Evidence from the field – Results from long-term research in maize-based CA systems of

Southern Africa Christian Thierfelder

Focus of the IFAD Grant 1309 Is conservation agriculture (CA) a more profitable,

viable and sustainable system than the conventional tillage-based agriculture?

What are the biophysical challenges to productive CA systems and how can they be overcome?

What socio-economic factors and circumstances affect the adoption and outscaling of CA systems in southern Africa?

What are the lessons learned and future research needs to increase up/outscaling of CA systems?

Summary of outcomesMore than 30 peer-reviewed high impact

journal articles, book chapters and conference papers from 2010-14

Fourteen extension bulletins

Thousands of farmers reached and hundreds of extension officers and researchers trained

IFAD grant provided the scientific background for large outscaling initiatives

Support to investment frameworks and technology release processes and upscaling

Introduction

Traditional farming systems in southern Africa ● Based on mouldboard plough or

hand hoe

● Largly focussed on maize (50-80% of land area) planted in monoculture

● Mostly rainfed systems

● Farming systems are diverse, sometimes with intensive crop/livestock interactions

Traditional farming systems in southern Africa ● Crop residues are burned,

grazed, or fed to animals

● Farmers rarely use improved varieties and/or mineral fertilizer (<10kg ha-1 NPK in SSA)

● Large cropping areas are on inheritantly poor sandy soils under an extremely variable climate

Maize Yield Gap

Difference between farmers’ yields and attainable yields (as %) in Southern and Eastern Africa

(Potgieter et al., 2010)

Time (years)

1970

1972

1974

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

2004

2006

2008

2010

2012

2014

Avera

ge m

aiz

e y

ield

kg

ha

-1

0

500

1000

1500

2000

2500

3000

Average maize yield in Zimbabwe

Average maize grain yields, Zimbabwe; 1970-2014

Adapted from: Thierfelder and Wall, 2009

Why Conservation Agriculture?

To combat increasing land degradation (physical, biological and chemical)

The need for sustainable intensification (more efficient use of resources)

If properly managed, CA can reduce production costs

CA is regarded as more water-, nutrient-, energy- and labor-use-efficient

CA can reduce risk of crop failure

CA can help mitigate and adapt production to climate variability….

Known challenges of CA system...

Biomass trade-offs in mixed crop livestock systems-competition for residues

Weed control in the initial years

CA needs changes in the mindset of farmers

Farm size – sometimes limits rotation

Yield benefit delayed in some systems

Moisture limits adoptability

•Basin planting

•Jab-planter

•AT Direct seeder

•Dibble stick

•Hoe-planter

•Magoye ripper

CA in SSA

New Ideas for Africa.... originating from South Asia and Australia

CIMMYT‘s work on CA in East and Southern Africa

● Ongoing research since 2004

● Major target countries, Ethiopia, Kenia, Tanzania -Malawi, Mozambique, Zambia and Zimbabwe

● Adaptive research on CA systems in 444 target communities

● Strategic research on 24 research locations

● Partnership approach with relevant NARES and NGOs

Results from long-term on-station and on-farm research in Sub-Saharan Africa...

Regional perspective – Southern Africa, 80% positive maize yield responses to CA

Conventional tillage yield (kg ha-1

)

0 2000 4000 6000 8000 10000

Co

nse

rvati

on

ag

ricu

ltu

re t

reatm

en

t yie

ld (

kg

ha

-1)

0

2000

4000

6000

8000

10000

1 :2 li

ne

1:1

line

Planting basins, Mozambique

Ripline seeding, Zambia

Manual direct seeding, Mozambique

Direct seeding, Zambia

Manual direct seeding, Malawi

Manual direct seeding, intercrop., Malawi

Ripline seeding, Zimbabwe

Direct seeding Zimbabwe

Thierfelder et al. 2015

Overall performance of CA systems in Malawi (a) and Zambia/Zimbabwe (b)

Maiz

e g

rain

yie

ld (

kg h

a-1)

0

2000

4000

6000

8000

10000

12000

Conventional ridge and furrow system,

sole maize

Conservation agriculture, sole maize

Conservation agriculture, maize/legume intercropping

3555 b 4707 a 4727 aa)

0

2000

4000

6000

8000

10000

12000

Conventional control Ripline seeding AT direct seeding

2760 b 3218 a 3521ab)

Maiz

e g

rain

yie

ld (

kg

ha

-1)

Thierfelder et al. 2015

Years under CA

0 1 2 3 4 5 6 7 8 9 10

-2000

-1000

0

1000

2000

3000

4000

Conventional tillage against rippingF(x)=180.7x - 247.8;

Conventional tillage against direct seedingF(x) = 31.5x + 185.0

b)

Ma

ize

yie

ld b

en

efit

CP

ag

ain

st C

A (

kg

ha

-1)

Years under CA

0 1 2 3 4 5 6 7 8 9

Maiz

e y

ield

benefit

CP

again

st C

A (

kg h

a-1

)

-2000

-1000

0

1000

2000

3000

4000

Conventional against CA, sole maize

F(x)= 54.3x + 1019.7

Conventional agains CA, maize/legume

F(x)= 100.6x + 855.9

a)

Thierfelder et al. 2015

CA performance depending on years of experience in Malawi (a) and

Zambia/Zimbabwe (b)

Economic viability of CA system

● CA systems in Malawi are more profitable

● Less labour needed for land preparation and weeding

● Increased cost for herbicides are easily compensated

● Advantages in groundnut systems

Gross margin (USD), groundnuts, Central Malawi

Harvest year

2012 2013 2014

Gro

ss

ma

rgin

s (

US

D)

gro

un

dn

uts

0

200

400

600

800

1000

1200

1400

1600

1800

2000

Conservation agriculture, groundnuts 1

Conservation agriculture, groundnuts 2

Conventional practice, groundnuts

Gross margins (USD) maize, Central Malawi

Harvest year

2012 2013 2014

Gro

ss m

arg

ins (

US

D)

maiz

e

0

200

400

600

800

1000

1200

1400

1600

1800

2000

Conventional ridge tillage, maize

Conservation agriculture, maize

Conservation agriculture maize/cowpea intercropping

Key results from component trials

● Weed control strategies involving herbicides are more profitable

● Weed numbers decline over time no matter what weed control strategy used

● Striga decline more pronounced under CA

● Residue benefits are over-shadowed by N-lockup, which can be overcome by greater N fertilization

● Carbon sequestration only measured where residues are continously applied – limited mitigation potential

2009-10 2010-11 2011-12 2012-13

Wee

d de

nsity

(m

-2)

0

200

400

600

manual

paraquat

glyphosate

atrazine

atrazine + glyphosate

atrazine + glyphosate + metalachlor

a

b

c c

bc

d

aa

a

b

a

b

aa

a

a a a

a a aa aa

Key results from component trials

● Rotations play a key role in the CA systems and are a major SI intervention point

● Major breakthroughs with groundnut rotations and cowpea relay cropping (TLC with CIMMYT)

● There is lack of experience with some non-traditional CA crops

● Adaptation to climate change is possibly by combining CA with drought-tolerant germplasm

Ma

ize

gra

in y

ield

(kg h

a-1

)

0

1000

2000

3000

4000

5000

6000

ihi

bcde

cdef

bcdabc ab

a

def

Conventional tillage CA-Basin planting CA-Direct seeding

cdefcdefcdef

ghi

efg efgdefg

fghefg defg

def def

Traditional variety, Matuba DT variety, ZM309

DT variety, ZM401

DT variety, ZM523

DT variety, ZM625

DT variety, Pan53

DT variety, Pristine601

Season

2004/05 2005/06 2006/07 2007/08 2008/09 2009/10

Perc

en

tag

e

0

20

40

60

80

100

120

Herbicides

Residues retention

Zero tillage

Dibble stick

Intercropping

Agroforestry

Crop rotation

Preferential adoption of CA components, Malawi

Source: Ngwira et al., 2014

Results from adoption surveys

Education level of the household head

Availability of credit and finance

Access to farmer-to-farmer extension

Private institution support

Labour and land constraints

Low rainfall increased propensity to adopt the full CA package

Areas close to the lakeshore showed negative correlations indicating high water tables and limited adoptability

Factor affecting the adoption of CA in Malawi:

.... there is need to test recommendation domains

Recent estimates of the use of CA practices on farms in southern Africa

Source: CARWG, 2014

COUNTRY No. of farmers Hectares

Malawi 84,625 11,124

Lesotho 18,500

Zimbabwe 330,000 70,000

Swaziland 9,575

Zambia 314,000

Namibia 110 110

Botswana 70

Tanzania 10,000 6,000

South Africa

400,000

Lessons learned from the IFAD grant

● CA is a more productive, profitable and environ-mentally friendly option than the conventional tillage-based farmers‘ practice

● The question is not if CA “can work” but “how to make it work for more (and the right) farmers“

● Large outscaling of CA is possible if research organ-izations form strategic alliances with development organizations with a common vision (e.g. CIMMYT-TLC)

Lessons learned from the IFAD grant● High quality extension support is mandatory – need

for Monitoring, Evaluation and Learning – capacity building of NARES partners

● If yield benefits are not present in the first year(s), what other benefits should be present to enhance adoptability?

● Successful outscaling methodologies have been identified (lead farmer approach, innovation system approach, demonstration-host-farmer approach)

● A step-wise introduction of CA or better resource allocation within farms may be pathways for sustained uptake of CA.

Research needs for the next years!● Tailored knowledge products are

needed for policy makers and other crucial stakeholders to enhance faster scale-up

● What are the social, economic and environmental benefits of larger outscaling of CA in southern Africa?

● How can CA systems be better targeted (e.g. to different farmers, farm types, agro-ecologies)?

Research needs● What are the longer term effects of

CA systems on carbon sequestration/ mitigation?

● How will CA technologies assist smallholder farmers to adapt to climate variability and change?

● What are the benefits of CA on water-and nutrient-use-efficiency, and yield stability with special emphasis on risk?

Research needs● How can markets be better integrated

into the CA initiatives, including small loan facilities for farmers?

● How can local research partners (e.g. DARS) be better supported and their capacity increased for improved monitoring under SAPP?

● Facilitating the widespread adoption on CA systems requires detailed decision guides, a CA toolbox, bio-physical and socio-economic recommendation domains.

Thank you very much!