Irrigation regime with organic and bio-fertilizers for faba bean production grown on sand clay loam soil.

Water scarcity is a major challenge for faba bean production, especially in arid and semi-arid regions. This study investigated the effect of deficit irrigation and organic or bio-fertilization on faba bean yield and water use efficiency (WUE). The experiment was conducted in two consecutive winter seasons in Egypt, and the average results of the two seasons were presented because there were no significant differences between the two seasons. The experimental design was split-plot with three replicates in each season. The main plots were assigned to the amounts of irrigation water [3330 m³ ha⁻¹ (I1), 2830 m³ ha⁻¹ (I2), and 2330 m³ ha⁻¹ (I3)] and the subplots were devoted to the fertilization treatments [control, humic acid (HA), fulvic acid (FA), and effective micro-organisms (EM)]. The results showed that the plant height and branch numbers were increased by 139.95 and 242.03%, respectively, for HA at irrigation treatment of I2 over the control. Adding HA increased chlorophyll and protein contents by 209.04 and 295.46%, respectively, over the control at irrigation regime of I2. Adding HA significantly increased pods number, pods weight per plant, and total green yield by 380.21, 314.51, and 420.28%, respectively, over the control. The WUE value was 4.51 kg m⁻³ by adding HA under deficit irrigation I2 compared to irrigation I3 (2.64 kg m⁻³) while the WUE value was 4.58 kg m⁻³ at normal irrigation (I1). Overall, the application of organic or bio-fertilizers, especially humic acid, could mitigate the negative effects of deficit irrigation and improve faba bean yield and WUE. [ABSTRACT FROM AUTHOR]