Effect of Different Rates of Lime and Split Phosphorus Application on Phosphorus Availability and Yield Performance of Soybean (Glycine max)

Soybean (Glycine max) is a globally significant crop, valued for its high protein and oil content. Under acid soils, amending with lime and split phosphorus fertilizer application can improve the yield of soybean due to an increase in soil phosphorus availability. This study aimed to evaluate the effect of lime rates and split phosphorus (P) application on phosphorus availability and soybean yield, to determine the optimal lime and P levels for soybean cultivation in the study area. Two-season field experiments (monsoon and post-monsoon 2024) were conducted at the Department of Soil and Water Science, Yezin Agricultural University (YAU), using a 4 × 3 factorial RCBD design with three replications. Treatments included four lime levels (0, 1.5, 3.0, 4.5ton ha⁻¹) and three split phosphorus application timings (100% basal, 50% basal + 50% V2, and 50% basal + 25% V2 + 25% R1) at a constant rate of 20 kg P ha⁻¹. The soybean variety, Yezin-15 was used. Results indicated that both the independent and combined applications of lime and split phosphorus significantly improved the yield attributes and overall yield of soybean, as well as the availability of phosphorus in the selected soil. After two seasons, the individual application of lime, L2 (3.0ton ha⁻¹) rate showed better performance for all parameters. In split P application, P2 (50% basal + 50% V2) outperformed with the number of pods plan-1, the number of seeds per pod-1 and seed yield. Also, L2P2 (3.0ton lime ha⁻¹ and 50% basal + 50% V2) treatment provided the maximum P availability and seed yield, the maximum number of pods plant-1, the greatest number of seeds pod-1 in both seasons. This study suggested that further investigations with lime and split-P applications for the long term were necessary.