EFFECT OF PLANTING FORAGE SHRUBS AND BARLEY ON ATTRIBUTES OF NATURAL VEGETATION IN ARID LANDS

This study compared some attributes of four forages grown in the arid rangelands of Jordan. Three experimental sites were selected, a plot of 0.8 ha was delineated at each site and subdivided into four equal subplots and contour ridges were constructed at all subplots to harness the surface runoff of rainfall. At each site, Atriplex halimus (ATP), Salsola ver miculata (SAL) and barley (BAR) were planted in the ridges in three out of four sub-plots and the fourth sub-plot was left without any intervention to represent natural vegetation (NV) resulting in four treatments: T-NV, TNV+ATP, TNV+SAL and TNV+BAR. Biomass production, rain use efficiency of forage production (RUEF), carrying capacity (CC), relative feed value (RFV) and Total Digestible Nutrients (TDN) were monitored in February and April representing early and late spring grazing. The highest fresh and dry weights of forage (240.1 and 131.1 kg ha(-1)), CC (1.35 SUM ha(-1)) and RUEF (1.75 kg DM ha(-1) mm(-1)) were observed in TNV+ATP. Planting Atriplex, Salsola or barley negatively affected the forage production of natural vegetation established in the ridges. The socio-economic aspects of production and utilization of TNV+ATP and its impact on rangelands biodiversity should be carefully investigated before out-scaling of this revegetation approach.