http://www.fao.org/globalsoilpartnership This presentation was made during the workshop 'Managing Living Soils' that took place at the FAO HQ, Rome, Italy from 5-7 DEC 2012. This presentation was made by Bernard Vanlawe, and it has the objective to present Status and challenges of soil management in Africa. ©FAO: http://www.fao.org

1. Status and challenges of soil
management in Africa
Bernard Vanlauwe
International Institute of Tropical Agriculture
Nairobi, Kenya
b.vanlauwe@cgiar.org

2. Food security for 9 billion people?
Closing the yield gap
Increasing production ceilings
Expanding aquaculture
Reducing waste (…30-40% of the produce)
Changing diets
Demography
The challenge…

4. The yield gap…
FAO and IFDC, 2002
J. Koo, 2010
Maize yield reduction (% of potential)

5. $ 200-500 /tonne urea world market 2010-2011
$ 900-1.400 /tonne urea in Bukavu (DRC)
The ‘Coca-cola’ paradox

6. The ‘Coca-cola’ paradox
$ 1.5-2 in Europe
$ 0.5 in Bukavu (DRC)

7. Lack of organic resources
Crop Oilpalm Imperata Manure
residues leaves
Availability? Acceptability? Quality?

8. Variability in soil fertility…

9. Variability in soil fertility…
Same farm…
Same variety…
Same inputs…
Same management…
Same weather…

10. Non-responsive soils
Occurrence: Non-responsive soils appear to occur in most
densely populated areas where resources are scarce.

11. Importance of policy and good governance
In Africa, there are good recent examples of where policy is
making a difference in farmer livelihoods (e.g., Malawi,
Rwanda, Kenya)

13. 70’s: First paradigm:
‘Overcome soil constraints to fit plant requirements
through purchased inputs’
‘When mechanization is feasible and
fertilizers are available at reasonable
cost, there is no reason to consider
the maintenance of SOM as a major
management goal’
Sanchez, 1976

14. 80’s: Focus on biological mgt of soil fertility

15. 80’s: First signs of no-till farming

16. 90’s: 2nd Paradigm (Sanchez, 1994):
‘Overcome soil constraints by relying on biological
processes by adapting germplasm to adverse soil
conditions, enhancing soil biological activity, and
optimizing nutrient cycling to
minimize external inputs and
maximize their use efficiency’
The revival of green manures in East
Africa (e.g., Tithonia diversifolia;
Crotalaria sp)

17. 90’s: First signs of uptake of CA in Brasil
1990

19. Productivity
Natural resource status
The destination is clear, less so the road to follow
X
√
√

20. Fertilizer works (and interacts with improved
varieties)…
FAO fertilizer
program
(FAO, 1989) :
 Average response
of 750 kg grain/ha to
medium NPK rates
 Value–to–Cost
ratios between 1.1
and 8.9, usually
above the required
ratio of 2
Maize yield in
East DR Congo

21. Keating, 2011
Desired
Outputs
(e.g. Yield)
or
Undesired
Outputs
(e.g. N loss,
GHG loss)
Inputs
(nutrients, water, labour, agro-chemicals, energy etc.)
Biological
Optimum
Economic
Optimum
Risk-
adjusted
Optimum
Agro-ecological principles…

22. Fertilizer is best applied in combination with
organic inputs!

23. Time, years
0 20 40 60 80 100
TotalC(tha-1
)
10
20
30
40
50
60
Commercial
Communal
Zingore, Manyame, Nyamugafata
and Giller (2002)
Impact of fertilizer x variety on soil C

24. Now: Integrated Soil Fertility Management
‘The application of soil fertility management
practices, and the knowledge to adapt these to
local conditions, which maximize fertilizer and
organic resource use efficiency and crop
productivity. These practices necessarily include
fertilizer and organic input management in
combination with improved germplasm’

25. Now: Integrated Soil Fertility Management

26. Principles of Conservation Agriculture
1. Minimize soil disturbance by reduced or zero-tillage
2. Keep the soil covered with organic materials (crop harvest
residues or cover crops)– at least 30% soil cover
3. Use crop rotations/associations
Important additional rule: No minimal tillage without mulch
retention!
4. Use fertilizer [additional principle for Africa]

27. http://www.fao.org/ag/ca/5.html
‘Time to’ CA

28. 0
20
40
60
80
100
0 5 10 15 20
Time (weeks)
Residuecover(%)
Good - with tillage Good - without tillage
Medium - with tillage Medium - without tillage
Poor - with tillage Poor - without tillage
SED
Guto et al. (2011), Agron. J. Guto et al. (2011), Agron. J.
Good
Medium
Poor
Tillage x residue management in
Central Kenya
Niches for CA
30%

29. ProductivityThe destination is clear, less so the road to follow
Natural resource status
Agronomicefficiency
Current
practice
Germplasm
& fertilizer
+ Organic
resource mgt
+ Local
adaptation
Germplasm
& fertilizer’
+ Organic
resource mgt
Germplasm
& fertilizer
‘Full ISFM’
Move towards ISFM
Increase in knowledge
Responsive soils
Poor, less-responsive soils
A
B
C
X

31. Importance of enabling conditions
Role of input and output markets: ISFM requires
investments in production factors; income is a requirement
to move towards full ISFM.
Models: Many interesting models to link smallholders to
input supply chains and profitable markets are being
piloted/implemented at scale.

32. Organic agriculture is constrained by
organic inputs; OK for niche markets
N: Some BNF  Low use efficiency!
P: Rock phosphates  Availability?
K: K salts; roots and tubers  Availability?
Other (micro)nutrients: S, Zn, Mg, etc  ??

33. The confusing life of a policymaker…
??

34. Farmer first!
Interview Prem Warrior, BMGF, 17 Oct 2012
Question:
‘What’s the right thing to do
for smallholders in Africa?’
Response:
‘It’s for her to decide!’
Thank you!
Merci beaucoup!
Asante sana!