Influence of Different Sources and Levels of Phosphorus on Yield and Quality of Soybean in Low Calcareous Soil

A field experiment was conducted during the kharif season of 2023 at Post Graduate Instructional Farm, College of Agriculture, Pune, to study the impact of different phosphorus sources and levels on soybean yield and quality of soybean in low calcareous soil. The experiment was laid out in randomized block design having eight treatments with three replications. The experiment was planned with the objective to study the efficacy of different phosphorous sources and their level of application to soybean crop. The treatments comprised T1- Absolute control, T2- RDF (50:75:45 kg ha-1 N: P2O5: K2O), T3- 50% P2O5 through PROM, T4- 75% P2O5 through PROM, T5 -100% P2O5 through PROM, T6- 100% P2O5 through DAP + FYM @12.5 t ha-1, T7 - 100% P2O5 through SSP + FYM @12.5 t ha-1 and T8- 100% P2O5 through vermicompost. The soil of the experimental site was clay loam in texture. The findings of the present investigation revealed that the higher pods per plant (49.66), seeds per plant (149), seed yield (27.63 q ha-1) and straw yield (33.43 q ha-1) were recorded in treatment 100% P2O5 through SSP + FYM @12.5 t ha-1. The application of 100% P2O5 through PROM recorded significantly higher number of pods per plant (47.33), number of seeds per plant (142), grain yield (22.62 q ha-1) and straw yield (24.88 q ha-1) than the application recommended dose of fertilizers to the soybean crop. In respect of quality parameter, the treatment with 100% P2O5 through vermicompost showed significantly higher protein content in soybean grain (38.77 %). In general, the application of organic fertilizers, FYM, PROM, and vermicompost, significantly enhanced soybean yield and quality, indicating their potential as sustainable alternatives to conventional chemical fertilizers in low calcareous soil.