Growth, yield, yield components, and grain qualities of groundnut (Arachis hypogaea L.) as affected by liming and phosphorus rates in southwest Ethiopia

Two field experiments were conducted in the main seasons of 2021/22 ​at the farmers' farm in two districts of southwest Ethiopia to investigate the effects of lime and phosphorus on groundnut yield and yield components, employing four levels of lime (0, 2, 4, and 6 ​t CaCO₃ ha⁻¹) and phosphorus (0, 46, 69, and 92 ​kg P₂O₅ ha⁻¹) arranged in factorial RCBD design with three replications. Data on the yield and its components were collected and subjected to an ANOVA using SAS software. The result demonstrated that plant height, number of branches, canopy spread, and shelling percentage were affected significantly by liming while effective nodule number, total peg, matured pod, and pod yield of groundnut significantly influenced by the main factors and their interactions. The combined application of 4 ​t lime and 46 ​kg P₂O₅ ha⁻¹ resulted in the highest number of effective nodules (147.23 plant⁻¹), total pod (72.6 plant⁻¹), mature pod (62.4 plant⁻¹), pod yield (4.49 ​t ​ha⁻¹), oil content (50.6%) and protein content (33.1%) whereas the lowest values of these parameters were seen in plots where neither lime nor phosphorus was applied. Therefore, it is advised that groundnut growers in the study areas, and similar agro-ecologies, apply the combination of 4 ​t lime and 46 ​kg P₂O₅ ha⁻¹.