By 1991 only partial surveys of Sudan's land resources had been made, and estimates of the areas included in different landuse categories varied considerably. Figures for potentially arable land ranged from an estimate of 35.9 million hectares made in the mid-1960s to a figure of 84 million hectares published by the Ministry of Agriculture and Natural Resources in 1974. Estimates of the amount actually under cultivation varied in the late 1980s, ranging from 7.5 million hectares, including roughly 10 or 11 percent in fallow, to 12.6 million hectares.
Substantial variations also existed in land classified as actually used or potentially usable for livestock grazing. The ministry and the United Nations Food and Agriculture Organization (FAO) have classified about 24 million hectares as pastureland. The 1965 estimate of land use classified 101.4 million hectares as grazing land, and in 1975 an ILO-United Nations Development Programme (UNDP) interagency mission to Sudan estimated the total potential grazing land at between 120 million and 150 million hectares.
Forestland estimates also differed greatly, from less than 60 million hectares by staff of the Forestry Administration to about 915 million hectares by the Ministry of Agriculture and Natural Resources and the FAO (see Forestry , this ch.). Dense stands of trees only covered between 20 million and 24 million hectares of the total forestland. Differences in land classification may have been accounted for by use of some woodland areas for grazing and some traditional grazing lands for raising crops. Given the dearth of rainfall during the 1980s and early 1990s, the ecological damage from mechanized farming, and the steady march of desertification, discrepancies in these statistics had little meaning in 1991.
It was generally agreed, however, that in the late 1980s Sudan still had a substantial amount of land suitable for future cropping. The ILO-UNDP mission believed that two-thirds of the potential area for livestock grazing, however, was already in use. In addition to land suitable for cultivation and livestock grazing, Sudan also had about 76 million to 86 million hectares of desert. Additionally, an area of about 2.9 million hectares was covered by swamps and inland water, and about 280,000 hectares were occupied by urban settlements and other man-made features.
Data as of June 1991