The Sultanate of Oman is located in the southeast of the Arabian Peninsula (Figure 1). On a total area of approximately 310,000 km2, Oman has a population of 2.2 million (Ministry of Information, 1997). Oman has a hot climate and is humid in the coastal areas, but is very dry in the interior. Average rainfall is 100 mm, except for in the south region which has a period of intense monsoon rainfall.
After oil, agriculture is the major economic sector for Oman, even though more than 80% of the land is desert. With 100,000 ha of cultivated land, the Sultanate is one of the major agricultural producers in the Arabian Peninsula, particularly regarding livestock production. However, only a very small percentage of land can be classified as agricultural land. Agriculture depends entirely on irrigation and more than one-third of the water used for irrigation is supplied by the traditional irrigation system called aflaj.