NUTRIENT EVALUATION OF SOME ARID RANGE PLANTS IN SAUDI-ARABIA

Sixty-one desert range plant species collected from the Harrat al Harr a Protected Area of the Al-Jauf region in the northern Saudi Arabia we re analysed to evaluate nutritional status and to identify the suitabi lity potentials of some of the species for rehabilitation in the arid region. Plant samples were analysed for N, P, K, Na, Ca, Mg, Fe, Zn, C u and Mn concentrations. The study showed higher nitrogen concentratio n in the Cruciferae species than the leguminous species. Of the specie s examined, 90% were palatable out of which 11% showed a high to very high class index for the NPK group of macro nutrients. The annual herb s Carrichtera annua, Diplotaxis acris (Cruciferae), Centaurea pseudosi naica (Compositae) and Hyoscyamus desertorum (Solanceae) showed high t o very high NPK levels. Phagnalon barbeyanum, a perennial herb, had th e highest concentration of all micro-nutrients followed by Astragalus kahiricus, an annual herb. Astragalus kahiricus and Atriplex leucoclad a had high indices of total nutrient concentration. Three of these spe cies were, however, rare in occurrence on the scale of abundancy ratin gs and face the possible threat of extinction.