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

Abstract

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.