Impact of Phosphorus Levels and PSB Application on Soil Physio-Chemical Properties in Mustard Fields under Gmelina-Based Agroforestry

This study examines how soil qualities are affected by phosphorus (P) levels and phosphate solubilising bacteria (PSB) inoculation techniques in an agroforestry system based on Gmelina arborea, with a particular emphasis on mustard (Brassica juncea L.) growing. The experiment was conducted from November to April in two consecutive years 2022-2023 and 2023-2024 at JNKVV in Jabalpur, used a split-plot design with PSB application techniques (soil, seedling, and combination) as sub-treatments and phosphorus levels (30, 40, and 50 kg/ha) as the primary treatments. For soil analyses soil sample was collected from three different depth (0-15, 15-30 and 30-45 cm) and the soil type is black cotton soil, the pH was estimated as 6.32, the organic carbon content was 0.57%, and the phosphorus content was 16.84 kg/ha. The findings showed that PSB inoculation further increased phosphorus availability (pooled maximum: 19.16 kg/ha with combined soil and seedling inoculation), even though phosphorus levels considerably improved accessible phosphorus content (pooled maximum: 18.94 kg/ha at 50 kg P/ha). A slight difference in bulk density, approximately 0.02 g/cm², was observed during the research trial period in the same way, water holding capacity showed a negligible increase of 0.05%. The findings underscore the potential of integrated P and PSB management to enhance soil nutrient availability, particularly phosphorus, within tropical agroforestry systems, promoting sustainable agriculture practices.