El Batán: results Maize

Management

practice

Average yield

(t ha-1 at 12% H2O)

Coefficient of

variation (%)

CT-Keep 5.31 BC 22.3 B

CT-Remove 5.04 C 23.2 B

ZT-Keep 5.96 A 19.0 B

ZT-Remove 3.92 D 35.8 A

ZT-Keep M1/3W 4.93 C 33.8 A

ZT-Keep1/2 5.59 AB 24.7 B

CT: conventional tillage; ZT: zero tillage

Cd. Obregón: Characteristics

● Arid coastal plains (39 masl)

● Irrigated agriculture

● Irrigation applied in furrows

Cd. Obregón: Characteristics

● Soil: Haplic Vertisol

(Calcaric, Chromic)

15 cm

35 cm

80 cm

110 cm

Cd. Obregon: target environment

Treatments

● Permanent beds

● Conventional tillage

after harvest

One pass with a chisel plough to 30 cm depth

Two passes with a disk harrow to 20 cm depth and two passes

with a spring tooth harrow to 10 cm.

the seed bed preparation

Remaking the beds => weed control

Cd. Obregón: results

CTB: conventionally tilled beds; PB: permanent beds

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009

Gra

in y

ield

(t/h

a at

12%

H2O

)

Year

CTB-Keep PB-Burn PB-Remove PB-Partial PB-Keep

Cd. Obregón: results

Management

practice

Average yield

(t ha-1 at 12% H2O)

Coefficient of

variation (%)

CTB-Keep 7.01 BC 10.69 A

PB-Burn 6.65 C 11.66 A

PB-Remove 7.24 AB 9.53 A

PB-Partial 6.91 BC 10.28 A

PB-Keep 7.42 A 8.65 A

CTB: conventionally tilled beds; PB: permanent beds

Cd. Obregón: results

Management

practice

Slope Inter-

cept

R²

CTB-Keep 1.07 -0.52 0.95

PB-Burn 1.09 -0.98 0.91

PB-Remove 0.96 0.42 0.96

PB-Partial 1.00 -0.11 0.93

PB-Keep 0.85 1.44 0.91

CTB: conventionally tilled beds; PB: permanent

beds 5.0

5.5

6.0

6.5

7.0

7.5

8.0

8.5

5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5

Tre

atm

en

t yie

ld (M

g/h

a a

t 12

% H

2O

)

Year mean yield (Mg/ha at 12% H2O)

CTB-Keep PB-Burn

PB-Remove PB-Partial

PB-Keep Linear (CTB-Keep)

Linear (PB-Burn) Linear (PB-Remove)

Linear (PB-Partial) Linear (PB-Keep)

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

PB-Full PB-Red CTB-Red CTB-Full

Yie

ld (

t/h

a)

Verhulst et al., 2010a

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

15 25 35 45 55 65 75 85 95 105 115 125 135 145

ND

VI

Days after planting

CTB-Full Br PB-Full Br

CTB-Red Br PB-Red Br

CTB-Full Dur PB-Full Dur

CTB-Red Dur PB-Red Dur

PB and CTB with full and reduced

irrigation

Yield: With reduced irrigation: 19% and 26% higher yield on PB than

CTB for bread and durum wheat, respectively

NDVI:

Conclusion System

● CA highest yielding in both environments

● Differences in stability were only found in rain

fed, more adverse conditions

● Straw fully removed or burned combined with ZT

is not sustainable

● More research is needed to design optimal

systems with partial residue retention

Literature review

● Govaerts et al., 2009

● West and Post (2002), Jarecki and Lal (2003),

VandenBygaart et al. (2003), Blanco-Canqui

and Lal (2008) + Literature search (Web of

Science)

● Only >5y and minimum 30cm

● Very little research in Africa, Central- Latin-

America, Asia

Literature review

● Conventional till Zero tillage

8/62 cases C stock decreased

21/62 cases C stock not significant different

33/62 case C stock increased

● Increased rotation

22/55 cases C stock decreased

5/55 cases C stock not significant different

28/55 cases C stock increased

Conclusions

● Not always increase in C stock

● Why? Not clear

● Underlying processes seem not fully

understood

● Need for an international network of hubs

linked to strategic research sites

● Even if CA does not lead always to C stock

increase it is still the best practice to promote

●

Dendooven et al. 2012

Dendooven et al. 2012

Dendooven et al. 2012

Conclusions

● The net global warming potential of CA was

negative while positive in CT

● For this agro-eco environment CA has the

potential to reduce global warming while CT

contributes to it

● For CA systems N management is key especially

in high input environments

● Changing to CA systems will require a change in

mindset.

● CA systems require complex innovation

networks networks that include promotion of

alternative fodder crops and takes into account

other socio-economic and biological limitations

and catalyzes innovations through appropriate

actors of change

http://conservacion.cimmyt.org

Thank you for your attention