Declining area of irrigated land

In recent years the world's two leading food producers have experienced a decline in irrigation. China's irrigated area has shrunk by some 2% since 1978. The USA' use of irrigation water dropped 9% between 1980 and 1985. The former Soviet Union in 1986 stopped plans to divert rivers now flowing into the Arctic Ocean into central Asia and while investment in irrigation continues the expected gain in the former Soviet Union are modest.
(E) Emanations of other problems