Effect of Biofertilizers and Recommended Dose of Fertilizers (RDF) on Growth, Yield, Oil Quality and Economics of Indian Mustard (Brassica juncea L.)

Abstract

Aims: Indian mustard (Brassica juncea L.) is a key oilseed crop in India but faces yield constraints from climatic variability, nutrient imbalances, and biotic stresses. This study evaluated the effects of integrating biofertilizers with graded levels of recommended dose of fertilizers (RDF) on growth, yield components, seed and oil yield, and profitability under subtropical conditions. Study Design: Randomized Block Design. Place and Duration of Study: Experiment was planned and carried out at the Student’s Instructional Farm (SIF) at the research farm of the R.M.P. (P.G.) College Gurukul Narsan (Haridwar) during Rabi season 2023-24. Methodology: The study was conducted with seven treatments and replicated thrice compared Control (T1), 25% RDF + Rhizobium (T2), 50% RDF + Azotobacter (T3), 75% RDF + Azospirillum (T4), 50% RDF + Azotobacter + Azospirillum (T5), 75% RDF + Rhizobium + Azotobacter (T6) and 100% RDF + Rhizobium + Azotobacter (T7) using variety ‘Kranti’ on sandy loam soil (pH 7.8; available N 185 kg/ha; P 15.25 kg/ha; K 265 kg/ha) with standard cultural practices. Results: T7 showed significantly enhanced growth traits (e.g., plant height at harvest 128.5 cm; LAI 3.70 at 45 DAS; dry matter 38.85 g/plant), yield attributes (siliquae/plant 225; seeds/siliqua 17.9; 1000-seed weight 4.12 g), and seed yield (1116 kg/ha) compared to Control and lower RDF combinations, while oil yield peaked with T7 (427 kg/ha) and oil content ranged narrowly (approx. 38.2–39.4%) with the highest content under 50% RDF + Azotobacter + Azospirillum (39.4%). Economic analysis indicated maximum gross return (₹31,677/ha), net return (₹18,054/ha), and return per rupee invested (1.32) in T7, closely followed by 75% RDF + Rhizobium + Azotobacter and 75% RDF + Azospirillum, demonstrating the agronomic and economic advantage of integrating biofertilizers with recommended fertilization in Indian mustard. Conclusion: Findings support adopting 100% RDF with Rhizobium + Azotobacter as a superior package, with 75% RDF + Rhizobium + Azotobacter or 75% RDF + Azospirillum as efficient alternatives where input optimization is prioritized.