Evaluation of Atriplx Shrubs Growth in Semi Arid Area

The effect of rainwater harvesting systems on the growth of Atriplx shrubs in semi arid land in western part of Libya was evaluated using two of rainwater harvesting systems (Contour lines and Negarim). Plant height, crown length, crown circumference and maturity were evaluated as measures to the effectiveness of these rainwater harvesting systems. Three micro-catchments area (10.2, 12.5, and 15.5 m²) for each system were used. The catchment area was calculated on the basis of the average annual rainfall, surface runoff coefficient, plant water requirement, and root zone area. The ratio of the cultivated area to the catchment area was found to be 1:15. The growth of Atriplx shrubs was evaluated for two consecutive years. Both contour lines and negarim rainwater harvesting systems gave better results compared with the growth of the control shrubs (shrubs that were planted outside the W.H. systems). The overall efficiency of the systems varied from system to system and from catchment area size to other size. The contour line system and the larger ratio of the catchment area to the cultivated area were found to be strongly related to the growth of the shrubs.