Effect of Different Rates of Phosphorus Fertilizer on Yield and Yield Components of Faba Bean (Vicia Faba L.) at Sidamo Zone, Southern Ethiopia

Low soil fertility, particularly phosphorus (P) deficiency, is a primary constraint to faba bean (Vicia faba L.) production in Ethiopia. A field experiment was conducted to evaluate the response of faba bean to varying P fertilizer rates and to identify a rate that optimizes productivity. The study was carried out at the Hawassa University Research Farm, Southern Ethiopia, during the 2020 off-season under irrigated conditions. A Randomized Complete Block Design (RCBD) was employed with three replications, using four P application rates (0, 50, 100, and 150kg P ha⁻¹) on the ‘’Hachalu'’ faba bean variety. Data analysis revealed that phosphorus application had a significant (P<0.05) positive effect on all measured parameters. The number of pods per plant, seeds per pod, 100-seed weight, and grain yield all increased with higher P rates. The highest grain yield (3913kg ha⁻¹) was achieved at the 150kg P ha⁻¹ rate, a significant increase over the control treatment (3666kg ha⁻¹). These results indicate that P is a critical limiting nutrient for faba bean in the study area. While the 150kg P ha⁻¹ rate was biologically optimal in this study, further multi-location trials that include an economic analysis are necessary to formulate a comprehensive fertilizer recommendation for farmers.