Double furrow with raised bed—A new improved mechanized water-harvesting technique for large-scale rehabilitation of arid rain-fed areas

A new water-harvesting (WH) furrow opening technique, double furrow with raised bed (DFR), was compared to a popular technique [Deep Furrow (DF)] under Mediterranean arid environment in Jordan. The two WH micro-catchments with 4, 8, and 12 m length of runoff area were planted with 1-, 2-, and 6-month old Atriplex seedlings. Sedimentation thickness and infiltration rate inside the micro-catchments, moisture regime in the soil profile, WH efficiency, plant productivity over 2 years, and ease of mechanization were evaluated. These parameters were employed in a new comprehensive and practical method for evaluation, and a simple method for calculating the overall seasonal WH efficiency was established. The implementation of the DFR technique, using a specially designed plough, showed a reasonable WH efficiency and better plant productivity at 8 m spacing. Moreover, it is expected that the formed sediments-free bed will allow for mechanized planting, whereas, the clear bottom will facilitate mechanical maintenance. Using either 1- or 2-month old Atriplex transplants resulted in greater plant productivity and guaranteed easier mechanized transplanting. Under Mediterranean dry conditions, the top 20-cm layer of the soil was unable to support the plant with water beyond 6 weeks without WH interventions. However, the investigated WH techniques doubled that period, and provided the soil reservoir with available water for more than one season.

Research highlights
► New mechanism for lower cost and faster implementation of ridges for shrubs.
► Mechanizing WH systems are decisive in revegetation and land degradation control.
► WH efficiency derived from the whole season is more applicable and realistic.
► WH intervention is more critical for survival than draught tolerance of the plant.
► A comprehensive method for evaluating WH techniques was developed.