Field experiment was conducted along two successive seasons of winter (2004/2005) and summer (2005) at Maryout Experimental Station of the Desert Research Center, to evaluate the performance of alternate–long furrow irrigation system, using three irrigation water inflow rates on faba bean and sunflower crops productivity grown in calcareous soil. The experiments carried out in a split plot design with four replicates at random procedure. Irrigation system treatments were used as the main plots (120 m length with longitudinal soil surface slope 0.25%) namely: every long-furrow irrigation (EFI), and alternate long-furrow irrigation (AFI). Three different water inflow rates designated as Q1, Q2, and Q3 represented the sub plots: 105, 90, and 65 lpm/furrow, respectively. The irrigation performance was evaluated through application efficiency (AE%) and distribution uniformity (DU) parameters. Irrigation water use efficiency (IWUE) was estimated, which is related to water management by different treatments.
The obtained results indicated that application of AFI led to high significant interrelations between the values of seed yield and increases in AE% and DU values compared with EFI treatments. The highest mean DU values in 1st. and 2nd. seasons were 0.85 and 0.83 obtained by Q2 and Q1 treatments, respectively. Both faba and sunflower seed yield had significant increases with increasing the inflow rates under both studied irrigation systems. The highest yield mean value, with faba bean season, was 1046.5 kg/fed., while with sunflower season; it was 659.95 kg/fed. obtained by (AFI+Q1) treatment. The highest IWUE mean value, with faba bean season, was 0.83 kg/m3, while with sunflower season; it was 0.27 kg/m3. obtained by (AFI+Q3) treatment.
The two combined treatments (AFI+Q1) and (AFI+Q2) were the best treatments for soil moisture distribution uniformity, improving calcareous soil productivity and percent of sunflower oil content (O C%) in seeds under the conditions of the present investigation.