Management of rice production systems to increase productivity

enefits of fertilizer use, the consumption of fertilizer is declining in Africa.
Fertilizer usage in SSA is the lowest in the world.
The extremely low usage of inorganic fertilizer in Africa is associated
with the high cost of fertilizer importation and transportation to rural areas
(Table 1). Consumption in 1998 was 45.5 kg/ha. This is 55% less than the
average world consumption of 100 kg/ha. In The Gambia, in absolute values,
nitrogen costs between $2 and $3 per kilogram when applied as 15‐15‐15 NPK
or 8‐24‐24 NPK compound fertilizer, while phosphorus and potassium cost
between $1 and $2 when applied as one of the two combinations.
Table 1. Fertilizer Importation and Usage in Africa
1980 1985 1990 1995 1998
Fertilizer
Consumption
(Kg/Ha)
Fertilizer
Imports
43.2 51.8 54.1 44.4 45.5
(billion Mt) 1.6 1.7 1.7 1.4 1.9
Source: FAO Database, World Bank Development Indicators for Africa, 2002.
Also inappropriate fertilizers are used in many areas because there is a
lack of soil testing, thus uneconomic blanket applications of expensive and
scarce fertilizer are used. Most crops are, of necessity, organically produced in
Africa. Shifting cultivation and fallowing is still the predominant means of
restoring soil nutrients. Fallow periods are becoming shorter, and acquiring
new land is now much more difficult with the increases in population and
urbanization. As stated earlier, government subsidies have been removed on
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