The remarkable improvements in Australian mixed farming
John Angus
Honorary Research Fellow, CSIRO Plant Industry, Canberraand ‘Wattle Flat’, Stockinbingal
Hector and Andrew Stewart Memorial Lecture,University of Western Australia, 18th March 2011
Average dryland
farm –
land area, crop area and livestock number
1990 1995 2000 2005 2010
Land
are
a (h
a)
0
500
1000
1500
2000
2500
3000
Shee
p nu
mbe
r
0
500
1000
1500
2000
2500
3000
Cat
tle n
umbe
r
0
100
200
300
Farm area
Crop area
Sheep number
Cattle number
ABARE data
Australian wheat yields, 1850-2010
Aust. J. Exp. Agric 41, 277-288
1860 1880 1900 1920 1940 1960 1980 2000
Yiel
d (t/
ha)
0.0
0.5
1.0
1.5
2.0
2.5
Nutrient exhaustion
SuperphosphateNew cultivars Fallowing
Milleniumdrought
Break crop (canola) in Sth. Aust
Legume nitrogenBetter rotationsMechanisation
Annual
5-year running mean
Trends
Selective grassherbicides
Semidwarfcultivars
N fertiliser in Sth. Aust
Break crop(lupin) in WA
Wheat yield gap below the water-limited potential
Evapotranspiration (mm)
0 100 200 300 400 500 600
Yiel
d (t/
ha)
0
1
2
3
4
5
6
n = 691
China Loess PlateauMediterranean BasinNorth American Great PlainsSE Australia
Aust. J. Agric. Res 57, 847-856
Contributions to increased wheat productivity
BreedingTimingDisease resistanceStress tolerance (www.patentlens.net
/ search: wheat & drought)
Stature –
semi dwarfsGrain quality
Crop managementTimingNutrition –
fertilisers and pasture-N
Crop sequences –
rotationTillage and stubble management Correcting soil acidity -
liming
Weed control –
herbicidesDisease control -
fungicides
Climate changeAdoption -
innovation
Studies evaluating the contribution of crop management to yield increase
Reference Region Percentage of yield improvement due to management
Warren (1971) Southern NSW 100Russell (1973) South Australia 78Greb
(1979 USA 70Ridley and Hedlin
(1980) Canada 85O’Brien (1982) Victoria 67Schmidt (1984) USA 47Perry and D’Antuono
(1989) Western Australia 71Bell et al (1994) Mexico 50Anderson and Impiglia
(2002) Western Australia 68Horie
(2004) Rice, Japan 100Mackay et al (2010) UK winter wheat ’48 -’82 40
Mackay et al. (2010) UK winter wheat ’83 -’07 0
Average 65
Trends of WA wheat yield on farms and in variety trials
1860 1880 1900 1920 1940 1960 1980 2000 2020
Yiel
d (t/
ha)
0.0
0.5
1.0
1.5
2.0
WA wheat yields(5-year running mean)
Variety yields by year of release (Perry and D'Antuono 1989)
Western Australian wheat and barley yields, 1876-2010
1860 1880 1900 1920 1940 1960 1980 2000 2020
Yiel
d (t/
ha)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
1860 1880 1900 1920 1940 1960 1980 2000 2020Yiel
d ra
tio (w
heat
/bar
ley)
0.6
0.8
1.0
1.2
1.4
1.6
WheatBarley
Wheat yields on farms and variety trials in the Victorian Wimmera
1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010
Yiel
d (t/
ha)
0
1
2
3
4
Pinnacle
Summit
Summit
KewellGhurka
FederationFree Gallipoli
Ghurka
Pinnacle
Free Gallipoli
Federation
Meering
Cocamba
Meering
BreedingSlice 2Management
Contributions to grain yield GRDC R&D investments
in 2005-06
Varieties $55.1mPractices $36.7mNew Products $11.2mCommunications $8.9mOthers $3.4m
.
Middle-distance speed of racehorses (selectively bred) and human males (not selectively bred)
1840 1860 1880 1900 1920 1940 1960 1980 2000 2020
Tim
e (m
:s)
3
4
5
Melbourne Cup
World mile record
Adoption of N fertiliser in Australia is recent
1950 1960 1970 1980 1990 2000 2010
Wor
ld n
itrog
en fe
rtili
ser (
x 10
6 t N
)
0
20
40
60
80
100
Aus
tral
ian
nitr
ogen
fert
ilise
r (x
103
t N)
0
200
400
600
800
1000
1200
World
Australia
ShootDens vs YldResp
Shoots / m20 200 400 600 800 1000 1200
Yiel
d re
spon
se to
40
kg N
/ha
topd
ress
ed
-800
-600
-400
-200
0
200
400
600
800
1000
After break crop
No break crop
Wheat yield response to topdressed
nitrogen fertiliser
1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000
Can
ola
area
(mill
ion
ha)
0
1
2
Fert
ilise
r N u
se (m
illio
n to
nnes
)
0.0
0.5
1.0
Lim
e in
NSW
(mill
ion
tonn
es)
0.0
0.1
0.2
0.3
0.4
0.5
Canola area
Fertiliser N use
NSW lime use
Canola triggered the use of lime and nitrogen fertiliser
NSW canola and lime use
1980 1990 2000 2010
Lim
e ( '
000
tonn
es)
0
50
100
150
200
250
300
350
400
Can
ola
area
('00
0 ha
)
0
100
200
300
400
500
600
MullawaMoree
GulargamboneGilgandra
AriahPark
Condobolin
MorawaKalannic
Mukinbudin
Lake Grace CascadeSalmon Gums
VarleyMerredin
Dalwallinu
ThuddungraNangus
Horsham
Loxton
Minnipa
Walpeup Kyalite
Prime hard wheat experimental sites
Grain protein (%)
0 5 10 15 20 25
Scre
enin
gs (%
)
0
10
20
30
40
50
NorthSEWest
Grain quality: screenings of wheat grain in 3 regions
Increased wheat production per farm since 1990Rotations
Crop sequences
Break crops
Wheat after wheat2 t/ha
Wheat after canola5 t/ha
One of 700 assessments of break crops
Possible mechanisms of the break-
crop effect
•
Root disease –
absence of host or biofumigation
?•
Foliar disease
•
Residual water•
Residual nutrients
•
Biologically fixed N residues•
Hydrogen fertilisation
•
Suppression of arbuscular
mycorrhizal
fungi (AMF)•
Better weed control / earlier sowing
Take-all fungus in wheat roots
Suppression of take-all by brassica
and linseed tissue ‘biofumigation’
Plant and Soil 162, 107-112
Hydrolysis of glucosinolates
releases isothiocyanates
N -
OSO3-
Glu
|| Glu
-
S -
C R-N=C-S
\ R Glucosinolate
Isothiocyanate
R = phenylethyl
(generally present in Brassica
roots)
= propenyl
(present in mustard roots)
N2
+6H+ 6e-12
ATP12
ADP 2NH3
3e- 6ATP
6ADP
3H+ 1.5H2
Hydrogen fertilisationNodule
Nitrogenase
Uptake Hydrogenase(HUP+)
3H+
3e-
N2
+6H+ 6e-12
ATP12
ADP 2NH3
3e- 6ATP
6ADP
3H+ 1.5H2
Nodule
Nitrogenase
Many symbioses are HUP-
Energy = 5-6% of daily photosynthesis HH22
Diffuse
Hydrogen fertilisation
.
.
Previous crop
Δ
wheat□
field pea
○
canola
Filled symbols no POpen symbols 17 kg P/ha
Plant and Soil (2005) 270: 275–286
.
Break crops regulate mycorrhizal colonisation of wheat
Break-crop effect of oats (0.47 t/ha)
Yield of wheat after wheat (t/ha)0 2 4 6 8 10
Yiel
d of
whe
at a
fter o
ats
(t/ha
)
0
2
4
6
8
10
SwedenAustraliaOther
Australian Agronomy Society 2008
Break-crop effect of canola (0.8 t/ha)
Yield of wheat after wheat (t/ha)0 2 4 6 8 10
Yiel
d of
whe
at a
fter c
anol
a (t/
ha)
0
2
4
6
8
10
AustraliaOther countries
Australian Agronomy Society 2008
Break cropsYields benefits of break crops for wheat
Barley +0.19 3.52 60Oats +0.50 3.68 150Canola +0.79 3.45 180Mustard +0.58 3.03 59Flax +0.91 3.20 38Field pea +1.00 2.63 82Fababean +1.10 4.00 41Lupin +1.46 2.24 53Chickpea +0.98 1.73 54Lentil +0.71 2.24 32
Break crop Yield benefit (t/ha)
Wheat yield
No. of obs.
Lupins give a greater break-crop benefit than field pea
Yield of wheat after wheat (t/ha)0 2 4 6 8
Yiel
d of
whe
at a
fter l
egum
e (t/
ha)
0
2
4
6
8
After field peaAfter narrow-leaf lupin
Effect of 3 different break crops on wheat yield
Barley Oats Canola Mustard Flax Field pea
Lupin Wheat Number
+0.21 +0.60 3.59 59
+0.60 +0.62 3.12 36
+1.08 +1.07 3.54 38
+1.55 +1.82 3.25 31
Sources of the break-crop effect and estimates of their contribution to additional yield for a 4 t/ha wheat crop
Mechanism Additional yield (t/ha)
Take-all suppression 0.5Suppression of other root diseases 0.3Net N benefit of canola 0.1Hydrogen fertilisation by legumes 0.4Suppression of AMF by non-hosts 0-0.1?Net N benefit of legumes 0.5
Adoption of break crops (particularly canola) triggered:
LimingIncreased yield of following cerealsMore extraction of soil water and N by wheatMore reliable cereal response to N fertiliserLime helped the return of lucerne and barley
Twenty-years of conservation cropping at Harden
Yield response to direct drilling in relation to seasonal rainfall
Growing season rainfall (mm)
0 100 200 300 400 500 600
Yiel
d di
ff (R
DD
-BC
) (t/h
a)
-1.5
-1.0
-0.5
0.0
0.5
1.0Longterm AverageYield gain
Yield loss
Wheat response to conservation cropping at Harden
1990 1992 1994 1996 1998 2000 2002 2004 2007 2008
DC
30 B
iom
ass
(g/m
2 )
050
100150200250300
* ** * * *
**
*
Burn/Cult Retain/DD
1990 1992 1994 1996 1998 2000 2002 2004 2007 2008
Yiel
d (t/
ha)
0
2
4
6
8
10
*
*
*
**
*
Burn No burn
Till 4.8 4.4
No till 4.6 4.3
Yield (t/ha) of wheat grown every second year, Harden 1990-2008
Grazing vegetative crops
Effects of grazing vegetative crops with sheep (~20 dse /ha for 30-50 days)delayed maturity (1 day’s flowering delay per ~4 grazing days
deferred water usepoor nitrogen uptake after grazing?reduced lodging of early-sown cropsyield response -
4 ±
25%
2.27 t/ha 2.80 t/ha
Wheat yield increased by grazing because water use is deferred until after flowering
Reintegrating livestock with croppingOpportunities
Perennial pasturesGrazed crops Failed crops as a feed sourceWool-shedding sheep (Dorper & Wiltipolls)
Fewer pests (flies, worms, PETA)Transporting northern cattle south?
ProblemsBreeding stock on grazed cropsExcess paddock sizeLess shade
‘The County Agent’, Norman Rockwell, 1948
Innovation and adoption
Adoption:
Delay of ~30 years between research andadoption on farms. Alston et al. 2010.
Innovation:
users of products and services—both firms and individual consumers—are increasingly able to innovate for themselves. von Hippel
2005
AcknowledgementsWal
Anderson
Bill Bowden
John Passioura
Tony Fischer Mark Peoples
Tony Good
Megan Ryan
John Kirkegaard
Victor Sadras
Lars Ohlander
Anthony van Herwaarden
John Oliver
Jim Virgona
N s
uppl
y an
d de
man
d (k
g ha
-1 d
ay-1
)
0
1
2
3
J F M A M J J A S O N D
Demand
Supply
Nitrogen supply and demand by a wheat crop
Grain protein (%)
0 5 10 15 20 25
Test
wei
ght (
kg/h
L)
50
60
70
80
90
100
NorthSEWest
Grain quality: test weight of wheat grain in 3 regions