Soils - 65
        
        
          i 
        
        
          Cotton is the main source of foreign currency for Mali and
        
        
          Burkina Faso (here near Ouagadougou).
        
        
          © Joerg Boethling/agenda
        
        
          i
        
        
          Maps are used by scientists to show the situation of fields around Kebila in the Sikasso
        
        
          Region of southern Mali.
        
        
          © Mamy Soumaré
        
        
          I
        
        
          ncreasing agricultural production in
        
        
          Sudano-Sahelian Africa is achieved
        
        
          mainly by increasing cultivated areas.
        
        
          However, demographic growth is 3% per
        
        
          year, with a doubling of the population
        
        
          every 20 years, and one can wonder if land
        
        
          resourceswill besufficient tomeet demand
        
        
          for food. Cotton growing developed in Mali,
        
        
          as elsewhere inWest Africa, forming a true
        
        
          agricultural revolution. Total cultivated
        
        
          area increased from 60 000 to 600000
        
        
          hectares, production from40000 to 600000
        
        
          tonnes and the number of draught oxen
        
        
          from 100000 to 600000 in 30  years. This
        
        
          leap in quality enabled farmers to develop
        
        
          a new farming system for their land.
        
        
          
            Cultivated land and fallow
          
        
        
          Fallow was gradually abandoned and the
        
        
          age of fields under continuous cultivation
        
        
          increased. This was seen by combining
        
        
          satellite images, maps as reported
        
        
          by stakeholders and the geographical
        
        
          positions of the fields of 15 farmers chosen
        
        
          according to the diversity of their practices.
        
        
          All the fields cultivated in 1985 still are
        
        
          whereas cultivation rarely exceeded 5 years
        
        
          in theoldsystem. Aerial photosandsatellite
        
        
          images can be used not only to reconstruct
        
        
          the history of land occupation but also
        
        
          to show the present situation. Farmers
        
        
          identify the main domains—cultivated
        
        
          land and fallow—from a simple coloured
        
        
          composition on the green, blue and red
        
        
          channels. This pilot work is to continue
        
        
          during the next three years within the
        
        
          framework of the
        
        
          
            Programme d’Appui aux
          
        
        
          
            Systèmes d’Exploitation en Zone Cotonnières
          
        
        
          
            du Mali
          
        
        
          (PASE2, ‘Support Programme for
        
        
          Farming Systems in the Cotton Belt in
        
        
          Mali’) under the direction of the Chamber
        
        
          of Agriculture and with support from
        
        
          
            Agence
          
        
        
          
            Française pour le Développement
          
        
        
          (AFD,
        
        
          French Development Agency).
        
        
          The elimination of fallow reduces the
        
        
          frequency of land clearance and slash-and-
        
        
          burn. The halting of bush fires, which are
        
        
          the main source of CO
        
        
          2
        
        
          emission in African
        
        
          agriculture contributes to improving the
        
        
          carbon balance. Transfer of matter results
        
        
          in an increase of the fertility of cultivated
        
        
          soils whereas it falls when crops and fallow
        
        
          are alternated. The viability of such a system
        
        
          depends on the presence of sufficient head
        
        
          of livestock to ensure transfer of fertility
        
        
          and also that of pasture to feed the animals.
        
        
          Farmers must improve the productivity of
        
        
          the pasture to ensure the sustainability of
        
        
          the system, but this is a problem in zones
        
        
          with high population density as in the old
        
        
          Mali cotton belt.
        
        
          
            Prospects for action
          
        
        
          The involvement of stakeholders in the
        
        
          production of maps makes it possible to
        
        
          compare the viewpoints of technicians and
        
        
          users. There are numerous constraints:
        
        
          the languages used are different and
        
        
          stakeholders tend to censor their
        
        
          expression and align their viewpoint with
        
        
          that of dominant thinking: the slogans
        
        
          uttered by politicians and by certain
        
        
          development bodies. However, the
        
        
          knowledge produced jointly helps the user
        
        
          in his work and enriches the analysis made
        
        
          by the researcher.
        
        
          
            Developing newmethods
          
        
        
          Technicians must use tact and pedagogic
        
        
          skills.
        
        
          In
        
        
          participative
        
        
          diagnosis,
        
        
          stakeholders said that shortage of land
        
        
          was a major difficulty in a context where
        
        
          the ratio of cultivated to non-cultivated
        
        
          land is 1:3 or even 1:5 and that fields can
        
        
          be further enlarged. How is it possible to
        
        
          make themunderstand that this constraint
        
        
          is not a valid one in their context? This is
        
        
          all the more delicate as people’s word is
        
        
          strongly significant, and there is above all
        
        
          a practically religious obligation for young
        
        
          people to respect their elders.
        
        
          The data will be updated in five places
        
        
          in Mali using SPOT5 images collected in
        
        
          2007. The changes observed will be used
        
        
          for forecasting and for developing new
        
        
          methods for managing areas. Based on
        
        
          this study, management plans will be
        
        
          developed, incorporating biomass flows
        
        
          between the various components and
        
        
          grouped rotations. All that on the basis
        
        
          of successful discussion between all the
        
        
          stakeholders.
        
        
          c
        
        
          Dr Mamy Soumaré,
        
        
          
            University of Bamako
          
        
        
          Mali
        
        
          Evolution of agricultural methods