Full Length Research Paper
1Abebe Zerihun, 2 Tolera Abera
Abstract
The experiment was conducted at Gedo highland with the objective of determining the effect of rhizobium inoculation, fertilizer and lime application rates on nodulation and yield of faba bean. Three factors, rhizobium inoculation (0 and 10 g/1 kg seed), fertilizer rates (75,100 and 125 kg ha-1 DAP) and lime rate (0, 2, 4 and 6 t ha-1 ) were combined in 2x3x4 factorial arrangements of RCBD in three replications. There were significant differences on nodule number, nodule volume and nodule dry due to the effect of fertilizer and lime application rates, but not by rhizobium inoculation. Nodule number was decreased as the function of increasing rates of either fertilizer or lime application. The residual effect of the lime in the second year also significantly reduced nodule numbers as compared to the control. Grain yield of the crop was highly affected by both fertilizer and lime application but not by strains. The highest significant economic yield was obtained at 100 kg ha-1 as compared to other rates. Significantly higher grain yield in both years was also obtained when 4 t ha-1 of Lime was applied, indicating that the residual effect of lime improved the yield of the crop though no significant difference was obtained on nodules when compared with untreated plots. Generally, applications of either 100 kg ha-1 DAP or 4 t ha-1 lime is advised around Gedo highlands. However, introduction of new rhizobium strains to the area did not significantly increase both nodule number and grain yield.