Desert forages of the Arabian Peninsula — the sustainable use of salt affected soils through conservation and evaluation

Abstract

The native plant biodiversity of the Arabian Peninsula, which comprises over 3500 species, is being rapidly depleted. The primary cause is overgrazing, particularly by the large population of ruminants (24 million and growing steadily). Increasing amounts of supplementary feed in the form of alfalfa and Rhodes grass is being produced to accommodate the shortfall from the rangeland. These species, introduced to the region, consume huge volumes of sweet water, mainly applied through irrigation from groundwater. The combined effects have meant that groundwater levels have fallen dramatically, the potential productivity of the land has fallen, salt levels have increased and in some cases, the land has had to be abandoned. Some of the National Agricultural Research Systems (NARS) of the Arabian Peninsula, working with the International Center for Agricultural Research in the Dry Areas (ICARDA), have taken steps to address the resulting degradation and increased salinity levels. This paper systematically describes a holistic approach that was begun in 1997 to address these problems. It started with the collection of indigenous knowledge and interviews with local bedouin farmers in the United Arab Emirates; continued through a series of training programs for human resource development, germplasm collection missions in the UAE, the Sultanate of Oman and the Republic of Yemen, including salt-affected areas; the development of herbaria, databases and one large genebank in the Republic of Yemen as well as a working collection in the UAE. Seed of selected species has been multiplied and evaluations for water-use efficiency and nutritive value are underway. Initial data shows that not only do the desert forages use less water than the introduced forages, but also their nutritive value is as good. In addition, research is underway to identify other forages that are more tolerant to salinity, research sites have been identified in the Sultanate of Oman, the United Arab Emirates (UAE) University and the new Biosaline Agricultural Center (BAC) in the Dubai. Collaborative research at the UAE University in Al-Ain on screening for salt tolerance in a perennial forage (Sporobulus spp.), perennial shrubs (Atriplex spp.) and two annual forages (Hordeum vulgare & Pennisetum glaucum) are also briefly described. This research will not only benefit the Arabian Peninsula countries, but also all countries that are likely to face the increasing impacts of global warming, desertification, drought and, in particular, salinity, in the 21st century.