Influence of Microbial Inoculants and Their Consortia on Pigeon Pea Productivity and Soil Nutrient Availability in a Vertisol

Beneficial soil microorganisms play an important role in improving nutrient availability and soil fertility, thereby enhancing pigeon pea productivity and promoting sustainable nutrient management. A field experiment was conducted during the Kharif seasons of 2024–25 and 2025–26 at the Research Farm of the ICAR-All India Network Project on Soil Biodiversity-Biofertilizers, Department of Soil Science, Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani. Ten treatments comprising different combinations of microbial inoculants and their consortia were evaluated in a randomised block design (RBD) with three replications. Laboratory stock cultures of Rhizobium Japonicum, Bacillus megaterium, Frateuria aurantia, Thiobacillus thioxidants and Pseudomonas striata were used for inoculation, and seed treatment was carried out immediately before sowing at 100 ml per 10 kg of seed. Among the treatments, RDF + Rhizophos + KSB inoculation through soil application (T8) recorded the highest seed yield (1735.33 kg ha-1) and straw yield (3551.33 kg ha-1). Treatment T10 (RDF + Rhizophos + ZnSB) recorded the highest soil-available N (216.40, 212.04, 210.70 and 203.32 kg ha⁻¹) and P (22.35, 20.74, 19.44 and 17.76 kg ha⁻¹), whereas treatment T8 (T2 + Rhizophos + KSB inoculation) recorded the highest soil-available potassium (619.06, 617.39, 612.22 and 612.22 kg ha⁻¹), at 45, 90 and 135 DAS and at harvest, respectively. Overall, treatment T8 recorded the highest seed and straw yields and higher soil-available potassium, whereas treatment T10 maintained higher soil-available nitrogen and phosphorus throughout crop growth in the Vertisol.