In the last half century, because of the raising world population and because of the many environmental issues posed by the industrialization, the amount of arable land per person has declined from 0.32 ha in 1961–1963 to 0.21 ha in 1997–1999 and is expected to drop further to 0.16 ha by 2030 and therefore is a severe menace to food security (FAO 2006). At the same time, about 12 million ha of irrigated land in the developing world has lost its productivity due to waterloggin