Effects of variety and phosphorus application on soybean (<i>Glycine max</i> L.) yield

There has been a decline in soybean production owing to poor adaptable variety and low soil fertility, especially phosphorus among other factors. A field and screen house experiments were conducted in National Center for Agricultural Mechanization (NCAM), Idofian and Kwara State University, Malete both in southern Guinea savannah environment to evaluate the response of five soybean varieties to different rates (0, 20, 40, and 60 kg SSP/ha) of phosphorus fertilizer application. The field experiment was laid out in a 5 x 4 split-plot arrangement fitted into randomized complete block design (RCBD) with each treatment replicated three times. The screenhouse experiment was arranged in a complete randomized design (CRD) with three replications too. Soil samples were collected from both experimental sites and analyzed for physical and chemical characteristics. Plant data collected on the vegetative and yield component characteristics. The pre-planting soil analysis showed that the soil of the experiential sites was low in soil essential nutrients. Having both studies, the coefficient of variation from the two studies showed that the data from the field study is more reliable due to the low coefficient of variation ranging from (19.33 and 53.09) for hundred seed weight and seed weight per plant compared to the screen house (138.43 and 75.25). Across both studies, variety recorded significant (p<0.05) variation on all yield parameters. Phosphorus application had a significant effect in the number of seeds per plant. While in the field, pair-wise interaction of (variety and phosphorus application) showed a significant difference (p<0.05) in the number of pods, the number of seeds per pod, the number of seeds per plant, pod weight, seed weight per plant, and hundred seed weight. In screen house phosphorus, there was a significant difference in the number of seeds per pod. The interaction between variety and phosphorus, on the other hand, revealed no significant differences in these yield characteristics. The number of pods recorded a highly positive and significant correlation with the number of seeds per plant. TGX 1740-1E performs better under phosphorus application than SOYA with no phosphorus application. The best performance was observed on TGX 1740-1E variety treated with 20kgSSP/ha.