A number of diagnostic studies have been carried out in Mali showing that farmers are seriously concerned about decline in soil fertility (Maiga et al., 1995; Coulibaly et al., 1997; Koné et al., 1998). This decline is also cited as one of the main constraints on agricultural productivity at national level (MDRE, 1994; van der Pol, 1992; Traoré, 1993; Kouyaté, 1998). However, management practices vary a great deal between regions, farmers and fields, and also change over time. The purpose of this research is to present a more detailed picture of soil fertility management in semi-arid regions of Mali, with a particular focus on the dynamics of millet production and the use of organic materials for fertilizing the land.