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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). Explaining. why C-sequestration is a difficult task for Sahelian countries.
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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)
Explaining • why C-sequestration is a difficult task for Sahelian countries • I. Introduction Goal • 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
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
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
zone carrying capacity 1) population density1) 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% Carrying capacity of agro-pastoral systems of Sahelian countries and their population density
III. More productive, remunerative and sustainable agriculture through ISFM maize crop establishment Control ISFM maize at end of cycle Control ISFM
farmer’s practices after 4 years of ISFM cereal yield kg/ha VCR fertilizers1) cereal yield kg/ha VCR fertilizers1) maize; bush field 750 2 – 5 2) 2,750 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 • value incremental yield/fertilizer cost; • no fertilizer use by farmers; estimates, based on fertilizer recovery data. ISFM improvement of crop yield and fertilizer profitability in West Africa.
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
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
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
V. Contribution of C-sequestration Carbon credits, a small contribution to soil investments C-sequestration in crop- , range- and forest land
Sahel Soudanian Savannah Guinea Savannah 1) 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 1) Careful ( limited data ) intensive and sustainable agriculture 5 16 28 Variability of above and below ground OM (t/ha dry matter) under different conditions in Sahelian countries
Sahel Soudanian Savannah Guinea Savannah improving cropland 1) 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 1) two extremes, intensive agriculture based on annual crops, all trees eliminated from the fields to allow for tractor plowing, and agroforestry; above ground 0.5 2 3 Total 6 13 25 The carbon sequestration potential of Sahelian coun
VI. ISFM x C-sequestration in practice • Strategic site selection, a private and a public angle of incidence • Public angle of incidence • ISFM options
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 pastoral production leguminous fodder or perennial pastures 1) agro(-pastoral) production park land agro(-pastoral) production 1) in rotation with cereals and other crops! ISFM production systems favorable for C-sequestration in dry West Africa with agro-ecological recommendation domains