However, as shown above, the limiting factor is water. At present, depletion of non-renewable fossil water is already taking place at a very fast rate. The central pivot sprinkler system covers prac-tically all the lands cropped with cereals. Normally, pumped groundwater from one deep well supplies one or two central pivots. Vegetables and fruit trees are in general irrigated by drip and bubbler methods respectively.
Water is free of charge.
The major irrigated crop is wheat. Since 1988, self sufficiency in wheat has been reached and part of the production is being exported. In 1992, wheat production was almost 4.1 million tons, while national demand was only about 1.2 million tons. Vegetables, fruits and dates and fodder are also exported. Waterlogging, drainage and salinity Waterlogging and drainage problems occur in the central and southern parts of the country, due to the existence of shallow, impervious layers.