IFDC Division Afrique Enhancing integrated soil fertility management through the carbon market to combat resource degradation in overpopulated Sahelian countries H.

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Transcript IFDC Division Afrique Enhancing integrated soil fertility management through the carbon market to combat resource degradation in overpopulated Sahelian countries H.

IFDC Division Afrique
Enhancing integrated soil fertility
management through the carbon
market to combat resource
degradation in overpopulated
Sahelian countries
H. Breman, A. Gakou, A. Mando and M. Wopereis
IFDC-Africa (Lomé TOGO)
IFDC Division Afrique
I. Introduction
Goal
Explaining

why C-sequestration is a difficult task for Sahelian
countries

why C-sequestration as tool for more sustainable
agriculture has a better chance of success than as goal
in itself

how C-sequestration can be part of an enabling
environment for more sustainable agriculture in the
Sahel
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Structure

Overpopulation, a serious bottleneck for sustainable land
use and C-sequestration

More productive, remunerative and sustainable agriculture
through Integrated Soil Fertility Management (ISFM)

Contribution of C-sequestration

ISFM x C-sequestration in practice
IFDC Division Afrique
II Overpopulation, a serious bottleneck for
sustainable land use and C-sequestration
Overpopulation = overexploitation of natural resources
Overexploitation = negative C-balance
Simple solution (= use of fertilizer) has limited accessibility
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Carrying capacity of agro-pastoral systems of Sahelian
countries and their population density
zone
carrying capacity 1)
population density
1) 2)
North Sahel
1
0 – 12
South Sahel
11
12 – 46
Soudanian
savannah
37
12 – 112
Guinea savannah
51
+ 42
1)
persons / km2 ; 2) in view of the 1985 density and a growth rate of 3%
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IFDC Division Afrique
IFDC Division Afrique
III. More productive, remunerative and
sustainable agriculture through ISFM
maize crop establishment
Control
ISFM
maize at end of cycle
Control
ISFM
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ISFM improvement of crop yield and fertilizer profitability in
West Africa.
farmer’s practices
after 4 years of ISFM
cereal yield
kg/ha
750
VCR
fertilizers1)
2 – 5 2)
cereal yield
kg/ha
2,750
VCR
fertilizers1)
4
maize;
compound field
3,000
5 2)
4,600
12
sorghum
1,000
2 – 5 2)
1,800
8
cotton
1,150
5
2,000
8
irrigated rice
3,000
8
5,500
12
maize; bush
field
1)
2)
value incremental yield/fertilizer cost;
no fertilizer use by farmers; estimates, based on fertilizer recovery
data.
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IV. An enabling environment for change
ISFM more than technology
 Strategic site selection enables local change
 Improved socio-economic and policy environment
enables general change
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Strategic site selection: favorable conditions
for fertiliser use
•
•
Criteria: isfm potential (not representativiness)
isfm potential:
 market access; reasonable prices
 favorable soil and climate
 irrigation systems
efficient transport and distribution
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Conditions to be fulfilled
•
•
Functioning development triangle, effective
cooperation between farmers’ organizations, the
private sector and public services
Socio-economic and policy environment, enabling


farmers to invest in their soil;
private sector to invest in input and
output market development
IFDC Division Afrique
V. Contribution of C-sequestration
Carbon credits, a small contribution to soil
investments
C-sequestration in crop- , range- and forest land
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Variability of above and below ground OM (t/ha dry matter) under
different conditions in Sahelian countries
Sahel
Soudanian
Savannah
Guinea
Savannah
SOM
well protected natural vegetation
27
54
106
exploited present vegetations
18
36
71
cropland and over-exploited rangeland
10
19
38
intensive and sustainable agriculture
18
37
37
above and below ground plant biomass
well protected natural vegetation
4
19
63
exploited present vegetations
3
15
55
cropland and over-exploited rangeland
2
9
25
intensive and sustainable agriculture
5
16
28
1) Careful ( limited data )
1)
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IFDC Division Afrique
The carbon sequestration potential of Sahelian coun
Sahel
Soudanian
Savannah
improving cropland 1)
Guinea
Savannah
SOM
1 to 9
4 to 19
- 8 to + 7
roots
0.5 to 1
0.5 to 3
- 1 to + 5
above ground
0.5 to 1
0.5 to 3
- 4 to + 5
Total 1)
2 to 11
5 to 25
- 13 to + 19
improving range and forestland
SOM
5
10
20
roots
0.5
1
2
above ground
0.5
2
3
6
13
25
Total
1)
two extremes, intensive agriculture based on annual crops, all trees
eliminated from the fields to allow for tractor plowing, and agroforestry;
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VI. ISFM x C-sequestration in practice
 Strategic site selection, a private and a public
angle of incidence
 Public angle of incidence
 ISFM options
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IFDC Division Afrique
ISFM production systems favorable for C-sequestration in dry
West Africa with agro-ecological recommendation domains
fertilizer use, crop by-product
recirculation and:
recommendation domain
semi-arid
improved fodder situation and range
management
pastoral production
improved crop production and
resources managem.
agro(-pastoral) production
sub-humid
perennial fodder banks
1) in
pastoral production
leguminous fodder or perennial
pastures 1)
agro(-pastoral) production
park land
agro(-pastoral) production
rotation with cereals and other crops!
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Agroforestry, an
ISFM option
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Thank you for your attention.