For a large part of this decade, Frame and Yitpi have combined to form
around one third of the South Australian wheat crop. This peaked in 2006 at just over 40% of the
grain delivered to ports around SA.
In recent times, new varieties have been released which aim to improve on the weaknesses of these
varieties. Each of these new varieties have higher yield than Frame and better stem rust resistance
than Yitpi (which is highly susceptible). Catalina, Correll, Derrimut and Peake are all AH, CCN resistant wheats that may have a place in the Mallee. However grainsize for some of them can be an
issue and is not to the standard of the very large grained Frame.
The recent variety Gladius (released in 2007) is also playing an important role in South Australia.
Although not CCN resistant, Gladius is the highest yielding variety from long term NVT yield analysis, has good levels of rust resistance, is tolerant of boron toxicity and has an AH quality classification. In the South Australian Mallee NVT trials, Gladius has been more than 7% higher yielding than
15
Yitpi and 14% higher than Frame. The highest yielding CCN resistant variety in the same trials has
been Correll, 2.5% higher than Yitpi.
Keep your eye out for another new variety from AGT, Mace. It will be available to growers for the
2010 season. It builds on two highly successful lineages of wheat. The two parents of Mace are
Stylet (which comes from the Spear family) and Wyalkatchem (related to Machete). In SA AGT trials
it has yielded 6% higher than Wyalkatchem. Along with very high yield, it combines moderate levels
of resistance to CCN (MR-MS) and Pratylenchus neglectus (MR), as well as tolerance to boron toxicity, good end use quality, and good levels of leaf (R) and stem rust resistance (MR). As it relies on
the Yr17 stripe rust resistance gene, its rating to this disease can be either R-MR or MS-S depending on the races prevalent.
There is always more that can be done
Unfortunately for farmers, no variety is perfect, and there are always things that need to be improved. With increasing adoption of minimum till, stubble retention and closer rotations, diseases
such as yellow leaf spot (and in wetter years, perhaps Septoria) are likely to increase in severity.
Breeders are aiming to package resistance to these diseases with the current suite of traits that
growers are already accustomed to.
New varieties with Clearfield® resistance are also likely to be available within the next couple of
years. These new varieties will be agronomically superior to Clearfield JNZ and Clearfield STL, and
will have a much higher level of tolerance to the imidazolinone herbicides. The first two of these
Clearfield resistant lines are in the NVT system this year.
Further information
Haydn Kuchel, Roseworthy Campus, Australian Grain Technologies
08 8303 7708 / 04 2881 7402
16
BARLEY VARIETIES AND AGRONOMY
Rob Wheeler, SARDI, Waite Precinct ph 8303 9480
Characteristics of newer varieties suitable for the Mallee
Buloke A
Buloke is a high yielding, malting variety developed by VicDPI and released in 2005. It is a tall, early
to midseason variety, with a flowering time similar to or slightly later than Schooner. Buloke offers
high yield potential, typically exhibiting a 10% yield advantage over Schooner. It has good levels of
resistance to scald and net form net blotch, better head retention than Schooner, but is susceptible
to CCN. Buloke has grain plumpness and test weight superior to Gairdner but slightly inferior to
Schooner and Flagship and has a short coleoptile. Buloke is available through AWB Seeds.
Commander A
Commander is a new mid maturing malting variety developed by the University of Adelaide and suitable for domestic and some export brewing markets. Across many seasons, Commander has demonstrated wide adaptation, higher yield than all other malting varieties, and typically 12% above
Schooner. Commander has significantly better grainsize in terms of both screenings and retention
but inferior test weight to Schooner and Flagship. Commander is resistant to CCN but susceptible to
leaf scald, leaf rust and spot form net blotch and moderately susceptible to net form net blotch and
therefore should not be grown on a barley stubble and areas prone to net form net blotch. Commander is available through ABB Grain and production from 2009 will be sought for processing by
Joe White Maltings.
Flagship A
Developed and released from the University of Adelaide Barley Program in 2005, Flagship exhibits
an outstanding malting quality profile, at least equivalent to the current elite European and Canadian
varieties, and ideally suited to the high volume export markets across South East Asia. Flagship is a
tall, early to midseason maturity variety, similar in plant type to Schooner and Sloop, but typically
exhibits a 6% yield advantage over Schooner. Flagship has excellent early vigour and weed competitiveness, but modest straw strength with lodging resistance similar to Schooner. Flagship is resistant to CCN and relative to Schooner and Sloop, offers improved foliar disease and Pratylenchus
neglectus resistance. Flagship is susceptible to sprouting and timely harvest is recommended. Flagship is available through ABB Grain and PlantTech.
Fleet A
Fleet is a new CCN resistant feed barley, developed by the University of Adelaide as a direct replacement option for Barque and Mundah. Fleet has a long coleoptile, and combines the plant type
of Barque, the disease resistance and yield potential of Keel, and the adaptation to deep sandy soils
of Mundah. Fleet exhibits an excellent disease resistance profile, plump grain but lower test weights
than other feed types, and a 5% yield advantage over Barque. Fleet seed is available through ABB
Grain and the Australian Field Crops Association (AFCA).
Hindmarsh A
Hindmarsh is a new, early maturing (similar to Barque), semi-dwarf, feed variety developed by
VicDPI and released in 2006. Hindmarsh offers excellent yield potential and grain plumpness with
resistance to CCN, moderate susceptibility to scald and mildew and susceptibility to the spot form
net blotch. Preliminary data suggests it might be rather susceptible to the Keel strain of net form net
blotch. Hindmarsh has a short coleoptile and attention to seeding depth is important in stubble systems and where triadimenol seed dressing is used. Seed is available from AWB Seeds.
Maritime A
Maritime is a tall, early maturing feed variety with CCN resistance released by the University of Adelaide in 2004. Maritime was developed specifically for manganese deficient soils where it exhibits a
significant yield advantage. Maritime has a yield potential between Barque and Keel on other soil
types, and offers a good disease resistance profile but is susceptible to the barley grass form of
stripe rust. Maritime has excellent physical grain quality and early vigour, and is a good option for
17
lower rainfall environments where tall straw and high test weights are sought. Maritime is available
through ABB Grain.
Barley Agronomy Research
(GRDC Project DAN0104 / SAGIT Project SA307R)
Project Officer: Martin Lovegrove, SARDI, Waite Precinct
Funding from GRDC and SAGIT has enabled an extensive range of barley agronomy experiments
to be initiated since 2007. This work has been in association with ‘farmer driven’ Farming System
sites (eg Hart, YPASG, LEADA, Mckillop, BCG).
The SAGIT funds target early vigour, metribuzin tolerance, row spacing and varietal issues in conjunction with brome grass competition within four locations across South Australia (Pinnaroo, Sherwood) and Victoria Mallee environments (through a SARDI, BCG collaboration).
The GRDC funds are directed at the medium to high rainfall barley cropping environments where
issues such as grazing potential, weed competition, nitrogen, canopy management, planting date,
seeding rate and fungicide responsiveness across a range of barley varieties are being studied. In
conjunction with phenology research, the project aims to develop variety specific management packages for elite lines and recently released barley varieties developed through Barley Breeding Australia for South Australia. This project will determine data for crop modelling tools such as APSIM and
Yield Prophet and future breeding objectives. Dr Neil Fettell, NSWDPI, leads the GRDC project in
collaboration with BCG (Kate Burke) and SARDI (Rob Wheeler).
Highlights of 2008 research in South Australia were:
Simulated grazing of barley has found defoliation at late tillering, can delay flowering by 7 to 10
days depending on variety, crop growth stage grazed and intensity of grazing. A single early graze
resulted in no impact on grain yield at Sherwood and Tarlee. An early ‘graze’ removed 220kg/ha,
while the late ‘graze’ removed 1.15t/ha of dry matter.
Sowing rate research at Hart indicated that a seeding rate of 80 plants per metre2 (approx. 30kg/
ha) resulted in greater grain yields compared to 150 and 220 plants per metre2. Sowing rate did not
have an impact on annual ryegrass populations. Barley varieties Flagship and Maritime were better
able to compete with annual ryegrass, recording lower weed infestations than Hindmarsh and Fleet.
Three dates of sowing were compared across nine barley varieties differing in growth habit and maturity on Yorke Peninsula. Keel, Hindmarsh and Maritime showed no grain yield penalty when sowing was delayed from the 18th of May til the 3rd of June. All other barley varieties; Commander Flagship, Fleet, Gairdner, Schooner and Yarra, lost significant grain yield by delaying the date of sowing.
Dry weather conditions late in the growing season have once again had a negative impact on varietal interactions with agronomy treatments. No variety differences were found in relation to changed
row spacing, fungicide application and nitrogen application at a range of research sites in 2008.
Barley Variety Tolerance to Herbicides
(GRDC Project DAS0070)
Project Officer: Courtney Ramsey, SARDI, Waite Precinct
Experiments investigating the tolerance of crop varieties to herbicides are conducted by State
agencies throughout Australia, supported by funding from GRDC. Details and results of the studies can be found in State publications, and now on the NVT web site, www.nvtonline.com.au.
The table below summarises this work in SA within trials conducted in the Hart/Kybunga districts
since 1993. Within these experiments, a wide range of herbicides and tank mixes are applied pre
and post sowing (crop dependent), at label recommended and twice recommended rates across
each variety, under weed free conditions. The treatment rates provided an estimate of the varietal
tolerance and safety margin likely through any differences in varietal response between the untreated control and the two rates applied.
18
Table 1: Long-term summary of safety rating and potential % yield loss for barley varieties to various herbicides and
tank mixes.
Product
Rate/ha
Timing
Years Tested
Barque Buloke
Commander
Keel
Hindmarsh
Sloop
Flagship
Maritime
1995 2000
20062007
2005-2007
1998 2001
2007-2008
1994 2000
2004 2006
2003 –
2005
N
N
-
-
-
-
-
N
Achieve®
380g
3-5
leaf
Affinity®
60g
4 leaf
Ally®
7g
4 leaf
Axial®
250mL
4 leaf
Banvel M®
1.4L
6 leaf
6-10
-
N
4
Broadstrike®
25g
6 leaf
-
-
-
Bromoxynil
MCPA
1.4L
4 leaf
8
10
-
Cadence®
200mL
6 leaf
9-11
12
-
N
Decision
1.0L
4 leaf
12
-
N
-
Diuron MCPA
Amine
280g-350ml
4 leaf
-
13
-
-
10
-
N
N
Glean®
20g
4 leaf
-
-
-
N
-
-
-
-
Hoegrass®
1.5L
4 leaf
4
-
22
N
9
Logran®
35g
4 leaf
-
-
6
-
-
-
Terbutryn
850ml
4 leaf
1-4
-
-
-
N
4-7
Jaguar®
1L
2-3
leaf
-
-
-
-
-
Tigrex®
1L
6 leaf
5
-
-
4-6
8
4-9
6-8
7
LVE MCPA
1.2L
6 leaf
3
-
-
4
-
-
-
4
Eclipse®
7g
3-6
leaf
-
-
-
-
-
Lontrel®
150ml
2
node
8
-
-
N
-
2-4D Amine
1.4L
booting
6
N
10
-
X–Y
12
-
-
N
-
-
N
-
N
-
12-24
16
-
-
N
16
-
5
8
-
4
12
N
-
-
N
-
11
N
-
-
% Yield reductions (range) in at least two years when the recommended rate was used
X
% Yield reduction in one year when the recommended rate was used
N
Narrow safety margin - yield loss with twice the recommended rate
-
No yield loss in at least two years of testing
19
20
OVERVIEW OF RISK MANAGEMENT
Barry Mudge, Rural Solutions SA
BACKGROUND
There is nothing like a few lean seasons to sharpen the focus on issues relating to farm profitability.
“Risk management” has become the key discussion issue. We all know that hindsight is a wonderful
vision but it is much more difficult working these things out as we go forward. The following discussion attempts to flesh out some of the thought processes behind improving our general approach to
risk management.
“Risk” implies variability and in farming this can come from many sources. The two that we normally
attempt to manage are price and climate variability.
“Management” implies choice. We may either choose to ignore the risk or implement processes
which will influence the consequences if the risk event occurs.
So “Risk Management” in its simplest form becomes the process by which we identify the various
choices or alternatives available to contend with the variability (or risk) and then arrive at decisions
which we believe will provide the best outcome over time.
COMPLEX DECISION MAKING
But at the farm level, the decision making process is extremely complex. Not only do managers
have to contend with the questions about agronomy, varieties, taxation issues, succession planning,
labour requirements etc etc they also have to deal with uncertainties surrounding pricing and
weather and the added complexity of personal factors such as preferences, peer pressure and family requirements. There is usually more than one right answer and the decision maker has to choose
which path to take.
There is usually a range of possible outcomes when a farm management decision is taken. The addition of nitrogen to cereal crops in spring will usually result in positive responses if the subsequent
weeks are wet while a dry period will not allow a response and may even see crop yields depressed.
The decision to not insure crops against hail and fire will usually prove correct but can have major
consequences if a random event occurs. The farm manager has to balance these upside benefits
with the downside risks in arriving at a decision which they feel is the best in the circumstances.
And some operators seem to be able to get it right a lot more than others. These are regarded as
the “good” or “astute” farmers and they are able to inherently balance up the potential risks and
benefits in arriving at the decision point.
Past experience and wisdom are important in the decision making process as is the art of storytelling to discuss the issues. The provision of objective information to help paint the picture is increasingly seen as a powerful decision support tool. An accurate knowledge of the risk profile being faced
becomes the important driver of the decision making process.
DEALING WITH VARIABILITY
Variability can be seen in both a positive and negative light.
In the longer term, variability is generally seen as a detriment and farm managers implement processes to allow their businesses to cope with the adverse situations that variability gives them. These
are called strategic responses to risk and are aimed at building resilient businesses.
21
However, in the shorter term (say within a season) the variability can, in fact, become a benefit if
systems can be implemented to harness the variability. This is called tactical risk management and
is aimed at developing responsive farm businesses. Flexibility is the key word in tactical risk management.
Examples of Strategic Responses to Risk
• Increase Scale
• Maintain High Equities
• Diversification
• Implementation of best practice policies
• Precision Agriculture and Variable Rate Technologies
• Alter livestock / cropping mix
• Off-farm investments
Examples of Tactical Responses to Risk
• Changes in cropping intensity and type across soil type depending on seasonal indicators
• Changes in input levels depending on seasonal indicators
• Variation in livestock intensity depending on feed budget and seasonal outlook
• Multipurpose crop outcomes (grazing, hay or grain)
• Forward selling into favourable markets
TOOLS TO IMPROVE DECISION MAKING
We have already indicated that risk management involves identifying the range of potential results
or outcomes which may occur following a particular action and then deciding on a response which
we consider will actually provide the best outcomes over time.
All of these potential responses need to be assessed using the best support tools available. These
tools aim to simplify the decision making process after incorporating the complexity talked about
earlier in this article- or “Simplicity at the far side of complexity”.
There are a range of tools available to assess business resilience within a business planning framework. These tools are usually (by necessity) quite complex and often will need to be used by experienced operators to get meaningful results.
Rural Solutions SA is currently developing a program for delivery across the state involving the assessment of business vulnerability and exposure to climate change and other risks which may impact on farm viability. This program will involve a workshop program aimed at assessing individual
farm business viability and evaluate options for improvement.
Tools that are used to enhance responsiveness in cropping based systems include soil characteristics (including moisture and nutrient measurements), growing season data, seasonal outlooks and
crop growth assessments. The APSIM computer model of crop growth (and its web based derivative
Yield Prophet) is being used increasingly as a tool for assessment of crop prospects and responses to inputs. Further refinement and local validation will strengthen this models capacity.
The industry challenge remains the need to work through the complexities of the decision making
process to enhance and improve the performance of in this vital area.
22
THE ROLE OF LIVESTOCK IN A NO-TILL FARMING
SYSTEM – PRODUCTION DRIVERS
Bruce Hancock, Livestock Consultant, Rural Solutions SA, Roseworthy Campus
TAKE HOME MESSAGES
• There is increasing demand for lean, healthy meat – make sure you produce it.
• Ensure you are a valued member of tighter and more formal supply links;
genetics - breeder – finisher – processor – retailer – consumer.
• Use new decision support tools in genetics, feed utilisation & cost of production.
• Seek training via Sheep Connect, Agricultural Bureau, Making More from Sheep,
More Beef from Pastures or your Farming Systems Group.
The Past, Present and in 10 years time
1995
2008/09
2020
Carcase weight (kg)
17.9
21.0
24
Carcase price ($/kg)
$2.20
$3.30
$3.30 - ?
Gross Value of Production
(on-farm)
$0.6bn
$1.4bn
$2.0-2.5bn
Production – Slaughter No.
- Volume
15m lambs
275 kt
18m
350 kt
20-21m
500 kt
108
150
240
Average Carcase Plus Index
Drivers of change
• Community expectations
o Environmental assurance
Water, greenhouse gases, minimal chemicals, ground cover
o Animal welfare
Mulesing, castration, survival, dogs, less transport
o Product nutritional value
Controlled amount of fat, improved fat composition – ie type of fat, specification
of vital nutrients such as omega-3s, minerals, vitamins.
o Product flexibility
Larger & higher yielding, consistent & controlled composition
• Technology
o Genetics
o Grazing management
o Rigorous focus on Cost of Production – Production drivers, scale
Risks and challenges
• Competition for access to land and resources
• Continual drive for business scale
• Innovation in truly national supply chains – Number, specs, feedback
• BIG, FAST (up/down) change on wool price
• Usual suspects – exotic disease, live export, welfare, incidence
Production Drivers for meat or wool
Revenue - Costs (Labour, Supp feed, pasture ) = PROFIT ($’s)
23
“Production Drivers Tool” – can be used for review, monitoring and change.
System
Stocking Rate
(??/ ha)
Repro rate Turn-off Wt
%
(Kgs)
KgLW/ha
(kgs)
Breeding/vealer
0.1
( 1 cow/ 10 ha)
90
300
30
Backgrounding (6mths)
1.0
-
125
125
FX lamb (trade)
1.0
95
40
38 (18)
FX lamb (feeder, 12wk)
1.5
110
33
55 (25)
1.0
-
7 kg/ewe
7kgwool/ha
(↓ supp feed, ↓ CoP)
Wool
( )
Denotes kg DW/ha at 45% dressing percentage
Water Use Efficiency Targets:
17 kgDW lamb / ha/ 100mm
3.5+ kg Greasy wool / ha / 100mm
Local issues and opportunities “on-farm” within the Production Drivers
(ie. What levers can you pull as you let the “hand brake off?”)
Stocking Rate
Reproduction
Turn-off Wt
Pasture
Quantity & Quality
Utilisation
Pasture growth curve
Condition score
Time of weaning
Time of lamb / calve
Feed
Grazing Mngt
Carrying capacity
ToC, ToL
Herd/flock structure
Target market
Genetics
Maternal - structure
Temperament
Growth
Muscle
Genetics
Terminal
Growth
Muscle
Fat
Fodder conservation
Cow / ewe age
Soils / ground cover
Heifer / hogget mngt
Animal Health
(maintenance)
Animal Health
(fertility)
Animal Health
(production)
Further information
Bruce Hancock, Livestock Consultant, Rural Solutions SA, Roseworthy, 08 8303 7691
Daniel Schuppan, Livestock Consultant, Rural Solutions SA, Jamestown, 08 8664 1408
Ian McFarland, SHEEP Connect Coordinator, Rural Solutions SA, Adelaide, 08 8226 1875.
24
THE ROLE OF LIVESTOCK IN A NO-TILL FARMING
SYSTEM – GRAZING MANAGEMENT
Daniel Schuppan, Livestock Consultant, Rural Solutions SA, Jamestown
TAKE HOME MESSAGES
• Livestock in the farm system is a key financial risk management tool.
• Increasing the amount of feed utilised by productive classes of stock is the most
efficient way of lifting the productivity of a livestock enterprise.
• Never forget minimising your losses in a down cycle is every bit important as
maximising your profits in an up cycle.
Why have livestock in your enterprise mix?
• Financial risk management tool
• Increase flexibility in the farming system
• Lower input cost as compared to cropping
What business are you actually in?
Livestock producers are managers of grass harvesting
How do I improve my feed utilisation?
• Increase stocking rate, slowly
• Implement low cost changes. Start with a small area and measure response.
• Start with improving livestock watering systems, paddock or mob size and rotational grazing.
• Grow more feed by growing cereals as fodder but be in the position to utilise as they come at
a cost.
• Quantify your feed supply and match your livestock demand to it.
• Have the right target market for your optimum production system.
What do you do in the poor season?
Have a plan in place with exit strategies to reduce stocking rate as the season progresses. Have
control rather then get to a point where you have limited options. Example strategies, sell sheep
early when prices are high (often the case in the Mallee), drought lotting, agistment, preg scanning,
condition scoring, time of lambing so you can wean in early finishing springs, run wethers or beefies,
own / lease a grazing block in different region.
Monitoring.
• Monitor stock condition and the amount of pasture on offer.
• “Feed budgeting” is important to plan grazing programs for an entire season or assist with
short term grazing management such as rationing out dry feed over summer.
• Animal intake – Allow: 1kg DM/DSE/Day for green feed
1.5kg DM/DSE/Day for dry feed
Grazing Green Feed
• Match stocking pressures to pasture growth. If a crop is growing at 30kg DM/ha per day then
the stocking pressure should be 30 dse/ha.
• Start grazing cereals early, defer graze regenerating pastures.
• Keep pressure on cereals to stop going rank & patchy. Graze hard, leave some leaf then give
them a rest to recovery before returning to graze.
• Use a simple four paddock rotation to allow rest to plants after grazing. This allows the plants
to recover. Try and keep pasture in phase 2.
25
•
•
Fencing into small paddocks increases stocking pressure which reduces selective grazing
and results in even grazing. Big mobs can do the same job.
Use temporary electric fencing to subdivide paddocks.
Grazing dry feed including stubbles and standing cereals
• A good water supply is critical.
• A combination of a good water supply and summer grazing management can be used to
maintain ground cover.
• Rotational grazing is critical to efficiently ration dry feed / stubbles, and to prevent overgrazing especially on sand hills, and in paddocks where animals tend to graze into the wind. Moving stock every week works well.
• The bigger the mob, and the more paddocks in the rotation, the more efficiently the dry feed
is used and ground cover retained.
• Combination of high stocking pressure (20-40 DSE /ha) and frequent shifts enables all feed
to be utilised not just the good bits.
• Small paddocks improve feed utilisation as trampling of feed is reduced. Electric fencing can
be used.
Livestock watering systems
• Livestock water requirements are determined by flow rate = pipe size and pressure, not
trough size.
• Use a tank to store water not a trough. Troughs 2.4m -3.6m are sufficient with good flow
rates. Pipe diameter into a trough should be 40-50mm.
• If livestock know there is always water in the trough they will not camp near the trough. Cool
and clean water is important.
• Location of water is essential for pasture utilisation.
•
•
•
Mob size (DSE)
Suggested Flow rate
L per second
1000-2000
1-1.5
2000-3000
1.5-2
3000-5000
2-3
Greater than 5000
3
Use portable troughs or central watering points to reduce costs.
Livestock should be able to come in and get a drink without waiting for water. Flow rates are
outlined.
Possible future whole farm system – Integrating cropping and livestock
Area 1 – Good cropping land continuously cropped with no livestock
Area 2 – Marginal cropping land, low inputs, regenerating pastures and growing
cereals (or vetch or canola as break crops) for fodder and providing
flexibility/choices in the good year. Grazing intensity high.
Area 3 – Non arable grazing consisting of perennial grasses, annual grasses,
medics and perennial shrubs used as feed source in autumn.
Area 4 – Feedlot to finish livestock, droughtlot to contain breeding stock when
necessary.
26
FARMING SYSTEMS TRIAL, 11 YEARS ON
Chris McDonough, Rural Solutions SA, Loxton
TAKE HOME MESSAGES
• Core site plots are now being treated the same to assess the impact of previous
farming system history on soil fertility and disease control.
• Rhizoctonia inoculum was high across most treatments
• Treatments with previous Canola history are showing lower root disease
TRIAL BACKGROUND
The Waikerie Core Site Farming Systems Trial was established in 1998 and has continued with the
generally the same farming systems treatments on the same plots for 11 years. Treatments ranged
from district practice crop / pasture systems, to intensive cereals and canola, direct drilled and using
higher inputs. This has lead to significant differences in soil microbial activity, fertility, production
and disease levels (see Table 1).
2009 Season
Due to changes in funding and research priorities the site has been maintained, but not studied to
the same extent in recent years. This year it was decided the site should all be sown to the same
variety (Mace wheat), at the low fertiliser rate of 30kg/ha DAP, to see what impact the previous systems would have in terms of fertility and disease control.
Due to initial uncertainty about the trial going ahead, it was sown late, after a period of volunteer
weed growth. While knockdown weed control was used prior to seeding, subsequent later germinations have lead to poor grass control in many plots. This has unintendedly given root disease every
chance to establish, and produced some interesting monitoring results.
The site was deep soil, surface and root disease tested on both the loamy, and sandy ends of each
treatment. Disease counts have been measured on both surface and seminal roots, along with visual assessment. The aim is to see how soil inoculum levels translate into crop damage, and the impact of treatment history.
Key findings include the much lower rhizoctonia soil inoculum and visual crop symptoms in rotations
with canola. Pulse / cereal rotations appear to be less robust in terms of soil health. The more district practice systems have very mixed results this season, reflecting soil fertility differences caused
by the rotations alignment to higher yielding cropping years.
It is hoped that next year the trial will continue, again with the same treatments across all sites, but
with agronomic management that allows for the best outcomes from all previous farming systems to
be assessed.
27
Table 1. 2009 Core Site Treatment Measurements
28
Fig 2. Root Disease Scores (Higher scores reflecting lower disease levels)
9.0
8.0
7.0
6.0
Visual Growth
5.0
Visual Disease
Wt/plant ave Flat
4.0
Wt/plant ave Sand
3.0
2.0
1.0
0.0
1
2
3
4
5
6
7
8
9
Further information
Chris McDonough , Loxton ph 0885959100
29
10
11
The South Australian Murray-Darling Basin Natural Resources Management
Board is proud to be a sponsor of the Mallee Sustainable Farming Inc. Field Day
The South Australian Murray-Darling Basin Natural Resources Management
Board has recently released their SA MDB NRM Plan.
The Plan aims to support a healthy, living landscape meeting the social,
environmental, economic and cultural needs of the community, and ensuring the
rights and well being of future generations.
To achieve this goal, priority assets with associated visions have been identified;
People – Communities living sustainably
Water – Water resources that are healthy, valued and supporting
communities and thriving ecosystems
Biodiversity – A healthy and ecologically productive environment that
sustains biodiversity and is valued by the community
Land – Sustainable, productive landscapes
Atmosphere – A clean and healthy atmosphere with effective adaptation
to climate change
Pick up your copy of the South Australian Murray-Darling Basin Natural
Resources Management Board Regional NRM Plan at the SA MDB NRM stand
30
PREDICTING AND MANAGING RHIZOCTONIA BARE
PATCH DISEASE IN CEREALS*
Gupta V.V.S.R1. and Emma Leonard2
CSIRO Entomology, Glen Osmond, SA and AgriKnowHow, Urania CB, SA
* Reproduced from an article written for Ground Cover, GRDC.
GRDC project code: CSE00048
The occurrence of soils which are suppressive to Rhizoctonia disease is conclusive but how these
soil conditions can be developed remains illusive.
Biological suppression soilborne diseases such as Rhizoctonia bare patch disease was first identified in soils under conservation agricultural systems. Almost 20 years ago CSIRO scientists identified that crops grown in the long term rotation and tillage trial at Avon, South Australia no longer suffered from the seedling root rot rhizoctonia. These soils were termed disease suppressive. Despite
this breakthrough in the control of rhizoctonia the management recipe to reproduce disease suppressive soils has been illusive. Rhizoctonia bare patch disease remains an important but unpredictable disease for cereals in southern Australian agricultural region.
At CSIRO a new project researching rhizoctonia in the paddock and in the laboratory aims to provide better prediction and management of this significant root disease of dryland cropping in southern Australia. The project is a multi-institute collaboration involving SARDI, NSW DPI, DAFWA, Agritech NSW and David Roget.
The expression of rhizoctonia in any paddock is due to management and environmental factors that
influence the level of pathogen inoculum, inherent suppressive activity, nitrogen availability and
crop/root vigour.
Conservation agriculture has been a double edged sword in the management of rhizoctonia. Minimising tillage systems substantially reduces any control by cultivation and the early removal of the
‘green bridge’ of weed roots, while stubble retention provides a valuable source of carbon for soil
organisms, enhancing the viability of disease suppressive organisms. Yet, suppression was first
identified in soils under conservation agricultural systems.
At Avon disease suppression increased over a period of five to 10 years following the introduction of
no-tillage, full stubble retention, limited grazing and high nutrient inputs to meet crop demand, consequently increasing production and the amount of stubble returned to the system.
More recently our research in the Mallee identified that as availability of mineral nitrogen increased,
particularly during the non-cropped period in summer and early autumn, the effectiveness of disease
suppression the following season decreased.
Other trials suggest that canola could reduce the level of rhizoctonia inoculum resulting in less root
disease and increased yield in the following cereal crop.
The new research project consists of core field trials in three soil types at Waikerie, SA (Mallee sand
– Mallee Sustainable Farming), Streaky Bay, SA (Alkaline calcareous loam – Eyre Pensinsula Farming Systems) and Galong, NSW (Red brown earth - Agritech). Treatments will provide differences in
level of tillage and rotation. Soil samples will be collected during the summer, early autumn period
and soil and root samples will be gathered in winter to assess changes in inoculum, disease levels
and microbial communities in relation to the treatments and the season.
Changes in Rhizoctonia inoculum during summer months are being monitored using soil samples
from nine field sites in SA, NSW and WA located on commercial paddocks with at least a three year
history of stubble retention and continuous cropping.
31
Annual field experiments to evaluate short term management options such as the use of seed applied fungicides, modifying crop nutrition and tillage are conducted at Waikerie, Streaky Bay and in
WA.
Laboratory investigations are conducted to determine the specific functional groups of microbial
communities that respond to carbon additions and their link to disease suppressive potential. Preliminary results indicate significant differences in the types of bacterial groups found in suppressive
and non-suppressive soils. Observations from this laboratory work will be used to select the microbial parameters that will be measured in the soil samples collected from the field trials and paddock
surveys.
Figure 1. A conceptual diagram showing the different factors that can influence the Rhizoctonia pathogen
inoculum and disease incidence in southern Australian cropping systems. Some key factors responsible for
the generally higher levels of Rhizoctonia disease incidence after drought are also listed.
Rhizoctonia bare patch disease in
Australian dryland soils
Factors…
Impact of Drought
• Crop (canola)
• Tillage
•
•
•
•
•
Tilth
Herbicides (SU)
Temp
Moisture
Nutrition
Growth of inoculum
from source to root
• C input
– Quantity
– Quality
• N level
• Soil type?
• Rotation
Inoculum survival & growth
during off-season
Disease
Suppression
Habitat
Infection &
Disease incidence
Nutrition
Plant response
to infection
32
• Decline in general
microbial activity
• Reduced degradation of
residual herbicides
• Increased min N levels –
reduced expression of
disease suppression
EVERCROP: EXPLORING THE POTENTIAL OF
PERENNIALS IN THE MALLEE
Patricia Hill, CSIRO Sustainable Ecosystems, Adelaide; Ph 08 83038528; [email protected]
TAKE HOME MESSAGES
• EverCrop is an important collaboration between farmers, consultants, NRM and
CMA agencies and researchers
• EverCrop aims to explore the real potential of perennials in Mallee cropping systems
• Farmers can be involved in the collaboration and guide local research
What is EverCrop?
EverCrop is a national project of the Future Farm Industries CRC. The project is exploring the potential of perennials in Mallee cropping systems. Perennials can provide unmatched triple-bottom
line benefits in the Mallee landscape, particularly in areas where soils are fragile, infertile or unproductive. EverCrop aims to provide farmers with new perennial-based systems that have higher associated profits (due to either higher yields or lower costs) and greater sustainability. EverCrop is
co-funded by GRDC and several partner organisations including CSIRO, SARDI and DPI. EverCrop
intends to answer the following questions:
How do perennial pasture options fit within a context of soil and cropping constraints in the
Mallee?
How can we optimise rotation structure to maximise yield, hydrological benefits, weed and
nutrient management, and seasonal risk minimisation?
How can we predict production and economic advantages of perennials using models?
Can we provide agronomy packages to farmers that achieve these triple bottom line benefits?
In the Mallee, two focal groups (known as Local Adaptation Groups) have been formed – one in
South Australia and one in Victoria. These groups are made up of farmers, Rural Solutions staff,
NRM and CMA staff, researchers from CSIRO, SARDI and DPI. The groups are provided with funding to address key research questions regarding perennials in their region. These groups are open
to any interested farmers, and we encourage you to contact your nearest facilitator if you are interested (Richard Saunders, Rural Solutions SA and Rob Harris, DPI, Victoria).
What are the goals of the Mallee EverCrop work?
The LRM region has several sustainability challenges. First, the region is challenged by salinity,
weed management issues (including herbicide resistance) and increasingly risky seasons. Because
the region is largely dominated by cropping and demonstrates limited adoption of perennials, the
LRM Node work will focus on attempting to identify and demonstrate perennial options for this area.
In addition, methods for integrating these perennials into cropping-based systems will be explored,
to underpin development of decision support tools in EverCrop Decide. We will undertake on-farm
adaptive research, complemented by strategic and highly targeted agronomic (“white-peg”) research, to achieve these goals. More broadly, the LRM Node seeks to bring together people involved in perennial research in the region, and to capture, complement and expand on this research. We aim to add value to existing research by using our resources and our capacity as a national network to provide a stage for this research. We also aim to fully develop the synergies be33
tween existing work, and to ensure that clear pathways to adoption are forged in the process.
For our purposes, we have delineated a zone (Figure 1) to represent our key area of interest, and to
which most of the Mallee EverCrop’s resources will be targeted. It can be seen that this region coincides with the Mallee-dominated 250-350 mm rainfall area. However, the boundaries of this zone
are fuzzy and our goal is to capture as much as possible of the research and development of perennials in the low rainfall region, regardless of whether they are occurring within this boundary or not.
Figure 1. The Low Rainfall Mallee zone highlighting the relationship between the SA-Vic Mallee
agroecological zone (GRDC 2006) and the 250-350mm rainfall zone.
What will EverCrop be doing in the next few years?
Reseachers have commenced five specific research activities, with some early results now available:
1. Biophysical constraints to production of saltbush (Patricia Hill, CSIRO)
2. Saltbush capability analysis for the LRM using spatial technologies (Nat Raisbeck-Brown and
Roger Lawes, CSIRO)
3. Dune-swale fodder shrub production (Anthony Whitbread)
4. Lucerne establishment and phase rotations research (Rob Harris, DPI)
5. Design and grazing strategies of perennial shrub-based systems (Jason Emms, SARDI)
6. Establishment & growth of perennial grasses (Birchip Cropping Group)
7. Enrich Fodder Shrub Evaluation trial (Bill Davoren)
Further information
Patricia Hill, CSIRO Adelaide ([email protected]); ph 08 83038528
Richard Saunders, Rural Solutions Loxton ([email protected]); ph 08 8595 9152
Rob Harris, DPI Hamilton ([email protected]); Ph: 03 5573 0963
34
ENRICH - POTENTIAL WOODY PERENNIAL FORAGES
Jason Emms, SARDI
TAKE HOME MESSAGES
• Livestock can help the business manage risk
• Native woody forage perennials can offer out of season feed
• A shortlist of the most promising species are being tested in a range of
environments across southern Australia, including six trials in SA
‘Enrich’ is a Future Farm Industries CRC (FFI CRC) research project creating more productive and
better adapted grazing systems through the incorporation of native woody perennial species.
Native woody perennial forages have the ability to grow in marginal, low-rainfall environments,
which can increase a livestock enterprise’s resilience during periods of drought and its ability to respond to unseasonal rainfall. For the farmer there are multiple benefits including:
Providing green feed over summer-autumn
Making use of unseasonal rain by being ready to convert it to edible biomass
Improving animal health through their nutritive and bioactive properties
Providing shade and shelter for livestock
Reducing salinity through more effective water use
Reducing erosion and soil degradation through better land cover.
The project has taken a multi-pronged approach to assessing the potential role of forage perennials
by:
(i) Considering woody perennials in a system with other pasture species being produced as complementary plants either within the shrub block or on nearby paddocks.
(ii) Quantifying their potential to improve feed utilisation and health.
(iii) Exploring Australian native species more thoroughly.
Forage systems based on single species are unlikely to be suitable as a sole feed source. However,
there is potential to integrate a mix of suitable plant types together to form what has been described
as “polyculture” grazing systems. A mixture of plant types may be more resilient and also supply a
more-balanced livestock diet. It has been suggested that it may be more productive to meet all objectives by using a suite of species than searching for a single species that meets all desirable criteria.
The project is also examining the significance of plant compounds in rumen function, reducing methane production, as well as options for self-medication. For example, species are being assessed for
their ability to enhance rumen health or control internal parasites. Initial laboratory data suggests
that further examination of some species in regard to their anthelmintic and rumen modulating potential is warranted.
Enrich has identified over 100 Australian woody perennial species with potential for inclusion in livestock grazing systems. Species were selected after a process involving a literature search and expert consultation. Species were chosen based on originating from the pastoral or livestock-cropping
regions of Australia, having a woody perennial life form, evidence of palatability and no weed history.
About 60 of these species are currently being evaluated to assess their performance as forages at
three sites in Condobolin (NSW), Merredin (WA) and Monarto (SA). To date, productivity has varied
widely, as has their ease of germination, reproductive habits, growth habit and sensitivity to frost.
35
Further evaluation will continue including assessing their regrowth after grazing. Work in WA as well
as at Monarto, is aiming to determine comparative grazing behaviour, diet selection, palatability and
livestock performance of the most promising species.
Putting woody forage perennials to the test
These larger sites are supported by 16 smaller sites in partnership with farmer and NRM groups.
With the support of the EverCrop project, one such trial is being undertaken at the MSF Waikerie
site. Here, a shortlist of 15 species were selected by the Enrich team based on favourable traits
from the data obtained thus far. These plants will be tested for their local adaptation, productivity
and palatability.
Woody perennial species being grown at the MSF Waikerie site
Name
Scientific name
River saltbush
Atriplex amnicola
Coastal saltbush
Atriplex cinerea
Old man saltbush
Atriplex nummularia
River Murray saltbush
Atriplex rhagodioides
Creeping saltbush
Atriplex semibaccata
Tagasaste (tree lucerne)
Chamaecytisus proliferus
Nitre goosefoot
Chenopodium nitrariaceum
Australian bindweed
Convolvulus remotus
Ruby saltbush
Enchylaena tomentosa
Tar bush
Eremophila glabra
Tree medic
Medicago strasseri
Fleshy leaved saltbush
Rhagodia crassifolia
Mealy saltbush
Rhagodia parabolica
Mallee saltbush
Rhagodia preissii
Spiny saltbush
Rhagodia spinecsens
Further information
Jason Emms, SARDI, Waite Campus, Adelaide
08 83039602; [email protected]
36
THE CHARACTERISTICS, YIELD POTENTIAL AND RISK
MANAGEMENT OF MALLEE SOILS
Anthony Whitbread, Rick Llewellyn and Bill Davoren.
CSIRO Sustainable Ecosystems, PMB2 Glen Osmond 5064, South Australia.
Phone: 08 83038455 Email: [email protected]
TAKE HOME MESSAGES
• Spatial variability within cropping paddocks can now be cost effectively mapped
using tools such as EM38 and yield monitors.
• Where paddocks have been zoned on the basis of soil variation, management of
that zone should consider the potential yield and season-to-season variation.
• Zones with high EM38 readings often have high levels of inherent fertility (eg. high
plant available soil P and N) but due to clay texture and shallow rooting depth,
crop growth is often limited by available soil moisture- zones with low EM38
readings are typically sandy but crop growth is often limited by nutrition.
• Yield expectations or in-season decisions such as topdressing N, grazing or cutting
for hay, crop insurance etc. can be made more confidently by understanding the
inherent risk of different soil types.
SUMMARY
Farmers have long been aware that crop performance within paddocks shows enormous spatial
variation. These differences in yield are driven predominantly by soil variation and are often as
great as season to season variability. With the advent of tools to detect soil variability such as
EM38, yield monitors and variable rate fertiliser spreaders, farmers are now in a position to better
manage variation. This paper outlines an approach where representative soils within the zones of
like yield performance were characterised for their plant available water capacity (PAWC) and subsoil chemical constraints. Crop-soil modelling tools (APSIM -Agricultural Productions Systems
sIMulator) were then used to simulate the potential yield and season-to-season variation in the
zones as well as in-season predictions of crop growth.
MATERIALS AND METHODS
Using the information collected in the MSF Reaping Rewards project, 4 sites were selected (Bimbie,
Carwarp, Pinnaroo and Loxton). At each site in 2006 the sites were intensively sampled for the
analysis of chemistry and texture. An EM38 survey was used to create 3 EM-based soil classifications for each paddock. The soil cores were assigned to the soil classifications in which they were
located and the results presented are averages of the cores falling into these zones. In order to
characterise the plant available water capacity (PAWC) of each zone, the drained upper limit (DUL)
was determined at a point within each zone by wetting up soil to saturation and allowing it to drain
and then measured. Crop lower limit (CLL), was also determined for each zone using the soil moisture measured at the harvest of wheat crops in 2006 (9 cores across the 3 soil classes) and in 2007
(27 cores across the 3 soil classes). The lowest soil moisture value measured in the 2 seasons was
used as the CLL. Using crop modelling and the long term weather records sourced from a nearby
weather station, a simulation of wheat growth in each year for the period 1957 to 2006 was undertaken with APSIM. The simulations are reset each year so that starting soil N and organic matter remain the same in all years. Starting soil mineral N was assumed to be the same (52 kg N/ha to
110cm) for each soil class in the paddock. The effects of rainfall, evaporation, drainage and water
extraction by the crops were all calculated by the model. Wheat (cv. Yitpi) was sown between April
25 and July 15 and sowing within this period was triggered by 10 mm rain over 5 days and the soil
profile had to contain at least 10 mm of available soil water.
37
RESULTS:
Mapping soil property boundaries
The use of EM38 to differentiate soil boundaries based on the sensing of subsoil characteristics
such as clay content and salt concentration has proved to be an effective method for zoning Mallee
paddocks into management zones of similar yield potential. An example of this is shown for a Loxton paddock where the EM38 measurements correlate well with 2006, 2007 and 2008 yield monitor
data (Fig. 1). These maps provide a good example of how EM can be used to help identify areas of
the paddock with differences in yield potential that can’t be easily identified based just on elevation.
The 2006 and 2007 seasons, where a dry finish meant that subsoil constraints were very important
factors, are examples of seasons where yield maps that are unaffected by other factors such as
frost, disease and weed patches can be expected to align reasonably well with EM maps. It should
be noted that a strong relationship between EM zone and yield will not occur in every season-type.
For example, in some seasons late rains make subsoil constraints and the availability of stored
moisture less critical to crop yield and less yield variation across the paddock could be expected.
Representative soil characterisations for each zone-Loxton example
Within in each zone the soil properties, particularly soil texture and the depth to sub-soil constraints,
determine how water behaves in the soil profile and how much is available to plant uptake or evaporation. Typically sandy textured soils (usually low EM38 values) have deep profiles and no chemical
sub-soil constraints. In heavier textured soils, particularly where sub soil constraints exist, the
amount of water available to plants can be limited to the surface layers. Whilst the plant available
water capacity may be high in these surface layers, evaporation losses are potentially much higher.
By measuring the soil moisture content at the crop lower limit (CLL) and at drained upper limit (DUL)
in the low EM (sandier) zones (Fig 2a), we found that soil moisture content at CLL was low, reflecting no subsoil constraints restricting the uptake of water from all layers in the soil profile. The soil
moisture content at DUL was also lowest in these sandier textured soils, but usually increasing with
depth with an increase in clay content. The soil moisture content at CLL of the soils in the zones
with high subsoil constraints was higher at all depths in the profile than the corresponding low zone
soils, and as the level of chemical constraints increased at depth soil moisture could not be extracted by roots from the profile (Figure 2c). DUL was also highest due to the increased clay context
of the soils in these constrained zones.
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Fig. 1. Loxton EM map, 2006, 2007 and 2008 wheat grain yield maps showing paddock elevation.
Zone 2- Intermediate EM zone
Zone 1 - Low EM zone
Volumetric water content ?v (% )
10
20
Volumetric water content ?v (% )
Volumetric water content ?v (% )
30
0
10
20
0
30
0
0
20
20
20
40
40
40
60
80
100
Soil Depth (cm)
0
Soil Depth (cm)
Soil Depth (cm)
0
Zone 3 - High EM zone
60
80
CLL
(Whe at)
140
Fig. 2a
CLL
DUL
120
Pote ntial rooting de pth ~ 110 cm
Organic carbon = 0.6%
De e p sand
No che mical constraints
0-10 cm av ailable P = 29 ppm
120
140
Fig. 2b
20
80
Crop
Lower
Limit
(Wheat)
Drained
Upper
Limit
DUL
120
Rooting depth ~ 110 cm
Organic carbon =0.6%
Sand over sandy clay loam
No chemical constraints
0-10 cm available P = 30 ppm
30
60
100
100
10
140
Fig. 2c
Rooting de pth ~ 80 cm
Organic carbon = 0.8 %
Sandy loam ov e r sandy clay
EC1.9 dS/m, Chloride >993ppm, Boron >19ppm
at 80 cm
0-10 cm av ailable P = 29 ppm
Fig. 2. The characterisation of the crop lower limit (CLL) and the drained upper limit (DUL) for the Loxton soil
profiles in the zones defined as containing low (Fig. 2a), moderate (Fig. 2b) or high (Fig. 2c)
subsoil chemical constraints that restrict rooting depth.
The simulation of wheat growth over the long term.
To enable yield potential to be determined in the zones over a wide range of season types, representative soils in all paddock zones were characterized and wheat yield simulations run using the
crop model APSIM. The simulated yields all the sites and seasons from 1957 to 2007 showed consistently large differences in median yield between the low or moderate zones and the high EM
zones. The probability of achieving low yields (<1 t/ha) was also much higher in these high EM
zones (Table 1).
Table 1. Simulated wheat grain yield (with a sowing N application of 30 kg/ha) within zones
surveyed as containing low, moderate and high subsoil constraints for all sites over the period 1957 to 2007.
Probability of yield
EM38
Zone
Bimbie
Carwarp
Loxton
Pinnaroo
Median
Yield (t/ha)
<1t
1 - 1.5 t
> 1.5 t
Low
1.42
0.29
0.29
0.42
Moderate
1.43
0.35
0.19
0.46
High
0.60
0.67
0.12
0.21
Low
1.52
0.27
0.21
0.52
Moderate
0.90
0.54
0.08
0.38
High
0.58
0.62
0.08
0.31
Low
1.51
0.08
0.38
0.54
Moderate
1.58
0.29
0.13
0.58
High
0.85
0.58
0.25
0.17
Low
1.42
0.37
0.17
0.46
Moderate
1.40
0.38
0.15
0.46
High
0.98
0.52
0.10
0.38
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FUTURE DIRECTIONS:
Zonal management, especially in relation to fertiliser and seed application, can be an opportunity to
reduce inputs into the constrained zones and capitalise on the performance of less constrained
zones by increasing inputs. The opportunities to strategically manage zones, for example by topdressing light sands in a promising year or deciding to cut/graze constrained zones at in a dry year,
are management options that should be informed by facts. These facts include the stage of the crop
and time of season, plant available N and water and seasonal outlook. Modelling tools, particularly
Yield Prophet, can take these factors into account and provide accurate predictions of likely yield
outcomes. Where crop performance is consistently poor, alternative land uses may be more profitable and result in other benefits such as increased ground cover or better fodder reserves.
Acknowledgements:
This work is part of a CSIRO-Rural Solutions-Mallee Focus-MSF project. The findings are the result
of GRDC projects “Training Growers to Manage Soil Water Project” and Reaping Rewards. The
support of the participating farmers at each site is gratefully acknowledged.
Further information:
Dr Anthony Whitbread
Phone: 08 83038455 Email: [email protected]
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AIRBORNE MULTISPECTRAL IMAGERY FOR
AGRICULTURE
Ross Lewin, LREye Imagery
TAKE HOME MESSAGES
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•
•
•
Good tool for broad scale crop assessment.
A ‘picture paints a thousand words’.
Imagery has the potential to save farmers money and increase returns
Application of this technology needn’t be complex.
What exactly is Airborne Multispectral Imagery?
A number of forms of airborne imagery are available; the most common type used for agriculture is
referred to as multispectral imagery. Multispectral cameras capture images from different bands of
the light spectrum, the most common being the Red, Green and Blue bands which together make up
a colour map (RGB image). The fourth band of light, which is not visible to the human eye, is the
Near Ifra Red (NIR) band of light. The NIR band is particularly useful in that it is sensitive to reflections from chlorophyll in plant leaves. Healthy, growing plants produce higher levels of chlorophyll
than stressed plants do. Recording the NIR reflectance in the form of an image means that plants
growing strongly and showing high vigour can be distinguished from stressed plants by depicting the
differences using different colours on a map.
How is imagery acquired?
Multispectral imagery is most commonly acquired from an aerial platform (aerial photography). The
technology supporting the image acquisition and processing is complex, needing to account for the
curvature of the earth, the location of the camera at the time of taking the pictures, the angle of the
aircraft, the angle of the sun and many other factors. Modern camera systems are precision navigated, meaning they have in built technology that manages most of these variables allowing for increased automation in acquiring and processing the imagery. This means that the product is better
suited to agriculture because imagery can be delivered in less time, leaving more scope for intervention; and at lower cost, meaning a higher return on investment. The quality of an image is specified
according to resolution (size of the image pixels on the map) and the spatial accuracy (position of
the pixel on the map relative to its true position on the ground). Image resolutions range from 25cm
to 1.0m for most agricultural applications with a spatial accuracy of 2-3 pixels.
How is this technology applied to farming?
Plants, or cropped areas, which are growing strongly, are differentiated from those under stress or
not growing as well. On the contrary, some plants such as weeds show particularly strong vigour
and are likely to ‘stand out’ amongst crops. These areas may be singled out for intervention without
necessarily having to treat the whole crop.
Information from multispectral imagery stretches to a wide range of agricultural applications and can
be used as a tool to assist farmers with assessing, amongst other things:
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Crop variability
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Yield forecasting
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Field compaction
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Field layout planning
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Soil fertility/nutrition deficiency
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Salinity problems
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Weed identification
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Pests and diseases
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Irrigation effectiveness
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Plant mortality
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Storm or frost damage
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Seasonal crop growth trends
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Insurance assessments
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Year on year crop growth trends
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Planting efficiency
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Delineation of specific areas of
interest
Benefits of using this technology
While there are a number of indirect benefits attributed to the use of multispectral imagery, direct
benefits of this technology clearly vary on a case by case basis. These are influenced by the scale
of the project, the severity of the cropping problems identified and the scope for timely remedial interventions or future improvements in management practices.
Further information
Contact Ross Lewin
M: 043 7487149
E: [email protected]
Illustrations
Figure 1: Operational setup of an LREye Multispectral Camera System
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Figure 2: Illustration showing image comparison at various stages in the
growing season.
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