Comparative Analysis of Impact of Soil Mixture and Fertilization on Growth and Seedling Quality of Selected Agroforestry Tree Species

The study was conducted to determine the most suitable soil amendment for germination and early seedling growth of selected indigenous multipurpose agroforestry tree species, viz., Cordia africana, Fiadherbia albida, Millettia ferruginea, and Moringa stenopetala at Haramaya University, Ethiopia. Seedlings were raised in polythene tubes having 10 cm diameter and 15 cm height and the experimental plots were laid out with eight treatments (i.e., potting soil mixture of, A = agricultural soil, M = manure, S = sand, D = DAP, and U = Urea) and three replications. The morphological attributes of seedlings such as shoot and root height, root collar diameter, leaf area were measured to assess tree seedlings vigor and robustness. Analysis of variance indicated that the shoot height of C. africana, F. albida, and M. ferruginea were significantly different ( P0.05 ) whereas shoot height of M. stenopetala was highly significant ( P0.01 ). Actual leaf area (cm2) of F. albida and M. stenopetala were significantly different ( P0.05 ) and estimated leaf area (cm2) of the four species were highly significant at ( P0.01 ). Treatment 8 (3A: 2M: 1S) for C. africana, treatment 5 (3A: 2M: 1S: 23U) for F. albida and treatment 2 (2A: 2M: 2S: 25D) for both M. stenopetala and M. ferruginea exhibited the lowest sturdiness quotient, which indicates that they are good-quality seedling for plantation. The shoot-to-height ratio indicated positive correlation with most seedling growth parameters whereas root collar diameter and sturdiness quotient showed negative correlation for all species. Treatment 3 (3A: 2M: 1S: 75D) is recommended as the best pot soil mix and fertilization compared to all other treatments, though it needs further study.