establishing pastures under cover crops...cover-cropping 3. use the dst to highlight the key factors...

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



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

establishing pastures under cover crops...cover-cropping 3. use the dst to highlight the key factors...

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