Establishing Pastures Under
Cover Crops
Making evidence-based decisions
Richard Hayes & Geoff Casburn – Wagga Wagga Agricultural Institute
PURPOSE: Evaluate and develop the role for perennials in the crop-livestock belt of southern Australia
LOCATIONS:– SW NSW,
– SA/Vic Mallee,
– Northern WA wheatbelt
TIMEFRAME: 2008 - 2016
- Overview
The case for increased perennials in NSW?
Not a strong case!
Grown lucerne since 1800’s
Approx 50% of land is under
pasture; 30% under perennial
pasture– Dear et al. 2010
Similar to optimal level of
adoption → MIDAS– Bathgate et al. 2010
72% of growers use lucerne
in their mix– McCormick et al. 2012
Pasture performance
69% of growers ranked poor establishment as one of the top 3 reasons for ending the pasture phase
75% of growers ranked poor persistence as one of the top 3 reasons for ending the pasture phase
– McCormick et al. 2012
Defined knowledge gap…
> 80 years of trials suggesting pastures should not be established under a cover-crop (Moodie 1936; Smith & Argyle
1964; Peart and Scott 1969; Cregan 1985; Dear 1986)
> 80% of farmers in southern NSW use covercrops (Li et al. 2010)
Definition
Cover-crop = undersowing
Simultaneous establishment of crop & pasture in same paddock
Sown in autumn/early winter
Crop harvested for grain in year 1; pasture persists beyond year 1
Importance of successful establishment
Enduring impact on production;
pastures last for 3-20+ yrs– Perennial plant longevity
– Annual plant seed set
– Sequence of years important
↑ production = ↑ return on
investment
↑ establishment = ↓ weed
incursion
↑ legume establishment = ↑ N2
fixation
Other benefits eg increased
groundcover, improved animal
health etc
Balancing agronomy & farm finance
Factors to consider:
– Grain price (value of the cover crop)
– Grain yield (competition plus reduced sowing rate)
– Livestock price (value of the pasture)
– Pasture yield (competition)
– Length of pasture phase
– Pasture value (to cropping enterprise)
– Seasonal conditions
Research activities - establishment
Small plot research
– Spring vs autumn
sowing
– Covercrop vs nil
covercrop
– Lucerne vs chicory vs
phalaris vs cocksfoot*
Farmer participatory research
20kg/ha Cover-Crop Nil Cover-Crop
Develop decision support tool
prototype
Can we define ‘success’ in
establishment? Not really?
– Few established benchmarks
– Complicated by cropping:livestock interactions on a
mixed farm
– Likely to differ between farms, between paddocks within
a farm, between years within a paddock
– Should it be measured in agronomic or economic terms
or both?
Therefore, its difficult to determine the best method
to achieve success
The workshop session
1. Discuss success in farmer
terms
2. Use case studies from
previous trial work to
assess the success of
cover-cropping
3. Use the DST to highlight
the key factors driving the
decision to sow pastures
under a cover-crop
Future research
1. A financial risk analysis on
the practice of cover-
cropping
2. Agronomy trials refining
techniques of cover-
cropping
3. Agronomy trials enhancing
establishment of pasture
mixtures in the absence of
cover-cropping
Slides for the workshop
Small plot study – Yerong Creek
2008-12
Experimental design
Autumn sown pastures
1) Lucerne/subclover
2) Chicory/subclover
3) Phalaris/subclover
4) Cocksfoot/subclover
Spring sown pastures
5) Lucerne
6) Chicory
7) Phalaris
8) Cocksfoot
Under-sown pastures
9) Crop + Lucerne/subclover
10) Crop + Chicory/subclover
11) Crop + Phalaris/subclover
12) Crop only
Small plot study research direction
2008 2009 2010
2011 2012 2013 2014
Pasture sown 2008 2009 2010
Cropping phases
Pasture phases
Canola WheatWheat Canola LupinsSplit plots
Canola WheatWheat Canola Lupins
Small plot study research direction
Table 2 Monthly rainfall during experimental period and long-term average rainfall (LTAR)
over 30 years at Yerong Creek, NSW, Australia.
Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Total
2008 50.4 18.4 18.2 13.0 19.8 46.3 62.4 27.4 22.1 15.0 54.8 49.0 396.8
2009 9.4 1.8 21.4 65.6 8.4 60.6 35.2 32.2 21.4 14.0 35.0 33.4 338.4
2010 0.2 84.7 73.8 27.6 60.8 27.2 69.4 77.4 50.8 201.1 109.4 97.2 879.6
2011 83.0 215.6 91.2 22.0 44.2 21.6 33.8 78.6 71.6 18.0 75.4 54.8 809.8
LTAR 37.8 39.4 36.1 39.4 45.7 53.8 61.5 53.4 45.6 45.9 44.2 45.8 548.6
This exercise…
AIM: To determine the effect of cover-cropping on
crop/pasture yields and pasture composition
Limit data to lucerne/subclover treatments, sown
with and without a cover-crop
Note terminology:
– Experiment 1 – trial sown in 2008
– Experiment 2 – trial sown in 2009
– Experiment 3 – trial sown in 2010
Results
Cumulative pasture DM over 3 years
+ Cover-crop Nil covercrop
SiteYear Species DM_Total Legumes DM_Total Legumes Proportion Exp1: 2008 Chicory 12646 6240 15995 5245 0.79 1.19
Lucerne 16059 10124 24176 20876 0.66 0.48
Phalaris 13531 6088 18618 5876 0.73 1.04 Exp2: 2009 Chicory 33263 9877 35279 9824 0.94 1.01
Lucerne 40716 27606 45435 36706 0.90 0.75
Phalaris 31030 12646 33561 10873 0.92 1.16 Exp3: 2010 Chicory 38218 11721 35966 8320 1.06 1.41
Lucerne 38129 21338 39158 33096 0.97 0.64
Phalaris 38242 15524 31060 8032 1.23 1.93
Results
Cumulative pasture DM over 3 years
+ Cover-crop Nil covercrop
SiteYear Species DM_Total Legumes DM_Total Legumes Proportion Exp1: 2008 Chicory 12646 6240 15995 5245 0.79 1.19
Lucerne 16059 10124 24176 20876 0.66 0.48
Phalaris 13531 6088 18618 5876 0.73 1.04 Exp2: 2009 Chicory 33263 9877 35279 9824 0.94 1.01
Lucerne 40716 27606 45435 36706 0.90 0.75
Phalaris 31030 12646 33561 10873 0.92 1.16 Exp3: 2010 Chicory 38218 11721 35966 8320 1.06 1.41
Lucerne 38129 21338 39158 33096 0.97 0.64
Phalaris 38242 15524 31060 8032 1.23 1.93