By Christian Thierfelder

1. How “Climate-smart” is Conservation
Agriculture in Southern Africa?
By: Christian Thierfelder

2. The Challenges:

3. Days after planting in each cropping season
0 20 40 60 80 100 120 140 160 180 200 220
Cummulativerainfal(mmd
-1
)
0
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
850
900
950
1000
1050
1100
2004/2005
2006/2007
2012/2013
2011/2012
2008/2009
2010/2011
2009/2010
2005/2006
2007/2008
Uncertenties increase!
Rainfall variability in
Zimuto Communal Area,
Zimbabwe 2004-2013
Thierfelder et al., 2014

4. Yield gaps in southern Africa are between
50% to more than 100%!

5. 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
Averagemaizeyieldkgha-1
0
500
1000
1500
2000
2500
3000
Average maize yield in Zimbabwe
Average Maize Grain Yields - Zimbabwe
Source: FAOSTAT, 2014

6. Projected change in agriculture productivity, 2080
Source: Hugo Ahlenius, UNEP/GRID-Arendal.

7. Climate change
mitigation
Climate-smart Agriculture (CSA)
CSA

8. How is Conservation Agriculture being
defined?
CA comprises the following
principles:
• Minimal soil movement
• Surface crop residue retention
• Crop rotations and green manure
cover crops

9. Why Conservation Agriculture?
 To combat increasing land
degradation (physical, biological and
chemical)
 To respond to climate variability and
change….
 The need for more efficient use of
resources (sustainable intensification)
 Rising production costs
 To reduce the risk of crop failure

10. Known challenges of CA system...
 Biomass trade-offs in mixed crop livestock systems-
competition for residues
The Malawi
“Sausage”

11. Known challenges of CA system...
 Weed control in the initial years
 CA needs changes in the way farmers do agriculture
 Availability of critical inputs (equipment, herbicides)
 Farm size – sometimes limits rotation
 Yield benefit delayed in some systems
 Moisture limits adoptability

12. •Basin planting
•Jab-planter
•AT Direct seeder
•Dibble stick
•Hoe-planter
•Magoye ripper

13. New mechanization ideas....?

14. How does CA adress the three different
pillars: adaptation, mitigation and
productivity.....?

15. Climate Change Adaptation

16. Conventional ridge tillage Conservation agriculture

17. Earthworm counts in the first 30 cm,
Monze, 2010/2011
d
a
abcd
abc
abcd
bcd
ab
a
bcd
cd
0.0
20.0
40.0
60.0
80.0
100.0
120.0
140.0
CP- Maize DS- Maize BA- Maize DS- Cotton/
Maize
DS- Maize/
Cotton
DS-
Sunnhemp/
Maize/ Cotton
DS- Maize/
Cotton/
Sunnhemp
DS- Cotton/
Sunnhemp/
Maize
CP- Cotton/
Maize
CP- Maize/
Cotton
Treatments
Earthwormcounts(counts/m²)
Conservation agriculture treatments

18. 0 5 10 15 20 25 30 35 40 45 50 55 60 65
Infiltrationinmmh-1
0
10
20
30
40
50
60
70
80
90
100
110
120
130
Conventional ploughing - Maize
CA- Dibble stick, Maize
CA- Dibble stick, Maize-Cowpea
Chitedze, Malawi
Time (min)
0 5 10 15 20 25 30 35 40 45 50 55 60 65
Infiltration(mmh-1
)
0
10
20
30
40
50
60
70
80
90
100
110
120
130
Conventional ploughing, maize
Rip-line seeded, maize
Direct seeding, maize
Rip-line seeded, maize-cowpea
Henderson, Zimbabwe
0 5 10 15 20 25 30 35 40 45 50 55 60 65
Infiltration(mmh-1)
0
10
20
30
40
50
60
70
80
90
100
110
120
130
CA- Direct seeding, maize
Conventional ploughing, maize
CA- Direct seeding, maize after sunflower
Sussundenga, Mozambique
Time (min)
0 5 10 15 20 25 30 35 40 45 50 55 60 65
Infiltrationrate(inmmh-1)
0
10
20
30
40
50
60
70
80
90
100
110
120
130
Direct seeding, maize-cotton
Conventional ploughing, maize
Direct seeding, maize-cotton-sunnhemp
Direct seeding, maize
Monze, Zambia
Infiltration is crucial in CA systems!

19. Soil moisture, 0-60cm, MFTC, 2011/2012
Date
07/11/11
21/11/11
05/12/11
19/12/11
02/01/12
16/01/12
30/01/12
13/02/12
27/02/12
12/03/12
26/03/12
09/04/12
Rainfall(mmd-1)
0
10
20
30
40
50
60
70
80
Availablesoilmoisture(mm)
0
20
40
60
80
100
120
140
160
180
200
220
240
Conventional ploughing, maize (CP-M)
Direct seeding, maize (DS-M)
Direct seeding, maize-cotton (DS-MC)
Rainfall 2011/2012
Yield gain DSM: 27%
DSMC: 53%

20. CA performance under seasonal dry
spells, Monze Farmer Training Centre
Date
05-D
ec-0512-D
ec-0519-D
ec-0526-D
ec-0502-Jan-0609-Jan-0616-Jan-0623-Jan-0630-Jan-0606-Feb-0613-Feb-0620-Feb-0627-Feb-0606-M
ar-0613-M
ar-0620-M
ar-0627-M
ar-0603-Apr-06
Rainfall(mmd-1)
0
10
20
30
40
50
60
70
80
Availablesoilmoisture(mm)
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
field capacity
50% avail. moist.
Rainfall in 2005/2006, total 734 mm
Basin planting (BA)
Conventional ploughing (CP)
Direct seeding (DS)
Source: Thierfelder and Wall, 2010

21. CA performance in a wet and dry year,
Malawi, 2007/08 and 2011/12Maizegrainyield(kgha-1
)
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
4018
4948 4789
Conventional ridge tillage
CA + sole maize
CA + maize/legume intercropping
Wet year
2007/2008
2485
4086
4223
Dry year
2011/12
+23% +19%
+64% +70%

22. Too much water…… Balaka 2015!

23. Maizegrainyield(kgha
-1
)
0
1000
2000
3000
4000
5000
6000
i
hi
bcde
cdef
bcd
abc ab
a
def
Conventional tillage CA-Basin planting CA-Direct seeding
cdefcdef
cdef
ghi
efg efg
defg
fgh
efg defg
def def
Traditional variety, Matuba DT variety, ZM309
DT variety, ZM401
DT variety, ZM523
DT variety, ZM625
DT variety, Pan53
DT variety, Pristine601
Adaptation to Climate Change –
Integration of Climate-smart Technologies

24. Climate Change Mitigation!

25. What do we know about the mitigation
potential of CA?
 Improved mitigation potential through more
efficient water and nutrient use (precision
agriculture, microdosing)
 Reduced fossil fuel needs for land preparation
 Small reductions (CO2) but also increased (NOx) in
GHG emissions
 Overstatement of the global potential for soil C
sequestration under no-till agriculture (Powlson et al.
2014)

26. Mitigation potential
● Data on soil carbon
sequestration inconclusive –
some studies report
benefits, some not…..!
(Govaerts et al. 2009, Ngwira et
al. 2012; Thierfelder and Wall
2012)
● Carbon accumulation
depends on organic inputs
and is often observed in the
first 0-30 cm but not in
deeper layers
Soil carbon dynamics, Monze FTC,
2005-2010
0-30 cm
Year
2004 2005 2006 2007 2008 2009 2010 2011
0
5
10
15
20
25
30
35
Conventional agriculture, maize
CA, maize
CA, maize-cotton rotation
CA, maize-cotton-sunnhemp rotation

27. Sustainable Increase in Maize
Productivity

28. Longer term maize grain yields on farmers
fields in Zambia – Monze, 2006-2014
Harvest year
2006 2007 2008 2009 2010 2011 2012 2013 2014
Maizegrainyield(kgha
-1
)
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
Conventional ploughing, maize (CPM)
Ripline seeding, maize (RIM)
Direct seeding, maize (DSM)
a
NS
b
b
NS
NS
a
a
a
a
ab
b
b
a
a
a
b
a
a
b
a
Thierfelder et al. 2013

29. Regional perspective – Southern Africa, 80%
positive maize yield responses to CA
Conventional tillage yield (kg ha-1
)
0 2000 4000 6000 8000 10000
Conservationagriculturetreatmentyield(kgha-1
)
0
2000
4000
6000
8000
10000
1:2line
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

30. Overall performance of CA systems in
Malawi (a) and Zambia/Zimbabwe (b)
Maizegrainyield(kgha
-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 3521a
b)
Maizegrainyield(kgha-1)
Thierfelder et al. 2015

31. Years under CA
0 1 2 3 4 5 6 7 8 9 10
-2000
-1000
0
1000
2000
3000
4000
Conventional tillage against ripping
F(x)=180.7x - 247.8;
Conventional tillage against direct seeding
F(x) = 31.5x + 185.0
b)
Maizeyieldbenefit
CPagainstCA(kgha-1)
Years under CA
0 1 2 3 4 5 6 7 8 9
Maizeyieldbenefit
CPagainstCA(kgha-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)

32. Economic viability of CA systems in Malawi
● 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 margins (USD) maize, Central Malawi
Harvest year
2012 2013 2014
Grossmargins(USD)maize
0
200
400
600
800
1000
1200
1400
1600
1800
2000
Conventional ridge tillage, maize
Conservation agriculture, maize
Conservation agriculture maize/cowpea intercropping
Gross margin (USD), groundnuts, Central Malawi
Harvest year
2012 2013 2014
Grossmargins(USD)groundnuts
0
200
400
600
800
1000
1200
1400
1600
1800
2000
Conservation agriculture, groundnuts 1
Conservation agriculture, groundnuts 2
Conventional practice, groundnuts

33. With CA - 25 labour days saved!

34.  Adaptation potential of CA is high
 CA improves infiltration and soil moisture
 CA conserves moisture if residues are applied
 Mitigation potential inconclusive!
 Soil carbon increase depend more on organic input than tillage
 Productivity increase documented after 3-5 cropping seasons
 CA is more profitable in some areas depending on cropping
systems and inputs used

35. Thank you very much!

36. Thank you very much!