2005 年 60 巻 5 号 p. 391-396
Small-scale automatic weather monitoring stations were placed on fields of 14 farmers in a semi-arid zone village (Niessoumana) and 15 farmers in a semi-humid zone village (Diou) in Mali, West Africa. Data on the farmers’ cropping practices were gathered weekly by interviews. In the semi-arid village, variation in precipitation during the seeding period 21 May-15 June was greater in 2001 and 2002 than in 2003, and the second of two seeding criteria (less than 7 days between 10 mm rains) was met earlier in 2003 (22 or 25 May) than 2001 (17 June) or 2002 (3 July). Farmers seeded upland crops later in 2002 (5 June-11 July) than 2001 (27 May-22 June) or 2003 (27 May-20 June). Reseeding rates for sorghum and millet seeded before the first seeding criteria (10 mm rainfall on one day) were 82% in 2001, but decreased to 44% in 2002 and 0% in 2003. In the semi-humid village, farmers seeded upland crops later, 20 June-30 July in 2001, 18 June-22 July in 2002, and 16 June-20 July in 2003. No millet or sorghum parcels were seeded before the first rainfall criterion date. Percentages of plots reseeded were 11-13% over the three years.
