Management of rice production systems to increase productivity

3.1. Introduction
CHAPTER THREE:
LOWLAND RICE PRODUCTION SYSTEMS
Rice is grown in agroecosystems that range from rainfed uplands to the
flood‐prone and coastal wetlands. Thus, its adaptive mechanism can be
characterized by the supply of water. Lowland rice yields are much higher
than upland rice yields. The average lowland rice yield in Africa is 2.2 t/ha
under rainfed conditions and 4.9 t/ha under irrigation. Approximately 75% of
the world’s rice is currently produced under irrigated systems.
Modern irrigated rice culture in tropical and subtropical environments
is perhaps the most intensive cereal production system in the world (Fisher,
1998). In West Africa, it is estimated that rice irrigation schemes cover about
520,000 ha, cutting across, from north to south, the Sahel, Sudan Savanna,
Guinea Savanna; and Humid Forest agro‐ecological zones (Matlon et al. 1996;
Wopereis et al., 1999). Massive investments in irrigation infrastructure started
in Mali with the Office du Niger Project, in the 1930s, in The Gambia, in 1966
with the Taiwanese Agricultural Technical Mission (Ceesay, 1997), and across
the whole region in the 1970s and 1980s, when severe droughts devastated
rainfed crops and livestock.
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