Impact of Phosphate Solubilizing Bacteria Formulations in Enhancing Phosphorous Use Efficiency in Blackgram

Blackgram, a leguminous plant, obtains atmospheric nitrogen through its root nodules. The availability of phosphorus to legume crops is a key constraint for production due to its role in root growth and development. This experiment aimed to assess the effect of PSB formulations on enhancing phosphorus use efficiency (PUE) in blackgram. The results revealed that the application of 37.5 kg/ha P2O5 with PSB @ 4 ml/kg seeds significantly increased phosphatase activity (72.31 μg PNP/g of soil/hr), leading to a higher PUE (30.42%). Consequently, nitrogen (120.05 kg/ha), phosphorus (11.41 kg/ha), and potassium (37.51 kg/ha) uptake were significantly higher in the main plot, sub-plot, and interacted plots compared to the carrier-based formulation (CBF). Statistical analysis confirmed that these differences were significant (p<0.05), reinforcing the effectiveness of liquid-based bio-fertilizer (LBF) over conventional CBF. Furthermore, the study highlights the economic advantage of LBF, as it offers improved nutrient uptake and efficiency, potentially reducing the need for higher phosphorus fertilizer applications. The liquid formulation @ 4 ml/kg seed proved superior to carrier-based formulations and other liquid formulations when compared with the recommended nutrient dose, making it a promising and updated technology for sustainable blackgram production.